Midas's Golden's pretax NPV at $2,136-million (U.S.)
2012-09-04 16:45 ET - News Release
Mr. Stephen Quin reports
MIDAS GOLD COMPLETES POSITIVE PRELIMINARY ECONOMIC ASSESSMENT FOR GOLDEN MEADOWS PROJECT, IDAHO
Midas Gold Corp. has released the results of an independent, National Instrument 43-101-compliant preliminary economic assessment completed on its Golden Meadows project in Idaho as summarized in the attached table. The purpose of the study was to: (a) provide a preliminary concept for the scale and type of mining project that the Golden Meadows project could support, (b) identify options and alternatives for consideration by Midas Gold in consultation with regulators, governments, communities and other interested parties, (c) identify areas where additional work is required before a prefeasibility study can be completed, and (d) demonstrate potential for positive economic returns that would support continued investment in the Golden Meadows project. With this study in hand, Midas Gold intends to actively engage with interested parties to evaluate potential options and considerations for the possible development of this large-scale, long-life mining operation in order to manage and mitigate impacts, and ensure the sustainability of Midas Gold's activities.
The Golden Meadows property has been the site of extensive open-pit and underground mining for almost 100 years and, as such, has seen considerable disturbance and environmental impact. Midas Gold's approach to the conceptual design of this project has been to select economic approaches and alternatives that mitigate and minimize the results of its proposed activities, to remediate considerable amounts of legacy disturbance and to develop a closure and reclamation concept that leaves the site with enhanced fisheries, wetlands and other productive environmental attributes. Midas Gold plans to engage with regulators, governments, communities, tribes, non-governmental agencies and other interested parties to consider the options identified in the PEA, to evaluate reasonable alternatives, and to develop preferred options that can be incorporated into a future PFS and, if warranted, the permitting process for a full-scale mining operation.
PRELIMINARY ECONOMIC ASSESSMENT HIGHLIGHTS GOLDEN MEADOWS PROJECT, IDAHO (1) (base case at $1,400 (U.S.) per ounce of gold) Life of mine Years one to eight (14.2 years) Annual Annual average Total average TotalPayable gold (Koz) 390 3,121 348 4,922Payable antimony (Mlb) 9.9 79.3 6.4 90.6Cash costs (US$/oz)(Net of byproduct credits) 331 425Initial capital (US$M) 879Pretax NPV 5% (US$M) 2,136After-tax NPV5% (US$M) 1,482IRR (pretax/after-tax) 33.7%/27.2%After-tax payback (production years) 3.0(1) In this release, M refers to million, K refers to thousands; all amounts are in U.S. dollars.
"This preliminary economic assessment demonstrates potential for a robust, long-life, low-cost mining operation at Golden Meadows that could be in the lowest quartile of global gold producers," said Stephen Quin, president and chief executive officer of Midas Gold. "The study provides the basis for us to engage the various interested parties in discussions related to the options and scenarios laid out, and to work with them to determine the optimal and preferred options. The Golden Meadows project represents a tremendous opportunity to create significant long-term, well-paid employment in an economically depressed part of Idaho, generate a substantial stream of revenue to county, state and federal governments, to remediate and improve the environmental sustainability of this heavily disturbed site, and to create attractive returns for our shareholders," he said. "With a positive study in hand, we have the basis from which to enter into meaningful discussions with interested parties to ensure we understand their perspectives, collect their input, and consider options to improve and enhance the conceptual plan laid out in the PEA."
Conference call, webcast and conferences
Midas Gold will be hosting a conference call and webcast to discuss highlights of the PEA at 7 a.m. PDT on Wednesday, Sept. 5, 2012. Details are provided toward the end of this news release.
Midas Gold is also attending and presenting at the Precious Metals Summit in Vail, Colo., on Sept. 6, 2012, and Sept. 7, 2012, and is attending the Gold Forum in Denver, Colo., from Sept. 9, 2012, to Sept. 12, 2012.
Preliminary economic assessment
The PEA was compiled by SRK Consulting (Canada) Inc., which was engaged by Midas Gold's wholly owned subsidiary, Midas Gold Inc. (MGI), to evaluate potential options for the conceptual development of a mine at the Golden Meadows project based on information available up to the date of the study. Ausenco Solutions Canada Inc. (infrastructure and mineral processing), Blue Coast Metallurgy Ltd. (metallurgy), RTR Resource Management Inc. (permitting, and social and environmental considerations), and JDS Energy and Mining Inc. (project management and economic analysis) also contributed to the study. Additional details are provided in a technical report to be filed on SEDAR by mid-September, 2012.
Midas Gold instructed SRK and the other study contributors to conduct the PEA with the sustainable operation and long-term reclamation of the project as a key design consideration, with the intent to build a project that would eventually result in an improvement of the environmental conditions that currently exist at Golden Meadows due to historic mining in the area.
The PEA summarized in this news release is intended to provide only an initial, high-level review of the project potential and design options, which is preliminary in nature. The PEA mine plan and economic model include the use of inferred resources. Inferred resources are considered to be too speculative geologically to be used in an economic analysis except as permitted under NI 43-101 in PEA studies. There is no guarantee that inferred resources can be converted to indicated or measured resources, and as such, there is no certainty the project economics described herein will be realized.
Project concept
The preliminary designs presented in the PEA are based on the recognition that the site has been previously extensively mined, and thus, considerations were made for economic feasibility, mitigation or cleanup of targeted legacy environmental issues, improvement of water quality, minimizing mining-related disturbance and protection of the fishery during operations, and on mine closure. In formulating the mine closure, consideration was given to re-establishment of the upstream fishery, backfilling open pits (when appropriate) as part of waste management and focusing meeting applicable water quality standards during operation with mechanical treatment and on passive water treatment for long-term closure. Additional details of these considerations are provided in the environmental, closure and remediation, and permitting sections in this press release.
The project, as currently envisioned, consists of three gold mineral resources with zones of antimony and silver mineralization located in an area of significant historic mining activity. Conventional open-pit methods are recommended for mining the three deposits (Yellow Pine, Hangar Flats and West End), all of which are located within three kilometres of each other.
The deposits contain oxide and sulphide mineralization that are contemplated to be treated with different extraction processes. The oxide material is amenable to milling and then vat leaching to recover gold and silver only. Sulphide materialization is recommended to be milled and treated with sequential flotation to produce two products: an antimony concentrate for off-site shipment to a third party smelter, and a gold concentrate that would be further processed on site using pressure oxidation (POX) followed by vat leaching and cyanide destruction within the plant building to produce gold-silver dore.
Production is assumed to be nominally 20,000 tonnes a day or 7.3 million tonnes a year of mill feed. With this assumed production rate, the mine life would be approximately 14.2 years, with approximately 101 million tonnes of material processed. The mine would have an overall strip ratio of 3.7 tonnes of waste rock per tonne of economic mineralized rock. Gold accounts for approximately 93 per cent of the value of the payable metals, antimony accounts for about 7 per cent of the payable value and silver has a negligible economic contribution.
Mineral resources
Updated mineral resources were estimated for each of the three deposits that comprise the Golden Meadows project. The mineral resource estimates are summarized in the attached table and were previously reported by deposit in news releases dated May 16, 2012, June 4, 2012, and June 27, 2012. Antimony and silver values were only estimated within certain limited subdomains and are summarized in another attached table. As a result, the grades for these metals in the table are reported averaged over the entire, much-larger gold mineral resource volumes, which may underrepresent the overall grades for these metals.
MINERAL RESOURCE ESTIMATE (1)-- ALL THREE DEPOSITS COMPRISING THE GOLDEN MEADOWS PROJECT IN IDAHO (prepared by SRK Consulting (Canada) Inc., June 25, 2012) Antimony Mineral Gold Contained Silver Contained grade Contained resource Tonnes grade gold grade(5) silver (4)(5) antimonycategory (000s) (g/t) (000s oz) (g/t) (000s oz) (%) (000s lb)Open-pit oxide(2) mineral resources Indicated 10,573 0.90 305 0.00 - 0.00% 122Inferred 2,201 0.97 68 0.00 - 0.00% 178Open-pit sulphide(3) mineral resources Indicated 67,653 1.80 3,925 0.60 1,312 0.07% 108,385Inferred 53,917 1.63 2,822 0.93 1,603 0.08% 92,606Total open-pit oxide plus sulphide(2)(3) mineral resources Indicated 78,226 1.68 4,229 0.52 1,312 0.06% 108,507Inferred 56,117 1.60 2,890 0.89 1,603 0.07% 92,784(1) Mineral resources are reported in relation to a conceptual pit shell. Mineral resources are not mineral reserves and do not have demonstrated economic viability -- see compliance with NI 43-101. All figures are rounded to reflect the relative accuracy of the estimate. All composites have been capped where appropriate. (2) Open-pit oxide mineral resources are reported at a cut-off grade of 0.42 gram per tonne gold. Cut-off grades are based on a price of $1,400 (U.S.) per ounce of gold and a number of operating cost and recovery assumptions, plus a 15-per-cent contingency (as detailed in the June 27, 2012, news release). (3) Open-pit sulphide mineral resources are reported at a cut-off grade of 0.75 gram per tonne gold. Cut-off grades are based on a price of $1,400 (U.S.) per ounce of gold and a number of operating cost and recovery assumptions, plus a 15-per-cent contingency (as detailed in the June 27, 2012, news release). (4) Where antimony grades are shown as 0.00, there is antimony present but it rounds to 0.00. (5) Antimony and silver were not estimated for the entire West End deposit and significant portions of the Hangar Flats and Yellow Pine deposits due to a lack of sufficient assays, and these unestimated volumes are averaged into the totals at an assumed zero grade. ANTIMONY SUBDOMAINS(1) MINERAL RESOURCE, YELLOW PINE AND HANGAR FLATS DEPOSITS (prepared by SRK Consulting (Canada), June 25, 2012, for the Golden Meadows project in Idaho) Mineral Gold Contained Silver Contained Antimony Containedresource Tonnes grade gold grade silver grade antimonycategory (000s) (g/t) (000s oz) (g/t) (000s oz) (%) (000s lb)Open-pit sulphide(2) mineral resources Indicated 9,999 2.31 743 3.15 1,012 0.49% 108,507Inferred 8,639 2.08 576 5.04 1,400 0.49% 92,784(1) Mineral resources are reported in relation to a conceptual pit shell. Mineral resources are not mineral reserves and do not have demonstrated economic viability -- see compliance with NI 43-101. All figures are rounded to reflect the relative accuracy of the estimate. All composites have been capped where appropriate. (2) Open-pit sulphide mineral resources are reported at a cut-off grade of 0.75 gram per tonne gold. Cut-off grades are based on a price of $1,400 (U.S.) per ounce of gold and a number of operating cost and recovery assumptions, plus a 15-per-cent contingency. The antimony subdomain is further limited to discrete zones of mineralization with grades that exceed 0.1 per cent antimony.
Mineral resources that are not mineral reserves do not have demonstrated economic viability. Mineral resource estimates do not account for minability, selectivity, mining loss and dilution. These mineral resource estimates include inferred mineral resources that are normally considered too speculative geologically to have economic considerations applied to them that would enable them to be categorized as mineral reserves. There is also no certainty that these inferred mineral resources will be converted to measured and indicated mineral resource categories through further drilling, or into mineral reserves once economic considerations are applied.
The mineral resource estimates for the Hangar Flats, West End and Yellow Pine deposits were prepared by SRK as summarized herein. The economically driven pit shell that limits the mineral resource was based entirely on gold value, with antimony and silver reporting within the resource-limiting pit but not defining it. Within the resource-limiting pit, antimony and silver grades are reported without any cut-off. Any mineralization lying outside the resource-limiting pit is not reported as mineral resources.
Since the date of this mineral resource estimate, additional drilling has been completed, and is continuing to infill and extend the mineralization reported herein and updated mineral resource estimates are targeted for the end of the first quarter of 2013.
Conceptual life-of-mine open-pit production schedule
Individual conceptual mine plans were developed for each of the Hangar Flats, West End and Yellow Pine deposits. The conceptual life-of-mine plan is summarized in the attached table at the end of this release. The mine plans utilized approximately 80 per cent of the recently reported mineral resource for the Golden Meadows project that is summarized in an attached table.
Processing
The gold in the three deposits comprising the Golden Meadows project is primarily contained in pyrite and arsenopyrite, while the antimony is contained in stibnite, and silver in pyrite, arsenopyrite and stibnite. As a result, the mineralized material contemplated to be processed would be crushed, ground and sulphides recovered by sequential flotation of the stibnite, and then, subsequently, the pyrite and arsenopyrite, yielding two concentrates. The mineralized material is considered to be of medium hardness, with bond ball mill work indexes ranging from 13.0 to 13.7 kilowatt-hours per tonne. The conceptual base-case approach to the sulphide concentrates is for the stibnite (antimony, along with minor gold and silver) concentrate to be sold to third parties for processing, while the pyrite-arsenopyrite concentrate (containing the gold) will be pressure oxidized on site and gold recovered as dore. Based on metallurgical test work completed to date, recoveries utilized in the PEA are as set out in the attached table. The grade of the gold concentrate is designed to manage sulphur grades for on-site pressure oxidation; if the gold concentrates were to be shipped off-site for processing, higher concentrations are achievable.
RECOVERIES UTILIZED IN PEA, GOLDEN MEADOWS PROJECT IN IDAHO Yellow Hangar Process Units Pine Flats West EndSulphides with recoverable antimony grades Antimony flotation Concentrate grade % Sb 50 50 n/aRecovery % 80 80 n/aGold-bearing sulphide flotation Concentrate grade % Sulphur 10+ 10+ n/aGold flotation recovery % 88 89 n/aPOX residue gold extraction % 98 98 n/aOverall gold recovery % 86 87 n/aSulphides without recoverable antimony grades Gold-bearing sulphide flotation Concentrate grade % Sulphur 10+ 10+ 10+Recovery % 93 92 Variable (1)POX residue gold extraction % 98 98 98Overall gold recovery % 91 90 Variable (1)Oxides Gold leach extraction % 80 80 Variable (1)(1) Depending on degree of oxidation.
Indicative economic analysis shows that the slightly lower overall gold recovery in the material with recoverable antimony is more than offset by the recoverable, payable antimony values.
Tailings and waste rock management
A total of 101 million tonnes (68.7 million cubic metres) of tailings are expected to be produced during the 14.2-year mine life of the recommended project. Based on results of current metallurgical test work and the recommended processing options, three separate tailings streams would be produced: oxide, POX and flotation tailings. The geochemistry of the POX and oxide tailings suggests they may require containment within a lined facility, while the flotation tailings are considered to be relatively benign and could be placed in a separate unlined facility. However, the buffering capacity of the flotation tailings may serve to neutralize the POX tailings and create a more benign product over all, which suggests that co-mingled tailings contained within a single, lined facility may be the better option. The recommended tailing storage facility (TSF) would consist of a lined basin and lined rock fill dam constructed in stages throughout the life of the mine. The downstream face of the rock fill dam would be buttressed by the waste rock facility (WRF), substantially reinforcing the dam. Waste rock from the mining operations at West End is recommended to be backfilled into the Yellow Pine pit. Other waste rock is recommended to be deposited in a designed WRF adjacent to the Hangar Flats deposit. In order to schedule waste placement within the waste facilities and isolate potential leachable material, a detailed waste management plan would be developed, including components of geochemical characterization, water management, and capping to limit infiltration.
Capital costs
Capital costs (capex) estimates were done based on the third quarter of 2012 and un-escalated U.S. dollars, and are summarized in the attached table. Vendor quotes were obtained for all major equipment. Some of the costs were developed from first principles, while some were estimated based on factored references and experience with similar projects.
CAPITAL COST ESTIMATE, GOLDEN MEADOWS PROJECT Preproduction Sustaining TotalArea Detail (M$) (M$) (M$)Direct costs Open-pit mine 121.9 107.2 229.1 Processing and utilities 243.0 79.6 322.6 On-site infrastructure 93.1 38.8 131.9 Off-site infrastructure 67.0 0.0 67.0Indirect costs 148.9 19.4 168.3Owner's costs 39.7 0.0 39.7Closure costs 0.0 53.0 53.0Capex without contingency 713.6 298.0 1,011.6Contingency (variable) 165.7 4.7 170.4Total capex estimate with contingency 879.4 302.6 1,182.0
Operating costs
Operating cost estimates (opex) were done based on the third quarter of 2012 and unescalated U.S. dollars, and are summarized in the attached table. Most costs were developed from first principles, although some were estimated based on factored references and experience with similar projects.
OPERATING COST ESTIMATE, GOLDEN MEADOWS PROJECT Unit cost estimate Cash cost ($ per AuItem $/t mined $/t milled ounce payable)Mining 1.67(1) 7.78 160Mineral processing 13.94 287General and administration 4.14 85Total (without byproduct credits) 25.86 532Total (with byproduct credits) 425(1) Excluding prestrip (year negative one) mining which is captured as a capital cost.
In the first eight years of operation, cash costs without byproduct credits average $479 (U.S.) per payable ounce of gold, and just $331 (U.S.) per payable oz of gold after byproduct credits are applied.
Costs were independently estimated for oxides, low-antimony sulphides and high-antimony sulphides, as set out in the attached table.
OPERATING COST ESTIMATE BY TYPE OF MINERALIZATION, GOLDEN MEADOWS PROJECTItem Unit Combined Oxide Sulphide High SbMining ($1.67/tonne $/t milledmined(i)) 7.78 7.78 7.78 7.78Stockpile material $/t milled 0.13 0.13 0.13 0.13handlingCrushing and $/t milled 2.83 2.83 2.83 2.83grindingOxide processing $/t oxide milled 0.82 5.53Sb flotation $/t high Sb milled 0.28 1.66Au flotation $/t sulphide milled 1.77 2.08 2.08POX $/t sulphide milled 7.87 9.23 9.23Water management $/t milled 0.25 0.25 0.25 0.25General and $/t milled 4.14 4.14 4.14 4.14administrativeTotal 25.86 20.66 26.44 28.10(i) Excluding prestrip (year negative one) mining which is captured as a capital cost.
Production schedule
Based on the conceptual mining schedule for the three deposits and recoveries summarized in the tables, another attached table sets out the estimated contained and payable metals over the life of the mine and is attached at the end of this release.
Economic analysis
The economic assessment in the PEA is preliminary in nature and uses inferred mineral resources that are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves, and there is no certainty that this PEA will be realized. The inferred mineral resource used in the mine plan is 37 per cent of the total life-of-mine mineral resource.
Four potential cash flow cases were studied using metal prices summarized in the attached table. All cash flow cases used the same mineral resource estimate, mine plan and production factors, as shown a separate attached table.
METAL PRICE ASSUMPTIONS FOR THE FOUR ECONOMIC CASES, GOLDEN MEADOWS PEA Gold Silver Antimony price price priceCase ($/ounce) ($/ounce) ($/pound) BasisCase A 1,200 20.00 5.50 Gold price used in the mine optimization. The gold price is approximately the five-year trailing average to the end of July, 2012.Case B (base 1,400 23.50 6.00 Approximate three-yearcase) trailing average gold price to the end of July, 2012.Case C 1,600 27.00 6.50 Approximate 18-month trailing average gold price to the end of July, 2012.Case D 1,800 30.00 7.00 An upside case to show project potential at a gold price about 12 per cent higher than prices at the end of July, 2012. SUMMARY OF PRODUCTION -- ALL CASES, GOLDEN MEADOWS PEAItem Unit ValueLife-of-mine productionWaste mined Mt 372Mineralized material mined Mt 101Strip ratio (waste tonnes tomineralized material tonnes) t:t 3.7Daily mill throughput t/d 20,000Annual mill throughput Mt 7.3Mine life production years 14.2Mill head grade -- over allGold g/t Au 1.72Silver g/t Ag 1.60Antimony % Sb 0.08Oxide processTonnes Mt 15.0Gold g/t Au 1.05Silver g/t Ag 0.10Gold flotation process(excluding antimony flotation)Tonnes Mt 69.0Gold g/t Au 1.75Silver g/t Ag 0.42Sb flotation process(greater than 0.1% Sb only)Tonnes Mt 17.4Gold g/t Au 2.18Silver g/t Ag 0.67Antimony % Sb 0.45Concentrate productionAntimony concentrate dry metric tonnes 126,474Life-of-mine payable metalGold Koz 4,922Silver Koz 335Antimony Klb 90,618
The results of the economic analysis are summarized in the attached table.
ECONOMIC RESULTS BY CASE, GOLDEN MEADOWS PEA Pretax After-taxParameter Unit results resultsCase A ($1,200 per ounce Au, $5.50 per pound Sb, $20 per ounce Ag) NPV 0% M$ 2,549 1,874NPV 5% M$ 1,464 1,036IRR % 27 22Payback period production years 2.8 3.7Case B ($1,400 per ounce Au, $6 per pound Sb, $23.50 per ounce Ag) -- base case NPV 0% M$ 3,580 2,557NPV 5% M$ 2,136 1,482IRR % 34 27Payback period production years 2.3 3.0Case C ($1,600 per ounce Au, $6.50 per pound Sb, $27 per ounce Ag) NPV 0% M$ 4,611 3,233NPV 5% M$ 2,808 1,923IRR % 40 32Payback period production years 1.9 2.6Case D ($1,800 perounce Au, $7 per pound Sb, $30 per ounce Ag) NPV 0% M$ 5,642 3,910NPV 5% M$ 3,480 2,364IRR % 46 36Payback period production years 1.7 2.3
The contribution to the project economics, by metal, is about 93 per cent from gold, 7 per cent from antimony and less than 1 per cent from silver.
Using a discount rate of 5 per cent, the after-tax break-even gold price for the project is $880 per ounce gold (63 per cent of the case B gold price) assuming no contribution from antimony or silver.
Sensitivity analysis
Sensitivity analyses were performed using metal prices, mill head grade, capex and opex as variables. The value of each variable was changed plus and minus 20 per cent independently while all other variables were held constant. The results of the sensitivity analyses are shown the attached table.
SENSITIVITY ANALYSIS -- ALL CASES, GOLDEN MEADOWS PEA After-tax NPV 5%(M$) Minus 20% 0% 20%Case Variable variance variance varianceCase A Capex $ 1,176 $ 1,036 $ 889 Opex 1,242 1,036 816 Metal price or grade 436 1,036 1,593Case B Capex 1,619 1,482 1,344(base case) Opex 1,683 1,482 1,277 Metal price or grade 828 1,482 2,122Case C Capex 2,060 1,923 1,786 Opex 2,124 1,923 1,721 Metal price or grade 1,193 1,923 2,652Case D Capex 2,501 2,364 2,227 Opex 2,565 2,364 2,163 Metal price or grade 1,547 2,364 3,181
Economic impacts
The economic analysis set out in the PEA also provides some indications of the potential economic impact of the Golden Meadows project on the local, Idaho and U.S. economies, should the future work and permitting support development of a mining operation. Highlights include:
- Direct employment of more than 400 people during the three-year construction phase and 425 people during the subsequent 14.2-year operating phase at annual salaries estimated to average more than double the average 2010 census reported salaries for Idaho;
- A study by the University of Idaho estimates 2.5 times as many community-based jobs are likely to be dependent on each direct job at such a mine, with such jobs related to contracting, transportation, services and other support activities;
- An average annual payroll of $20-million during the conceptual 14.2-year life of mine;
- Gross investment of approximately over $500-million in capital equipment and equipment manufacturing during the construction phase, with an additional $200-million or more during operations, the substantial majority of which is expected to be sourced from within the United States;
- Approximately $1,023-million in direct taxes to all levels of government, including payments to the local county ($3-million), state ($220-million) and federal ($800-million) governments over the 14.2-year operating life of the project, but excluding payroll taxes, state sales taxes and income taxes paid by employees.
MGI is already having a significant impact on the local economy, with upward of 115 people directly employed or working with contractors on site in 2011 and 146 so far in 2012, making MGI the largest private-sector employer in Valley county, more than 70 per cent of whom reside in the state of Idaho and almost half are from Valley and adjacent Adams counties. MGI has also been able to utilize a significant number of contractors and suppliers from within Valley and Adams counties and the state of Idaho, with an estimated 85 per cent of its project expenditures being spent in Idaho, approximately half of which is being spent with local entities.
Environmental
Midas Gold and MGI recognize the importance of protecting the environment and, to facilitate the development of a sustainable project, Midas Gold established the following environmental objectives for the project:
- Protect surface and groundwater quality;
- Protect and enhance the fishery;
- Maintain or enhance the objectives of CERCLA-ordered (Comprehensive Environmental Response, Compensation, and Liability Act) environmental improvements;
- Minimize potential for sedimentation and spills along transportation corridors;
- Incorporate environmental enhancement opportunities into the conceptual concurrent and final reclamation plans.
In order to achieve Midas Gold's and MGI's objectives, SRK has incorporated the following design considerations, from an environmental perspective, into the recommended project:
- Minimize the project footprint: The concepts of backfilling pits, where practical, and concentrating tailings storage in one location (rather than multiple smaller locations) are high priorities for design. Minimizing the footprint enables better protection of water quality and simpler, more-effective water management.
- Management of water: A comprehensive water management strategy to minimize and reuse water supplies in order to support in-stream flow requirements for important fish species has been developed for additional study as part of this PEA.
- Management of waste: The waste management plan for the project involves the potential for segregation and selective handling and placement of potentially reactive waste rock, and storage of flotation, oxide and POX tailings in a synthetically lined facility. Further, blending of the plus-90-per-cent-by-volume, inert flotation material with the small-volume POX tailings is expected to chemically neutralize any residues in the POX tailings.
- Reduce contact of project infrastructure (including roads in particular) with waterways: The conceptual design presented in this PEA of an alternative road corridor to the project site would move the main transportation route away from much of the environmentally sensitive Johnson Creek and South Fork of the Salmon River (SFSR) waterways.
- Enhance the fishery: The environmental design also involves the creation of three fish spawning reaches in the East Fork of the SFSR (EFSFSR) above the planned Yellow Pine pit, backfilling of the Yellow Pine pit, and construction of a new channel through the backfilled area that would provide fish passage into the upper reaches of the EFSFSR and Meadow Creek drainage areas that are currently inaccessible due to the steep gradient within the abandoned Yellow Pine pit.
- Clean up past environmental degradation: Selective environmental cleanup projects would be considered as part of the overall mine plan, where feasible; additional reclamation treatments at the historic spent ore disposal area (SODA) is an example of this opportunity.
- Management of air quality: The use of the best-practice control technology and practices to control air emissions at the site would be employed.
- Environmental monitoring: Monitoring to ensure compliance with all applicable air, water, waste and reclamation objectives, and to validate the effectiveness of water treatment and best-management-practice (BMP) technologies is a fundamental component of the project.
Closure and remediation
The conceptual closure plan is focused on effective remediation of a considerable area degraded by historic mining practices (including waste dumps, abandoned pits, leach pads, and former mill and smelter location) by remining areas of past disturbance, creating substantially improved containment, and managing waste materials in fully engineered and contained facilities. The conceptual closure plan would create more than 60 hectares of new wetlands, restore local drainages, reopen fish pathways along the EFSFSR south of the current Yellow Pine pit lake to migratory species (including salmon), and create three fisheries enhancement habitats. In addition, all newly generated waste would be covered and planted to create sustainable vegetative cover.
Recognizing that there is already substantial disturbance from extensive past open-pit and underground mining within its Golden Meadows project boundaries, over the past several years, Midas Gold has undertaken a series of voluntary remediation efforts to mitigate the coninuing impact of legacy environmental disturbance, including reclaiming more than five acres of ground disturbed prior to Midas Gold's involvement in the area, planting 5,000 trees in 2011 (with a further 7,800 scheduled for planting in the fall of 2012) to reduce suspended solids run-off, application of dust suppression materials to almost seven miles of public roads, and replaced or repaired numerous culverts and other stream crossings, all of which has helped to reduce the sediment loading of local drainages, enhancing the downstream water quality and fish habitat.
Permitting
Midas Gold has developed an integrated plan to address the potential environmental impact statement (EIS) and the potential regulatory process for any new mining operation, should such be warranted after the additional recommended work and further studies are completed. The plan considers: (a) environmental baseline study needs, (b) MGI's ultimate preferred alternative to be described in the PFS, (c) a concurrent EIS and permitting schedule, (d) environmental risk management strategy, including offsets to potential impacts, and (e) an internal management program driven by scheduling milestones and cost tracking.
Substantial existing environmental baseline information generated by previous operators and governmental agencies is being confirmed and supplemented by MGI. This baseline is a compilation of previous studies and several environmental impact statements conducted for recent mining operations, remedial cleanup investigations and multiple resource agency inventories. The new supplemental studies by MGI are aimed at describing current mining environmental conditions at the site.
Project risks and opportunities
Aside from the risks typical of all large-scale mining projects, such as confidence in mineral resource estimates, metallurgical performance, capital and operating cost increases and commodity price decreases, the principal project risks identified in the PEA include the following:
- Ability to acquire a mining permit while maintaining an reasonable development timeline;
- Success in converting inferred resources to measured or indicated categories;
- The ability to attract and retain experienced professionals given the competitive state of the global mining industry.
Excluding the typical opportunities for such a mining project as that conceptualized in the PEA, such as higher metal prices and lower costs, a number of specific opportunities have been identified at Golden Meadows and include the following:
- Increases in mineral resources: All of the three deposits that contributed mineral resources to the conceptual plan laid out in the PEA are open to expansion, and drilling is continuing. Additional mineral resources could extend the mine life, increasing the project's net present value and internal rate of return.
- Higher-grade mineral resources: If MGI were successful in defining higher-grade mineral resource within or around the existing deposits or in completely new deposits, these mineral resources could displace lower-grade material into the future, increasing the project's net present value and internal rate of return.
- Increased byproducts: As noted in the mineral resource section, antimony and silver grades have only been estimated for a small portion (approximately 17 per cent) of the overall mineral resource. As additional drilling and modelling are completed, were byproduct values extended into the unestimated areas, higher byproduct production could be contemplated and could result in reduced net operating costs, increasing the project's net present value and internal rate of return.
- Conversion of in-pit unclassified material: The currently contemplated pits have significant volumes of material with little to no drilling that are therefore unclassified tonnes treated as waste in the current financial model. Drilling has been continuing in 2012 and is continuing, with the objective of converting some portion of these unclassified tonnes to mineral resources above contemplated cut-off grades, which would result in increased mineral resources and mine life, positively affecting the net present value and internal rate of return of the project.
- Improved geotechnical parameters: The currently contemplated pits have slopes assigned to them based on limited geotechnical information. Geotechnical drilling is currently in process to assist with better defining the appropriate geotechnical parameters which could result in steeper pit walls, reducing strip ratios and therefore lowering operating costs.
- Potential increases in design throughput: Such increases could result in an improved capital return scenario.
- Alternate oxide material processing options: Such options could allow earlier or parallel processing of oxide materials, increasing production and economic returns.
- Generation of quicklime: Generation of quicklime from local limestone sources could reduce costs and the number of vehicles required to bring materials to site.
Moving forward
MGI intends to use the recommendations in the PEA as the basis for informed discussions with tribal and other governments, non-governmental organizations, regulatory agencies, recreational groups, local communities and others in order to co-operatively develop a project that is sustainable both from an economic and environmental perspective.
MGI did not wait for completion of the PEA to initiate activities it knew would be required to advance the project toward completion of a PFS and design of a project that may subsequently warrant the filing of permit applications. MGI has already completed approximately 38,246 metres of infill and step-out drilling in 2012 in and around the mineral resources summarized herein with the objective of: (a) upgrading the confidence in the existing inferred mineral resources and better defining potential byproduct values, (b) testing currently unclassified material within the current pit limits for its potential to host mineralization, (c) testing for possible extensions to the existing mineral deposits, (d) geotechnical drilling, and (e) commencing the testing for other potential deposits such as Scout. In addition, MGI has begun collecting additional metallurgical samples for further testing, is continuing its geotechnical and baseline environmental assessments, is assessing potential local sources of limestone, and is continuing with other project-related activities.
All of the new 2012 drilling is to be incorporated in a new mineral resource estimate scheduled for completion in the first quarter of 2013, while all other information, including possible 2013 drilling, is to be incorporated into future studies (whether an updated PEA or a PFS) and to provide sufficient detail and confidence to contemplate the filing of permit applications, should the project economics warrant once this additional information has been collected and incorporated into such studies.
Full article at Stockwatch.
PS. Interesting gold project.
Cheers,
Dave.
