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Polymet Mining (PLM)

Filed: 29 Jul 04, 8:00pm

P. DOWNEY AND ASSOCIATES

INDEPENDENT TECHNICAL REPORT

on the

NorthMet Project

Located in N-E Minnesota, USA, near the town of Babbitt

     Technical Update of the NorthMet Project Incorporating the
established Cliffs-Erie crushing/milling/concentration facilities with
the Hydrometallurgical processes described in the May 2001
Pre-feasibility study.

for

POLYMET MINING INC.

PATRICK G. DOWNEY, P.ENG
P. DOWNEY AND ASSOCIATES

July 2004

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Table of Contents

1.     Title Page
2.     Table of Contents
3.     Summary
4.     Introduction and Terms of Reference
5.     Disclaimer
6.     Property description and Location
7.     Accessibility, Climate, Local Resources, Infrastructure & Physiography
8.     History
9.     Geological setting
10.     Deposit Types
11.     Mineralization
12.     Exploration
13.     Drilling
14.     Sampling Method and Approach
15.     Sample Preparation, Analysis and Approach
16.     Data Verification
17.     Adjacent Properties
18.     Mineral Processing and Metallurgical Testing
19.     Mineral Resource and Mineral Reserve Estimates
20.     Other Relevant Data and Information
21.     Interpretation and Conclusions
22.     Recommendations
23.     References
24.     Date
25.     Additional Requirements for Technical Reports on Development Properties and Production Properties
26.     Illustrations
 
Appendix I            Mining- Independent Mining Consultant update report May 2003 
 
Appendix II            Penguin Automated Systems Inc. - update report on capital and 
            operating costs for process plant and infrastructure; using the Cliffs- 
            Erie plant 

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GLOSSARY OF TERMS

Au    Gold 
Co    Cobalt 
Corps    United States Army Corps of Engineers 
Cu    Copper 
Definition Study Estimate    Early Estimate of Capital and Operating Costs 
DNR    The Minnesota Department of Natural Resources 
EIS    Environmental Impact Statement 
Fleck    Fleck Resources 
G & A    General and Administrative 
IMC    Independent Mining Consultants Inc. of Tucson 
IPGMT    International PGM Technologies Ltd. 
Lakefield    Lakefield Research Limited 
NRRI    Minnesota Natural Resources  Research Institute
NaHS    Sodium Hydrosulphide 
Ni    Nickel 
North    North Limited 
NSR    Net Smelter Return 
PASI    Penguin Automated Systems Inc. 
PCA    Pollution Control Agency of Minnesota 
PGM    Platinum Group Metals 
PlatSol™ Process    Patented Pressure Oxidation Leach Process 
PolyMet    PolyMet Mining Corp. 
RC    Reverse Circulation Drilling 
Rio Tinto    Rio Tinto Limited 
SO2    Sulphur Dioxide 
SRK    SRK Consulting 
SX-EW    Solvent Extraction and Electro-Winning 
The Company    PolyMet Mining Corp. 
The Project    NorthMet Project 
USX    US Steel 

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3.

Summary

PolyMet Mining Corporation ("PolyMet") is currently reviewing development options for their wholly owned NorthMet project located in St. Louis County, Minnesota.

The NorthMet Project (the "Project") is a large, polymetallic disseminated magmatic sulphide deposit containing copper, nickel, palladium, platinum, cobalt, gold and silver. It is located in northern Minnesota, USA, close to the Canadian border in the Duluth Complex (the world´s fourth largest layered mafic intrusive complex) and is approximately ten kilometers from large LTV Steel's Mine (now called "Cliffs-Erie") iron ore mill/concentrator with its established infrastructure. The Duluth Complex is a similar geologic setting to the very large Ni-Co-PGM Noril'sk deposit in Russia. NorthMet is one of the largest undeveloped nonferrous metals projects in North America. The geological resource at a 0.2% copper cut-off amounts to greater than 900 million tons containing low grades of copper, nickel, cobalt, platinum group metals ("PGM's"), silver and gold.

The NorthMet deposit was originally targeted for copper and nickel values. With low grades and poor quality concentrates, NorthMet and other neighbouring deposits remained undeveloped. The key to advancing the NorthMet project was the development of a propriety hydrometallurgical process for the treatment of a bulk concentrate on site. This single step process, now trademarked as the PlatSol™ Process, has the advantage of extracting the PGM's in addition to the base metals. After dissolution of the metals in the PlatSol™ Process step of the process, they can then be individually extracted on site -thereby avoiding dependence on off-site smelters. A successful pilot plant using the PlatSol™ Process on NorthMet ores was completed at Lakefield Research in 2000. An independent Pre-feasibility study was subsequently completed in April 2001 under the supervision of Independent Mining Consultants ("IMC") of Tuscon, Arizona with input from several international consulting firms including AMEC Mining and Metals ("Amec").

This study, for a 50,000 tonnes per day ("tpd") mine, demonstrated unacceptable project economics due to low mined grades and high capital costs. Subsequently, due to funding restraints, PolyMet was not able to optimize the study. The reader is requested to refer to the PolyMet Pre-feasibility study of April 2001 which can be found on the SEDAR website.

In March 2003, new management took over PolyMet to complete optimization work and to study ways of improving project economics. A new technical program, supervised by the author, and a project execution strategy was completed in July 2003. Recommendations included:

  • Re-working the mining data base to produce a mine plan at the 25,000 tpd levelto increase mined head-grade.
  • Simplification of the process circuits by only producing copper metal on site and producing separate PGM's and nickel hydroxide concentrates for off-sitetreatment.
  • Acquiring the nearby Cliffs-Erie mothballed crusher/mill/concentrator and all ofthe land needed for stockpiles, tailings disposal, water supply and storage. This

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    facility also provides preferential electricity rates and includes a fully establishedinfrastructure of roads, rail, warehouses, offices, workshops and spare parts. SeeFigure 3.1.
  • Utilizing a mining contractor, to avoid up front capital on the mining fleet.

This rework of the Pre-feasibility material indicated that a technically simpler project, with lower daily tonnage, higher grades and considerably lower up front capital could result in a viable economic project. PolyMet subsequently completed an option agreement with Cleveland Cliffs Inc. to acquire key buildings, land and equipment from the recently closed Cliffs-Erie mill/concentrator.

Figure 3.1 - Aerial photograph of the Cliffs-Erie facilities:

The area within the black line has been optioned by PolyMet

Cliffs-Erie was built in 1955 and processed 100,000 tpd of taconite ore prior to closure in 2000.

This report deals mainly with the option agreement dated February 16, 2004 whereby PolyMet has the right to acquire certain key assets of the Cliffs-Erie process plant and infrastructure (outlined in the above photograph) which are located within 10 km of PolyMet's proposed open pit. The focus of this report is on the integration of the established Cliffs-Erie infrastructure plus existing crushing, milling and flotation circuits with a new hydrometallurgical plant for on site metal recovery. In addition certain process simplifications have been made to the 2001 Pre-Feasibility. The 2001 study was based on producing nickel and cobalt metal. The current flowsheet is based on production of separate nickel metal hydroxides and PGM hydroxides, thereby greatly simplifying the process circuit.

No new work has been done on geology, exploration or resource definition. However certain relevant sections of the 2001 PolyMet Pre-feasibility study have been included for ease of reference.

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Re-use of this "brownfields" facility and its established infrastructure could, by current estimate, enable (fully loaded) capital cost savings of approximately US$196 million, based on the figures produced for the 2001 Pre-Feasibility Study. The elimination of the circuits to produce nickel metal and a cobalt salt on site could also reduce up-front capital by approximately $60 million and use of a mining contractor could reduce the preproduction capital by approximately $95 million in capital costs based on the 2001 Pre-feasibility. Together these approaches should reduce technical risk and financial exposure. The scoping level capital required for an initial 25,000 tpd operation is estimated to be US$235 million with an expected accuracy range of +30%/-20%. The capital costs were completed by Penguin Automated Systems Inc. ("PASI") for the mill and infrastructure which were supervised and reviewed by the author. The mining capital costs are based on the original Pre-Feasibility study completed by IMC and updated to reflect a smaller tonnage throughput and contract mining.

The estimated operating cost is US$ 10.44/tonne of ore based on first quarter 2004 dollars. These costs reflect the current mine plan with mining by contractor. The costs also reflect the simplified flowsheet and current power costs for the Cliffs-Erie facility. A contingency of 5% has also been included. The operating costs exclude the selling costs, shipping and smelting costs associated with the products.

The scoping study is based on measured indicated and inferred resources that are considered too speculative geologically to have economic considerations applied to them that would enable them to be categorized as mineral reserves. Therefore there is no certainty that the results produced by this scoping study will be realized.

The results of this scoping study do indicate that the NorthMet project, integrated with the existing Cliffs-Erie, facilities, shows sufficient potential to be carried forward into the next phase of engineering, a feasibility study. The purpose of the feasibility will be to examine further all aspects of the project and establish with greater accuracy its technical and economic viability.

This conclusion is based on the resource data and order-of-magnitude capital and operating costs presented in this study.

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4.

Introduction and Terms of Reference

The author was initially retained in 2000-2001 by PolyMet to review the pre-feasibility study completed for PolyMet in April 2001 and conduct a technical audit of process and infrastructure matters on behalf of PolyMet at that time. The author has therefore been intimately involved with the project with particular reference to process development of the new PlatSol™ Process, the mining program and the infrastructure required for the initial planned development. No further technical work was conducted on the NorthMet project between the completion of the 2001 Pre-feasibility and this report.

The author was retained by PolyMet in 2001 to conduct a technical audit of the processing aspects of the Pre-feasibility study and visited the project site at that time. The PlatSol™ Process was developed at Lakefield Research, Ontario, under the supervision of Messrs O'Kane, Dreisinger, Fleming and Feron; who subsequently became the patent holders of PlatSol™. Amec (formerly Agra Simons - Mining & Metals group) of Vancouver, B.C., was the company responsible for developing the engineering parameters of the process as well as infrastructure aspects for the 2001 Pre-feasibility study. Ore resource calculations, mine plan and mine capital and operating costs were completed by IMC.

PolyMet subsequently retained the author in May 2003 to conduct an assessment of the project whereby the infrastructure, material transport, crushing, milling and flotation elements of the original Amec study were to be replaced by the established Cliffs-Erie plant and infrastructure. The author either directly produced the new project data or supervised the work of other specialists. The results of this technical program are contained in this interim report.

IMC was also retained in May 2003 to re-examine their resource data base, established for the 2001 Pre-feasibility study, and requested to produce a new mine model for a reduced production rate. This work is included as Appendix I.

A scoping study by PASI was completed in April 2004 and is included as Appendix II to this report. The PASI study integrated the existing front end of the Cliffs-Erie plant and infrastructure with new hydrometallurgical plant at the Cliffs-Erie site. Capital and operating costs were updated to March 2004.

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5.

Disclaimer

Amec was the company responsible for developing the engineering parameters of the process as well as infrastructure aspects for the 2001 Pre-feasibility study. Ore resource calculations, mine plan and mine capital and operating costs, were completed by IMC. A scoping study by PASI was completed in April 2004 and is included as Appendix II to this report.

The author visited the NorthMet site in 2001 as part of his responsibility in completing an audit review of the process and infrastructure work conducted by Amec Engineering Co.

The costs reported here have been updated to March 2004. In the recalculation of mineable grade, IMC used operating costs prepared by P. Downey and Associates but did not factor in the improved capital costs in terms of determining mineable tonnage.

The author has relied on the data that was made available to him by, Lakefield Research, AMEC, IMC, PASI, the 2001 Pre-feasibility Study, and does not take any responsible for any errors or omissions. Reports that contain information relevant to this report are listed in item 23. The material supplied and that in the public domain, combined with personal knowledge-observations were sufficient to allow a comprehensive examination of the NorthMet Project.

P. Downey and Associates has no propriety interest in the technology described here and does not own any equity stake in PolyMet.

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6.Property Description and Location
  
6.1

Areas and location

The NorthMet project is located in northern Minnesota, USA, close to the Canadian border, in the Duluth Complex. See Figure 6-1. The NorthMet Project is located in the Great Lakes region of North America, near the town of Babbitt, Northern Minnesota, USA. The area is approximately 65 km from the Canadian border and 75 miles from a bulk materials dock on Lake Superior. Materials and supplies may be brought in by an extensive rail and road network accessing destinations across North America.

The proposed NorthMet open pit lies immediately south of the mined out Cliffs-Erie taconite iron ore open pits and about 10 km to the N-S-E of the Cliffs-Erie plant. The Minnesota Iron Range extends for approximately 200 km, east to west, and the iron formations dip gently to the south at about 5 degrees. At the eastern end of the range, south of the town of Babbitt, there are certain magmatic deposits which overlie the iron formations. The deposits are low grade and polymetallic- typically 0.4% copper; 0.12% nickel; 0.05 grams per tonne (g/t) gold; 0.08 g/t platinum and 0.36 g/t palladium.

Figure 6.1 - Location of NorthMet Project

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6.2

Ownership

The underlying mineral rights are owned by US Steel Corp and a 3% NSR royalty applies to production from the project. Most of the surface land is controlled by the US Forestry Service ("USFS"). The rights to the project are held by PolyMet's US subsidiary, PolyMet Mining Inc.

In 1989, PolyMet (as Fleck Resources) acquired a twenty year renewable lease for the mineral rights to the NorthMet deposit from USX-see Figure 6.2. The lease is subject to a yearly lease payment before production and then to a 3 to 5% sliding scale Net Smelter Return royalty based on the value of the ore. The lease payments prior to production are considered advance royalties and will be credited to the production royalty.

The USFS acquired the surface rights to the NorthMet property from USX in the 1930's and, at present, the USFS remains the surface rights owner of most of the NorthMet property. USX retained the mineral rights and the right to explore and mine on the site. As a result of this retention, while the USFS is the surface rights owner for most of the NorthMet Property, they cannot prohibit mining on the site. LTV Steel Mining Company/Cliffs Erie Mining Company owns portions of sections 10, 11 and 12 near their private railroad. However, it may be beneficial for the Project to enter into land swap arrangements with the USFS to simplify the permitting process and to allow the project access to lands for waste rock stockpiling. The use of the existing Cliffs-Erie abandoned pits for waste storage from the Northmet mine could obviate such forestry issues and this will be evaluated during the feasibility study. US regulations require an equivalent value of land to be swapped for the land to be used by the Project. The USFS has indicated to PolyMet their willingness to carry out such a land swap. Costs for completing land swap arrangements have not been included in Estimates of Capital Costs.

As both the Environmental Impact Statement ("EIS") and permitting of the project will be subject to the arrangements of the land swap, PolyMet believes that this land swap with USFS should be completed in conjunction with the Bankable Feasibility Study. PolyMet therefore intend to commence those negotiations with USFS early in the Bankable Feasibility Study timetable.

Table 6.2 - Land Swap
 

Task Cost(US$ Million) Start(MonthNumber) Timing(Months) 
US Forest Service Land Swap 3.5 1 24 

Figure 6.3 shows surface owners in the area of the potential NorthMet pit and waste dumps. Information on the land map was compiled from preliminary work done by North Mining and from the St. Louis County Land Atlas and Plat Book (1996).

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Figure 6.2 – Mineral Rights Owners

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Figure 6.3 – Surface Owners

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6.3

Environmental

During the Pre-feasibility study, PolyMet had on staff a number of environmental consultants to coordinate both the environmental studies and the permitting required to bring the NorthMet Project to production. No cultural sites were identified either from a review of existing data and literature, or from aerial photographs. The neighboring Babbitt Project (also called Minnmax) completed a full EIS which was filed as a public document by then operator Amax Mining and this study did not produce any significant findings. NorthMet completed their-own preliminary Baseline Environmental Study in April 2000. This study addressed:

  • Wildlife Usage, including threatened and endangered wildlife;
  • Preliminary Wetlands Survey;
  • Ground Water Quality; and
  • The Development of the Geochemical Study Plan.

No evidence was found of any threatened or endangered animals in the area. The area was identified as a major wetland area with some 70% of the land being classified as wetlands. The wetlands that will be disturbed by operations at NorthMet will have to be replaced on at least a 1:1 ratio in terms of the existing wetland mitigation scheme. The practice of replacing wetlands is well established in the area and this can be a relatively high ongoing operating cost for a project. The use of the extensive tailings and water storage areas which are part of the Cliffs-Erie deal should mitigate most of such costs. Disturbance of the wet lands in the open pit area would be the most affected area.

Table 6.3 - Estimated NorthMet Wetlands Mitigation Requirements
 

Area      Acres 
Pit      1020 
Rock Dump West -  CE Pit back fill      0 
Rock Dump East -  CE Pit back fill      0 
Flotation Tailings Dam -  CE permitted site      0 
Hydro-Metallurgical Residue Dam -  CE existing      0 
Plant and Roads -  CE existing      0 
Total      1020 
Wetlands Mitigation Requirement at 70%      714 

In terms of the Federal and State Wetland Mitigation legislation, the NorthMet Project must replace any wetlands disturbed on the NorthMet property on at least an acre for acre basis. Initial surveys undertaken have shown 70% of the NorthMet open pit area is classified as wetlands. Land use estimates from the 2001 Pre-feasibility study by Steffen Robertson & Kirsten ("SRK") and IMC are given in Table 6.3. The use of Cliffs-Erie obviates almost all of the previous requirements from the 2001 study.

The option to use key lands and impoundments in the Cliffs-Erie deal lessens the original estimates of the Wetlands Mitigation requirements. These are currently considered to be limited to the open pit area of 1020 acres. Wetlands Mitigation is a key step in bringing the NorthMet Project into production. With this reduced Wetlands Mitigation scope the costs will now be part of the required project capital and not an up-front cost component within the Bankable Feasibility Study.

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The major steps, estimated costs and timetable required to complete all environmental matters to obtain the necessary State and Federal permits are generally described in Table 6.4 below. The use or re-use of the Cliffs-Erie site will obviate much of the costs and requirements projected in the 2001 Pre-feasibility study since critical items like tailings areas are already included.

The land swap with USFS has been included separately in the cost and timing estimates given in Table 6.4. While it could have a significant impact on the EIS and permitting process, the early completion of this land swap should simplify and accelerate the EIS and permitting process .

Ground water quality was also found to be very good. Given the extensive waterways and related fishing activities in Minnesota, there are exceptionally low State limits (0.0013 micrograms/litre) for mercury discharges. There was no evidence of mercury in the NorthMet ore body, and process and pilot plant test work to date have not shown any mercury in tailings or residues.

During the Bankable Feasibility Study, further geochemical work on the waste rock and various process plant tailings and residues should be conducted to test for their acid forming and metal release potentials under normal climatic conditions. This work will determine storage and disposal solutions for mine and plant waste, tailings and residues.

In order to enable the timely completion of project permitting and meet Federal and State environmental requirements, the EIS process will be initiated during the Bankable Feasibility Study. The Pertinent aspects of the permitting process must be constantly monitored during the feasibility study. A draft EIS will be released for public comment prior to completion of the Bankable Feasibility Study. Subject to the satisfactory completion of the EIS, the Project will then apply to obtain the necessary construction and operating permits to develop the Project. The EIS will include the following:

  • Collection of all Baseline data for submission to EIS team;
  • Development and submission of Plan of Operation;
  • Minnesota Department of Natural Resources ("DNR") selection and appointment ofsub-contractor (environmental consultants) to prepare EIS;
  • Sub-contractor preparation of draft EIS;
  • Draft EIS released for public comment;
  • Final EIS prepared and issued;
  • Federal Findings of No Significant Impact and Record of Decision;
  • Awarding of State Environmental Permits.
  
6.4

Permits

The major permits required by the Project are:

  • Plan of Operations/Environmental Impact Statement;
  • Mining and Reclamation Permit (Mining and Closure Plan) issued by the DNR;
  • Air Emissions Permits (one for construction and one for operations) issued byPollution Control Agency of Minnesota ("PCA");
  • State Wetlands Review;

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  • Minnesota Non Ferrous Mine Permit and Five Year Operating Plan;
  • Storm Water Permit;
  • 401 Water Quality Certification;
  • Water Discharge Permits (Surface and Ground Water) issued by PCA; and
  • 404 Wetlands Mitigation Permit issued by the United States Army Corps of Engineers("Corps").

As the project moves forward PolyMet will need to work with the relevant agencies to amend existing permits where required for use on the base metal operations at NorthMet and Cliffs-Erie.

Table 6.4 - NorthMet EIS and Permitting Cost and Timing Estimates

Task                Cost 
               (US$ Million) 
 Start
 (Month  Number) 
       Timing 
       (Months) 
Baseline Study                0.45  1        6-10 
Plan of Operations                0.15  6        2 
Preparation of Draft EIS                0.30  11        12 
Preparation of Final EIS                0.60  23        6 
Major Permits                0.40  8        22-29 
Federal Record of Decision   30-32        1 
Total                1.90         34 

As can be seen from Table 6.4, the expected time line from start to receipt of the required permits for the operations could be approximately 3 years at an estimated cost of US$1.90 million. This excludes any cost of land acquisition or swapping for wetlands mitigation and the estimated cost of US$3.5 million for the USFS land swaps.

The political climate in Minnesota is favourable for permitting of a new mining operation. The communities in the Iron Ore Range have been badly affected by the recent mine closures, and the existing labour force is seeking employment. Officials throughout the Minnesota state government have indicated a strong desire to replace the lost income and jobs and to assist in getting new economic development underway in the area.

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7.     Accessibility, Climate, Local Resources, Infrastructure & Physiography
 
7.1     

Topography, elevation and vegetation

The surrounding country is flat lying with some low rolling hills. Much of the terrain has relatively poor drainage, with numerous lakes and wetlands. Much of the NorthMet pit is covered with poor quality second growth timber and the land is generally of a marshy nature and poorly drained.

The deposit is within 10 km of the Cliffs-Erie crusher/mill/concentrator facility. The project area is essentially flat and at an elevation of around 490m above sea level.

 
7.2     
Access, towns and transport
 
 The large iron ore mines in the area have been developed since the mid 1950's and the NorthMet project lies immediately adjacent to one of these mines. As such, there exists, fully developed transportation, infrastructure and communication systems close to the NorthMet property. A well maintained system of road and rail transport allows shipment in of supplies and export of finished product. The property is located 95 km by rail to a harbour on Lake Superior and certain materials for the NorthMet project will be subject to marine transport.
 
 The NorthMet property is located close to various townships that served the iron ore mines. With the closure of certain taconite operations, there is a sizeable and trained workforce available in the immediate area. The nearby town of Hoyt Lakes was built specifically for the Cliffs-Erie operation.
 
 The acquisition of the Cliffs-Erie site will provide greater than 80% of infrastructure required for the development of the project, including excellent road and rail access and low cost industrial power. The Cliffs-Erie rail tracks and established roads run alongside the planned NorthMet pit and a new spur and rail load-out facility will link to this existing rail infrastructure.
 
 The electrical distribution and sub-stations from the main feed at the plant site are fully operational and will be used for the PolyMet project. Water permits also exist for the Cliffs-Erie facility. The town of Babbitt, 10 km to the north of NorthMet, and Hoyt Lakes 10 km to the south have the community infrastructure to support the requirements of the NorthMet workforce.
 
 Reclaim water, utilities and services, compressed air supply, power supply and distribution, offices, warehousing and laboratories will all be provided for by existing facilities at the Cliffs-Erie plant site. New assay laboratory equipment will be purchased for the NorthMet project.
 
7.3     

Climate

The northern Minnesota climate is continental, characterized by wide variations in temperature. The temperature in Babbbit (10 miles north of the property) averages -14ºC (7ºF) in January and 19ºC (66ºF) in July. The average annual precipitation is 28 inches with about 30% during the months of November and April and 70% from May through October.

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8.

History

The NorthMet Project was discovered by US Steel Corp. ("USX") in 1969. Originally, it was thought to be a high-grade, underground copper-nickel resource. Drilling in the 1970's demonstrated that it was in fact a high tonnage, low grade deposit, amenable to open pit mining. The grade improved at depth. The inability to produce separate clean nickel or copper concentrates led to further process evaluation and development. At that time there was no recognition of any contained PGM's.

The Minnesota Department of Natural Resources ("DNR") subsequently discovered that PGM's were associated with the nickel and copper in the resource. In 1989, Fleck Resources ("Fleck") acquired a 20-year renewable mining lease over the property from USX and commenced an investigation into the potential for mining and recovering copper, nickel and PGM's. Fleck re-assayed pulps and rejects from previous drilling to obtain data on PGM's. The encouraging potential to produce extra revenue attracted joint venture partners (Nerco and Argosy Mining) who assisted in identifying and quantifying the PGM values. However these companies were not able to develop a metallurgical process that could economically produce separate acceptable concentrates for sale to a smelter, or economically extract the contained metals from a bulk concentrate.

In the mid-90's, Fleck began investigating the use of hydrometallurgical processes, including bio-leaching and pressure oxidation, to determine the benefit to the Project. Fleck Resources changed its name to PolyMet Mining Corporation in 1998 and focused on a hydrometallurgical extractive technology. This led to the development of the PlatSol™ Process in 1998. The operating conditions of the PlatSol™ Process are such that the copper, nickel, cobalt and precious metals are all placed in solution in a single operation. Since the initial PlatSol™ Process testwork, the process has evolved and testwork on concentrates other deposits around the world led to improved recoveries of PGMs from the 92% level to 97%.

In July 2000, PolyMet entered into a joint venture arrangement with North Limited ("North"), a major Australian mining company, to progress the NorthMet Project to commercial production. Under the joint venture arrangement, North had the opportunity to ultimately earn an 87.5% interest in the PolyMet Project through funding and production of a Bankable Feasibility Study and funding 100% of the total capital costs to develop the project.

In August 2000 Rio Tinto Limited ("Rio Tinto") completed an on-market takeover of North. Subsequently, Rio Tinto decided not to proceed with the NorthMet project and PolyMet exercised its 30-day pre-emptive right, under a "change of control" clause, to terminate the joint venture arrangement. Consequently, PolyMet has regained a 100% interest in the NorthMet Project.

Following completion of the metallurgical pilot plant work in November 2000, PolyMet commissioned a Pre-Feasibility Study on the project in November 2000, based on the PlatSol™ Process. This study was completed in April 2001. The Pre-Feasibility Study was for a 50,000 tpd operation. The economics of this project were found to be unacceptably low and required a high up front capital expenditure. No further work was done until March 2003, when new management took over the company and commenced a detailed review of the project.

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9.Geological Setting
  
9.1

Regional Geology

The geology of northeastern Minnesota is predominantly Precambrian in age. Approximately 1.1 billion years ago, intra-continental rifting resulted in mafic volcanics and associated intrusions along a portion of the Midcontinent Rift System, which extends through the Lake Superior Region to Kansas (Figure 9.1) . The rift system is characterized by a gravity high and the thinning or absence of continental crust.

The Midcontinent Rift consists of three parts: thick lava flows, intrusive rock and overlying sedimentary rock. The volcanic sequences are generally tholeiitic to sub-alkaline flood basalts derived from a mantle source. Minor felsic to intermediate flows exhibit crustal contamination. There are three major intrusive complexes: the Coldwell Complex of Ontario, the Mellen Complex along the south shore of Lake Superior and the Duluth complex along the north shore. The sedimentary rocks are mainly fluvial red beds filling the rift structure. The Duluth Complex (Figure 9.2) is the host of NorthMet mineralization. The complex lies along the projection of the Great Lakes Tectonic Zone, an Archean suture zone, the Archean Vermilion Fault and the Early Proterozoic shelf margin. It extends in an arcuate belt from Duluth to the northeastern tip of Minnesota. Emplacement of the intrusion appears to have been along a system of northeast-trending normal faults that form half-grabens stepping down to the southeast (Figure 9.3) . The magma was intruded as sheet-like bodies along the contact between the Early Proterozoic sedimentary rocks of the Animikie Group and the basaltic lava flows of the North Shore Volcanic Group.

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Figure 9.1 – Midcontinent Rift System

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Figure 9.2 - Regional Geology

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Figure 9.3 – West Edge Deluth Complex

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9.2Local Geology and Deposit Description
  
9.2.1

Rock Types

The Duluth Complex is represented by the Partridge River Intrusion in the NorthMet area. The intrusion consists of light to dark gray troctolitic rock varying from troctolitic anorthosite to augite troctolite, with thin layers of melatroctolite or picrite. The rock types are classified by percentage of plagioclase, olivine and clinopyroxene. The melatroctolite layers tend to be fine grained with distinct layering. The Partridge River Intrusives have been sub-divided into seven lithologic units (Figure 9.4):

  • Unit 7 and Unit 6 – texturally homogeneous plagioclase-rich troctolite, each with apersistent ultramafic base. Unit 6 contains a mineralized horizon in the southwesternportion of NorthMet which is relatively enriched in PGM's relative to copper. Units 6and 7 are each about 400 ft. thick.
  • Unit 5 – coarse grained anorthositic troctolite (300 ft.) grading down to Unit 4.
  • Unit 4 – homogeneous augite troctolite and troctolite, with a less persistent ultramafichorizon. The contact between 4 and 5 is difficult to establish and the two units mayactually be a single unit.
  • Unit 3 – the most easily recognized unit because of its mottled appearance due toolivine oikocrysts. It is fine grained troctolitic anorthosite to anorthositic troctolite.
    Average thickness is 250 ft. but locally can be up to 500 ft.
  • Unit 2 – homogeneous troctolite with abundant ultramafic units and a generallypersistent basal ultramafic. This unit shows the most variation in thickness and maybe absent entirely.
  • Unit 1 – the most heterogeneous unit, both texturally and compositionally. Grain sizeis generally coarser at the top of the unit and fines downward. The unit containsabundant inclusions of the footwall rock and is noritic towards the base. This is themain sulfide bearing unit. Two ultramafic layers are generally present. Unit 1 isprobably the result of multiple pulses of magma injection. Average thickness is about450 ft.

22


Figure 9.4 – Generalized Igneous Stratigraphic Column

The footwall consists of Proterozoic sedimentary rocks of the Animikie Group, which resulted from a single depositional sequence in a transgressive sea. The oldest formation, the Pokegama Quartzite, represents well sorted clastic material deposited on a stable shelf. The Biwabik Iron Formation contains alternating sequences of ferruginous chert and slate. The Iron Formation has been extensively studied because of its importance to the iron mining industry and contains several members and sub members. The youngest formation is the Virginia Formation, consisting of argillite and graphitic argillite with interbeds of greywacke, siltstone and minor calc-silicate. The Virginia Formation appears to decrease in thickness from the surface contact with the Duluth Complex toward the interior of the Complex to the southeast. Inclusions of the Virginia Formation, as biotite hornfels, can be found in all units, but are especially abundant in Unit 1.

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9.2.2

Structure

The general trend of the sedimentary rocks at the NorthMet deposit is to strike to the east-northeast and to dip to the southeast about 15-25°, and the Partridge River Intrusion appears to follow this general trend. Two east-northeast trending faults have been identified through the construction of cross sections. The faults are steeply dipping and normal in character; offset ranges from negligible to 600 ft. down to the southeast. A third major fault has been identified in the western portion of the area and can be traced to the Northshore Mine in the north. Movement on this fault is down to the east. Numerous other faults can be identified in the cross-sections, but offset is small and they lack continuity. The cross-sectional view shows considerable offset in the more southerly fault, and less offset on the more northerly fault. This relationship can vary over the strike of the deposit.

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10.

Deposit Types

There are two types of mineralization related to the rift system: hydrothermal and magmatic. The hydrothermal deposits include native copper in basalts and sedimentary interbeds, such as on the Keewenaw Peninsula, sediment-hosted copper sulfide and native copper, represented by the White Pine Mine of Michigan, copper sulfide veins in volcanics and polymetallic veins (Ag-Ni-Co-As-Bi) in volcanics. The magmatic deposits include Cu-Ni-PGM mineralization and Ti-Fe mineralization in the Duluth complex, uranium and rare earth elements in carbonatites and Cu-Mo in breccia pipes. More locally (Figure 10.1), the magmatic deposits lie along the northwestern contact of the Duluth Complex with the underlying sediments and Giants Range Batholith. NorthMet and the Babbit (or Minnamax) deposits are the largest of the Cu-Ni-PGM mineralization.

The majority of the rock at NorthMet is unaltered, with minor alteration found along fractures and micro-fractures. Alteration consists of serpentine, chlorite and magnetite replacing olivine, uralite and biotite replacing pyroxene, and sausserite and sericite replacing plagioclase. As would be expected in a magmatic deposit of this type, sulfide mineralization does not appear to be directly related to alteration.

25



Figure 10.1 – Midrift Cross Section

26



11.

Mineralization

The metals of interest at NorthMet are copper, nickel, cobalt, platinum, palladium, gold and lesser amounts of rhodium and ruthenium. In general, the metals are positively correlated with copper mineralization; cobalt is the main exception. Mineralization occurs in four horizons throughout the NorthMet property. Three of these horizons are within basal Unit 1 and in some drill holes the horizons are indistinguishable from each other. The thickness of each of the three horizons varies from 5 to more than 200 feet. Unit 1 mineralization is found throughout the deposit. A less extensive mineralization zone is found in Unit 6 and it is relatively enriched in PGM's compared to Unit 1.

Sulfide mineralization consists of chalcopyrite, cubanite, pyrrhotite and pentlandite with minor bornite, violarite, pyrite, sphalerite, galena, talnakhite, mackinawite and valleriite. Sulfide minerals occur mainly as blebs interstitial with plagioclase, olivine and augite grains, but also occur within plagioclase and augite grains, as intergrowths with silicates, or as fine veinlets. The percentage of sulfides varies from trace to about 5%. Palladium, platinum and gold are associated with the sulfides.

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12.

Exploration

Exploration has been on-going on the NorthMet property since the 1960's by various companies. The stage of exploration has advanced through several drill programs sufficient to complete a resource estimate and a Pre-feasibility study. Detailed discussion of the drill programs are addressed in Item 13 – Drilling.

Prospectors first discovered copper and nickel near Ely, Minnesota about 20 miles north of NorthMet in the 1940's. Subsequently, Bear Creek Mining Company conducted a regional exploration program resulting in the discovery of the Babbitt or Minnamax deposit (northeast of NorthMet and within the Duluth Gabbro). US Steel (USX) stated an exploration program in the Duluth Complex in the late 1960's and over the next few years frilled 112 core holes into the NorthMet property (then called Dunka Road). USX investigated the deposit as a high-grade, underground copper-nickel resource, but it was considered to be uneconomic due to lower than expected copper and nickel grades, and the inability to produce separate, clean nickel and copper concentrates. At this time, there was no recognition of any contained platinum (PGM's) or gold in the deposit.

In 1987, the Minnesota Natural Resources Research Institute ("NRRI") published data suggesting that a large resource of platinum group minerals or PGM's could be contained within the base of the Duluth Complex. PolyMet leased the NorthMet property from USX in 1989. PolyMet re-assayed pulps and rejects from the previous USX drilling to obtain data on the PGM's.

Nerco Minerals and later Argosy Mining leased the property from PolyMet in the early 1990's. Work continued on the delineation of the contained PGM's and a few additional core holes were drilled. At that time there was no metallurgical process that could economically produce either (a) separate, clean copper and nickel concentrates for sale to a smelter, or (b) economically extract the various contained metals from a bulk concentrate.

From 1998 to present, PolyMet has conducted three drilling programs totaling 87 holes for approximately 49,500 ft. of core and reverse circulation drilling. The third drilling program (13 holes for about 9,000 ft.) was completed in December, 2000.

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13.

Summary of Drilling Programs

No further drilling has occurred since the 2001 Pre-Feasibility Study however; the following is included for reference purposes.

Table 13.1 summarizes the drilling campaigns for the NorthMet property. Figure 13.1 and 13.2 summarize the drill campaigns. The US Steel drilling which was done during the late 1960's. The original US Steel work was based on a copper/nickel underground mining scenario. US Steel's assaying did not include the PGM's.

In 1989, PolyMet (then Fleck Resources) entered into a 20-year renewable lease with US Steel for the NorthMet (then Dunka Road) deposit. At that time, PolyMet did some logging and considerable re-assaying, including gold and PGM assays, but did not drill additional holes.

Nerco Mineral Co. leased the property from PolyMet during 1990 and drilled 4 holes (2 were unsampled metallurgical holes) and did a resource calculation as part of an evaluation of the property. Nerco allowed their option to expire during 1991.
 

Table 13.1: Summary of Drilling Programs   
Company    Drilling Type              No. of Holes No. of Feet      Assay Intervals 
US Steel    BX Core              112  133,909      5,037 
Nerco(met only)    BQ Core              2  842      167 
1998 PolyMet    RC              14  6,370      1,274 
1999 PolyMet    BTW Core 
   RC 
   Mixed Core/RC 
             3 
             18 
             3 
 2,476 
 9,300 
 2,660 
     455 
     1,868 
     534 
2000 PolyMet    BTW Core 
   RC 
             16 
             20 
 10,714 
 8,980 
     1,984 
     1,798 
PolyMet Total               74  40,500      7,913 
TOTAL               188  175,251      13,117 
    Core Total 
   RC Total 
   Mixed Total 
             133 
             52 
             3 
 147,941 
 24,650 
 2,660 
     7,643 
     4,940 
     534 

During 1998, 1999 and 2000, PolyMet did considerable additional RC core drilling, as shown in Table 13.1. Much of this drilling was to supply material for metallurgical testing, as well as resource definition.

Table 13.1 shows that the drilling through October 2000 consists of 133 core holes for 147,941 ft., 52 RC holes for 24, 650 ft. and 3 mixed holes (initial RC followed by core) for 2,660 ft. PolyMet drilled 13 core holes in November-December 2000 that are not included in this Pre-feasibility study.

Figure 13.3 is a map showing the locations of the US Steel and PolyMet drilling. The NERCO holes are also posted, but they are not obvious since they twinned US Steel

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holes. The map shows that the PolyMet drilling is mostly in the area where the deposit is near the surface (since the deposit strikes about N57oE and dips 25o to 36oSE. The only deep drilling is provided by the US Steel holes.

Figure 13.4 shows a cross section of the deposit with the rock type geology included. It can be seen that the geologic interpretation consists of 20o dipping rock units offset by near vertical faulting. Copper grades are also shown on the section.

Figure 13.1 – Area 1999 - 2000 Drilling

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Figure 13.2 – Location of Metallurgical Samples

31



Figure 13.3 – US Steel and PolyMet Drilling

32



33



Figure 13.4 – Cross Section Drill Holes

34



35



14.

Sampling Method and Approach

This was reported on in the 2001 Pre-Feasibility Study. There is nothing further to report.

36



15.

Sample Preparation, Analysis and Security

This was reported on in the 2001 Pre-Feasibility Study. There is nothing further to report.

37



16.

Data Verification

This was reported on in the 2001 Pre-Feasibility Study. There is nothing further to report.

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17.

Adjacent Properties

This section is not applicable to PolyMet as it does not own any adjacent properties.

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18.Mineral Processing and Metallurgical Testing
  
18.1

Process Technology

The PlatSol™ Process metallurgical extraction process was developed in 1998/99 at Lakefield Research Ltd. In May 2000, a continuous, fully integrated pilot plant testing program was initiated at Lakefield to demonstrate this hydrometallurgical extraction process for the NorthMet Project.

Both bench and pilot plant testwork for NorthMet used mineralized material obtained from reverse circulation ("RC") drilling samples. A total of 26 tonnes of RC cuttings was used for the bench tests and a further 33 tonnes of RC cuttings was used for the pilot plant tests. For the pilot plant tests, the 33 tonnes of RC cuttings were milled to the prescribed fine grind size and concentrated into a bulk concentrate of 839 kg using flotation. This bulk concentrate, combined with the remaining concentrate from the bench tests, was treated in an autoclave under the PlatSol™ Process operating conditions.

The PlatSol™ Process entails an autoclave operating at 225oC with 100 psi oxygen over pressure. The addition of a small amount of chloride creates a unique leaching environment whereby all the base metals (copper, nickel and cobalt) and precious metals (gold, silver, platinum, palladium, etc.) are brought into solution in one step. The ability to recover the PGM's into solution is what makes the PlatSol™ Process unique and patentable. The metals can then be recovered sequentially from the solution, commencing with the PGM's.

The precious metals (PGM's, silver and gold) are precipitated using sodium hydro-sulphide. The copper recovery uses well established solvent extraction and electro-winning ("SX-EW") techniques. In its new approach, PolyMet has elected not to recover nickel metal on site. The process circuits have been dramatically simplified to convert the remaining metals in solution after copper SX/EW (dominantly nickel with small amounts of cobalt, copper and zinc) into a nickel concentrate. PolyMet is currently planning to produce a nickel hydroxide which is a precipitate. The precipitate will be filtered, dried and shipped off-site to a metal refinery. Production of nickel sulphide is an alternative to hydroxide.

In general, mineral recoveries and values for the bulk concentrate produced in the pilot plant confirmed the results obtained in the bench top testwork. Nickel recovery in the flotation concentrate was lower than expected. Mineralogical testwork showed that this was due to nickel in association with silicates which is not amenable to flotation recovery. Overall flotation and hydrometallurgical recoveries for the pilot plant tests are given in Table 18.1.

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Table 18.1 - Pilot Plant Metal Recoveries

 Percent Grams/Tonne 
Cu Ni Co Au Pt Pd 
Ore Grade 0.43 0.12 0.009 0.05 0.08 0.36 
Flotation 
Conc. Recovery 93.7 69 42 75.7 76.9 79.6 
Conc. Grade 14.6 3.1 0.15 1.4  2.3 10.4 
PlatSol™ Process 
Process Recovery 98.1 96.9 92 88.4 95 93.6 
Overall Recovery 91.9 66.9 38.6 66.9 73.1 74.5 

PolyMet has attempted to keep the new operation as simple as possible. The crushing, grinding and flotation processes proposed for the NorthMet Project are tried and tested and are used extensively in other processing plants worldwide. The Cliffs-Erie mill concentrator which functioned efficiently prior to shut down in 2001 will be utilized for these process steps. Similarly, the SX-EW process which will be used to produce cathode copper on site is industry standard.

Copper will be the only metal produced on the NorthMet site. Since copper is the largest contributor to revenue, the project is being characterized as a copper project - with important credits obtained from nickel and the PGM's. The PGM's are recovered first and precipitated as sludge immediately prior to copper SX/EW. After copper extraction, the metals remaining in solution are principally nickel with small amounts of copper, cobalt and zinc. This solution is first treated to remove iron. Magnesium oxide is then added which causes the remaining metals to precipitate as the hydroxide. When filtered and dried, nickel hydroxide concentrate can be shipped off - site for treatment in an established facility. This eliminates the complex circuits for nickel and cobalt recovery described in the original 2001 flow sheet. The objective is to start the project with minimum technical risk.

The proposed autoclave circuit for the pressure oxidation process at NorthMet is similar to several other operations - principally the gold autoclaves operating at Barrick's mines in Nevada and a new copper project at Phelps Dodge's Bagdad operation in Arizona.

The PlatSol™ Process uses relatively low levels of chloride in the leach solution which allows efficient leaching of the PGM's and precious metals (gold and silver) as well as the base metals. Process recoveries of PGM's in the 2000 pilot plant have been improved from approximately 94% to 98% in recent test programs. International PGM Technologies Ltd. ("IPGMT"), an Ontario, Canada, corporation developed the PlatSol™ Process and has patented the technology in a number of countries. PolyMet has an agreement with IPGMT for the use of this technology, free of any royalty charge.

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The PlatSol™ Process performed well during the continuous, fully integrated pilot plant operations conducted in 2000. The simultaneous leaching of base and precious metals in the autoclave from the bulk concentrate was confirmed. Optimum operating conditions established in the pilot plant were:

 % solids 10.5 – 11% 
 temperature 225°C 
 oxygen overpressure 100 psi 
 retention time 120 minutes
 chloride concentration 9 g/l 

Under the optimized operating conditions tested in the autoclave, the leach efficiencies obtained for all the pay metals, with the exception of gold, were either equal to or better than those achieved in bench testing in 1999.

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19.Mineral Resource and Mineral Reserve Estimates
  
19.1

Resource estimates and categorization

The resource estimates were completed by Independent Mining Consultants Inc. of Tucson ("IMC") for the 2001 Pre-feasibility study and the May 2003 re-statement for a lower tonnage higher grade pit are shown in Table 19.1, below. IMC used the assumptions detailed in Appendix I to prepare the estimates in this summary and their May 2003 report is included as Appendix I. It should be noted that in this mine modeling, completed in May 2003, IMC did not factor in the benefit of reduced capital by use of the Cliffs-Erie facilities because this had not been finalized at the time. In their limited review, at lower daily tonnages, IMC also did not introduce smaller scale mining equipment for a selective mining approach. They continued to use the same scale of equipment as described in the 50,000tpd (2001) Pre-feasibility study with attendant high dilution factors. For this 2003 technical update, IMC were directed to produce a mine plan with smaller daily tonnage, reduced mine life - all in an attempt to obtain higher metal grades.

The pit resource completed by IMC has a maximum 50 degree pit wall slope angle. IMC's estimates show a measured, indicated and inferred resource of 139 million tonnes. There is the potential to add to this resource base, as the deposit is open at both ends and at depth (see Appendix I).

The drilling to date has been adequate to complete the Pre-feasibility level work required for mine planning. It is proposed to complete further in-fill drilling, sufficient to establish a mineable pit reserve, as part of a Bankable Feasibility Study.

Table 19.1 

Status Ktonnes Above Cutoff% Of Total   Average Grades  Total  KtonnesWaste To Ore Ratio
   NSR  CuEq  Cu  Ni  Co  Pd  Pt  Au 
   US$/t %  %  %  g/t  G/t  %  g/t 
Geologic Resource 
Measured 315,61833.05%   11.82 0.847 0.333 0.086 66.00 0.298 0.081 0.042  
Indicated 295,60130.96%   12.76 0.914  0.338  0.087  61.39  0.336  0.094  0.049   
Inferred 343,50935.99%   13.16 0.943  0.347  0.088  58.88  0.355  0.096  0.050   
Total 954,738    12.59 0.903  0.333  0.087  62.01  0.330 0.090  0.047   
Preliminary Pit Resource
Measured, Indicated & Inferred 139,145100%   10.00 0.97  0.40  0.11  0.009 0.361 0.133 0.082 720,7704.18:1

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20.Other Relevant Data and Information
  
20.1

Mining

The original mine plan for the Pre-feasibility study of 2001 was for a mining rate of 20,075 ktons per year (55,000 tpd for 365 days). This plan was modified for the current update to 9,125 ktonnes per annum (25,000 tpd for 365 days). The mine is scheduled to operate 360 days per year. The new mine plan is based on using a mine contractor to complete all mining operations with PolyMet staff supervising mine plan operations and mine geology.

Mine development will generally follow that outlined by IMC in the Pre-feasibility study with the exception that Phase 6 and 7 will only occur if metal prices and capital and operating costs warrant this development. The goal of the phases is to develop the mine in a logical order by commencing the mine with the higher grade material which also has lower strip ratio. The mine plan will then progress to higher strip ratios. Phase 1 is in the northeastern part of the deposit with phase 2 in the southwestern portion. The remaining three phases will push the hanging wall south. Exits will be maintained to the south during all phases of mining so that access can be obtained to the rail load-out facility.

Waste rock will be stored in dumps located to the north and east of the main ore body The waste dumps will be located outside of any potential ore body extensions should PolyMet decide to expand the pit. Waste facilities will be constructed in 7m lifts with an overall slope angle of 22° (2.5H:1V) .

Mining operations will be carried out by a mining contractor. The contractor will provide all necessary fleet requirements for a turn-key mining operation based on the required annual mine production schedule. Work activities will include:

  • Construction of the initial out-of-pit access roads from the pit area to the rail load-outfacility and the mine rail spur and to the waste rock storage areas.
  • Removal of all topsoil from the mine and waste storage areas. Replace topsoil on thewaste storage areas at completion of mining as part of ongoing mine reclamation.
  • Pre-production development required to expose ore for initial production.
  • Mine and transport ore to the rail load-out facility.
  • Maintain all mine work areas, in-pit haul roads, and external haul roads.
  • Maintain waste storage areas.

The major mine fleet will consist of nine 185 t trucks, one 18m3 and one 11m3 loaders, two 23 m3 shovels and two blasthole drills. Support equipment will include track dozers and motor graders to maintain road surfaces, dumps and operating benches.

Mining will be conducted year round based on three 8 hour shifts per day.

Mine operating costs are based on data from similar mining operations and contract mining costs. The costs cover all general labour and consumable costs, amortization of initial equipment capital investment, equipment depreciation and contractor profit.

The costs associated with PolyMet mine personnel and administration associated with direct mine operations are included separately within the operating cost section.

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20.2

Process Plant

A revised process plant design has been completed by PASI. The revised flowsheets are based on a throughput of 25,000 tpd and utilizing the existing Cliffs-Erie crushing and grinding facilities. The flotation plant and all downstream process will be new but will generally utilize existing buildings and infrastructure within the Cliffs-Erie facilities as follows:

  • one circuit of the rail dump pocket and the 60" gyrosphere crusher;
  • the withdrawal feeder and the transfer conveyors to the coarse ore bins;
  • 2-7' standard cone crushers and associated feeders;
  • 4-7' short head cone crushers and associated feeders and screens;
  • belt conveyors and tripper to the fine ore bins;
  • 8 sets of rod/ball mill circuits;
  • three regrind mills (two for concentrate regrind and one for limestone);
  • ancillary facilities and offices;
  • infrastructure including power supply and distribution; and
  • tailing storage and reclaim water facility.

An overall mass balance was developed for the NorthMet process based on the hydrometallurgical mass balance provided by PolyMet, which set the feed headgrades and recoveries for copper, nickel, cobalt and PGM's at and a throughput of 9,125,000 tonnes per annum.

The development of the flowsheet and equipment sizing for the crushing, grinding and flotation process facilities was based on flowrates derived from this mass balance, plus process design criteria developed from the AMEC study and information by SGS Lakefield who were responsible for the pilot plant flotation trials. The flowsheet for the hydrometallugical facilities – pressure oxidation, solid-liquid separation, PGM recovery, copper SX/EW and nickel/cobalt hydroxide recovery – was derived primarily from the AMEC study with equipment resized accordingly for the new plant throughput. Testwork data from SGS Lakefield was reviewed for sizing of thickeners and filters.

Work indices used for crushing and grinding circuit calculations are estimates provided by SGS Lakefield based on limited grinding testwork.

Process Design Criteria

The detailed process design criteria is presented in Appendix II and the key criteria is summarized in Table 20.1.

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Table 20.1 - Process Design Criteria Summary

Parameter Design Criteria
Annual mill throughput 9,125,000 tonnes
Average daily mill throughput 25,000 tpd dry
Plant Availability 91.34 % 
Operating Hours per day 24
Hourly Throughput 1140 tph dry
Concentrate produced 703 tpd dry
Rod mill work index 14 kWh/t
Ball mill work index 17 kWh/t
Regrind work index 7.5 kWh/t
Feed size to flotation 200 micron
Feed size to pressure leach 15 micron
Pressure leach residence time 2 hours
Autoclave operating temperature 225 C 
Autoclave operating pressure 475 psig
H2SO4 concentration 50-60 g/l
Cl concentration 10 g/l 
Cu SX plant 2 extraction; 1 wash; 2 strip
Organic / Acid ratio 1.5:1
PLS Cu 18.4 g/l 
Raffinate Cu 0.99 g/l 
SX Cu recovery 94.62 % 
E/W current density 260 amp/m²
Cathodes per cell 54
Total cells required 125

46


Process Description

The overall process flow is described in Figure 20.1.

Crushing

Run of mine ore will be delivered by rail to the Cliffs-Erie process plant and dumped into the primary crusher surge pocket. From the surge pocket, the ore will flow to a single existing 60" by 89" gyratory crusher set to produce a nominal coarse ore product with a P80 sizing of 6 inches. The existing secondary gyratory crushers will be removed and a surge pocket will be constructed allowing the crushed ore to discharge onto an existing apron feeder. The apron feeder will in turn discharge onto the exiting coarse ore surge bin feed conveyor. Ore from the coarse ore surge bin will discharge via the existing vibrating feeders onto existing belt feeders feeding two existing 7' standard cone crushers. Each 7' cone will discharge onto two existing vibrating feeders, each feeding an existing 6' x 10' vibrating screen. Screen oversize discharges into one of four existing 7' shorthead cone crushers. The minus ¼" discharge from the tertiary shorthead crushers will combine with the screen undersize onto the existing feed conveyor to the existing fine ore bin.

Grinding

Ore from the fine ore bin will discharge via existing vibrating and belt feeders to the existing rod and ball mill circuits. For the design throughput of 25,000 tpd, 8 of the existing 12 circuits will be utilized. Each rod mill will operate in open circuit, with the rod mill discharge feeding a ball mall in closed circuit with new hydrocylones. The grinding circuit will produce a flotation feed of 30% solids at a P80 sizing of 200 micron.

47



Figure 20.1 – Blocked Flowsheet

48


Flotation and Regrind

Cyclone overflow from the grinding circuits combine to feed a conditioning tank with a 5-minute retention time. The conditioner will feed a single bank of 4-160m3rougher tank cells providing a total residence time of approximately 8 minutes. Rougher discharge will feed 2 parallel banks of 5-160m3 tank cells providing a residence time of 20 minutes.

Rougher concentrate combines with re-cleaner tail to feed the first cleaner flotation circuit. The cleaner flotation circuit will consist of a single bank of four 20m3conventional cells providing 16 minute retention time. Scavenger concentrate, mixed with cleaner tail, will be reground in an existing regrind ball mill to a target P80 of 30 micron prior to recirculation back to the conditioning tank. Cleaner concentrate will be fed to a single re-cleaner column cell, providing 16-minute retention time, for final concentrate cleaning. Cleaner concentrate will report to the concentrate regrind mill where the concentrate will be reground to the target P80 sizing of 15 micron, prior to pressure oxidation. A second existing regrind mill (using ceramic balls as grinding media to reduce iron contamination) will be used for this purpose.

Reground concentrate thickened to 50% solids and stored in a concentrate storage tank, which provides 12 hours of surge capacity between the flotation circuit and downstream hydrometallurgical processing.

Flotation tailings will be pumped to the existing Cliffs-Erie tailings impoundment. The flotation circuit reagents (MIBC, PAX, Flex 31, and WW1 752) are based on the AMEC study and was developed for effective base metal recoveries with associated high PGM recovery.

Pressure Leaching

Pressure Leaching is based on standard Autoclave technology and utilizes the patented PlatSol™ Process. Concentrate will be blended in the autoclave feed tank with sodium chloride prior to pumping into the autoclave at 50% solids. Recycled copper SX/EW raffinate will be pumped into the autoclave to maintain temperature control.

The two autoclaves will provide the required 2-hour residence time for the feed slurry. Each autoclave will have 6 compartments, and will be designed to operate at 225°C and approximately 475 psig. These pressures and temperatures are standard for autoclave design in the refractory gold ore/concentrate oxidation process. The NorthMet autoclave design will comprise a mild steel pressure vessel with a polymer-thermoplastic membrane corrosion barrier and two layers of acid resistant brick for thermal and abrasion resistance. This design follows the reported design of the Phelps Dodge copper concentrate autoclave at Bagdad, Arizona. The Phelps Dodge autoclave has been designed for temperatures up to 235°C and pressures of up to 4000 kPa.

49


The slurry is cooled to below 63°C via a single stage let down and slurry coolers prior to downstream metal extraction processes.

Leach Residue

Prior to metal recovery, the leach residue will be separated from the pregnant leach solution (PLS) to provide a high recovery of solute via filtration and washing of the leach residue. To accomplish this, the circuit will include a primary thickener followed by a pressure plate filter unit. A wash ratio of 4:1 will be used to maintain high solute recoveries. Autoclave residue filter cake will be re-pulped and fed to a scavenger flotation circuit to recover residual PGM's. The PGM concentrate will be re-circulated back to the feed end of the autoclave and the flotation tailing will be pumped to a new hydromet tailings impoundment constructed inside the existing tailings impoundment.

PGM Recovery

The PLS will be mixed with S02 to ensure total reduction of oxidized iron species in solution (Fe (III) is reduced by Fe (II) in solution by SO2). The SO2 will be produced by a packaged sulphur burner system. After ferric iron reduction, the solution will be processed through a two-stage pipe reactor system, with the addition of NaHS, to precipitate the platinum and precious metals. After filtration, the PGM precipitate will be releached in a sulfuric acid solution in a batch autoclave to leach any co-precipitated base metals (Cu, Ni, Co) and sulfur/sulfides to produce a high grade PGM precipitate for toll refining. Batch autoclave leach solution will be recirculated back to the PLS surge tank before precious metal recovery to ensure full recovery of valuable metals.

Neutralization

The PLS filtrate from the PGM precipitation system will require neutralization to pH 2 prior to copper solvent extraction. Filtered PLS will be pumped from the neutralization surge tank to the solution neutralization cascade that consists of three tanks with a total retention of 180 minutes. Limestone is added to maintain a pH of 2 and prepare the solution for copper solvent extraction.

The slurry exiting the precipitation tanks will be pumped to a thickener. Thickener underflow is filtered using an automatic plate and frame pressure filter package. The filter cake solids (saleable grade gypsum) will be discharged to a conveyor and stockpiled prior to re-sale.

50


Copper Solvent Extraction and Electrowinning

Copper PLS from the neutralization circuit will be stored in the copper SX feed tank providing 4 hours of surge capacity. PLS will be filtered to avoid crud formation in the SX circuit. The filtration will use multi-media pressure filters and the backwash will be returned to the gypsum thickener. Copper will be extracted from the PLS into an organic solution.

The extraction circuit consists of three mixer settlers, in which the aqueous feed and the barren organic flow counter-current to one another. Raffinate leaving the final extractor will report to the copper raffinate tank, from which solution will either be recirculated back to pressure oxidation for use as cooling liquid, or sent forward to bleed treatment.

Copper loaded organic is pumped from the first stage extractor to the loaded organic tank where entrained aqueous solution will have the chance to settle out. Solution recovered in this way will be collected in a sump at the bottom of the tank and periodically returned to the extraction circuit.

Loaded organic will be contacted, in a two-stage copper strip circuit, with lean electrolyte recycled from copper EW. The stripped organic will pass through to extraction, while the rich electrolyte will be pumped through organic recovery columns, and anthracite based multi-media filters to coalesce any residual organic, before discharging into the electrolyte recirculation tank.

Rich electrolyte will be trim heated to approximately 120°F before entering the tankhouse EW cells, using an indirect hot water heating system. A 125-cell tankhouse will provide the capacity required to harvest 33,000 tonnes per year of cathode copper.

Cathodes from the EW cells will be harvested on a daily basis, after a 7-day growth cycle. The copper sheets will be mechanically stripped from the stainless steel blanks using a standard fully automatic cathode washing and stripping machine. The stripping machine will also provide mechanical stacking, strapping, and weighing of the cathode bundles in preparation for shipping to market.

Nickel-Cobalt Hydroxide

Iron and aluminum must be removed from copper SX raffinate bleed solution before the extraction of nickel and cobalt.

In the first of three precipitation cascades, iron will be removed as goethite. In order for goethite to be formed, the bleed stream will be pre-heated to 170°F by direct steam injection into a tank with 45 minutes retention time. Direct injection will be used to negate the problem of gypsum scaling on the solution side of a shell and tube heat exchanger.

Hot solution from the pre-heat tank will enter the first of five tanks in the iron precipitation cascade. Limestone will be added to the first tank to neutralize free acid in the copper raffinate, and will result in gypsum precipitation. Air is sparged

51


into tanks l, 2 and 5 to facilitate ferrous oxidation, allowing ferric precipitation as goethite. In the third and fourth tanks ferrous oxidation will be enhanced using a mixture of oxygen and sulfur dioxide. More limestone will be added to neutralize the acid generated by the goethite precipitation and maintain a discharge pH of 3.5. At this pH a significant percentage of the aluminum hydrolyses and precipitates while loss of the valuable metals (Ni, Co, Zn) is minimized.

Overflow from the fifth tank will be pumped to a thickener where the solids settle to a density of 40% by weight. A significant portion of the thickened underflow will be returned to the precipitation cascade, where the solids act as seeds to facilitate the growth of larger particles, which in turn improves settling and filtration characteristics. The balance of the thickener underflow will be filtered through a plate-type pressure filter. After washing to recover entrained nickel and cobalt, the cake will discharge into a tank where it is slurried with reclaim water and pumped to a new tailings impoundment on the existing tailings dam

Overflow from the iron thickener will be neutralized with magnesium oxide in two stirred tanks to precipitate a combined nickel/cobalt hydroxide. Slurry will discharge from the second tank into a thickener. Thickener underflow is filtered in a plate-type pressure filter. The filter cake will be collected and steam dried prior to bagging for dispatch to an off site nickel/cobalt refinery.

Thickener overflow will be treated with lime in two stirred tanks to precipitate any remaining valuable metal content. Slurry will discharge from the second tank to a thickener. Thickener underflow will be recycled back to the leach residue thickener. Thickener overflow will be pumped to a new tailings impoundment on the existing tailings dam.

The valuable metals (Ni, Co) will be redissolved under the strong acid conditions prevailing in the leach residue thickener.

Tailings

The existing tailings facility at Cliffs-Erie will be used to contain tailings products from the NorthMet process plant. Flotation plant tailings will form the bulk of the tailings products and will be discharged to the existing dam using the existing pumping and piping arrangement.

There will be three new hydromet tailings produced:

  • leach residue flotation tailings,
  • iron/aluminum gypsum sludge; and
  • solution from the hydroxide precipitation circuit.

Each of these tailings will be contained in separate lined ponds constructed on the existing tailings dam. Each pond will have an initial capacity of 3 years storage.

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Reagents

Included on the equipment list are the proposed reagent systems to support the process plant operations. Reagent systems included are:

  • Limestone: Rail receipt and off-load, conveying, crushing and grinding,slurry storage and distribution loop. (An existing mill will be used forgrinding.)
  • MIBC: Bulk liquid storage and distribution.
  • PAX: Mixing, storage and distribution.
  • Flex 31: Bulk liquid storage and distribution.
  • WW 1752: Bulk liquid storage and distribution.
  • Flocculent: Mixing, storage and distribution
  • Sulfuric Acid: Bulk liquid storage and distribution.
  • NaHS: Bulk liquid storage and distribution.
  • NaCl: Mixing, storage and distribution.
  • MgO: Mixing, storage and distribution.
  • CaO: Mixing, storage and distribution.
  • Sulphur: Bulk storage, burner, distribution and SO 2scrubbing.

Capital and Operating Cost Estimates

Estimates of capital and operating costs were generated at the Pre-feasibility level in the April 2001 Pre-Feasibility Study led by IMC. Since the project was taken over by new management in March 2003, four critical elements have been revised as follows:

 1.     Smaller higher grade mine plan.
 2.     Elimination of complex nickel cobalt recovery circuits and conversion to nickel hydroxide.
 3.     Securing the mothballed Cliffs-Erie Mill concentrator.
 4.     Use of a contract miner.

Based on the above, P. Downey and Associates, with the assistance of PASI and IMC, have revised the 2001 capital and operating costs and updated to current first quarter 2004 pricing.

Capital Costs

The revised capital is summarized in Table 20.2.

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Table 20.2 - Revised Capital Cost Estimate

Description Totals (US$ Millions) 
Mining- using contract miner 5.76 
Crushing/Milling/Flot'n(Existing Cliffs/Erie) 24.91 
PlatSol™ Process- 31.05 
Copper SX/EW Plant 25.19 
PGM Recovery Circuit 20.62 
Nickel Hydroxide recovery circuits 6.00 
Tailings, Water & Services(Existing Cliffs-Erie) 4.55 
Plant Site Utilities & Facilities(Existing Cliffs-Erie) 12.59 
Sub Total Direct Costs 130.67 
Indirect Costs (Inc. Fees, working capital & 20% Contingency) 73.13 
Other Acquisition-incl. land and infrastructure 31.00 
Total Project Costs 234.80 

The capital cost estimate includes the estimated direct cost for equipment, material and labour. In addition, cost estimates were developed for the project indirect costs including EPCM, start up, construction indirects, first fill, spares and contingency. The estimate was developed based on a site visit and inspection of existing equipment and facilities, and the following main sources of information:

  • Contract Mining and Associated Services.
  • Process Design Criteria by PASI.
  • Process Flow Sheets.
  • Facility General Arrangement Drawings.
  • Electrical and Mechanical Equipment List.
  • Budget Quotations from Equipment Suppliers.
  • Current Labour and Material Costs for the Area.
  • The AMEC Simons Mining & Metals 2001 Prefeasibility Report.

54


Operating Costs

The 2001 Pre-Feasibility Study estimate of operating costs included an owner operated mining fleet, an all new processing plant, infrastructure and G&A costs associated with the on-site production of a PGM concentrate, copper cathode, nickel cathode and cobalt sulphide.

The current revised project operating costs use the same basic project data updated to 2003 but are based on a simplified flowsheet whereby only copper cathode is produced on site. The revised operating costs also reflect a contract mining operation and use of the Cliffs-Erie crusher/mill/concentrator. The Cliffs-Erie facility also received a beneficial electrical power rate for the first 25 MW of usage and this rate has been carried in the current operating cost estimate. Labour rates are based on data available from Minnesota Iron Range mines. The operating cost estimates include a 5% contingency, as detailed in Table 20.3.

Table 20.3 – Revised Operating Cost Estimate

Cost Area Annual Cost 
(US$ Millions) 
Cost/Tonne Ore 
(US$/Tonne/Ore) 
General & Administrative ("G & A") 4,856,600  
   Subtotal G & A 4,856,600 0.53 
Mine   
   Contract miner   
   Sub Total Mine 28,938,000 3.21 
Mill & Process   
   Reagents & consumables 22,142,258  
   Labour Costs 10,977,823  
   Operating Supplies 400,000  
   Maintenance Supplies 1,915,896  
   Environmental 300,000  
   Sub Total Mill & Process 35,735,977 3.91 
Power 16,746,886 1.84 
Total Operating Costs 86,277,463 9.49 
5% Contingency 4,313,873 0.95 
Total Operating Costs 90,591,336 10.44 

The following items are not included in the direct cash operating cost estimate:

  • Product delivery to smelters or copper cathode end users
  • Selling and marketing costs
  • Corporate overhead
  • Depreciation, amortization and depletion
  • Interest charges

Manpower requirements were estimated in detail for each area of the mine, process plant and administration. Allowances were made to cover vacations, sick time and other types of leave such as training.

55


The following Table 20.4 summarizes the overall manpower requirements for the operation. Salary and overhead costs were based on data from the recently closed Cliffs-Erie operation and from data from other similar sized operations.

Table 20.4 Manpower Requirements

Administration Staff 29 
G& A Salaried 22 
Process Plant Staff 27 
Process Plant Salaried 140 
Total 218 

56



21.

Interpretation and Conclusions

The results of this scoping level study indicate that the NorthMet project, as currently defined, shows sufficient potential to be carried forward to the next phase which is a feasibility study. The purpose of the feasibility study will be to examine all aspects of the project development and to establish with greater accuracy its economic and technical viability.

This conclusion is solely based on the resource data and the order of magnitude capital and operating costs developed for this study.

57



22.

Recommendations

It is recommended that PolyMet proceed to the next stage of development of the NorthMet Project which is the Feasibility Study level stage. This will include sufficient drilling to bring the current resources to the reserve category. Additional test work will also be required to further refine the ore process prior to completion of a bankable Feasibility Study.

58


 

23.References
   
 -     Independent Mining Consultants, Inc., April 2001, NorthMet Project, Minnesota Pre- Feasibility Study
 
 -     AMEC Simons Mining & Metals, April 2001, Pre-Feasibility Report for the NorthMet Project Process Plant Facilities
 
 -     Penguin Automated Systems Inc., April 2004, NorthMet Project Processing Facilities Scoping Study
 
 -     Lakefield Research, February 1, 2001, A Pilot Plant Investigation into the Recovery of Copper, Nickel, Gold and PGM's from NorthMet Bulk Concentrate – Progress Report No. 1

59



24.The date of this report is July 22nd, 2004.

60



25.

Additional Requirements for Technical Reports on Development Properties and Production Properties

There is no information to report for this item in the Pre-feasibility stage of exploration.

61



26.Illustrations
  
 Figure 3.1 - Aerial photograph of the Cliffs-Erie facilities 
 Figure 6.1 - Location of NorthMet Project 
 Figure 6.2 – Mineral Rights Owners 
 Figure 6.3 – Surface Owners 
 Figure 9.1 – Midcontinent Rift System 
 Figure 9.2 - Regional Geology 
 Figure 10.1 – Midrift Cross Section 
 Figure 9.3 – West Edge Duluth Complex 
 Figure 9.4 – Generalized Igneous Stratigraphic Column 
 Figure 13.1 – Area 1999 - 2000 Drilling 
 Figure 13.2 – Location of Metallurgical Samples 
 Figure 13.3 – US Steel and PolyMet Drilling 
 Figure 13.4 – Cross Section Drill Holes 
 Figure 20.1 – Block Flowsheet 
  
  
  
 Table 6.2 – Land Swap 
 Table 6.3 – Estimated NorthMet Wetlands Mitigation Requirements 
 Table 6.4 – NorthMet EIS and Permitting Cost and Timing Estimates 
 Table 13.1 – Summary of Drilling Programs 
 Table 18.1 – Pilot Plant Metal Recoveries 
 Table 19.1 – Lower Tonnage Higher Grade 
 Table 20.1 – Process Design Criteria Summary 
 Table 20.2 – Revised Capital Cost Estimate 
 Table 20.3 – Revised Operating Cost Estimate 
 Table 20.4 – Manpower Requirements 

62


APPENDIX I

MINING – INDEPENDENT MINING CONSULTANT UPDATE REPORT

MAY 2003

63


1

MEMO

TO: Terry O'Kane, Bill Murray, Don Gentry
FROM: M. Hester, H. Welhener
DATE: May 25, 2003
SUBJECT: Project Summary

Summary

PolyMet Mining Corporation (PolyMet) requested that Independent Mining Consultants, Inc. (IMC) update the April 2001 mine pre-feasibility study with new economics and develop a scoping level trial mine production schedules. The project approach has shifted from processing the polymetalic ore to final metals on the property to generating three concentrates: copper, nickel-cobalt and a PGM. The copper concentrate would be further processed on site using SXEW to produce copper metal. The other two concentrates would be shipped off site for further processing.

Table 1 shows the new economic input parameters. The metal prices have changed from the 2001 study with increases for most of the metals except palladium, which dropped significantly. The new prices were incorporated into the cash flow of the 2001 study and show a large drop in the project economics (Tables 3 and 4).

The block model was updated to better reflect the selectivity near the NSR cutoff grade for the present economics. The 2001 model ore zones were based on a $4.00 NSR ore-waste boundary. The current economics have a $7.42 NSR internal cutoff grade. The ore-waste boundaries were re-set in the block model using a $6.00 NSR to better reflect selectivity at a higher NSR value.

Floating cones were run and the results are summarized on Table 5. Based on the cone geometries, five mining phases were designed, three in the southwest pit area and two in the northeast. Unlike the 2001 study, the two pit areas do not join. The sum of the five phases (the total pit) contains 176,199 ktons of measured, indicated and inferred ore using the $7.42 NSR/t cutoff grade, and 720,199 ktons of total material. The inferred class material is included in this scoping study to show the best potential of the project.

Preliminary production schedules were developed for 15,000 tpd and 25,000 tpd ore rates. The 25,000 tpd schedules show a better NPV during the early years of the trial schedules. Schedules at 25,000 tpd have an average mine life of 19 years and the 15,000 tpd schedules extend the mine life to 32 years.

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Economic Parameters

Table 1 summarizes the economic parameters used for this study.

Table 1: Economic and Recovery Parameters  
Base Mining Cost Per Total Ton $0.534
Lift Cost Per Total Ton Per Bench Below 1580 Elevation $0.009
Benches Mined Per Year / Annual Discount Rate 12/12%
G&A Cost Per Ore Ton $0.51
Processing Cost Per Ore Ton $6.91
Flotation Recoveries:  
Copper 93.7%
Nickel 69.0%
Cobalt 42.0%
Palladium 79.6%
Platinum 76.9%
Gold 75.7%
Copper Refining Cost Per Payable Pound Included
In Price
Nickel/Cobalt Refining Cost Per Payable Pound 
PGM Refining Cost Per Payable Ounce $15.00
Process Recoveries (Payables): 
Copper 97.6%
Nickel 96.9%
Cobalt 92.0%
Palladium 94.0%
Platinum 95.0%
Gold 94.0%
Metals Prices:  
Copper Per Pound $0.80
Nickel Per Pound (70% of $4.00) $2.80
Cobalt Per Pound (70% of $10.00) $7.00
Palladium Per Troy Ounce/Gram $150/4.82
Platinum Per Troy Ounce/Gram $600/19.29
 Gold Per Troy Ounce/Gram $350/11.25

The recovery, price, and processing cost parameters were provided by NorthMet personnel.

The mining cost was estimated by IMC based on the engineered cost estimate prepared for the Preliminary Feasibility Study (PFS). First, mining costs estimated for each

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3

mining year of that study were plotted against the average mining elevation to obtain the base and lift (elevation related) components of the cost. Second, mining costs were examined by cost center (drilling, blasting, loading, hauling, auxiliary equipment, general mine, general maintenance, and mine supervision) and a fixed and variable component of each were extracted. These were used to scale the base mining cost from that of the 70 to 100 million annual tons of the preliminary study to the 40 to 50 million annual tons contemplated for this revised study. Third, the costs were escalated 2.5% per year for two years to obtain 2ndquarter 2003 US dollars. Overall mining cost is anticipated to be about $0.60 per ton for this revised study, about the same as the average for the PFS. The expected higher cost of the lower mining rate is countered by the elimination of the longest truck hauls off the back end of the larger project.

The table also shows a time value of money component of the parameters that was used with some of the floating cones. For these cones, a mining rate of 12 benches per year and an annual interest rate of 12% were assumed for a discounting factor of 1 % per mining bench. This was used to discount the revenues and costs as a function of pit depth. For the PFS the maximum advance rates were about 10 benches per year from a mining phase.

An NSR value was calculated for each block and used in the floating cones, tonnage tabulations, and production scheduling. Table 2 shows the factors applied to each metal for the PFS and for this current study. The NSR for each block for the current study was calculated as:

NSR=       14.63 x copper (%)+37.44 x nickel (%) 
 +       0.0054 x cobalt (ppm)+2.95 x palladium (ppm) 
 +       12.47 x platinum (ppm)+6.95 x gold (ppm) 

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Table 2: NSR Factors for Prefeasibility and Current Study 
 Prefeasibility Current 
NSR Factor for Copper ($/%) 13.95 14.63 
NSR Factor for Nickel ($/%) 29.23 37.44 
NSR Factor for Cobalt ($/ppm) 0.0055 0.0054 
NSR Factor for Palladium ($/ppm) 11.73 2.95 
NSR Factor for Platinum ($/ppm) 10.44 12.47 
NSR Factor for Gold ($/ppm) 5.17 6.95 
Internal NSR Cutoff Grade ($US) $4.31 $7.42 

It can be seen that the relative value of nickel has increased significantly from the PFS. Moderate increases are also noted for copper, platinum, and gold. The relative value of the palladium has reduced significantly.

The NSR value represents the value of the ore after paying for SXEW, refining, and freight charges. The NSR value needs only to pay for mining, G&A, and processing costs that are common to every ore ton (crushing, grinding, flotation, pressure oxidation, and tailings, etc). The NSR factors shown on Table 2 are calculated from the Table I parameters as follows:

Copper:      ($0.80)(0.937)(0.976)(20)(Cu%) 14.63 x Cu% 
Nickel:      ($2.80)(0.69)(0.969(20)(Ni%) 37.44 x Ni% 
Cobalt:      ($7.00)(0.42)(0.920)(20)(Co ppm)/10000 0.0054 x Co ppm 
Palladium      ($150 - $15)(0.796)(0.94)(Pd ppm)/34.285 2.95 x Pd ppm 
Platinum:      ($600 - $15)(0.769)(0.95)(Pt ppm)/34.285 12.47 x Pt ppm 
Gold:      ($350 - $15)(0.757)(0.94)(Au ppm)/34.285 6.95 x Au ppm 

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5

It can be seen that the metal recoveries, prices, and refining costs are accounted for in the NSR calculation.

Prefeasibility Study Economic Model With Current Prices

The metal prices proposed for this updated study were incorporated into the detailed cash flow model of the PFS. The prices used are as shown on Table 1 with $4.00 for nickel and $10.00 for cobalt.

Table 3 shows the financial results for the before-tax case.


Table 4 shows the financial results for the after-tax case.


It can be seen that the changes in metal prices have a significant negative impact on the PFS case.

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6

Block Model Update

The block model for the PFS was developed by manually selecting drillhole composites inside the ore zone based on a $4.00 NSR cutoff grade. These composites were then used to select the ore zone blocks using an indicator kriging approach. The model was optimized to be accurate at about a $4.00 NSR cutoff grade.

Table 1 shows that with the revised economics the internal NSR cutoff grade is about $7.42 per ore ton (processing plus G&A). It is likely that the PFS model will be slightly over-smoothed (slightly high on ore tonnage and slightly low on metal grades) at the cutoff grades of current interest.

For this study, the block model was updated based on a $6.00 NSR cutoff grade. Drillhole composites were re-examined and those inside a $6.00 NSR ore zone were selected. A revised ore zone boundary was developed and grades of the various metals re-estimated based on the same methods used for the PFS. Resource classifications were also re-assigned using the same methods as the PFS model.

The section of this memo titled "Changes in Reserves - Preliminary Feasibility Study Case to Current" documents the change in reserves attributed to this revised model.

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Floating Cone Evaluation

Table 5 summarizes the results of floating cone runs on the NorthMet deposit at various metal prices and other conditions.

Cases 1 through 5 are floating cones at various metal prices without time value of money discounting and with an hangingwall slope angle of 50 degrees. Mechanically, the various metal prices were handled by applying a recovery factor to the block NSR value, i.e. 100% of NSR is the base case prices, 80% of NSR is 80% of base case prices, etc. Only measured and indicated resources were allowed to contribute to economics to develop floating cone geometries. However, inferred resource within the developed geometries is included on the Table x tabulations. The inferred resource generally amounts to slightly over 10% of the total resource. It can be seen that ore tonnes range from 194.5 million tons to 55.8 million tons for these cases with the largest break occurring between Cases 4 and 5. Total tons range from 760 million to 145 million. The base case cone for the PFS contained 498.3 million ore tons within a geometry with 1.8 billion total tons. It is evident that the revised economics significantly reduce the size of the project.

Cases 6 and 7 include time value of money discounting of 1% and Y2% per bench. In both cases the results fall in between the results for Cases 2 and 3. Case 8 examines a reduced slope angle on the hangingwall to account for more road on that wall than originally contemplated. It does not have a large impact on results.

In general, as effective metal prices are decreased in Cases 1 through 5, the cone targets more profitable material. It is important to note that metal grades do not change significantly in these cases. Higher profitability comes from reduction in strip ratio. The implication is the general lack of significant higher grade ore zones in the NorthMet deposit resource model. This could be a reflection of the true geologic character of the deposit, or alternatively it could be partially due to insufficient density of drilling data and over-smearing of the available data.

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Another aspect of the NorthMet deposit that is not evident from Table 5, but is evident from examining measured, indicated, and inferred resources by category is that the grade of measured resources is less than the grade of indicated resources and the grade of indicated resources is less than the grade of indicated resources. This implies that grade increases with depth, which is not the desirable case for a mining project. For example, for the Case 1 cone the copper grade of measured, indicated, and inferred resource is 0.360%, 0.383%, and 0.398% respectively. This is also evident for nickel, palladium, platinum, and gold; only cobalt reverses this trend and exhibits decreasing grade at less confident resource classes.

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Table 5

Table x
Floating Cone Resources at Various Metal Prices (Based on Percent Recovery of Available NSR Value)
Measured and Indicated Resource Only Used to Develop Cone Geometry
Tabulation Includes Inferred Material in the Geometry
Resources Tabulated at $US 7.42 NSR Cutoff Grade

Case % of NSRDiscount  Rate HVV Slope AngleOre  Ktons NSR ($US)Copper  (%) Nickel  (%) Cobalt (ppm)Palladium  (ppm) Platinum (ppm)Gold (ppm)Cu Eq  (%) Total     Ktons Strip  Ratio 
100% none 50194,500 12.160.370 0.097 66.14 0:372 0.1050.0520.901 759,857 2.91 
95% none 60186,019 12.250.374 0.097 68.070.374 0.1050 .053 0.908 720,358 2.87 
90%none 50141,030 12.370.378 0.098 68.510.374 0.1070.0540.915 497,612 2.53 
85%none 50119,361 12.470.382 0.098 68.120.379 0.1080.055 0.926 403,264 2.38 
580%none 5055,808 12.400.375 0.099 69.000.379 0.1080.0530.914 144,763 1.59 
6100%1 %/ben 50159,873 12.180.371 0.097 68.640.370 0.1040.0530.898 576,836 2.61 
100%0.5%/ben 50181,405 12.170.371 0.097 68.520.370 0.1040.0520.900 690,709 2.81 
8100%0.5%/ben 42164,166 12.200.372 0.097 68.420.371 0.1050.0530.901 639,643 2.90 

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Mine Phase Designs

Five mining phases were designed. Table 6 summarizes the tonnage and grade results for each phase at the internal NSR cutoff grade ($7.42/t) . The floating cones indicated that the most profitable material was in the south of the orebody; the first three mining phases are located in the south. The final two mining phases are in the north. The final geometry includes a north and a south final pit that are not connected. Note that starting of mining in the south is different than the PFS case, which started in the north. This change is due to the revised economics and change in relative importance of the various metals.

The final pit contains 176,199 ktons of measured, indicated and inferred ore using a $7.42 NSR/t cutoff grade and 720,199 ktons of total material. In terms of ore tonnage it approximates floating cone Cases 2 and 7. It is also close to Case 2 in terms of total tons. The final pit strip ratio is a bit higher than the cones. The 50 degree hangingwall slope angle used in the cones was steeper than could be achieved during pit design due to haulage roads.

Table 7 shows the phase tonnages at higher NSR cutoff grades. Increasing the NSR cutoff grade from $7.42/t to $12.00/t reduces the contained measured, indicated and inferred ore from 176.2 million tonnes to 83.2 million tonnes. Raising the NSR cutoff to $15.00/t drops the contained ore tonnage to 25.6 million tonnes.

Table 8 shows the measured and indicated only ore tonnage within the mining phases at various NSR cutoff grades. Removing the inferred ore grade material has the largest impact on phases 1-South and 3-South.

The net value of each mining phase was calculated to rank the phases and determine the best mining sequence for mine production schedules. The net value was calculated at the internal NSR cutoff grade of $7.42/t. The floating cone input costs of $0.60/t mining and

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$7.42/t for processing and property G&A were used to calculate the costs. Table 9 shows the results on a net value and a value per ton of ore (at internal cutoff grade) calculation. The net value per ton of ore shows that the mining sequence should be south pit and then north pit.

Figure 1 shows the final geometry of the South pit (combination of south phases 1, 2, and 3. Figure 2 shows the final North Pit (north phases 1 and 2). Figure 3 shows the relationship of the 5 mining phases on the 1500 bench.

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Table 6
Mining Phase Resources
Includes Measured, Indicated, and Inferred Resources
Tabulated at $US 7.42 NSR Cutoff Grade

Phase Name Ore Ktons NSR ($US) Copper (%) Nickel (%) Cobalt (ppm)Palladium  (ppm) Platinum (ppm) Gold (ppm)Cu Eq (%) Total Ktons Strip Ratio
ph1sthtr4          23,283 13.50 0.407 0.091 58.59 0.447 0.162 0.070 1.065      109,070 3.68 
ph2sthtrl          20,911 11.20 0.346 0.096 73.25 0.287 0.081 0.042 0.783          47,937 1.29 
ph3sthtr2        62,883 12.66 0.398 0.096 66.91 0.372 0.111 0.057 0.941      277,004 3.41 
phlnthtrl          26,684 11.71 0.350 0.103 71.55 0.337 0.084 0.047 0.845      110,208 3.13 
ph2nthtrl          42,438 11.48 0.342 0.098 70.88 0.366 0.086 0.043 0.842      175,980 3.15 
TOTAL       176,199 12.17 0.372 0.097 68.22 0.365 0.104 0.052 0.900      720,199 3.09 

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13

Table 7

Polymet Mining - MorthMet Project, May 2003 Update
Summary of Mining Phases by NSR Cutoff Values

MEASURED, INDICATED & INFERRED

Table 8

Polymet Mining - MorthMet Project, May 2003 Update
Summary of Mining Phases by NSR Cutoff Values

MEASURED AND INDICATED ONLY

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14

Table 9

Net Value of Mining Phases

Mining Phase Bottom Bench ORE (=+ $7.42 NSR) Waste Total Phase Net Value Phase, Net  Value per  ton of Ore 
         Ore ktons NSR, $ Cu, % CuEq, % ktons ktons $ x 1000 
PH 1 South 880        35,151 $13.52 0.412 1.061 130,944 166,095 $114,765 3.26 
PH 2 South 1200        30,911 $11.20 0.346 0.783 27,026 47,937 $50,281 2.40 
PH3South 700        51,015 $12.44 0.393 0.915 168,962 219,976 $124,517 2.43 
PH 1 North 1040        26,684 $11.71 0.350 0.845 83,524 110,208 $48,350 1.81 
H 2 North 840        42,438 $11.48 0.342 0.842 133,542 175,980 $66,710 1.57 

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15




16





17



18

Mine Production Schedules

Preliminary mine production schedules were developed using the tonnage tabulations of the five mining phases for ore production rates of 15,000 tons per day (tpd) and 25,000 tpd. It is assumed that the plant will operate 365 days per year, thus the annual ore rate is 5,475,000 tons per year (tpy) for the 15,000 tpd case and 9,125,000 tpy for the 25,000 tpd schedules. The year 1 ore rate is at 85% of the nominal throughput rate and includes any ore mined during pre-production.

The mining sequence is phases 1, 2 and 3 in the south, then phases 1 and 2 in the north pit. Phases 1 and 2 in the south are independent phases and either one of them could be mined ahead of the other. Schedules were tried for both alternatives and starting with Phase 1 give a much higher net value during the earlier years at both production rates. Starting with Phase 1 requires a higher pre-production tonnage but this is more than offset by the higher head grades that are achieved.

The preliminary schedules developed for the two mill throughput rates have not been optimized and are intended to give an initial impression of the response to different cutoff grade sequences. Five cutoff grade schedules were run for each mill rate and the present value of the schedule at the end of years 5, 10 and end of mining was tabulated. This net value includes an allowance for the mine fleet capital (assuming new equipment) using a cost of $1.05 per ton of mining capacity. A discount rate of 8% was used to calculate the present value of the future revenues.

The NSR cutoff sequence used for the five production schedules summarized in Tables 10, 11 and 12 are: Schedule 1: All years at internal cutoff grade of $7.42 Schedule 2: Pre-production through Year 2 at $10.00, Years 3 to 7 at $9.00, Years 8 through 10 at $8.00, and all years after Year 10 at $7.42 Schedule 3: Pre-production through Year 5 at $10.00, Years 6 to 8 at $9.00, Years 9 and 10 at $8.00, and all years after Year 10 at $7.42

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Schedule 4: Pre-production through Year 5 at $9.00, Years 6 through 10 at $8.00, and all years after Year 10 at $7.42

Schedule 5: Pre-production through Year 10 at $8.00, and all years after Year 10 at $7.42

Higher cutoffs than $10.00 NSR were not evaluated because of the rapid decline of ore tonnage as the cutoff is increased, as seen on Table 7. For the sum of the South and North pits, the ore tonnage decreases by 37 million tons when the cutoff is raised from $7.42 to $10.00; this is a 21% decrease. When the cutoff is raised to $12.00, an additional 56 million tons is lost, or 40% of the ore tonnage at the $10.00 cutoff. The corresponding increase in NSR value per ton of ore is $0.80 (7%) when the cutoff is raised from $7.42 to $10.00, and an increase of $1.34 (10%) for the cutoff change from $10.00 to $12.00. The tonnage decrease is faster than the increase in net value as the cutoff is raised.

Table 10 is a summary of the preliminary schedules at 15,000 tpd ore and shows that there is some increase in the net value of the project with a modest increase in the cutoff grade in the early years. A smaller Phase 1 south was developed for the 15,000 tpd ore schedules to see if a smaller pre-production tonnage would improve the economics. Schedules with this sequence of phase designs are shown on Table 11. The smaller preproduction does improve the Year 5 NPV, but by Year 10 it and the schedules shown on Table 10 are similar. The smaller Phase 1 south was not used for the 25,000 tpd schedules because mining would occur too quickly through the benches in the phase.

The 25,000 tpd schedules are shown in Table 12 and show that a less aggressive cutoff grade strategy might be better at the higher throughput rate. The higher rate moves faster through the relative higher grade ore in Phase 1 South, thus bringing lower grade ore forward in time at a faster rate as the cutoff grade is raised. In all cutoff grade cases tested to date, the net values are similar for the preliminary nature of the input data. A 25,000 tpd rate was run with the smaller Phase 1 South and the NPV at Year 5 was about

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20

half of that shown on Table 12 for the sequence of cutoff grade trials. This is because of reduced amount of higher grade ore in the smaller phase 1.

Table 13 shows a 25,000 tpd ore schedule that has been refined from the preliminary schedules on Table 11. The total mining rate has been smoothed, but at this time is does not match the assignment of integer loading units per mining area. Additional refinements can be made to this schedule.

 INDEPENDENT 
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21


22


23


24

Table 13

Mine Production Schedule at 25,000 TPD Ore Rate

 ORE WASTE TOTAL 
Year Cutoff ktons NSR,$US Cu, % CuEq, % ktons Ktons 
        
PP 9.00 2,093 13.94 0.401 1.132 25,907 28,000 
9.00 5,663 12.92 0.384 1.001 31,161 36,824 
9.00 9,125 12.86 0.391 0.985 29,875 39,000 
9.00 9,125 12.94 0.396 1.000 29,875 39,000 
9.00 9,125 12.63 0.387 0.967 29,875 39,000 
8.00 9,125 11.75 0.356 0.869 29,875 39,000 
8.00 9,125 12.49 0.382 0.922 29,875 39,000 
8.00 9,125 11.87 0.370 0.824 29,875 39,000 
8.00 9,125 11.90 0.373 0.585 29,875 39,000 
8.00 9,125 12.30 0.395 0.882 29,875 39,000 
10 8.00 9,125 12.18 0.394 0.877 29,875 39,000 
11 8.00 9,125 12.83 0.413 0.939 29,875 39,000 
12 8.00 9,125 12.83 0.396 0.956 29,875 39,000 
13 8.00 9,125 13.09 0.392 1.003 29,875 39,000 
14 8.00 9,125 11.98 0.354 0.885 29,875 39,000 
15 7.42 9,125 11.52 0.339 0.843 29,875 39,000 
16 7.42 9,125 11.45 0.338 0.835 29,875 39,000 
17 7.42 9,125 11.13 0.327 0.783 27,798 36,923 
18 7.42 9,125 11.24 0.338 0.814 10,478 19,603 
19 7.42 9,125 12.58 0.389 0.970 3835 12,960 
20 4.42 724 13.37 0.417 1.057 163 887 
Total  172,730 12.25 0.375 0.907 547,467 720,197 

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25

Changes in Reserves - Preliminary Feasibility Study Case to Current

The purpose of this section is to document the changes in the stated potential minable resources from the Preliminary Feasibility Study published in April 2001 versus the current potential minable resource and to show the sources of the changes. Table 13 shows the resource change due to several different items.

Item 1 shows the potential minable resource at a $4.31 NSR cutoff grade as published in the PFS document. It shows 486.8 million ore tons in a total pit of 1.9 billion tons.

Item 2 shows the impact of excluding inferred resources as per the rules written in Canadian National Instrument 43-101 that became law about the time the PFS was completed. It can be seen that this amounted to 82.3 million tons of ore and the material was at higher average grades than the measured and indicated resources for all metals except cobalt.

Item 3 shows results due to a model developed in March 2001 with 13 additional holes. This model was documented in appendices to the original PFS, but was not the base case model used for that study. It can be seen that the impact was small as 4.7 million tons of low grade ore were added.

Item 4 shows the impact of the revised metal prices, recoveries, and process costs introduced during this May 2003 update. Note that the NSR cutoff grade increased from $4.31 to $7.42 with the revised economics. This resulted in the reduction of 99.7 million ore tons that were at quite low metal grades. Note that compared to Case 3 the metal grades increased significantly, but the NSR value did not increase. There were actually two components in Item 4. The first was the change to prices and recoveries. This caused a large change in NSR values but did not have much impact on ore tons. The second was the change to the process cost which caused the change to NSR cutoff grade. Almost all of the ore decrease is due to this second factor. The "N.A.'s" on the table mean that the calculation is nonsensical due to changes in base parameters between cases.

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26

Item 5 shows the impact of the May 2003 revision to the model, due to designing ore zones at the higher cutoff grades, as discussed previously. This resulted in a 52.9 million ton decrease in ore tons, but an increase in grade since the ore lost was at marginal values.

Note that Items 1 through 5 were all tabulated inside the PFS final pit design. Note also that the strip ratio increased from 2.95 to 6.49 with the various changes. Item 6 shows the results of a re-design of the final pit to be more appropriate for the current economic conditions. It can be sent that the pit size was decreased by 1.2 billion total tons and that 102.7 million ore tons were lost in the change. The strip ratio is back down to 3.68.

Item 7 shows the effect of adding back inferred material in the pit design. This adds 22.3 million ore tons. The final ore tons and grade shown, as well as total tons, are the same as on Table 6. The strip ratio is similar to the original Item 1 results.

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27



PolyMet Mining Corporation

 

NorthMet Project
Processing Facilities Scoping Study



PolyMet Mining Corporation

NorthMet Project
Processing Facilities Scoping Study

Table of Contents

Section Page 
   
1.0 Introduction 
 1.1 Background and Scope of Work1-1
 1.2 Basis of Design1-2
   
2.0 Summary2-1
 2.1 Introduction2-1
 2.2 Project Location and Access2-2
 2.3 Process Plant2-4
 2.4 Capital Cost2-5
 2.5 Operating Cost2-6
   
3.0 Process Plant 
 3.1 Existing Facilities at Cliffs Erie3-1
 3.2 Metallurgical Testwork and Design3-3
 3.3 Process Design Criteria3-5
 3.4 Process Description3-6
 3.5 Equipment List3-14
   
4.0 Operating Cost Estimates 
 4.1 Summary4-1
 4.2 Basis of Estimate4-2
   
5.0 Capital Cost Estimates 
 5.1 Summary5-1
 5.2 Basis of Estimate5-3
   
   
   
Appendices 
 Appendix 1- Process Design Criteria 
 Appendix 2- Drawings 
 Appendix 3- Equipment List 
 Appendix 4- Operating Costs 
 Appendix 5- Capital Costs 



 

 

 

 

 

 

 

 

 

1.0 Introduction

 

 

 

 

 

 

 

 

 

 

 




NorthMet Project Processing Facilities Scoping Study

1.0 Introduction

1.1 Background and Scope of Work

PolyMet Mining Corporation (PolyMet) intends to develop the NorthMet deposit located in the Mesabi Iron Range in Northeastern Minnesota. The project is located approximately 70 miles north of Duluth. The NorthMet Project is a polymetallic magmatic sulfide deposit containing platinum, palladium, gold, copper, nickel, cobalt, and silver. The deposit is hosted near the base of the Duluth Mafic Complex and is one of the largest undeveloped non-ferrous metal project in the U.S.

In 2001, (AMEC) (formerly AGRA Simons Inc.) completed a pre-feasibility level study for the NorthMet project. In 2003, a new management team review of the pre-feasibility work concluded that a technically simpler, lower tonnage project would be more appropriate to advance the project to feasibility level. As part of the strategy of the new management team, Polymet has secured an option to purchase and utilize the processing facilities available at the Cliffs Erie site in Hoyt Lakes, Minnesota. These assets were formerly owned by LTV Steel Mining Company, which permanently closed its iron ore mining and palletizing operations in January 2001. The Cliffs Erie site historically processed 100,000 st/day of iron ore through crushing, grinding and flotation. The Cliffs Erie plant acquisition therefore provides the "front end" of the proposed Polymet plant for treatment of NorthMet ore as well as land, buildings (for concentrate processing and metal recovery). Rail access and tailings dam facilities. As part of this revised approach, Polymet intend to utilize part of the existing processing facilities at the Cliffs Erie site in Hoyt Lakes, Minnesota. These assets were formerly owned by LTV Steel Mining Company, which permanently closed its iron ore mining and pelletizing operations in January 2001.

Penguin Automated System Inc. (Penguin ASI) was contracted in January 2004 to prepare a scoping level study for the NorthMet process plant facilities based on the revised concept as a prelude to proceeding to a feasibility study.

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NorthMet Project Processing Facilities Scoping Study

The Scope of Work was defined in the proposal issued January 21st 2004 and is summarized as follows:

  • Develop scoping level capital and operating cost estimates for a stand aloneconcentrator capable of treating 9,125,000 tonnes per annum and utilizing parts of theexisting Cliffs Erie processing facilities.


  • Prepare preliminary flowsheets, material balances, process design criteria, equipmentsizing and process plant layouts to support the development of the capital andoperating costs.

This study is based on the AMEC pre-feasibility report, testwork reports from SGS Lakefield, metallurgical data supplied by Polymet and site visits and discussions with key personnel at the Cliffs Erie site.

1.2 Basis of Design

The basis of design was to develop capital and operating costs to a scoping level estimate of +/- 30 %.

The capital cost estimates are based on flowsheets and layouts. Process equipment costs are based on preliminary budget quotes or factored from the previous study.

Operating cost estimates are based upon the estimated manpower requirements and reagent and consumable quantities developed jointly between Polymet and Penguin ASI and updated to reflect current cost data. Power costs are based on data gathered from site.

All currency amounts are stated in first quarter 2004 US dollars. All units of measurement are in metric units unless otherwise noted.

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2.0 Summary

 

 

 

 

 

 

 

 

 

 

 




NorthMet Project Processing Facilities Scoping Study

2.0 Summary

2.1 Introduction

The NorthMet Project is a large disseminated polymetallic deposit located North of Duluth Minnesota. It is proposed that the project be developed to exploit the mineral resources to produce the following three primary products:

  • copper cathode,


  • a nickel/cobalt hydroxide and


  • a concentrate containing platinum group metals (PGM's).

The project will utilize crushing, grinding and flotation processes followed by a standard autoclave circuit based on the patented PlatSol process. The copper metal will be recovered utilizing a conventional SX/EW circuit.

The nickel/cobalt and PGM concentrates will be refined offsite. The process will also produce significant quantities of gypsum and carbon dioxide gas as potentially saleable by-products. This is something that will be examined more completely during feasibility.

The average daily milling rate will be 25,000 tonnes per day based on a 91% overall plant availability equivalent to 9,125,000 tonnes per annum. Grades, recoveries and metal production are summarised in Table 2.1.

Table 2.1 NorthMet Production
 CuNiCoAuPtPd
Head grade
Recovery to concentrate
Concentrate grade
Pressure Leach Extraction
Recovery from Leach Solution
Overall Recovery
Metal Production tonnes per year
0.4%
93.7%
14.6%
99.6%
99.0%
92.4%
33,723
0.11%
69.0%
2.94%
98.9%
99.0%
67.6%
6,755
0.0088%
42.0%
0.14%
96.0%
99.0%
39.9%
319
0.0g/t
75.7%
1.6g/t
96.0%
99.0%
72.0%
0.36
0.11g/t
76.9%
3.32g/t
96.0%
99.0%
73.1%
0.74
0.38g/t
79.6%
11.82g/t
96.0%
99.0%
75.7%
2.63

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NorthMet Project Processing Facilities Scoping Study

2.2 Project Location and Access

The NorthMet deposit is located in northeastern Minnesota, St. Louis County, 100 miles north of Duluth and 4 miles south of Babbitt (see Figures 2.1 and 2.2) . The famous large-scale open-pit Mesabi Range iron mining operations are within two miles of the project. The Polymet process plant will be constructed on the site of the existing Cliffs Erie iron ore facilities located some 5 miles away by railroad from the deposit. The assets were formerly owned by LTV Steel Mining Company, which permanently closed its iron ore mining and pelletizing operations in January 2001. Founded as Erie Mining Company, LTV Steel Mining Company was one of the first taconite production facilities in Minnesota and in the iron mining industry. The construction of the Hoyt Lakes mine, plant, loading dock and the power plant facilities at Taconite Harbor was completed in 1957 at a cost of $300 million. Polymet has already acquired ownership of certain land, crushing and concentrating facilities, as well as shops, warehouses and other assets at the Cliffs Erie location and also has access to already established roads, tailings disposal facilities, water, electricity, offices and rail service. Rail lines connect to ports on nearby Lake Superior, all of USA and Canada.

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NorthMet Project Processing Facilities Scoping Study

Figure 2.1 NorthMet Deposit Location

Penguin Automated Systems Inc.2-3


NorthMet Project Processing Facilities Scoping Study

Figure 2.2 NorthMet Deposit Location

Accommodations and full services are located nearby in both Hoyt Lakes and Babbitt. Experienced general construction and operations labour can be obtained from the local area population.

2.3 Process Plant

The NorthMet Project will utilize parts of the existing processing facilities at the Cliffs Erie site for crushing and grinding of the ore. A new flotation plant will be installed in the existing concentrator building with new facilities and equipment installed for the downstream hydrometallurgical processes. The existing infrastructure and plant services will be utilized for the project.

Penguin Automated Systems Inc.2-4


NorthMet Project Processing Facilities Scoping Study

2.4 Capital Cost

A scoping level capital cost estimate for the process facilities was prepared. The capital cost of the processing facilities was estimated to be $199,426,621. This estimate is summarized in the following table 2.4.1.

Table 2.4.1 NorthMet Project Initial Capital Cost
Item Cost ($000)
  
             Crushing 3,082
             Grinding 4,282
             Flotation & Regrind17,546
             Pressure Leaching31,052
             Solid / Liquid Separation6,667
             PGM Recovery5,082
             Neutralization8,867
             Solvent Extraction6,439
             Electrowinning18,749
             Fe & Hydroxide Precipitation6,003
             Infrastructure & Auxiliary Services12,587
             Tailings4,549
             Mining5,760
             Subtotal Direct Costs130,665
             EPCM19,600
             Construction Indirects2,872
             Capital Spares4,323
             First Fills4,000
             Vendor Representatives1,319
             Freight2,499
             Start Up and Commissioning910
             Contingency33,238
             Total Project Cost$199,426

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NorthMet Project Processing Facilities Scoping Study

The capital cost estimate includes the estimated direct cost for equipment, material and labour and cost estimates for the project indirect costs including EPCM, start up, construction indirects, first fill, spares and contingency.

2.5 Operating cost

The annual operating costs for the processing facilities were estimated to be $60.2 million including a 5% contingency or $6.59 per ton milled. The processing operating cost estimate is summarized in the following table 2.5.1.

Table 2.5.1 Operating Cost Summary
Description Total Cost US$ US$/tonne 
Consumables 22,142,258 2.43 
Labour 10,977,823 1.20 
Power 16,746,886 1.84 
Plant Operating Supplies 400,000 0.04 
Maintenance Supplies 1,915,896 0.21 
Environmental Monitoring 300,000 0.03 
G&A 4,856,600 0.53 
Sub total 57,339,463 6.28 
Contingency 5 % 2,866,973 0.31 
Total 60,206,436 6.59 

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3.0 Process Plant

 

 

 

 

 

 

 

 

 

 

 




NorthMet Project Processing Facilities Scoping Study

3.0 Process Plant

3.1 Existing Facilities at Cliffs Erie

The polymet process will incorporate standard crushing, grinding and flotation to produce a concentrate for hydromettalurgical processing to produce copper cathodes, nickel cobalt hydroxide and a PGM concentrate.

The NorthMet project process facility will be located within the existing Cliffs Erie plantsite making use of the following:

  • one circuit of the rail dump pocket and the 60" gyrosphere crusher;
  • the withdrawal feeder and the transfer conveyors to the coarse ore bins;
  • 2-7' standard cone crushers and associated feeders;
  • 4-7' short head cone crushers and associated feeders and screens;
  • belt conveyors and tripper to the fine ore bins;
  • 8 sets of rod/ball mill circuits;
  • three regrind mills (two for concentrate regrind and one for limestone);
  • ancillary facilities and offices;
  • infrastructure including power supply and distribution;
  • tailing storage and reclaim water facility.
Penguin Automated Systems Inc.3-1



NorthMet Project Processing Facilities Scoping Study

 

Photograph 3.1.1 Overall Facilities at Cliffs Erie

 

Photograph 3.1.2 Concentrator Building

 

Penguin Automated Systems Inc.3-2


NorthMet Project Processing Facilities Scoping Study

In early January 2004, the facilities were visually inspected by Equipment Specialist Dave Phelps (FFE Minerals) and Mickey Trader (Penguin ASI) and found to be in good standing. The plant is generously designed with good maintenance and service crane access to all major equipment.

It was noted that the previous operators kept excellent records of all equipment maintenance and spare parts.

3.2 Metallurgical Testwork and Design

Polymet conducted benchscale and pilot plant work at SGS Lakefield in preparation for the AMEC feasibility study. This work was reviewed and evaluated by T.O'Kane of Polymet and was reported separately at the same time as the AMEC study. The metallurgical testwork results, recommendations and flowsheet design as provided by Mr O'Kane were incorporated into the AMEC process facility design and equipment list without audit by AMEC. In compiling this scoping study, Penguin ASI has relied on process design criteria data in the AMEC report and in the hydrometallurgical mass balance provided by Polymet and has not audited or confirmed this data except for the following:

  • Penguin ASI reviewed the filtration data from the pilot plant work and used theappropriate filtration rates for sizing the leach residue and gypsum filters
  • Penguin ASI reviewed the calculation accuracy and completeness of thehydrometallurgical mass balance but did not conduct a metallurgical audit

In the next phase of the project a full review of all testwork completed to date will be required. Based upon the limited review that has been completed, Penguin ASI recommends the following additional testwork:

  • Grinding testwork to confirm work indices of the ore and concentrate, and
  • Filtration testwork on PGM concentrates to determine filtration rates.

There may be other areas that require additional or confirmatory work. This can only be assessed after a full review of all testwork completed to date.

Penguin Automated Systems Inc.3-3



NorthMet Project Processing Facilities Scoping Study

Penguin ASI developed an overall mass balance for the NorthMet process based on the hydrometallurgical mass balance provided by Polymet, which set the feed headgrades and recoveries for copper, nickel, cobalt and PGM's at and a throughput of 9,125,000 tonnes per annum.

The development of the flowsheet and equipment sizing for the crushing, grinding and flotation process facilities was based on flowrates derived from this mass balance, plus process design criteria developed from the AMEC study and information by SGS Lakefield who were responsible for the pilot plant flotation trials. The flowsheet for the hydrometallugical facilities – pressure oxidation, solid-liquid separation, PGM recovery, copper SX/EW and nickel/cobalt hydroxide recovery – was derived primarily from the AMEC study with equipment resized accordingly for the new plant throughput, plus input from T.O'Kane of Polymet for the autoclave circuit. Testwork data from SGS Lakefield was reviewed for sizing of thickeners and filters.

Work indices used for crushing and grinding circuit calculations are estimates provided by SGS Lakefield based on limited grinding testwork. These numbers will require confirmation in the next phase.

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NorthMet Project Processing Facilities Scoping Study

3.3 Process Design Criteria

The detailed process design criteria is presented in Appendix 1 and the key criteria is summarized in Table 3.1.1.

Table 3.1.1 Process Design Criteria Summary

Parameter 

Design Criteria
Annual mill throughput
Average daily mill throughput
Plant Availability
Operating Hours per day
Hourly Throughput
Concentrate produced
Rod mill work index
Ball mill work index
Regrind work index
Feed size to flotation
Feed size to pressure leach
Pressure leach residence time
Autoclave operating temperature
Autoclave operating pressure
H2 SO4 concentration
Cl concentration
Cu SX plant
Organic / Acid ratio
PLS Cu
Raffinate Cu
SX Cu recovery
E/W current density
Cathodes per cell
Total cells required
9,125,000 tonnes
25,000 tpd dry
91.34%
24
1140 tph dry
703 tpd dry
14 kWh/t
17 kWh/t
7.5 kWh/t
200 micron
15 micron
2 hours
225C
475 psig
50-60 g/l
10g/l
2 extraction; 1 wash; 2 strip
1.5:1
18.4g/l
0.99g/l
94.62%
260 amp/m²
54
125

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NorthMet Project Processing Facilities Scoping Study

3.4 Process Description

The overall process flow is described in the block flow diagram presented overleaf.Process flowsheets, general arrangements and site plan are provided in Appendix 2.

3.4.1 Crushing

Run of mine ore will be delivered by rail to the Cliffs Erie process plant and dumped into the primary crusher surge pocket. From the surge pocket, the ore will flow to a single existing 60" by 89" gyratory crusher set to produce a nominal coarse ore product with a P80 sizing of 6 inches. The existing secondary gyratory crushers will be removed and a surge pocket will be constructed allowing the crushed ore to discharge onto an existing apron feeder. The apron feeder will in turn discharge onto the exiting coarse ore surge bin feed conveyor. Ore from the coarse ore surge bin will discharge via the existing vibrating feeders onto existing belt feeders feeding two existing 7' standard cone crushers. Each 7' cone will discharge onto two existing vibrating feeders, each feeding an existing 6' x 10' vibrating screen. Screen oversize discharges into one of four existing 7' shorthead cone crushers. The minus ¼" discharge from the tertiary shorthead crushers will combine with the screen undersize onto the existing feed conveyor to the existing fine ore bin.

3.4.2 Grinding

Ore from the fine ore bin will discharge via existing vibrating and belt feeders to the existing rod and ball mill circuits. For the design throughput of 25,000 tpd, 8 of the existing 12 circuits will be utilized. Each rod mill will operate in open circuit, with the rod mill discharge feeding a ball mall in closed circuit with new hydrocylones. The grinding circuit will produce a flotation feed of 30% solids at a P80 sizing of 200 micron.

Penguin Automated Systems Inc.3-6



NorthMet Project Processing Facilities Scoping Study

 

Figure 3.1 Block Flowsheet

 

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NorthMet Project Processing Facilities Scoping Study

3.4.3 Flotation and Regrind

Cyclone overflow from the grinding circuits combine to feed a conditioning tank with a 5-minute retention time. The conditioner will feed a single bank of 4-160m3 rougher tank cells providing a total residence time of approximately 8 minutes. Rougher discharge will feed 2 parallel banks of 5-160m3 tank cells providing a residence time of 20 minutes.

Rougher concentrate combines with re-cleaner tail to feed the first cleaner flotation circuit. The cleaner flotation circuit will consist of a single bank of four 20m3conventional cells providing 16 minute retention time. Scavenger concentrate, mixed with cleaner tail, will be reground in an existing regrind ball mill to a target P80 of 30 micron prior to recirculation back to the conditioning tank. Cleaner concentrate will be fed to a single re-cleaner column cell, providing 16-minute retention time, for final concentrate cleaning. Cleaner concentrate will report to the concentrate regrind mill where the concentrate will be reground to the target P80 sizing of 15 micron, prior to pressure oxidation. A second existing regrind mill (using ceramic balls as grinding media to reduce iron contamination) will be used for this purpose.

Reground concentrate thickened to 50% solids and stored in a concentrate storage tank, which provides 12 hours of surge capacity between the flotation circuit and downstream hydrometallurgical processing.

Flotation tailings will be pumped to the existing Cliffs Erie tailings impoundment.

The flotation circuit reagents (MIBC, PAX, Flex 31, and WW1 752) are based on the AMEC study and was developed for effective base metal recoveries with associated high PGM recovery.

Flotation circuit metallurgical accounting will be accomplished using the sample data from an on-stream analyzer, and automated shift sample collection that will be obtained from sample multiplexers on the on-stream analyzer system.

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3.4.4 Pressure Leaching

Pressure Leaching is based on standard Autoclave technology and utilizes the patented PlatSol process. Concentrate will be blended in the autoclave feed tank with sodim chloride prior to pumping into the autoclave at 50% solids. Recycled copper SX/EW raffinate will be pumped into the autoclave to maintain temperature control.

The two autoclaves will provide the required 2-hour residence time for the feed slurry. Each autoclave will have 6 compartments, and will be designed to operate at 225°C and approximately 475 psig. These pressures and temperatures are standard for autoclave dsign in the refractory gold ore/concentrate oxidation process. The NorthMet autoclave design will comprise a mild steel pressure vessel with a polymer-thermoplastic membrane corrosion barrier and two layers of acid resistant brick for thermal and abrasion resistance. This design follows the the reported design of the Phelps Dodge copper concentrate autoclave at Bagdad, Arizona. The Phelps Dodge autoclave has been designed for temperatures up to 235C and pressures of up to 4000 kPa.

Autoclave utilities and ancillary equipment include a packaged steam boiler for start-up heating, agitator seal water systems, compressed air, water treatment units, and oxygen blowout vessels. Oxygen supplied, at 98% purity, to the pressure oxidation circuit will be delivered via an "over the fence" type contract.

The slurry is cooled to below 63° C via a single stage let down and slurry coolers prior to downstream metal extraction processes.

3.4.5 Leach Residue

Prior to metal recovery, the leach residue will be separated from the pregnant leach solution (PLS) to provide a high recovery of solute via filtration and washing of the leach residue. To accomplish this, the circuit will include a primary thickener followed by a pressure plate filter unit. A wash ratio of 4:1 will be used to maintain high solute recoveries. Autoclave residue filter cake will be re-pulped and fed to a scavenger flotation circuit to recover residual PGM's. The PGM

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concentrate will be re-circulated back to the feed end of the autoclave and the flotation tailing will be pumped to a new hydromet tailings impoundment constructed inside the existing tailings impoundment.

3.4.6 PGM Recovery

PLS will be mixed with S02 to ensure total reduction of oxidize iron species in solution (Fe (III) is reduced by Fe (II) in solution by SO2). The SO2 will be produced by a packaged sulphur burner system. After ferric iron reduction, the solution will be processed through a two-stage pipe reactor system, with the addition of NaHS, to precipitate the platinum and precious metals. After filtration, the PGM precipitate will be releached in a sulfuric acid solution in a batch autoclave to leach any co-precipitated base metals (Cu, Ni, Co) and sulfur/sulfides to produce a high grade PGM precipitate for toll refining. Batch autoclave leach solution will be recirculated back to the PLS surge tank before precious metal recovery to ensure full recovery of valuable metals.

3.4.7 Neutralization

The PLS filtrate from the PGM precipitation system will require neutralization to pH 2 prior to copper solvent extraction. Filtered PLS will be pumped from the neutralization surge tank to the solution neutralization cascade that consists of three tanks with a total retention of 180 minutes. Limestone is added to maintain a pH of 2 and prepare the solution for copper solvent extraction.

The slurry exiting the precipitation tanks will be pumped to a thickener. Thickener underflow is filtered using an automatic plate and frame pressure filter package. The filter cake solids (saleable grade gypsum) will be discharged to a conveyor and stockpiled prior to re-sale.

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3.4.8 Copper Solvent Extraction and Electrowinning

Copper PLS from the neutralization circuit will be stored in the copper SX feed tank providing 4 hours of surge capacity. PLS will be filtered to avoid crud formation in the SX circuit. The filtration will use multi-media pressure filters and the backwash will be returned to the gypsum thickener. Copper will be extracted from the PLS into an organic solution containing 30% by volume of Cognis LIX-984.

The extraction circuit consists of three mixer settlers, in which the aqueous feed and the barren organic flow counter-current to one another. Raffinate leaving the final extractor will report to the copper raffinate tank, from which solution will either be recirculated back to pressure oxidation for use as cooling liquid, or sent forward to bleed treatment.

Copper loaded organic is pumped from the first stage extractor to the loaded organic tank where entrained aqueous solution will have the chance to settle out. Solution recovered in this way will be collected in a sump at the bottom of the tank and is periodically returned to the extraction circuit.

Loaded organic will be contacted, in a two-stage copper strip circuit, with lean electrolyte recycled from copper EW. The stripped organic will pass through to extraction, while the rich electrolyte will be pumped through organic recovery columns, and anthracite based multi-media filters to coalesce any residual organic, before discharging into the electrolyte recirculation tank.

The copper EW circuit reflects ISA stainless steel cathode tankhouse technology. Rich electrolyte will be trim heated to approximately 120°F before entering the tankhouse EW cells, using an indirect hot water heating system. A 125-cell tankhouse will provide the capacity required to harvest 33,000 tonnes per year of cathode copper.

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NorthMet Project Processing Facilities Scoping Study

Cathodes from the EW cells will be harvested on a daily basis, after a 7-day growth cycle. The copper sheets will be mechanically stripped from the stainless steel blanks using a standard fully automatic cathode washing and stripping machine. The stripping machine will also provide mechanical stacking, strapping, and weighing of the cathode bundles in preparation for shipping to market.

3.4.9 Nickel-Cobalt Hydroxide

Iron and aluminum must be removed from copper SX raffinate bleed solution before the extraction of nickel and cobalt.

In the first of three precipitation cascades, iron will be removed as goethite. In order for goethite to be formed, the bleed stream will be pre-heated to 170° F by direct steam injection into a tank with 45 minutes retention time. Direct injection will be used to negate the problem of gypsum scaling on the solution side of a shell and tube heat exchanger.

Hot solution overflows the pre-heat tank and will enter the first of five tanks in the iron precipitation cascade. Limestone will be added to the first tank to neutralize free acid in the copper raffinate, and will result in gypsum precipitation. Air is sparged into tanks l, 2 and 5 to facilitate ferrous oxidation, allowing ferric precipitation as goethite. In the third and fourth tanks ferrous oxidation will be enhanced using a mixture of oxygen and sulfur dioxide. More limestone will be added to neutralize the acid generated by the goethite precipitation and maintain a discharge pH of 3.5. At this pH a significant percentage of the aluminum hydrolyses and precipitates while loss of the valuable metals (Ni, Co, Zn) is minimized.

Overflow from the fifth tank will be pumped to a thickener where the solids settle to a density of 40 wt%. A significant portion of the thickened underflow will be returned to the precipitation cascade, where the solids act as seeds to facilitate the growth of larger particles, which in turn improves settling and filtration characteristics. The balance of the thickener underflow will be filtered through a plate-type pressure filter. After

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washing to recover entrained nickel and cobalt, the cake will discharge into a tank where it is slurried with reclaim water and pumped to a new tailings impoundment on the existing tailings dam

Overflow from the iron thickener will be neutralized with magnesium oxide in two stirred tanks to precipitate a combined nickel/cobalt hydroxide. Slurry will discharge from the second tank into a thickener. Thickener underflow is filtered in a plate-type pressure filter. The filter cake will be collected and steam dried prior to bagging for dispatch to an off site nickel/cobalt refinery.

Thickener overflow will be treated with lime in two stirred tanks to precipitate any remaining valuable metal content. Slurry will discharge from the second tank to a thickener. Thickener underflow will be recycled back to the leach residue thickener. Thickener overflow will be pumped to a new tailings impoundment on the existing tailings dam.

The valuable metals (Ni, Co) will be redissolved under the strong acid conditions prevailing in the leach residue thickener.

3.4.10 Tailings

The existing tailings facility at Cliffs Erie will be used to contain tailings products from the NorthMet process plant. Flotation plant tailings will form the bulk of the tailings products and will be discharged to the existing dam using the existing pumping and piping arrangement.

There will be three new hydromet tailings produced:

  • leach residue flotation tailings,
  • iron/aluminum gypsum sludge
  • solution from the hydroxide precipitation circuit.
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Each of these tailings will be contained in separate lined ponds constructed on the existing tailings dam. Each pond will have an initial capacity of 3 years storage.

3.4.11 Reagents

Included on the equipment list are the proposed reagent systems to support the process plant operations. Reagent systems included are:

  • Limestone: Rail receipt and off-load, conveying, crushing and grinding, slurry storage and distribution loop. (An existing mill will be used for grinding.)
  • MIBC: Bulk liquid storage and distribution.
  • PAX: Mixing, storage and distribution.
  • Flex 31: Bulk liquid storage and distribution.
  • WW 1752: Bulk liquid storage and distribution.
  • Flocculent: Mixing, storage and distribution
  • Sulfuric Acid: Bulk liquid storage and distribution.
  • NaHS: Bulk liquid storage and distribution.
  • NaCl: Mixing, storage and distribution.
  • MgO: Mixing, storage and distribution.
  • CaO: Mixing, storage and distribution
  • Sulphur: Bulk storage, burner, distribution and SO2 scrubbing

3.4.12 Infrastructure and Ancillary Services

Reclaim water, utilities and services, compressed air supply, power supply and distribution, offices, warehousing and laboratories will all be provided for by existing facilities at the Cliffs Erie plant site. New assay laboratory equipment will be purchased for the NorthMet project.

3.5 Equipment List

A mechanical equipment list was developed and is presented in Appendix 3.0.

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4.0 Operating Cost

 

 

 

 

 

 

 

 

 

 

 




NorthMet Project Processing Facilities Scoping Study

4.0 Operating Costs

4.1 Summary

The operating cost estimate for the study is based on the following six major cost centers:

  • Reagents and consumables
  • Manpower
  • Electrical power
  • Plant operating supplies
  • Maintenance supplies
  • General and administration (G&A)

The development of the project mine operating costs is beyond the scope of this study and have not included.

A contingency of 5% has been applied and all costs are estimated in first quarter 2004 US dollars.

Average operating expenditures for the process plant facilities are estimated to be $60.2 million dollars per year or $6.59 per tonne milled based on an annual plant throughput of 9,125,000 tonnes. A breakdown of the costs is summarized in Table 4.1 and details are provided in Appendix 4.

Table 4.1 Operating Cost Estimates
Description Total Cost US$ US$/tonne 
Consumables 22,142,258 2.43 
Labour 10,977,823 1.20 
Power 16,746,886 1.84 
Plant Operating Supplies 400,000 0.04 
Maintenance Supplies 1,915,896 0.21 
Environmental Monitoring 300,000 0.03 
G&A 4,856,600 0.53 
Sub total 57,339,463 6.28 
Contingency 5 % 2,866,973 0.31 
Total 60,206,436 6.59 

 

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4.2 Basis of Estimate

4.2.1 Consumable Unit costs

All costs are expressed in terms of US$ and metric tonnes and are based largely on unit rates FOB mine site provided by Polymet and reviewed by Penguin. In some cases, Penguin has sourced unit rates directly from vendors. For some items, unit rates from the AMEC study have been used. In all cases, the unit cost source is listed in the detailed operating cost breakdown in Appendix 4.

4.2.2 Consumable Consumption Rates

Crusher, mill liners and grinding media

Estimated liner and steel media consumption rates are based on Penguins in-house experience. Consumption of ceramic grinding media used in the final concentrate regrind mill is based on vendor experience.

Reagents and chemicals

Unit consumption rates for flotation reagents have been taken from the AMEC study. Unit rates for the hydrometallurgical plant consumables are based on the Polymet mass balance.

4.2.3 Manpower

The total workforce for the process plant facilities is estimated to be 170 supervisory, operating and maintenance personnel. The staffing plan by component is in Table 4.2.

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Table 4.2 Staffing Plan

STAFF No. MAINTENANCE No. OPERATIONS No. 
Mill Superintendant Maintenance Superintendent General Foreman Operations 
Chief Metallurgist General Foreman Maintenance Operations Shift Foreman 
Metallurgist Maintenance Planner Mill Clerk 
  Maintenance Clerk Crusher Operator 
MILL WAREHOUSE No. Millwright/Mechanic 12 Grinding Operator 
Warehouse Supervisor Millwright Apprentice Flotation/ Regrind/Tails Operator 
Warehouseman Welder Operator 
Warehouse Clerk Machinist POX Operator 
  Chief Electrician PGM Operator 
LABORATORY No. Electrician Neutralization Operator 
Chief Chemist Instrumentation Tech Cu SX/TF Operator 
Chief Assayer   Cu EX Operator 
Assayer   Cu Cathode Stripping Operator 
Sample Prep   Hydroxide Operator 
Lab Clerk   Limestone Plant Operator 
    Reagents Operator 
    Labourer 14 
    Railhead Operator 
    Janitor 

 

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NorthMet Project Processing Facilities Scoping Study

The process plant facility labor plan utilizes two different shift schedules:

Type I Day shift only. One shift per day, eight hours per shift, five days per week, for a total of 2,080 hours per year per employee.

Type II Shift work - 24-hour operations coverage. Three shifts per day, eight hours per shift, shift rotation for a total of 2,080 hours per year per employee.

All supervisory, technical, and warehouse personnel are on a Type I schedule, as well as most maintenance personnel except for service mechanics who are on a Type II rotation.

It is assumed that non-union labour will be employed at the NorthMet plant. Wages and salaries are based on the current ranges in the region for similar operations levels. Employees on a Type II shift rotation are paid overtime. For overtime, employees are paid at 1.5 times the base hourly rate plus any applicable shift differential. An allowance of 20% has been included in the labor operating costs for Type II employees for overtime.

Fringe benefits are estimated at 30% of the base annual cost for salaried and wage personnel, in accordance with fringe benefit costs experience by local mines.

These include allowances for the following:

  • Payroll taxes
  • 401 k contributions
  • Group medical and life insurance
  • Accidental death and dismemberment insurance and long term disability insurance
  • Medical stop loss
  • Worker's compensation premiums of 5%.

Fringe benefits are included in the labour cost calculation

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NorthMet Project Processing Facilities Scoping Study

4.2.4 Electrical Power

The load list developed for the AMEC study was factored accordingly to reflect the current process plant design and the total load estimate required for the process plant will be 48 MW. The local utility provider, Minnesota Power, will supply power at a unit power rate of $0.033 per kWh for the first 25 MW and $0.036 thereafter.

4.2.5 Supplies

Operating and maintenance supplies are estimated on the basis of industry averages. The maintenance supplies allowance is approximately 3% of the mechanical equipment capital cost for the process plant. Operating supplies allow for general plant supplies and plant mobile equipment operations and maintenance. The operating supply annual cost for plant assay supplies and general mill supplies is estimated at $200,000. The annual expenditure for operating and maintaining the mill mobile equipment fleet is estimated at $200,000.

4.2.6 Freight

Operating consumables are to be purchased FOB at the mine site. A freight estimate of $30 per ton has been assumed for purchases of grinding media and liner steel, as well as general allowances for reagents, chemicals and other consumables.

4.2.7 Inflation

The operating cost estimates include no allowance for inflation

4.2.8 Taxes

As per the AMEC study, the only consumable subject to Minnesota State sales tax is crushing and grinding media (liners and balls). A sales tax of 6.5% has been included in the costs for these items.

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5.0 Capital Cost

 

 

 

 

 

 

 

 

 

 

 

 



NorthMet Project Processing Facilities Scoping Study

5.0 Capital Costs

5.1 Summary

The preproduction capital cost estimate for the design, procurement and construction of the NorthMet Project facilities was developed based upon the process and ancillary facilities previously defined.

The initial capital for the processing facilities and infrastructure was estimated to be $199.4 million. Table 5.1 -1 summarizes the preproduction capital costs for development of the project including direct and indirect costs associated with the construction of the facilities. Sustaining capital costs are not included. The capital cost estimate was largely based on factored estimates and is considered accurate to within +/- 30% at the summary level. All costs are in 1st quarter, 2004 U.S. dollars. The detailed cost estimate is included in Appendix 5.

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Table 5.1 -1: Capital Costs Breakdown
Item Cost ($000)
  
             Crushing3,082
             Grinding4,282
             Flotation & Regrind17,546
             Pressure Leaching31,052
             Solid / Liquid Separation6,667
             PGM Recovery5,082
             Neutralization8,867
             Solvent Extraction6,439
             Electrowinning18,749
             Fe & Hydroxide Precipitation6,003
             Infrastructure & Auxiliary Services12,587
             Tailings4,549
             Mining5,760
  
             Subtotal Direct Costs130,665
  
             EPCM19,600
             Construction Indirects2,872
             Capital Spares4,323
             First Fills4,000
             Vendor Representatives1,319
             Freight2,499
             Start Up and Commissioning910
             Contingency33,238
  
             Total Project Cost$199,427

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NorthMet Project Processing Facilities Scoping Study

5.2 Basis of Estimate

The Capital Cost Estimate for the NorthMet Project was completed for the design previously specified in this report. The estimate assumes a conventional EPCM project delivery methodology. The capital cost estimate includes the estimated direct cost for equipment, material and labour. In addition, cost estimates were developed for the project indirect costs including EPCM, start up, construction indirects, first fill, spares and contingency. The estimate was developed based on a site visit and inspection of existing equipment and facilities, and the following main sources of information:

  • Process Design Criteria.
  • Process Flow Sheets.
  • Facility General Arrangement Drawings.
  • Electrical and Mechanical Equipment List.
  • Budget Quotations from Equipment Suppliers.
  • Current Labour and Material Costs.
  • The AMEC Simons Mining & Metals 2001 Prefeasibility Report.

5.2.1 Direct Costs

The Direct Costs include the estimated costs of the equipment, material and labour required to construct the facility.

Equipment

All process equipment is considered purchased new for the project with the exception of the crushing, screening and grinding equipment, which will be reused from the existing plant. The equipment costs were based upon budget quotations where ever possible. Equipment pricing that was not based upon budget quotations were based on current data from other projects or factored from the AMEC Simons Prefeasibility Study.

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The SX and EW plant equipment was factored from the AMEC study based on the revised equipment sizing for this study using commonly applied size factors. The AMEC SX and EW plant estimates include all piping, civil, structural, mechanical, piping, electrical and instrumentation requirements.

The equipment being reused for the crushing and grinding circuits will be utilized in place. An allowance for the material and labour requirements to re-start the existing crushing and grinding equipment and facilities has been included in the estimate. The allowance includes the supply and installation of new materials to cover the replacement of wear items such as liners, idlers, conveyor bets and drive components for the existing equipment as well as repairs and upgrades recommended by the previous operations personnel. The allowances were developed based on an inspection of the equipment and facility condition conducted during a visit to the facility in April 2004. The site visit included a detailed estimate review with the former plant operations personnel on a site where repair/refurbishment material costs and labour manhours were confirmed. There is a significant opportunity for cost savings by utilizing spare parts available from the previous operation. This inventory of spare parts available will require an investigation during the feasibility study.

It has been assumed that no mobile equipment is available on site. The estimate includes the purchase of new equipment for the plant operations and maintenance.

Materials

The material cost estimates were based either on quantity take-offs for areas that could be derived from the drawings or upon factored quantities from similar projects where drawing information was not available.

Concrete quantities are derived from layouts, historical factors or factored from the AMEC study adapted to the requirements of this study. Quantities are estimated as in-place, unit prices include formwork, reinforcing steel, imbedded metals, concrete supply,

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NorthMet Project Processing Facilities Scoping Study

transport, placing, finishing, curing and the suppliers' quality control testing. Costs for independent quality control and testing are included in the indirects.

Platework quantities were estimated from the equipment list and flowsheets and historical experience from similar projects. Structural steel quantities are factored based on square footage obtained from general arrangement drawings. The unit prices include supply, detailing, fabrication, painting and delivery.

Cost for process piping, electrical, lighting and instrumentation distribution within the facilities is factored from similar installations or the AMEC study.

Buildings

The crushing, grinding and flotation circuits will utilize portions of the existing buildings. The existing warehouse will be utilized for the solid/liquid separation, PGM recovery, neutralization, solvent extraction, electrowinning and Fe & hydroxide precipitation. The pressure leaching circuit will be constructed in a new pre-engineered insulated metal building adjacent to the existing warehouse. Where existing facilities are utilized an allowance has been made for repairs and modifications, including replacement of doors/windows, repairs to the building envelope and new openings for HVAC piping and electrical. An architectural allowance has been provided for the warehouse for installation of offices, compressor rooms and electrical rooms.

The estimate assumes the reuse of the existing administration building, truckshop, mine administration and operations office and laboratory. An allowance has been provided in the estimate for minor repairs, painting and furnishings for these existing buildings.

Labour

The labour component of the cost estimate was estimated using installation man-hours, based on historical data applied to a blended ‘all in' labour rate. The blended construction hourly labour rate was estimated at $68/hour from current rates for crew configurations for this type of industrial construction. The labour rate component

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NorthMet Project Processing Facilities Scoping Study

includes for the base pay and the payroll burden, including payroll taxes and workman's compensation. The hourly rate also includes supervision, small tools and consumables, contractor's site and home office overhead and profit. The labour rate is based on a 40 hour work week including an allowance for casual overtime; no allowance has been made for scheduled overtime. The workforce will be housed locally and no construction camp has been provided for in the estimate.

5.2.2 Indirect Costs

Indirect costs for the project were calculated for EPCM, project start up, contractor's indirects, and contingency. The indirect costs were developed from industry standard percentages and are considered reasonable for a project of this scope.

EPCM

Engineering, Procurement and Construction Management (EPCM) costs were estimated based on currently accepted percentages for these services applied to the total direct costs. The EPCM costs include allowances for subconsultant costs including geotechnical, survey and site quality control for soils and concrete testing.

Contractor's Indirects

Contractor's indirect costs for overhead are included in the calculated blended labour

rate. An equipment allowance was calculated at $6.00 per construction man-hour.

Startup and Vendors Representatives

Startup costs including commissioning were calculated as an allowance and include retaining contractor forces during the commissioning phase to assist with start up. An allowance has been included for vendor assistance during commissioning for pre-operational testing of equipment and operations and maintenance training.

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NorthMet Project Processing Facilities Scoping Study

Freight, Spare Parts

Indirect costs for freight, spare parts and initial fills were included in the project indirects. Freight costs were estimated as 3% of the direct cost for the equipment and materials. Spare parts were estimated at 5% of the process equipment. There is a significant opportunity for cost savings if spare parts are available from the previous operation for use by the project. This inventory of spare parts available is to be further investigated during the feasibility study.

Contingency

A blended contingency of 20% was applied to the Project Direct and Indirect Costs. The contingency is to cover items not adequately defined based upon the current level of engineering. This allowance is included to cover these unknowns but is not intended to cover changes in the project scope.

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Appendix 1- Process Design Criteria

 

 

 

 

 

 

 

 

 

 

 



PENGUINASI DESIGN CRITERIA April-04 
NorthMet Project  Rev. C 
Hoyt Lakes, Minnesota   
 UnitDesign Source          Note 
                                     Key                       Source     
                                       1                           Polymet     
                                       2                           Assumption     
                                       3                           Calculation     
                                       4                           AMEC pre-feasibility report     
                                       5                           Lakefield     
                                       6                           Vendor     
       
Ore Characteristics      
                   Ore Specific Gravity    3.01 
                   Moisture Content   %6.41 
                   Bond Work Index  Ball kWh/mt175 
  Rod kWh/mt145 
Production      
                   Average daily thru'put  dry mt/d25,0001 
                   Operating days   days per year3652 
                   Ore Treated per annum dry mt/y9,125,0001 
                   Availability   %91.343 
                   Daily Thu'put @ 91.34% avail dry mt/d27,3703 
                   Daily Thu'put @ 91.34% avail wet mt/d29,2423 
       
Primary Crushing      
         Crusher      
                   Type  Existing  Gyratory  
                   Size   inches60"x 89"  
                   Number    one3 
                   Open side setting   inches6"  
                   Motor   HP900  
         Apron Feeder      
                   Type  Existing    
                   Size   mm1500 x 4800  
                   Number    one3 
                   Motor   HP115  
       
Secondary Crushing      
                   Type  Existing  Cone  
                   Size    7' standard  
                   Number    two3 
                   Closed side setting    3"  
                   Motor   HP350  
       
Tertiary Crushing      
                   Type  Existing  Cone  
                   Size    7' shorthead  
                   Number    four3 
                   Closed side setting    3/4"  
                   Motor   HP350  


PENGUINASI DESIGN CRITERIA April-04 
NorthMet Project  Rev. C 
Hoyt Lakes, Minnesota   
 UnitDesign Source          Note 
Primary Milling      
                   Feed size    3/4"  
                   Type  Existing  Rod  
                   Size   feet 10'x 14'   
                   Number    83 
                   Motor   HP 800  
                   Grind size  p80 micron 1000  
                   Rod size    3"  
       
Secondary Milling      
         Mills      
                   Type  Existing  Ball  
                   Size   feet 10'x 14'   
                   Number    8  
                   Motor   HP 1250  
                   Grind Size  p80 micron 1000  
                   Ball Size   inch 3"  
       
         Cyclones  New    
                   Size   mm 8403 
                   Number  per mill  1op/1sb3 
                   Circulating load   2502 
       
       
Flotation      
         Reagents      
                   Flex 31        collector   g/t 18.24 
                   PAX           collector   g/t 45.54 
                   MIBC          frother   g/t 40.94 
                   WW1752   g/t 90.94 
       
         Rougher conditioning      
                   Residence Time   mins 54 
                   Tank size   7.5D x 8.03 
       
         Roughers      
                   Residence Time   mins 84 
                   Cell Volume required   m 3 6403 
                   Cell size   m 3 1602 
                   Number of cells    43 
                   Cell type    Tank4 
                   Rougher conc prod.  Average % mill feed ~ 7.04 
       
         Scavengers      
                   Residence Time   mins 204 
                   Cell Volume required   m 3 1,6003 
                   Cell size   m 3 1602 
                   Number of cells    103 
                   Cell type    Tank4 
                   Scavenger conc prod.  Average % mill feed ~ 3.24 


PENGUINASI DESIGN CRITERIA April-04 
NorthMet Project  Rev. C 
Hoyt Lakes, Minnesota   
 UnitDesign Source          Note 
Cleaners     
         Residence Time   mins204 
         Cell Volume required   m 31683 
         Cell size   m 3212 
         Number of cells   83 
         Cell type   Conventional2 
         Cleaner conc prod.  Average % mill feed~7.04 
       
       
Re-cleaner     
         Residence Time   mins164 
         Cell Volume required   m 31183 
         Cell size   m3.7 D x 12.23 
         Number of cells   13 
         Cell type   Column2 
         Cleaner conc prod.  Average % mill feed2.571 
       
       
Regrind mill - Scavenger conc/cleaner tail     
         Work Index   7.55 
         Type  Existing Regrind ball  
         Size   12'2" x 24'   
         Motor   HP1500  
         Ball size   1" steel  
         Feed size  f80 micron815 
         Regrind size  p80 micron315 
       
Regrind mill - Feed to Pressure Oxidation     
         Work Index   7.55 
         Type  Existing Regrind ball  
         Size   12'2" x 24'   
         Motor   HP1500  
         Ball size   1" ceramic4 
         Feed size  f80 micron815 
         Regrind size  p80 micron154,5 
       
Concentrate production   t/d7033 
         Thickener unit area   m2/tpd 0.24 
         Thickener diameter   m13.43 
       
Concentrate storage     
         Residence Time   hrs124 
         Tank size   m8.0D x 9.03 


PENGUINASI DESIGN CRITERIA April-04 
NorthMet Project  Rev. C 
Hoyt Lakes, Minnesota   
 UnitDesign Source          Note 
Pressure Oxidation      
Autoclave feed tank      
                   Residence Time   hrs14 
                   Tank size   m3.0D x 3.53 
       
         Autoclaves      
                   Slurry solids  %11.51 
                   Number required   21 
                   Flowrate per autoclave  m 3/hr 961 
                   Availability   %901 
                   Flowrate per autoclave  m 3/hr 1071 
                   Residence time total   hr21 
                   Capacity per autoclave  %751 
                   Factor per autoclave  1.151 
                   Volume required per autoclave  m 33273 
                   Size per autoclave ID m4.11 
  length m24.61 
                   Volume installed per autoclave  m 33251 
                   Compartments per autoclave  51 
                   Agitators per autoclave  61 
                   Power per agitator   kW901 
Operating conditions      
                   Temperature   o C2251 
                   Pressure   psi O1001 
   2   
                   Pressure   psig~4751 
                   Pulp density   g/l10501 
                   H SO   g/l50-601 
                       2 4      
                   Chloride   g/l101 
                   Cu   g/l~201 
                   Ni   g/l~201 
       
Slurry Cooling      
         Flash tanks      
                   Solution loss to steam   %191 
       
Leach Residue Liquid-Solid Separation      
Thickener      
         Feedrate   t/d6123 
                   Thickener unit area   m2/tpd 0.44 
                   Thickener diameter   m17.73 


PENGUINASI DESIGN CRITERIA April-04 
NorthMet Project  Rev. C 
Hoyt Lakes, Minnesota   
 UnitDesign Source          Note 
Filter      
         Feedrate   tph dry25.9 3 
                   Cake density   1.4 5 
                   capacity   m3/hr 18.50 3 
                   cycle time   mins14.94 5 
                   cycles per hour   4.02 3 
                   Volume   litres4607 3 
                   scale up factor   1.25 2 
                   Volume required   litres5758 3 
                   Filter type   Pressure   
                   Model   VPA 2050 6 
                   volume   l/chamber205 5,6 
                   chambers req   28.09 3 
                   chambers installed   30   
       
Leach Residue Flotation      
         Roughers      
                   Residence Time   mins20 4 
                   Cell Volume   m 315 3 
                   Cell size   m 33 
                   Number of cells   3 
                   Cell type   conventional 2 
       
         Cleaners      
                   Residence Time   mins10 4 
                   Cell Volume   m 30.24 3 
                   Cell size   m 30.08 3 
                   Number of cells   3 
                   Cell type   conventional 2 
       
PGM Recovery      
         Reactors      
                   Reactor type   pipe 4 
                   number   4 
                   residence time   secs30 4 
                   size   315mm x 55m 3 
       
         Clarifier      
                   number   4 
                   diameter   m4scaled 
                   angle   degree60 4 
                   sidewall ht   m2.0 4 


PENGUINASI DESIGN CRITERIA April-04 
NorthMet Project  Rev. C 
Hoyt Lakes, Minnesota   
 UnitDesign Source          Note 
Neutralisation      
                   pH required   4 
                   Retention time   hr4 
       
         Feedrate   t/d612 3 
                   Thickener unit area   m2/tpd 1.45 5 
                   Thickener diameter   m33.6 3 
       
         Gypsum Filter      
                   Feedrate   tph dry14.9 3 
                   Cake density   0.704 5 
                   capacity   m3/hr 21.16 3 
                   cycle time   mins12.28 5 
                   cycles per hour   4.89 3 
                   Volume   litres4332 3 
                   scale up factor   1.25 2 
                   Volume   litres5415 3 
                   Filter type   Pressure 5,6 
                   Model   VPA 2050 6 
                   Volume   l/chamber205 6 
                   chambers req   26.41 3 
                   chambers installed   30   
       
Copper Solvent Extraction      
         Mixer tank      
                   Residence time   mins2   Typical 
                   Size   m3.5 D x 4.0 3 
        PLS surge tank      
                   Residence time   hrs4 
                   Size   m3.5 D x 4.0 3 
                   PLS flow   m3/hr 225 3 
                   scale factor   1.2 2 
                   PLS flow   m3/hr 270 3 
                   No of SX trains   2   Lakefield p/p 
                   Extraction stages   2   2ex, 1w, 2 s 
                   Wash stages   2 
                   Strip stages   2 
                   O/A ratio   1.5 2 
                   Total flow   m3/hr 675 3 
                   Settling Rate   m3/hr/m2 4.4 2 
                   Organic depth   mm300 2 
                   Av aqueous depth   mm450 2 
                   Settler area   m2153 3 
                   Av sol velocity   cm/sec2 
                   Settler width   m8.3 3 
                   Settler length   m18.4 3 
                   Add for weirs   m2 
                   Add for distr. fence   m2.5 2 
                   Total length   m21.9 3 



 

 

 

 

 

 

 

 

 

Appendix 2- Drawings

 

 

 

 

 

 

 

 

 

 

 



POLYMET MINING CORPORATION
NORTHMET PROJECT

SCOPING STUDY
DRAWING LIST

DRAWING NO.  DESCRIPTION 
  
METALLURGY 
  
100-03-F00  SIMPLIFIED FLOWDIAGRAM 
100-03-F01  CRUSHING AND SCREENING-FLOWSHEET # 1 
100-03-F02  GRINDING CIRCUIT-FLOWSHEEET # 2 
100-03-F03  FLOTATION AND REGRIND-FLOWSHEET # 3 
100-03-F04  PRESSURE LEACHING-FLOWSHEET # 4 
100-03-F05  SOLID/LIQUID SEPARATION-FLOWSHEET # 5 
100-03-F06  PRECIOUS METAL RECOVERY-FLOWSHEET # 6 
100-03-F07  Cu SOLVENT EXTRACTION-EXTRACTION CIRCUIT-FLOWSHEET # 7 
100-03-F08  Cu SOLVENT EXTRACTION-STRIPPING CIRCUIT-FLOWSHEET # 8 
100-03-F09  COPPER ORGANIC SYSTEM-FLOWSHEET # 9 
100-03-F10  Cu ELECTROLYTE CLEANING AND RECIRCULATION-FLOWSHEET # 10 
100-03-F11  Cu ELECTROWINNING AND CATHODE HANDLING-FLOWSHEET # 11 
100-03-F12  Fe & HYDROXIDE PRECIPITATION-FLOWSHEET # 12 
100-03-F13  LIMESTONE HANDLING-FLOWSHEET # 13 
 
GENERAL LAYOUT 
 
100-10-001  OVERALL PLANT SITE-PLAN 
100-10-002  CONCENTRATOR-GA-PLAN 
100-10-F03  CONCENTRATOR-GA-SECTION 
100-10-F04  REGRIND MILLS-GA-PLAN 
100-10-F05  HYDROMET PLANT-GA-PLAN 
100-10-F06  FLOTATION CIRCUIT-GA-PLAN AND SECTIONS 
100-10-F07  PRESSURE LEACHING-GA-PLAN AND SECTION 
100-10-F08  SETTLING TANKS-GA-PLAN AND SECTION 
100-10-F09  Cu ELECTROWINNING CIRCUIT-GA-PLAN AND SECTIONS 
100-10-F10  RECOVERY & PRECIPITATION-GA-PLAN AND SECTIONS 


The drawings and illustrations discussed above have been excluded from this filing due to file size issues.



 

 

 

 

 

 

 

 

 

Appendix 3- Equipment List

 

 

 

 

 

 

 

 

 

 

 




PENGUINASI MECHANICAL EQUIPMENT LIST April-04 
NorthMet Project   
Hoyt Lakes, Minnesota   
Equip. #Qty. Description SizeMaterial
 Specification
HP
Each
HPTotalRemarksNew /
Existing
         
CRUSHING AND SCREENING        
 PRIMARY CRUSHER SURGE POCKET       EXISTING 
 PRIMARY CRUSHER 60 x 89 GYRATORY 900 900  EXISTING 
 CRUSHED ORE SURGE POCKET       NEW 
 APRON FEEDER 1500 x 4800 115 115  EXISTING 
 CONVEYOR 1A 60" 900 900  EXISTING 
 CONVEYOR 2A 60" 900 900  EXISTING 
 CONVEYOR 2A-TRIPPER 60" 15 15  EXISTING 
 COARSE ORE SURGE BIN 2000T    EXISTING 
 12 COARSE ORE RECLAIM FEEDERS 4'x 6' VIBRATING  48  EXISTING 
 COARSE ORE RECLAIM CONVEYORS 48" 20  EXISTING 
 RETRACTABLE CONVEYORS 48" 10  EXISTING 
 SECONDARY CRUSHER (PRIME) 7' STD. CONE 350 700  EXISTING 
 SECONDARY CRUSHER SURGE BIN       EXISTING 
 CRUSHER RECLAIM FEEDER 4'x 5' VIBRATING  16  EXISTING 
 SIZING SCREENS 6'x 10' VIBRATING 15 60  EXISTING 
 TERTIARY CRUSHER 7' SH. HD. CONE 350 1400  EXISTING 
 CONVEYOR 3A 60" 75 75  EXISTING 
 CONVEYOR 4A 60" 750 750  EXISTING 
 CONVEYOR 5S 60" 450 450  EXISTING 
 CONVEYOR 5S-TRIPPER 60" 15 15  EXISTING 
  SUMP PUMPS       EXISTING 
          
GRINDING CIRCUIT        
 FINE ORE SURGE BIN 650 T LIVE CAPACITY    EXISTING 
 FINE ORE RECLAIM BELT FEEDERS    24  EXISTING 
 FINE ORE RECLAIM CONVEYORS 24 24  EXISTING 
 ROD MILL 10'x 14' 800 6400  EXISTING 
 BALL MILL 10'x 14' 1250 10000  EXISTING 
 CYCLOPAC 1 OP 1 STDBY 2 x 33" dia    NEW 
 CYCLONE FEED PUMPBOX       NEW 
 CYCLONE FEED PUMPS       NEW 
 OVERHEAD CRANE 200T 100 100  EXISTING 
  SUMP PUMPS       EXISTING 
          
FLOTATION & REGRIND        
 CONDITIONING TANK 7.5 m dia x 8 m    NEW 
 CONDITIONING TANK AGITATOR       NEW 
 ROUGHER CELLS 160m3 260 1040 Tank cellNEW 
 10 SCAVENGER CELLS WITH DISTRIBUTER 160m3 260 2600Tank cellNEW 
 CLEANER CELLS WITH DISTRIBUTER 21m3 45 360Conventional cell NEW 
 FLOTATION TAILS PUMPBOX      NEW 
 FLOTATION TAILS PUMPS      NEW 
 RECLEANER FEED PUMPBOX       NEW 
 RECLEANER FEED PUMPS       NEW 
 RE CLEANER COLUMN CELLS 3.7m x 12.2 m   Column NEW 
 RECLEANER TAILS PUMP       NEW 
 RECLEANER BLOWER       NEW 
  FLOTATION BLOWERS       NEW 
  SAMPLERS       NEW 
 ANALYSER       NEW 
 FLOTATION AREA OVERHEAD CRANE       EXISTING 
 SCAVENGER REGRIND CYCLONE FEED PUMPBOX    NEW 
 SCAVENGER REGRIND CYCLONE FEED PUMPS    NEW 
 SCAVENGER REGRIND CYCLOPAC       NEW 
 SCAVENGER REGRIND MILL 12'-2" x 24'  1500 1500  EXISTING 
 FINAL CONC. REGRIND CYCLONE FEED PUMPBOX    NEW 
 FINAL CONC. REGRIND CYCLONE FEED PUMPS    NEW 
 FINAL CONC. REGRIND CYCLOPAC       NEW 
 FINAL CONC REGRIND MILL 12'-2" x 24'  1500 1500  EXISTING 
 SUMP PUMPS       NEW 



PENGUINASI MECHANICAL EQUIPMENT LIST April-04 
NorthMet Project   
Hoyt Lakes, Minnesota   
Equip. #Qty. Description SizeMaterial
 Specification
HP
Each
HPTotalRemarksNew /
Existing
         
PRESSURE LEACHING        
 1 CONCENTRATE THICKENER 13.4 m dia.    NEW 
 1 THICKENER O/F PUMP        NEW 
 1 THICKENER U/F PUMP        NEW 
 1 CONCENTRATE STORAGE TANK 8 m dia. X 9 m    NEW 
 1 CONCENTRATE STORAGE TANK AGITATOR        NEW 
 2 CONCENTRATE FEED PUMPS        NEW 
 2 AUTOCLAVE FEED TANK 3 m dia. X 3.5 m    NEW 
 2 AOTOCLAVE FEED PUMPS        NEW 
 2 AUTOCLAVES 4.1m x 24.6m    NEW 
 2 FLASH TANKS            NEW 
 2 SLURRY COOLER FEED PUMPS        NEW 
 2 SLURRY COOLERS        NEW 
 1 COOLING TOWER        NEW 
 1 VENT GAS SCRUBBER        NEW 
 1 VENT GAS SCRUBBER DISHARGE PUMP        NEW 
 2 RAFFINATE INJECTION PUMPS        NEW 
 1 BOILER PACKAGE        NEW 
 2 BOILER BLOWOUT VESSELS        NEW 
 1 HP AIR COMPRESSOR        NEW 
 1 LP AIR COMPRESSOR        NEW 
 1 SEAL WATER COOLER        NEW 
 1 SEAL/RINSE WATER PACKAGE        NEW 
 2 OXYGEN BLOWOUT VESSEL        NEW 
 3 SEAL WATER PUMPS        NEW 
 1 WATER TREATMENT PACKAGE        NEW 
 3 SUMP PUMPS        NEW 
 1 NaCL STORAGE SYLO        NEW 
 1 NaCL FEED SCREW        NEW 
 1 NaCL WEIGH BELT        NEW 
 2 AUTOCLAVE AREA OVERHEAD CRANE        NEW 
           
SOLID LIQUID SEPARATION             
 1 LEACH THICKENER 17.7 m dia.    NEW 
 1 LEACH THICKENER U/F PUMP        NEW 
 1 FILTER FEED TANK 3 m dia. X 3.5 m    NEW 
 1 FILTER FEED TANK AGITATOR        NEW 
 1 FILTER FEED PUMP        NEW 
 1 LEACH RESIDUE FILTER 2050 x 12 Plates   Plate & Frame NEW 
 1 TAILINGS REPULP TANK 3 m dia. X 3.5 m    NEW 
 1 TAILINGS REPULP TANK AGITATOR        NEW 
 1 TAILINGS REPULP PUMP        NEW 
 1 THICKENER O/F SURGE TANK 5 m dia. X 5.5 m    NEW 
 2 POLISH FILTER 3.5 m dia.    NEW 
 2 POLISH FILTER BLOWER        NEW 
 5 ROUGHER/SCAVENGER FLOTATION CELL 2.8m3     NEW 
 3 CLEANER FLOTATION CELLS 0.08m3     NEW 
 1 ROUGHER/SCAV FLOT CELLS RETURN PUMP        NEW 
 1 CONCENTRATE STORAGE TANK FEED PUMP        NEW 
 1 LEACH RESIDUE TAILINGS PUMPBOX        NEW 
 2 LEACH RESIDUE TAILINGS PUMP        NEW 
 2 SUMP PUMPS        NEW 



PENGUINASI MECHANICAL EQUIPMENT LIST April-04 
NorthMet Project   
Hoyt Lakes, Minnesota   
Equip. #Qty. Description SizeMaterial
 Specification
HP
Each
HPTotalRemarksNew /
Existing
         
PGM RECOVERY       
 1SULPHUR MELT PIT      NEW 
 1SULPHUR FEED PUMP      NEW 
 1SULPHUR FILTER      NEW 
 1SULPHUR BURNER PACKAGE      NEW 
 1SULPHUR BURNER BLOWER      NEW 
 1IN LINE MIXER      NEW 
 1Fe REDUCTION TANK 6.5 m dia x 7 m     NEW 
 1Fe REDUCTION TANK AGITATOR      NEW 
 2PIPE REACTOR FEED PUMP      NEW 
 2PIPE REACTOR 315mm D x 55m     NEW 
 2CLARIFIER      NEW 
 3PGM FILTER      NEW 
 2CLARIFIER O/F STANDPIPE      NEW 
 1POLISH FILTER FEED PUMP      NEW 
 2CLARIFIER U/F DIAPHRAM PUMP      NEW 
 1REPULP TANK 1m dia x 1.2m     NEW 
 1REPULP PUMP      NEW 
 1AUTOCLAVE HOLDING TANK 2m dia x 2.5m     NEW 
 1AUTOCLAVE CHARGE PUMP      NEW 
 1BATCH LEACH AUTOCLAVE 1m dia x 1.5m     NEW 
 1FILTER FEED TANK 2m dia x 2.5m     NEW 
 1FILTER FEED TANK AGITATOR      NEW 
 1FILTER FEED PUMP      NEW 
 1TRAY DRYER      NEW 
 1SUMP PUMP       
 1PGM PRODUCT BIN      NEW 
         
NEUTRALIZATION       
 1NEUTRALLIZATION SURGE TANK 8m dia x 8.5m     NEW 
 1NEUTRALIZATION SURGE TANK AGITATOR      NEW 
 1NEUTRALIZATION FEED PUMP      NEW 
 3NEUTRALISATION TANKS 6.5m dia x 7m     NEW 
 3NEUTRALIZATION TANK AGITATORS      NEW 
 1THICKENER FEED PUMPBOX      NEW 
 3THICKENER FEED PUMP      NEW 
 1NEUTRALISATION THICKENER 33.6m dia     NEW 
 2NEUTRALISATION THICKENER O/F PUMP      NEW 
 2NEUTRALISATION THICKENER U/F PUMP      NEW 
 1FILTER FEED TANK 2.5m dia x 3m     NEW 
 1FILTER FEED PUMP      NEW 
 1GYPSUM FILTER 2050mm x 8 chamber     NEW 
 1GYPSUM STOCKPILE CONVEYOR      NEW 
 2SUMP PUMPS      NEW 



PENGUINASI MECHANICAL EQUIPMENT LIST April-04 
NorthMet Project   
Hoyt Lakes, Minnesota   
Equip. #Qty. Description SizeMaterial
 Specification
HP
Each
HPTotalRemarksNew /
Existing
         
SOLVENT EXTRACTION AND STRIPPING       
 1 SX FEED TANK      NEW 
 1 SX FEED PUMP      NEW 
 1 SX FEED FILTER WATER PUMP      NEW 
 1 Cu SX FEED FILTERS      NEW 
 1 SX BLOWER      NEW 
 5 MIXER TANKS      NEW 
 10 MIXER TANK AGITATORS      NEW 
 1 LOADED ORGANIC ADVANCE PUMP      NEW 
 1 RICH ELECTROLYTE PUMP      NEW 
 1 ORGANIC BLEED PUMP      NEW 
 1 LOADED ORGAINIC TANK      NEW 
 2 LOADED ORGANIC PUMP      NEW 
 1 AQUEOUS REMOVAL PUMP      NEW 
 1 RAFFINATE TANK      NEW 
 1 RAFFINATE FEED PUMP      NEW 
 1 EXTRACTANT ISOTAINER PACKAGE      NEW 
 1 GUNK REMOVAL FRAME      NEW 
 1 GUNK REMOVAL PUMP      NEW 
 1 GUNK TANK      NEW 
 1 GUNK TANK AGITATOR      NEW 
 1 GUNK TANK PUMP      NEW 
 1 RECOVERED SOLUTION TANK      NEW 
 1 CLAY FILTER PRESS FEED PUMP      NEW 
 1 CLAY TREATMENT FILTER PRESS      NEW 
 1 RECOVERED SOLUTION PUMP      NEW 
 1 DILUENT STORAGE TANK      NEW 
 1 DILUENT TRANSFER PUMP      NEW 
         
ELECTROLYTE CLEANING       
 1 ELECTROLYTE COLUMN CELL      NEW 
 1 FILTER FEED TANK      NEW 
 1 FILTER FEED PUMP      NEW 
 1 FILTER BACKWASH PUMP      NEW 
 2 ELECTROLYTE FILTERS      NEW 
 1 ELECTROLYTE FILTER BLOWER      NEW 
 2 ELECTROLYTE HEAT EXCHANGER      NEW 
 1 ELECTROLYTE RECIRCULATION TANK      NEW 
 1 LEAN ELECTROLYTE PUMP      NEW 
 2 ELECTROWINNING FEED PUMPS      NEW 
 1 SUMP PUMP      NEW 
         
ELECTROWINNING       
 1 WASH WATER HEAT EXCHANGER      NEW 
 1 LOADING CONVEYOR      NEW 
 1 DEMISTER      NEW 
 1 DEMISTER EVACUATION FAN      NEW 
 1 DEMISTER WASH CHAMBER      NEW 
 1 DEMISTER RECIRCULATION PUMPS      NEW 
 1 FLEXING STATION      NEW 
 1 STRIPPING STATION      NEW 
 1 BUFFING STATION      NEW 
 1 CORRUGATING PRESS      NEW 
 1 DISCHARGE CONVEYOR      NEW 
 1 WEIGH SCALE      NEW 
 1 STAND ALONE BUFFING UNIT      NEW 
 1 REJECT MOTHERBLANK RACK      NEW 
 1EDGE STRIP INSTALLATION AND REPAIR STATION      NEW 
 1 ANODE STORAGE RACKS      NEW 
 1 CATHODE STORAGE RACKS      NEW 
 130 ELECTROWINNING CELLS   54 CATHODES    NEW 
 1 ELECTROWINNING AREA O/H CRANE      NEW 
 1 TANKHOUSE CRANES      NEW 
 2 SUMP PUMPS      NEW 
   CATHODE MOTHER BLANKS      NEW 



PENGUINASI MECHANICAL EQUIPMENT LIST April-04 
NorthMet Project   
Hoyt Lakes, Minnesota   
Equip. #Qty. Description SizeMaterial
 Specification
HP
Each
HPTotalRemarksNew /
Existing
         
Fe & HYDROXIDE PRECIPITATION          
 1 Fe THICKENER                  6.35 M DIA.    NEW 
 1 Fe THICKENER U/F PUMP     NEW 
 1 Fe FILTER FEED TANK 3.5 x 4    NEW 
 1 Fe FILTER FEED TANK AGITATOR         NEW 
 1 Fe FILTER FEED PUMP         NEW 
 1 Fe FILTER         NEW 
 1 Fe FILTER FILTRATE TANK 2m x 2.5    NEW 
 1 Fe FILTRATION PUMP         NEW 
 1 Fe FILTER REPULP TANK 2m x 2.5    NEW 
 1 Fe FILTER REPULP TANK AGITATOR         NEW 
 1 Fe SLUDGE TAILINGS PUMP         NEW 
 2 1st STAGE HYDROXIDE PRECIPITATION T 4 x 4.5    NEW 
 2 1st STAGE HYDROXIDE PRECIP TANK AGITATOR         NEW 
 1 HYDROXIDE THICKENER 9m    NEW 
 1 HYDROXIDE O/F PUMP         NEW 
 2 2nd STAGE HYDROXIDE PRECIPITATION T 4 x 4.5    NEW 
 2 2nd STAGE HYDROXIDE PRECIP TANK AGITATOR         NEW 
 1 TAILINGS THICKENER 9m    NEW 
 1 TAILINGS THICKENER U/F PUMP         NEW 
 1 HYDROXIDE PRECIPITATION U/F PUMP         NEW 
 1 FILTER FEED TANK 2 x 2.5    NEW 
 1 FILTER FEED TANK AGITATOR         NEW 
 1 FILTER FEED PUMP         NEW 
 1 HYDROXIDE FILTER         NEW 
 1 FILTRATE TANK         NEW 
 1 FILTRATION PUMP         NEW 
 1 TRAY DRYER         NEW 
 6 Fe PRECIPITATE TANKS 4m x 4.5    NEW 
 6 Fe PRECIPITATE TANKS AGITATORS         NEW 
 1 Fe THICKENER FEED PUMPBOX         NEW 
 1 Fe THICKENER FEED PUMP         NEW 
 1 Fe PRECIPITATION BLOWER         NEW 



 

 

 

 

 

 

 

 

 

Appendix 4- Operating Costs

 

 

 

 

 

 

 

 

 

 

 



PENGUINASI  PLANT REAGENTS AND CONSUMABLES COST  April-04 
NorthMet Project    Rev. A 
Hoyt Lakes, Minnesota     
 Tonnes ore milled per annum9,125,000   
AREASUPPLYUnit/tonne
Source 
UNIT UNITS/TONNE
MILLED
UNITS PER
     ANNUM
UNIT COSTUnit price
Source
TOTAL COSTESCALATION
FACTOR
TOTAL COST
2004
COST PER
TONNE ORE
Crush/Grind












Flotation 






POX 



S/L Separation 



PGM Recovery 






Neutralization 


Primary Crusher Liners
Secondary Crusher Liners
Tertiary Crusher Liners
Rod Mill Liners
Ball Mill Liners
Regrind Mill Liners
Rods
Ball Mill Balls (2" & 3")
Regrind Mill Balls (1") steel
Regrind Mill Balls (1") ceramic
6.5% Tax on liners and media
Conveyor Belting (allowance)

Flex 31
PAX
MIBC
WW1752
Flocculant (Percol 155)

NaCl
Water Treatment (allowance)
Oxygen (over the fence)

Flocculent (Percol 355)
Filter Aid (allowance)
Limestone (to leach residue tails)

Sulfur for SO2
NaHS
Flocculant
Filter Aid (allowance)
H2SO1 (allowance)
Oxygen (incl in POX)

Limestone
Flocculant
Filter Aid (allowance)

AMEC
Penguin
Penguin
Penguin
Penguin
Penguin
Penguin
AMEC
AMEC
Penguin
calc
Penguin

AMEC
AMEC
AMEC
AMEC
Polymet

Mass Balance

Mass Balance

AMEC

Mass Balance

Mass Balance
Mass Balance AMEC




Mass Balance AMEC

kg
kg
kg
kg
kg
kg
kg
kg
kg
kg



kg
kg
kg
kg
kg


kg

mt

kg

mt

kg
kg
kg




mt
kg
0.0073
0.0045
0.0045
0.0386
0.0291
0.0082
0.4545
0.3636
0.2273
0.1136



0.0182
0.0455
0.0409
0.0909
0.0004


0.4776

0.016

0.0005

0.006

0.1240
0.0474
0.0002




0.009
0.0005

66,364
41,477
41,477
352,557
265,455
74,659
4,147,727
3,318,182
2,073,864
1,036,932



165,909
414,773
373,295
829,545
3,733


4,358,338

148,107

4,148

56,285

1,131,160
432,502
1,659




82,854
4,563
$2.82
$4.46
$4.46
$4.80
$4.80
$3.54
$0.44
$0.44
$0.61
$1.80



$2.75
$1.54
$1.43
$2.20
$3.85


$0.04

$19.72

$3.85

$10.00

$0.06
$0.64
$3.85




$10.00
$3.85

AMEC
AMEC
Penguin
AMEC
Penguin
AMEC
Penguin
AMEC
AMEC
Penguin



AMEC
AMEC
AMEC
AMEC
Polymet


Polymet
Polymet
AMEC

Polymet

Polymet

Polymet
Polymet
Polymet
Polymet
Polymet


Polymet
Polymet
Polymet
$186,880
$185,146
$185,146
$1,691,638
$1,273,704
$263,950
$1,825,000
$1,460,000
$1,254,688
$1,866,477
$662,521
$400,000

$456,250
$638,750
$533,813
$1,825,000
$14,372


$153,414
$41,500
$2,920,670

$15,969
$100,000
$562,852

$64,702
$278,791
$6,388
$46,500
$18,600


$828,542
$17,566
$93,000
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0

1.0
1.0
1.0
1.0
1.0


1.0
1.0
1.0

1.0
1.0
1.0

1.0
1.0
1.0
1.0
1.0


1.0
1.0
1.0
$186,880
$185,146
$185,146
$1,691,638
$1,273,704
$263,950
$1,825,000
$1,460,000
$1,254,688
$1,866,477
$662,521
$400,000

$456,250
$638,750
$533,813
$1,825,000
$14,372


$153,414
$41,500
$2,920,670

$15,969
$100,000
$562,852

$64,702
$278,791
$6,388
$46,500
$18,600


$828,542
$17,566
$93,000
0.020
0.020
0.020
0.185
0.140
0.029
0.200
0.160
0.138
0.205
0.073
0.044

 
0.050
0.070
0.059
0.200
0.002
 

 
0.017
0.005
0.320

 
0.002
0.011
0.062

 
0.007
0.031
0.001
0.005
0.002

 

 
0.091
0.002
0.010


PENGUINASI  PLANT REAGENTS AND CONSUMABLES COST  April-04 
NorthMet Project    Rev. A 
Hoyt Lakes, Minnesota     
 Tonnes ore milled per annum9,125,000   
AREASUPPLYUnit/tonne
Source 
UNIT UNITS/TONNE
MILLED
UNITS PER
     ANNUM
UNIT COSTUnit price
Source
TOTAL COSTESCALATION
FACTOR
TOTAL COST
2004
COST PER
TONNE ORE
Cu SX/EW










Fe Precipitation





Hydroxide ppt'n





TOTAL
Extractant (M5640)
Diluent (SX 11)
H2 SO
Cobalt Sulphate
Clay (allowance)
Cathodes (10yrlife)
Anodes (7 yr life)
Cathode Bundling Supplies
FC1100 (allowance)
Guar (allowance)

Limestone
Sulfur for SO2
Flocculant
Filter Aid (allowance)
Oxygen (ind in POX)

MgO
CaO
Hydroxide Bundling Supplies
Flocculent
AMEC
AMEC
AMEC
AMEC

Calc
Calc




Mass Balance
Mass Balance
AMEC



Mass Balance
Mass Balance

AMEC

litres
litres
mt
kg

plate
plate




mt
kg
kg



kg
kg

kg
0.0061
0.0140
0.0011
0.0006







0.002
0.0335
0.0002



0.5868
0.0914

0.0002
55,267
127,805
10,038
5,392

675
965




19,286
305,296
1,659



5,354,716
833,693

1,659
$9.12
$0.71
$60.00
$5.50

$250.00
$165.00




$10.00
$0.06
$3.85



$0.10
$0.06

$3.85
Polymet
Polymet
Penguin
Polymet
Polymet
Polymet
Polymet
Polymet
Polymet
Polymet

Polymet
Polymet
Polymet
Polymet


Polymet
Polymet
Polymet
Polymet
$503,992
$91,159
$602,250
$29,656
$30,000
$30,000
$30,000
$30,000
$40,000
$20,000

$192,863
$17,463
$6,388
$58,000


$535,472
$53,190
$8,400
$6,388
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0

1.0
1.0
1.0
1.0


1.0
1.0
1.0
1.0
$503,992
$91,159
$602,250
$29,656
$30,000
$30,000
$30,000
$30,000
$40,000
$20,000

$192,863
$17,463
$6,388
$58,000


$535,472
$53,190
$8,400
$6,388


$22,142,258
0.055
0.010
0.066
0.003
0.003
0.003
0.003
0.003
0.004
0.002

0.021
0.002
0.001
0.006


0.059
0.006
0.001
0.001


$2.43



 

 

 

 

 

 

 

 

 

Appendix 5- Capital Costs

 

 

 

 

 

 

 

 

 

 

 



PENGUINASI CAPITAL COST ESTIMATE April-04 
NorthMet Project  SUMMARYRev. C 
Hoyt Lakes, Minnesota   
Item Item Description Total   Labor   Material   Subcontract   Total 
 SUMMARY - OVERALLMhrs         Costs   Costs 
              
100 CRUSHING 15,842  $1,075,130  $2,007,038  $ -  $3,082,168 
               
210 GRINDING 15,640  $1,049,723  $3,174,011  $58,501  $4,282,235 
               
220 FLOTATION & REGRIND 65,827  $4,476,264  $13,004,243  $65,900  $17,546,408 
               
300 PRESSURE LEACHING 118,638  $8,067,369  $22,981,576  $3,000  $31,051,945 
               
410 SOLID / LIQUID SEPARATION 26,903  $1,830,793  $4,822,330  $13,381  $6,666,504 
               
420 PGM RECOVERY 19,927  $1,356,385  $3,712,286  $13,381  $5,082,053 
               
510 NEUTRALIZATION 38,661  $2,633,222  $6,220,210  $13,381  $8,866,813 
               
520 SOLVENT EXTRACTION 35,242.9  $2,397,018  $4,011,187  $30,767  $6,438,971 
               
530 ELECTROWINNING 55,855  $3,800,408  $14,930,476  $18,678  $18,749,562 
               
540 Fe & HYDROXIDE PRECIPITATION 30,868  $2,100,460  $3,889,689  $13,381  $6,003,530 
               
600 INFRASTRUCTURE & AUXILIARY SERVICES 46,404  $3,168,312  $8,912,206  $506,193  $12,586,710 
               
700 TAILINGS 2,740  $186,320  $385,000  $3,977,524  $4,548,844 
               
800 MINING 6,185  $439,810  $411,700  $4,908,239  $5,759,749 
               
 TOTAL DIRECT COSTS 478,732  $32,581,212  $88,461,953  $9,622,327  $130,665,492 


PENGUINASI CAPITAL COST ESTIMATE April-04 
NorthMet Project  SUMMARYRev. C 
Hoyt Lakes, Minnesota   

Item Item Description  Total Labor  Material   Subcontract   Total 
 SUMMARY - OVERALL  Mhrs      Costs   Costs 
              
920 EPCM  15% On Direct Costs  $19,599,824  $19,599,824 
              
930 CONSTRUCTION INDIRECTS  $6 On Manhours for Construction Equipment  $2,872,394  $2,872,394 
    Site Costs and Contractor O/H and Profit included in labour rate    
941 CAPITAL SPARES  5% On Process Materials Excluding Crushing  $4,322,746  $4,322,746 
              
942 FIRST FILLS  LS 3 Months Consumables  $4,000,000  $4,000,000 
              
950 VENDOR REPRESENTATIVES  LS     $1,319,508  $1,319,508 
              
960 FREIGHT  3% On Materials    $2,498,427  $2,498,427 
              
970 START UP AND COMMISSIONING  LS     $910,460  $910,460 
           
 CONTINGENCY  20% On Direct and Indirect Costs    $33,237,770 
    Excluding Owners Costs     
 PROJECT TOTAL         $199,426,621 


PENGUINASI CRUSHING AND SCREENING April-04 
NorthMet Project  Rev. C 
Hoyt Lakes, Minnesota   

Area
100 
 Item Description
 CRUSHING AND SCREENING  
Qty Unit  Unit
Mhrs 
Total
Mhrs 
MH
Rate 
Labor   Unit
Matl 
Material  Subcontract
Specl Costs
Total
Costs 
              
 Existing equipment refurbishment costs include an allowance for labour and an allowance for materials based on 10% of new equipment cost for liners, idlers etc.    
              
110PRIMARY CRUSHING            
              
  REMOVE EXISTING 36'' GYRATORYRemoved at no cost for salvage1EA - $ 68$        - $         - $         -  $ - 
  CRUSHER SURGE POCKET DEMOLITION 1LS 500 500 $ 68$34,000 $         - $         -  $34,000 
  CRUSHER SURGE POCKET MODIFICATIONS 20TN 30 600 $ 68$40,800 $ 3,000 $60,000  $100,800 
 EXISTING PRIMARY CRUSHERDischarge Skirt Repairs 60x89 GYR, 900 HP1EA 300 300 $ 68$20,400 $250,000 $250,000   
  and New Lube Uni t                 $270,400 
 EXISTING APRON FEEDER 1500 x 4800, 115HP1EA 299 299 $ 68$20,323 $29,887 $29,887  $50,210 
 EXISTING CONVEYOR 1AChange Troughing Idler Sets at 60", 900 HP 1EA 250 250 $ 68$17,000 $25,000 $25,000   
  Feed End                 $42,000 
 EXISTING BELT WEIGHSCALE     1EA 12 12 $ 68$     816 $ 2,000 $ 2,000  $2,816 
 EXISTING CONVEYOR 2AChange Troughing Idlers at 60", 900 HP 1EA 250 250 $ 68$17,000 $25,000 $25,000   
  Feed En d                 $42,000 
 EXISTING CONVEYOR 2A-TRIPPERModify Tripper Drive 60", 15 HP1EA 700 700 $ 68$47,600 $70,000 $70,000   
                   $117,600 
 EXISTING CONV. 2A TRIPPER SUPPORT REPAIR    20TN 60 1,224 $ 69$84,456 $ 3,000 $61,200  $145,656 
 NEW RE & RE PRIMARY CRUSHER CHUTEWORK LINERS 15TN 30 450 $ 68$30,600 $ 3,500 $52,500  $83,100 
              
 EXISTING PRIMARY CRUSHER PIPING20% of new for inspection/repair1LS 158 158 $ 68$10,744 $15,800 $15,800  $26,544 
 EXISTING PRIMARY CRUSHER ELECTRICAL/LIGHTING10% of new for repair1LS 274 274 $ 68$18,627 $27,393 $27,393  $46,020 
 EXISTING PRIMARY CRUSHER INSTRUMENTATION20% of new for repair1LS 40 40 $ 68$ 2,720 $10,400 $10,400  $13,120 
 EXISTING PRIMARY CRUSHER HVAC/SERVICESAllowance 1LS 80 80 $ 68$ 5,440 $ 5,000 $ 5,000  $10,440 
 EXISTING PRIMARY CRUSHER FIRE PROTECTIONAllowance 1LS 80 80 $ 68$ 5,440 $ 5,000 $ 5,000  $10,440 
 EXISTING PRIMARY CRUSHER BUILDINGAllowance for Repairs/Modifications1LS 250 250 $ 68$17,000 $25,000 $25,000  $42,000 
              
120SECONDARY AND TERTIARY CRUSHING AND SCREENING                  
              
 EXISTING RE & RE COARSE ORE SURGE BIN LINERS 2000 T BIN24TN 100 2,400$ 68$163,200 $350 $ 8,400   
  Liners in Stock                 $171,600 
 EXISTING COARSE ORE RECLAIM FEEDERS 4'x 6' VIB, 4 HP 12EA 177 2,119 $ 68$144,109 $14,717 $176,604  $320,713 
 EXISTING COARSE ORE RECLAIM CONVEYORS 48", 5 HP4EA 39 156 $ 68$10,608 $325 $ 1,300   
  Recently Replace d                 $11,908 
 EXISTING RETRACTABLE CONVEYORS 48", 5 HP 2EA 39 78 $ 68$5,304 $3,250 $ 6,500  $11,804 
 EXISTING SECONDARY CRUSHERReplace Lube Unit 7' STD. CONE, 350 HP 2EA 150 300 $ 68$20,400 $150,000 $300,000  $320,400 
 EXISTING CRUSHER RECLAIM FEEDER 4'x 5' VIB, 4 HP4EA 175 700 $ 68$47,600 $14,717 $58,868  $106,468 
 EXISTING SIZING SCREENSSpare Parts in Stock 6'x 10' VIB, 15 HP 4EA 50 200 $ 68$13,600 $17,000 $68,000  $81,600 
 EXISTING TERTIARY CRUSHERReplace Lube Unit 7' CONE, 350 HP 4EA 150 600 $ 68$40,800 $100,000 $400,000  $440,800 
 EXISTING RELACE BOTTOM SECTION OF DISCHARGE     10TN 30 300 $ 68$20,400 $3,000 $30,000   
  CHUTES                 $50,400 
 EXISTING CONVEYOR 3AChange Troughing Idlers at 60", 75 HP1EA 250 250 $ 68$17,000 $25,000 $25,000   
  Feed En d                 $42,000 
 EXISTING CONVEYOR 4AChange Troughing Idlers at 60", 750 HP 1EA 250 250 $ 68$17,000 $25,000 $25,000   
  Feed En d                 $42,000 
 EXISTING CONVEYOR 5SChange Troughing Idlers at 60", 450 HP1EA 250 250 $ 68$17,000 $25,000 $25,000   
  Feed En d                 $42,000 
 EXISTING CONVEYOR 5S-TRIPPER 60", 15 HP1EA 200 200 $ 68$13,600 $20,000 $20,000  $33,600 
 EXISTING SUMP PUMPS 2EA 100 200 $ 68$13,600 $1,500 $ 3,000  $16,600 
 NEW RE & RE SEC AND TER CHUTEWORK LINERS 4TN 50 200 $ 68$13,600 $3,500 $14,000  $27,600 
 NEW REPLACE DUST COLLECTION COLLECTOR DUCTINGMaterial on Site1sum 400 400 $ 60$23,856 $4,000 $ 4,000  $27,856 


PENGUINASI CRUSHING AND SCREENING April-04 
NorthMet Project  Rev. C 
Hoyt Lakes, Minnesota   
Area
100 
 Item Description
 CRUSHING AND SCREENING  
Qty Unit  Unit
Mhrs 
Total
Mhrs 
MH
Rate 
Labor   Unit
Matl 
Material  Subcontract
Specl Costs
Total
Costs 
                         
 EXISTINGSECONDARY CRUSHER PIPING  1LS316 316 $ 68$21,488$31,600$31,600 $53,088
 EXISTINGSECONDARY CRUSHER ELEC/LIGHTING  1LS548 548 $ 68$37,254$54,786$54,786 $92,040
 EXISTINGSECONDARY CRUSHER INSTRUMENTATION  1LS208 208 $ 68$14,144$20,800$20,800 $34,944
 EXISTINGSECONDARY CRUSHER HVAC  1LS100 100 $ 68$6,800$10,000$10,000 $16,800
 EXISTINGSECONDARY CRUSHER FIRE PROTECTION  1LS100 100 $ 68$6,800$10,000$10,000 $16,800
 EXISTINGSECONDARY CRUSHER BUILDINGAllowance for Repairs/Modifications 1LS500 500 $ 68$34,000$50,000$50,000 $84,000
                   
110  SUB TOTAL CRUSHING AND SCREENING     15,842  $1,075,130 $2,007,038 $3,082,168


PENGUINASI 200 - GRINDINGApril-04 
NorthMet Project  Rev. C 
Hoyt Lakes, Minnesota   
Area
210
Item Description
GRINDING
QtyUnit   Unit
Mhrs
 Total
Mhrs
 Labor Unit
Matl
MaterialSubcontract
Specl Costs
 Total
Costs
             
  Existing equipment refurbishment costs include an allowance for labour and an allowance for materials based on 10% of new equipment cost for liners, idlers etc.   
             
  EQUIPMENT AND STEEL DEMOLITIONRemoved at no cost for salvage1LS- - $           -$           -$           -$           -$           -
  GRINDING CIRCUIT DEMOLITION 1LS500 500 $34,000$3,500$3,500$2,000$39,500
  BACKFILL 1LS200 200 $13,600$2,000$2,000$1,500$17,100
  NEW CONCRETE FOOTINGS AND PIERS 1LS400 400 $27,200$300$300$           -$27,500
  NEW STRUCTURAL STEEL AND PLATFORMS 8TN30 240 $16,320$3,200$25,600$           -$41,920
  FINE ORE SURGE BIN BULKHEADSNot Required 0TN30 - $            -$3,200$         -$           -$           -
 EXISTINGRE & RE FINE ORE SURGE BIN LINERS 650 T LIVE CAPACITY16TN25 400 $27,200$3,500$56,000$           -$83,200
             
 EXISTINGFINE ORE RECLAIM CONVEYORS 24', 3 HP 8ea 147 1,176 $79,968$14,717$117,736$           -$197,704
 EXISTINGROD MILL 10'x 14', 800 HP8ea 300 2,400 $163,200$100,000$800,000$           -$963,200
 EXISTING BALL MILL10'x 14', 1250 HP 8ea 300 2,400 $163,200$100,000$800,000$           -$963,200
 NEW CYCLOPAC 1 OP 1 STDBY 2 x 33" dia8ea 100 800 $54,400$40,000$320,000$           -$374,400
 NEW CYCLONE FEED PUMPBOX      8ea 80 640 $43,52$10,000$80,000$           -$123,520
 NEW CYCLONE FEED PUMPS      8ea 100 800 $54,40$50,000$400,000$           -$454,400
 EXISTINGREPLACE 42" PROCESS WATER HEADER      1EA210 210 $         -$21,000$21,000$          1$21,001
 EXISTINGOVERHEAD CRANE      1ea 40 40 $2,720$25,000$25,000$5,000$32,720
 EXISTINGSUMP PUMPS 6"2ea 100 200 $13,600$750$1,500$           -$15,100
             
  RE & RE GRINDING CHUTEWORK / LINERS 20TN30 600 $40,800$3,500$70,000$           -$110,800
  GRINDING PIPING 1LS1,695 1,695 $115,260$169,500$169,500$           -$284,760
  GRINDING ELECTRICAL/LIGHTING 1LS1,271 1,271 $86,445$127,125$127,125$           -$213,570
  GRINDING INSTRUMENTATION 1LS848 848 $57,630$84,750$84,750$           -$142,380
  GRINDING HVAC/SERVICESAllowance 1LS160 160 $10,880$10,000$10,000$           -$20,880
  GRINDING FIRE PROTECTIONAllowance 1LS160 160 $10,880$10,000$10,000$           -$20,880
  GRINDING BUILDINGAllowance for Repairs/Modifications 1LS500 500 $34,500$50,000$50,000$           -$84,500
  SEPARATION WALL ALLOWANCE 1LS     $50,000$50,000
             
             
210  SUB TOTAL GRINDING    15,640 $1,049,723 $3,174,011$58,501$4,282,235


PENGUINASI FLOTATION AND REGRINDApril-04 
NorthMet Project  Rev. C 
Hoyt Lakes, Minnesota   

Area
220
 Item Description
 FLOTATION & REGRIND
Qty  Unit  Unit
Mhrs
Total
Mhrs
Labor Unit
Matl
Material
 
Subcontract
Specl Costs 
Total
Costs
               
  EQUIPMENT AND STEEL DEMOLITIONRemoved at no cost for salvage 1LS00$        -$       -$ -$-$ -
  GRINDING CIRCUIT DEMOLITION  1,100CY11100$$74,800$       -$ -$8,800$83,600
  BACKFILL  700CY0.170$4,760$      85,600$2,100$12,460
  NEW CONCRETE FOOTINGS/PIERS/SLABS  400CY83200$217,600$300120,000 $337,600
  STRUCTURAL STEEL AND PLATFORMS  70TN221540$104,720$2,800196,000 $300,720
  GENERAL BUILDING MODIFICATIONS  1LS500500$34,000$50,00050,000 $84,000
 EXISTINGFLOTATION AREA CRANE 25T/5T 20/5 HP 1EA4040$2,720$8,0008,000$5,000$15,720
 NEWCONDITIONING TANK 7.5 m dia x 8 m 31,700 LB0.03951$64,668$      131,700 $96,368
 NEWCONDITIONING TANK AGITATOR  1EA100100$6,800$48,00048,000 $54,800
 NEWROUGHER CELLSQuoted 160 m3 TANK CELL 4EA60240$16,320$307,5001,230,00 0 $1,246,320
 NEWSCAVENGER CELLSQuoted 160 m3 TANK CELL 10EA60600$40,800$338,2503,382,50 0 $3,423,300
 NEWCLEANER CELLS WITH DISTRIBUTORQuoted 21 m3 CONV. CELL 8EA120960$65,280$99,000792,00 0 $857,280
 NEWFLOTATION TAILS PUMPBOX  1EA250250$17,000$15,00015,000 $32,000
 NEWFLOTATION TAILS PUMPS  2EA400800$54,400$200,000400,000 $454,400
 NEWRECLEANER FEED PUMPBOX  1EA4040$2,720$10,00010,000 $12,720
 NEWRECLEANER FEED PUMPS  2EA60120$8,160$30,00060,000 $68,160
 NEWRE CLEANER COLUMN CELLS 3.7mx12.2 m COL CELL1EA120120$8,160$99,00099,000 $107,160
 NEWRECLEANER TAILS PUMP  2EA60120$8,160$30,00060,000 $68,160
 NEWRECLEANER BLOWER  1EA6060$4,080$15,00015,000 $19,080
 NEWFLOTATION BLOWERS  2EA61122$8,296$15,00130,002 $38,298
 NEWSAMPLERS  3EA50150$10,200$10,00030,000 $40,200
 NEWANALYSER  1EA900900$61,200$500,000500,000 $561,200
 NEWSUMP PUMPS  4EA60240$16,320$15,00060,000 $76,320
 NEWSCAVENGER REGRIND CYCLONE FEED PUMPBOX  1EA100100$6,800$10,00010,000 $16,800
 NEWSCAVENGER REGRIND CYCLONE FEED PUMPS  2EA125250$17,000$50,000100,000 $117,000
 NEWSCAVENGER REGRIND CYCLOPAC  1EA8080$5,440$50,00050,000 $55,440
 EXISTINGSCAVENGER REGRIND MILL 12'-2" x 24', 1500 HP 1EA250250$17,000$150,000150,000 $167,000
 NEWFINAL CONC. REGRIND CYCLONE FEED PUMPBOX  1EA100100$6,800$10,00010,000 $16,800
 NEWFINAL CONC. REGRIND CYCLONE FEED PUMPS  2EA60120$8,160$50,000100,000 $108,160
 NEWFINAL CONC. REGRIND CYCLOPAC  1EA8080$5,440$50,00050,000 $55,440
 EXISTINGFINAL CONC REGRIND MILL 12'-2" x 24', 1500 HP 1EA250250$17,000$150,000150,000 $167,000
             
  FLOTATION PIPING  1LS14,76614,766$1,004,115$1,476,6401,476,640 $2,480,756
  OUTSIDE LINESTo Pressure Leaching and Reagent Supply  1LS18,47818,478$1,256,504$1,847,8011,847,801 $3,104,305
  FLOTATION ELECTRICAL  1LS11,08711,087$753,903$1,108,6801,108,680 $1,862,583
  FLOTATION INSTRUMENTATION  1LS7,3837,383$502,058$738,320738,320 $1,240,378
  FLOTATION HVAC  1LS8080$5,440$10,00010,000 $15,440
  FLOTATION FIRE PROTECTION  1LS8080$5,440$10,00010,000 $15,440
  FLOTATION BUILDINGAllowance for Repairs / Modifications  1LS500500$34,000$50,00050,000 $84,000
             
  SEPARATION WALL ALLOWANCE  1LS        $50,000$50,000
             
220 SUB TOTAL FLOTATION & REGRIND     65,827$4,476,264 $13,004,243$65,900$17,546,408


PENGUINASI PRESSURE LEACHINGApril-04 
NorthMet Project  Rev. C 
Hoyt Lakes, Minnesota   

Area
300
 Item Description
 PRESSURE LEACHING
Qty  Uni Unit
Mhrs
Total
Mhrs
Labor Unit
Matl
Material Subcontract
Specl Costs
Total
Costs
  SITE PREPARATION AND CIVIL  1LS 500 500 $34,000$10,000$10,000$3,000$47,000
  PRE ENGINEERED BUILDINGIncluding Concrete and Architectural  24,000SF 0.70 16,800 $1,142,400$70$1,680,000 $2,822,400
  BUILDING HVAC  24,000SF 0.05 1,200 $81,600$8$192,000 $273,600
  BUILDING FIRE PROTECTION  24,000SF 0.02 480 $32,640$4$96,000 $128,640
  BUILDING ELECTRICALlighting/convenience electrical  24,000SF 0.05 1,200 $81,600$6$144,000 $225,600
  CONCRETE EQUIP FOUNDATIONS AND PIERS  350YD 2,100 $142,800$300$105,000 $247,800
  EQUIPMENT SUPPORT STRUCTURAL STEEL  35TN 30 1,050 $71,400$3,200$112,000 $183,400
  AUTOCLAVE AREA OVERHEAD CRANE 5t/1t 2EA 240 480 $32,640$80,000$160,000 $192,640
                
 NEW CONCENTRATE THICKENERBudget Quotation 44 ft. dia 1EA 1,500 1,500 $102,000$301,125$301,125 $403,125
 NEW THICKENER O/F PUMP  2EA 40 80 $5,440$15,000$30,000 $35,440
 NEW THICKENER U/F PUMP  2EA 40 80 $5,440$8,000$16,000 $21,440
 NEW CONCENTRATE STORAGE TANK 26 ft dia. X 29 ft 45,000LBS 0.03 1,350 $91,800$1$45,000 $136,800
 NEW CONCENTRATE STORAGE TANK AGITATOR 29.52 1EA 100 100 $6,800$50,000$50,000 $56,800
 NEW CONCENTRATE FEED PUMPS  2EA 40 80 $5,440$12,000$24,000 $29,440
 NEW AUTOCLAVE FEED TANK 3 m dia. X 3.5 m 8,000LBS 0.03 240 $16,320$1$8,000 $24,320
 NEW AUTOCLAVE FEED TANK AGITATOR  2EA 40 80 $5,440$10,000$20,000 $25,440
 NEW AUTOCLAVE FEED PUMPS  2EA 80 160 $10,880$75,000$150,000 $160,880
 NEW NaCL ADDITION SYSTEM  1EA 400 400 $27,200$150,000$150,000 $177,200
 NEW AUTOCLAVESAdjusted to 65% of AMEC study 4.1m x 24.6m 2EA 4,000 8,000 $544,000$3,475,046$6,950,092 $7,494,092
 NEW AUTOCLAVE AGITATORS  12EA 150 1,800 $122,400$200,000$2,400,000 $2,522,400
 NEW FLASH TANKSAdjusted to 65% of AMEC study  2EA 1,000 2,000 $136,000$656,398$1,312,795 $1,448,795
 NEW SLURRY COOLER FEED PUMPS  2EA 60 120 $8,160$35,000$70,000 $78,160
 NEW SLURRY COOLERS  2EA 80 160 $10,880$50,000$100,000 $110,880
 NEW COOLING TOWER  1EA 1,200 1,200 $81,600$200,000$200,000 $281,600
 NEW VENT GAS SCRUBBER  1EA 60 60 $4,080$260,000$260,000 $264,080
 NEW VENT GAS SCRUBBER DISCHARGE PUMP  2EA 40 80 $5,440$5,000$10,000 $15,440
 NEW RAFFINATE INJECTION PUMPS  2EA 80 160 $10,880$75,000$150,000 $160,880
 NEW BOILER PACKAGEAdjusted to 65% of AMEC study  1EA 4,000 4,000 $272,000$617,786$617,786 $889,786
 NEW BOILER BLOWOUT VESSELS  2EA 40 80 $5,440$8,000$16,000 $21,440
 NEW HP AIR COMPRESSOR  1EA 40 40 $2,720$60,000$60,000 $62,720
 NEW LP AIR COMPRESSOR  1EA 40 40 $2,720$40,000$40,000 $42,720
 NEW SEAL WATER COOLER  1EA 80 80 $5,440$50,000$50,000 $55,440
 NEW SEAL/RINSE WATER TREATMENT PACKAGE  1EA 100 100 $6,800$50,000$50,000 $56,800
 NEW OXYGEN BLOWOUT VESSEL  2EA 40 80 $5,440$8,000$16,000 $21,440
 NEW SEAL WATER PUMPS  3EA 40 120 $8,160$8,000$24,000 $32,160
 NEW WATER TREATMENT PACKAGE  1EA 200 200 $13,600$100,000$100,000 $113,600
 NEW SUMP PUMPS  3EA 60 180 $12,240$12,000$36,000 $48,240
             
  PRESSURE LEACHING PIPINGAdjusted to 65% ofAMEC study  1LS 33,808 33,808 $2,298,967$3,380,833$3,380,833 $5,679,800
  OUTSIDE LINES TO SOLID LIQUID SEPARATIONAllowance  1LS 16,904 16,90 4 $1,149,483$1,690,417$1,690,417 $2,839,900
  PRESSURE LEACHING ELECTRICAL/LIGHTINGAdjusted to 65% AMEC 1LS 12,680 12,680 $862,244$1,268,006$1,268,006 $2,130,249
  PRESSURE LEACHING INSTRUMENTATIONAdjusted to 65% AMEC 1LS 8,865 8,86 5 $602,835$886,523$886,523 $1,489,358
                
300  SUB TOTAL PRESSURE LEACHING        118,638 $8,067,369 $22,981,576$3,000$31,051,945


PENGUINASI SOLID / LIQUID SEPARATIONApril-04 
NorthMet Project  Rev. C 
Hoyt Lakes, Minnesota   

Area
410 
 Item Description
 SOLID / LIQUID SEPARATION
Qty  Unit  Unit 
Mhrs 
Total
Mhrs 
Labor   Unit
Matl 
Material   Subcontract
Specl Costs 
Total
Costs
             
  SITE PREPARATION 1LS 500 500 $34,000 $5,000 $5,000 $3,000 $42,000 
  DEMOLITION 1,185YD 1,185 $80,593 $- $- $9,481 $90,074 
  BACKFILL 1,200CY 0.08 96 $6,528 $5 $6,000 $900 $13,428 
  CONCRETE EQUIP FOUNDATIONS AND PIERS 120YD 720 $48,960 $300 $36,000  $84,960 
  TANK FARM CONCRETE 180YD 1,260 $86,940 $301 $54,180  $141,120 
  PLATFORMS 1,000SF 0.15 150 $10,350 $12 $12,000  $22,350 
  EQUIPMENT SUPPORT STRUCTURAL STEEL 20TN 30 600 $40,800 $3,200 $64,000  $104,800 
  BUILDING MODIFICATIONS 1LS 500 500 $34,000 $100,000 $100,000  $134,000 
  BUILDING ARCHITECTURALAllowance 1,200SF 1,200 $81,600 $75 $90,000  $171,600 
  BUILDING HVAC 4,000SF 0.05 200 $13,600 $8 $32,000  $45,600 
  BUILDING FIRE PROTECTION 4,000SF 0.02 80 $5,440 $5 $20,000  $25,440 
  BUILDING ELECTRICALLighting/Convenience Electrical 4,000SF 0.05 200 $13,600 $6 $24,000  $37,600 
  CRANE 1EA 400 400 $27,200 $50,000 $50,000  $77,200 
             
 NEW LEACH THICKENERBudget Quotation 17.7 m dia.1EA 3000 3,000 $204,000 $380,000 $380,000  $584,000 
 NEW LEACH THICKENER O/F PUMP       2EA 60 120 $8,160 $15,000 $30,000  $38,160 
 NEW LEACH THICKENER U/F PUMP       2EA 40 80 $5,440 $8,000 $16,000  $21,440 
 NEW FILTER FEED TANK 3 m dia. X 3.5 m1EA 200 200 $13,600 $30,000 $30,000  $43,600 
 NEW FILTER FEED TANK AGITATOR       1EA 40 40 $2,720 $6,000 $6,000  $8,720 
 NEW FILTER FEED PUMP       2EA 30 60 $4,080 $8,000 $16,000  $20,080 
 NEW LEACH RESIDUE FILTER - Budget Quote       1EA 500 500 $34,000 $1,690,000 $1,690,000  $1,724,000 
 NEW TAILINGS REPULP TANK 3 m dia. X 3.5 m1EA 200 200 $13,600 $30,000 $30,000  $43,600 
 NEW TAILINGS REPULP TANK AGITATOR       1EA 40 40 $2,720 $6,000 $6,000  $8,720 
 NEW TAILINGS REPULP PUMP       2EA 40 80 $5,440 $8,000 $16,000  $$21,440 
 NEW THICKENER O/F SURGE TANK 5 m dia. X 5.5 m1EA 600 600 $40,800 $100,000 $100,000  140,800 
 NEW POLISH FILTER FEED PUMP       2EA 40 80 $5,440 $6,000 $12,000  $17,440 
 NEW POLISH FILTER 3.5 m dia.2EA 120 240 $16,320 $175,000 $350,000  $366,320 
 NEW POLISH FILTER BLOWER       1EA 60 60 $4,080 $15,000 $15,000  $19,080 
 NEW ROUGHER/SCAVENGER CELLSBudget Quote 2.8m35EA 30 150 $10,200 $18,000 $90,000  $100,20 0 
 NEW CLEANER FLOTATION CELLSBudget Quote 0.08m33EA 40 120 $8,160 $8,333 $25,000  $33,160 
 NEW ROUGHER/SCAV FLOT CELLS RETURN PUMP       1EA 40 40 $2,720 $6,000 $6,000  $8,720 
 NEW CONCENTRATE STORAGE TANK FEED PUMP       1EA 40 40 $2,720 $5,000 $5,000  $7,720 
 NEW LEACH RESIDUE TAILINGS PUMPBOX       1EA 80 80 $5,440 $20,000 $20,000  $25,440 
 NEW LEACH RESIDUE TAILINGS PUMP       2EA 80 160 $10,880 $45,000 $90,000  $100,880 
 NEW SUMP PUMPS       2EA 40 80 $5,440 $6,000 $12,000  $17,440 
             
  SOLID / LIQUID SEPARATION PIPING       1LS 5,890 5,890 $400,520 $589,000 $589,000  $989,520 
  SOLID LIQUID SEPARATION ELECTRICAL       1LS 4,418 4,418 $300,390 $441,750 $441,750  $742,140 
  SOLID LIQUID INSTRUMENTATION       1LS 3,534 3,534 240,312 $353,400 $353,400  $593,712 
                  
410  SUB TOTAL SOLID / LIQUID SEPARATION               26,903 $1,830,793  $4,822,330 $13,381 $6,666,504 


PENGUINASI PGM RECOVERYApril-04 
NorthMet Project  Rev. C 
Hoyt Lakes, Minnesota   

Area
420
 Item Description
 PGM RECOVERY
Qty  Unit Unit
Mhrs
Total
Mhrs
Labor Unit
Matl
Material Subcontract
Specl Costs
Total
Costs
             
  SITE PREPARATION  1LS 500 500 $34,000 $5,000 $5,000 $3,000 $42,000 
  DEMOLITION  1,185YD 1,185 $80,593 $- $- $9,481 $90,074 
  BACKFILL  1,200CY 0.08 96 $6,528 $5 $6,000 $900 $13,428 
  CONCRETE EQUIP FOUNDATIONS AND PIERS  120YD 720 $48,960 $300 $36,000  $84,960 
  TANK FARM CONCRETE  180YD 1,260 $86,940 $301 $54,180  $141,120 
  PLATFORMS  500SF 0.15 75 $5,175 $12 $6,000  $11,175 
  EQUIPMENT SUPPORT STRUCTURAL STEEL  20TN 30 600 $40,800 $3,200 $64,000  $104,800 
  BUILDING MODIFICATIONS  1LS 500 500 $34,000 $100,000 $100,000  $134,000 
  BUILDING ARCHITECTURALAllowance  1,200SF 1,200 $81,600 $75 $90,000  $171,600 
  BUILDING HVAC  4,000SF 0.05 200 $13,600 $8 $32,000  $45,600 
  BUILDING FIRE PROTECTION  4,000SF 0.02 80 $5,440 $5 $20,000  $25,440 
  BUILDING ELECTRICALLighting/Convenience Electrical  4,000SF 0.05 200 $13,600 $6 $24,000  $37,600 
  CRANE  1EA 400 400 $27,200 $50,000 $50,000  $77,200 
             
 NEW PLANT AIR COMPRESSOR  1EA 60 60 $4,080 $40,000 $40,000  $44,080 
 NEW INSTRUMENT AIR COMPRESSOR  1EA 60 60 $4,080 $40,000 $40,000  $44,080 
 NEW SULPHUR BURNER PACKAGE  1EA 800 800 $54,400 $200,000 $200,000  $254,400 
 NEW SULPHUR BURNER BLOWER  1  - -  -  - 
 NEW IN LINE MIXER  1EA 40 40 $2,720 $10,000 $10,000  $12,720 
 NEW Fe REDUCTION TANK 6.5 m dia x 7 m 1EA 800 800 $54,400 $120,000 $120,000  $174,400 
 NEW Fe REDUCTION TANK AGITATOR  1EA 40 40 $2,720 $13,000 $13,000  $15,720 
 NEW PIPE REACTOR FEED PUMP  2EA 40 80 $5,440 $17,000 $34,000  $39,440 
 NEW PIPE REACTOR 315mm D x 55m 2EA 120240 $16,320 $10,000 $20,000  $36,320 
 NEW CLARIFIER  2EA 120 240 $16,320 $80,000 $160,000  $176,320 
 NEW PGM FILTER  2EA 500 1,000 $68,000 $690,002 $1,380,005  $1,448,005 
 NEW CLARIFIER O/F STANDPIPE  2EA 40 80 $5,440 $8,000 $16,000  $21,440 
 NEW POLISH FILTER FEED PUMP  2EA 80 160 $10,880 $30,000 $60,000  $70,880 
 NEW CLARIFIER U/F DIAPHRAM PUMP  4EA 40 160 $10,880 $8,000 $32,000  $42,880 
 NEW REPULP TANK 1m dia x 1.2m 1EA 20 20 $1,360 $2,000 $2,000  $3,360 
 NEW REPULP TANK AGITATOR  1EA 20 20 $1,360 $4,000 $4,000  $5,360 
 NEW REPULP PUMP  2EA 30 60 $4,080 $4,000 $8,000  $12,080 
 NEW AUTOCLAVE HOLDING TANK 2m dia x 2.5m 1EA 40 40 $2,720 $6,500 $6,500  $9,220 
 NEW AUTOCLAVE HOLDING TANK AGITATOR  1EA 40 40 $2,720 $5,000 $5,000  $7,720 
 NEW AUTOCLAVE CHARGE PUMP  2EA 40 80 $5,440 $5,000 $10,000  $15,440 
 NEW BATCH LEACH AUTOCLAVE 1m dia x 1.5m 1EA 80 80 $5,440 $60,000 $60,000  $65,440 
 NEW BATCH LEACH AUTOCLAVE AGITATOR  1EA 40 40 $2,720 $25,000 $25,000  $27,720 
 NEW FILTER FEED TANK 2m dia x 2.5m 1EA 40 40 $2,720 $6,500 $6,500  $9,220 
 NEW FILTER FEED TANK AGITATOR  1EA 40 40 $2,720 $5,000 $5,000  $7,720 
 NEW FILTER FEED PUMP  2EA 40 80 $5,440 $8,000 $16,000  $21,440 
 NEW PGM FILTER  1EA 50 50 $3,400 $50,000 $50,000  $53,400 
 NEW TRAY DRYER  1EA 80 80 $5,440 $50,000 $50,000  $55,440 
 NEW PGM PRODUCT BIN  1EA 10 10 $680 $5,000 $5,000  $5,680 
             
  PGM RECOVERY PIPING  1LS 4756 4,756 $323,409 $475,600.97 $475,601  $799,010 
  PRESSURE LEACHING ELECTRICAL/LIGHTING  1LS 2253 2,253 $153,204 $225,300.36 $225,300  $378,505 
  PRESSURE LEACHING INSTRUMENTATION  1LS 1462 1,462 $99,416 $146,200.24 $146,200  $245,616 
             
420  SUB TOTAL PGM RECOVERY         19,927 $1,356,385  $3,712,286 $13,381 $5,082,053