Faraday Copper Announces PEA for Copper Creek with NPV US$713M and 4.2 Billion Pounds of Measured and Indicated Copper Mineral Resources
NEWS RELEASE May 3, 2023
Faraday Copper Announces PEA for Copper Creek with NPV US$713M and 4.2 Billion Pounds of Measured and Indicated Copper Mineral Resources
May 3, 2023 – Vancouver, British Columbia – Faraday Copper Corp. (“Faraday” or the “Company”) (TSX:FDY) (OTCQX:CPPKF) is pleased to announce the results from a Preliminary Economic Assessment (“PEA”) and an updated Mineral Resource Estimate (“MRE”) for its Copper Creek Project, located in Arizona, U.S. (“Copper Creek”). The PEA provides an economically viable base case for the development of Copper Creek.
All financial results are in U.S. dollars unless otherwise stated. The Company will hold a conference call and webcast on May 4, 2023 at 4:30pm ET to discuss the results of the PEA and MRE. Details are provided below.
Paul Harbidge, President and CEO, commented, “In the twenty months since restarting technical activities at Copper Creek, we have delivered an MRE with 4.2 billion pounds of copper in the Measured and Indicated category, an economically robust PEA and a pipeline of exploration targets. The PEA provides an excellent basis for the future development of Copper Creek and is the beginning of the Faraday story. The projected low initial capital and upfront open pit mine unlocks a large underground operation, for a combined mine life of more than 30 years. The project is expected to grow over time as the property is endowed with numerous untested exploration targets. Importantly, the results from our ongoing 10,000metre drill program, which are not incorporated in the current studies, are anticipated to contribute to this growth in the future. We are planning a further 20,000-metre drill program to commence in the fourth quarter of this year as we continue to advance the project and unlock value for our stakeholders.”
Highlights of the Copper Creek PEA*
- Attractive economics: Post-tax Net Present Value (“NPV”) (7%) of $713 million and Internal Rate of Return (“IRR”) of 16% (Table 1) and significant upside to higher metal prices (Table 4).
- Strong standalone open pit economics: Standalone open pit operation supports a pre-tax NPV (7%) of $337 million (Table 2).
- Robust project: Open pit mining provides a rapid payback on initial capital of four years and fully funds development of a bulk underground mine for a combined total mine life of 32 years (Table 1).
- Long life production profile: Average anticipated payable production during active miningi of 51,100 copper equivalent (“CuEq”)ii tonnes per year (“tpa”), with peak production of 82,100 tonnes CuEqii in Year 2. Generating 3.4 billion pounds (“lbs”) payable CuEqii metal over the anticipated life of mine (3.2 billion lbs copper, 45.1 million lbs molybdenum, and 9.7 million troy ounces (“oz”) silver) (Table 3, Figure 2).
- Low initial capital investment: $798 million, with a construction period of two years (Table 1).
- The metrics presented in this news release are based on a PEA that includes an economic analysis of the potential viability of
be realized. See “Qualified Person and NI 43-101” below. For reference i, ii, and iii, please refer to endnotes at the end of the document. Mineral Resources. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability. This PEA is preliminary in nature, includes 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 the PEA will
- Competitive operating cost profile: Average life-of-mine (“LOM”) production cash costs iii of $1.67/lb copper and all-in sustaining costsiii (“AISC”) of $1.85/lb copper (Table 3).
- Favourable strip ratio: Average open pit strip ratio of 1:1.2 due to the nature of the near-surface breccia mineralization that allows sequencing of high-grade production.
- High metallurgical recoveries: Over 94% average copper recovery from sulphide material, producing high-quality clean concentrates.
- Enhanced environmental, social, and governance (“ESG”) practices: Dry stack tailings to reduce water requirements and environmental footprint as well as utilization of renewable solar power to reduce emissions.
- Updated Mineral Resource Estimate: An updated MRE is the basis for the PEA. Measured and Indicated resources are 421.9 million tonnes (“Mt”) at an average grade of 0.45% copper for a contained 4.2 billion pounds of copper.
- Exploration upside: The mineral resource remains open at depth and laterally, as highlighted by the intersection of massive sulphides beneath the Copper Prince breccia (see news release dated January 17, 2023). In addition, there are over 400 breccia occurrences mapped at surface, 35 drilltested and 17 included in this MRE, as well as additional porphyry potential.
Zach Allwright, VP Projects and Evaluations, stated, “The outcome of the PEA demonstrates the potential for Copper Creek to become a significant source of U.S. domestic copper production. The study is underpinned by empirical data, acquired through extensive geological and geotechnical assessments, comprehensive metallurgical test work, first principles costing and diligent schedule optimization. This base case forms a foundation on which the Company can continue to add value through resource expansion, new discoveries on the property, the potential to add a gold by-product and various opportunities to increase the production capacity.”
Conference Call and Webcast
Investors, media and the public are invited to join the conference call and webcast, during which management will discuss the result of the Copper Creek PEA.
- Thursday, May 4, 2023, at 1:30pm PT (4:30pm ET)
- Toll-free in U.S. and Canada: +1 (800) 319-4610
- All other callers: +1 (604) 638-5340
- Webcast: https://services.choruscall.ca/links/faradaycopper202305.html
- Webcast replay: Available on the Company’s website for one year and by phone at +1 (855) 669- 9658 or (604) 674-8052 for three months. Please enter passcode 3013#
PEA Overview
The 2023 PEA outlines a low initial capital project that processes approximately 345 Mt of mill feed material from a combined open pit and underground operation. The PEA contemplates a 30,000 tonnes per day (“tpd”) conventional flotation process plant producing high-quality copper and molybdenum concentrates, with silver by-product credits. The PEA also captures value from an additional 20 Mt of oxide material sourced from pre-strip mining and processed via a heap leach facility (“HLF”) utilizing solvent extraction and electrowinning (“SXEW”), further supporting a rapid payback on initial capital. The PEA does not incorporate any results from the Phase II drill program, which is currently ongoing and expected to conclude near the end of the second quarter of 2023.
Payback of initial capital is expected to occur in Year 4, with the post-tax cash flows funding the expansionary capital, which includes the addition of a molybdenum circuit and development of the underground footprint, both of which commence in Year 3 (Figure 1, Table 1 & Table 13).
Table 1: PEA Economic Highlights
| Base Case Economics | Unit | LOM |
|---|---|---|
| Post-tax NPV (7%) | $ millions | $713 |
| Post-tax IRR | % | 15.6% |
| Post-tax Payback Period | Years | 4.1 |
| NPV / Initial Capital | Ratio | 0.9 |
| Initial Capital | $ millions | $798 |
| Sustaining and Expansion Capital | $ millions | $1,689 |
| Closure and Reclamation | $ millions | $170 |
| Economic Assumptions | ||
| Copper | $/lb | $3.80 |
| Molybdenum | $lb | $13.00 |
| Silver | $/oz | $20.00 |
| Financial Metrics a | ||
| Annual Revenue | $ millions | $428 |
| Annual Operating Costs | $ millions | $210 |
| Annual EBITDA b | $ millions | $218 |
| Annual Cash Flow (post-tax) | $ millions | $141 |
Notes to Table 1:
a Averages based on active mining during Years 1 – 29.
b EBITDA is a financial performance measure with no standardized definition under IFRS, defined as “earnings before interest, taxes, depreciation and amortization”.
Table 2: Pre-Tax NPV Contributions
| Pre-Tax NPV Contributions | $ million |
|---|---|
| Mill Initial Capital | ($640) |
| Open Pit | $977 |
| Underground | $509 |
| Total | $846 |
| Standalone Open Pit a | $337 |
Notes to Table 2:
a Standalone open pit includes mill initial capital.
Table 3: PEA Operating Highlights
| Operating Statistics | Unit | Average LOM |
|---|---|---|
| Mine Life a | Years | 32 |
| Tonnes Milled b | ktpa | 10.8 |
| Open Pit Strip Ratio | Ratio | 1.2 |
| Payable Production (per year) c, d | ||
| Copper | Million lbs | 106 |
| Molybdenum | Million lbs | 1.4 |
| Silver | Thousand oz | 324.6 |
| CuEq ii | Kt | 51.1 |
| Costs (by-product) iii | ||
| LOM Production Cash Costs | $/Cu lb | $1.67 |
| LOM All-in Sustaining Costs | $/Cu lb | $1.85 |
Notes to Table 3:
a Mine life includes active mining (Year 1 – 29) and final processing of stockpiles (Year 30 – 32)
b Tonnes milled are exclusive of oxide and represent the average over the 32-year life of mine.
c Average annual production considers the period of active mining during Years 1 - 29, Year 30 – 32 includes processing of stockpiles only.
d Based on payability in concentrate of 96.5%, 95% and 98.5% for copper, silver, and molybdenum, respectively. Copper cathode payability of 98% is applied.
Table 4: Economic Sensitivity
| Parameter | Unit | PEA | Alternative Copper Prices a | |
|---|---|---|---|---|
| Copper Price | $/lb | $3.80 | $4.25 | $5.00 |
| Molybdenum Price | $/lb | $13.00 | $13.00 | $13.00 |
| Silver Price | $/oz | $20.00 | $20.00 | $20.00 |
| Post-Tax NPV (7%) | $ millions | $713 | $1,144 | $1,843 |
| Post-Tax NPV (8%) | $ millions | $566 | $951 | $1,576 |
| Post-Tax IRR | % | 15.6% | 21.0% | 29.6% |
| Post-Tax Payback Period | Years | 4.1 | 2.9 | 2.1 |
Notes to Table 4:
a An increase of $10/lb or $5/oz in molybdenum or silver price assumptions increases the post-tax NPV(7%) by approximately $129 million or $15 million, respectively.
Figure 1: Annual Cash Flows
Note to Figure 1: Table 13 provides the amounts used to generate Figure 1. Total operating costs above are inclusive of royalties and offsite charges.
Figure 2: Copper Equivalent Payable Metal Production
Design and Production Profile Overview
The open pit and underground mine plans were developed by SRK Consulting Inc. (“SRK”). Future mining is expected to be by contractor-operated conventional truck and shovel method at surface and during underground development (pre-production), transitioning to owner-operated block caving underground method to achieve a base annual mill feed rate of 11.0 Mt (30,000 tpd). Surface mining provides mill feed until Year 11. A four-year open pit ramp down coincides with the underground production ramp-up, achieving steady state production by Year 12 and continuing until Year 29. Current mine plan optimization has applied an open pit stockpiling strategy whereby low-grade material mined from the pits would be stockpiled and processed as supplementary mill feed or fed to the mill at the end of the mine life. The lowgrade stockpile peaks at 56.5 Mt, 20.0 Mt of which would be processed as supplementary feed between Years 7 and 11, and the remaining 36.5 Mt would be processed between Years 28 and 32.
The base annual throughput would be primarily of sulphide material, with some transitional material mined from the open pits. Oxide material recovered near surface in the early years of the anticipated mine life would be segregated and processed separately in a heap leach facility, in addition to the 11.0 Mt base annual throughput (Figure 3).
Figure 3: Total Processed Material by Material Type
Figure 4: Mine Design Overview (isometric view looking northeast)
Note to Figure 4: Mammoth pit includes the Mammoth and Childs-Aldwinkle breccias, and the Copper Prince pit includes numerous breccias such as the Copper Prince, Copper Giant, Copper Duchess, and Copper Knight.
Figure 5: Mined Material by Period
Note to Figure 5: All material reflected in this chart is mineralized mill feed unless denoted as 'Waste'.
Open Pit Mine Design and Schedule
Open pit mine designs utilized the updated MRE. The resource model was imported into Minesight mine planning software where a Lerch Grossman algorithm was applied to the model to determine possible open pit limits. Each open pit area was assessed across a series of revenue factors to target the optimal balance of NPV contribution, footprint requirements and strip ratio. The results of the assessment culminated in pit shell selections that are reflective of an average revenue factor of 0.81 ($3.06/lb copper). Upon selection of discrete pit shells for each pit area, a full pit design was completed in alignment with geotechnical parameters developed as part of the PEA. All pit designs incorporated ramp placement, haulage networks, pit phasing and backfill opportunities.
Open pits include Mammoth, the largest open pit, and several smaller satellite pits. Mammoth would be mined in three phases, generally from the northwest to the southeast, while each of the satellite pits would be a single phase. Table 5 summarizes the pit inventories.
Table 5: Inventory by Pit
| Processed Tonnage (Mt) | Processed Grade (% Copper) | Waste Tonnage (Mt) | Strip Ratio | |||
|---|---|---|---|---|---|---|
| Open Pit | Sulphide/Transitional | Oxides | Sulphide/Transitional | Oxides | ||
| Copper Prince | 20.7 | 5.9 | 0.45 | 0.36 | 11.5 | 0.43 |
| Globe | 9.9 | 2.7 | 0.40 | 0.37 | 5.0 | 0.40 |
| Old Reliable | 12.9 | 4.0 | 0.36 | 0.20 | 10.9 | 0.65 |
| Mammoth | 59.9 | 2.9 | 0.37 | 0.25 | 109.6 | 1.75 |
| Marsha | 21.1 | 4.3 | 0.24 | 0.25 | 3.2 | 0.12 |
| Bald/Jailhouse | 8.5 | 0.0 | 0.48 | 0.16 | 41.7 | 4.92 |
| Rum | 1.0 | 0.0 | 0.73 | 0.44 | 1.0 | 1.04 |
| Total a | 133.9 | 19.8 | 0.37 | 0.29 | 182.9 | 1.19 |
Notes to Table 5:
a Numbers may not sum due to rounding.
Mineralization is hosted in three material types: sulphide, transitional and oxide. Sulphide and transitional material would be processed at the flotation plant, while oxide material would be heap leached.
Table 6: Open Pit Summary – Material Processed by Year
| Units | Total | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 28-32 | |
| Total Processed Pit Material | Mt | 153.7 | 10.3 | 14.3 | 16.3 | 14.6 | 12.6 | 14.7 | 10.8 | 9.3 | 7.4 | 5.2 | 1.7 | 36.5 |
| Sulphides and Transitional | Mt | 133.9 | 8.3 | 11.0 | 11.0 | 11.0 | 11.0 | 10.9 | 10.8 | 9.3 | 7.4 | 5.2 | 1.7 | 36.5 |
| %Cu | 0.37 | 0.50 | 0.78 | 0.38 | 0.44 | 0.39 | 0.42 | 0.48 | 0.49 | 0.29 | 0.17 | 0.17 | 0.17 | |
| Oxides | Mt | 19.8 | 2.1 | 3.3 | 5.3 | 3.6 | 1.6 | 3.8 | 0.0 | 0.0 | - | - | - | - |
| %Cu | 0.29 | 0.29 | 0.27 | 0.41 | 0.20 | 0.21 | 0.25 | - | - | - | - | - |
Cut-off grades (“COG”) are dictated by metal price, and consider material type, processing costs, recovery, and selling costs. The direct feed CuEqii COG for sulphide and oxide material is 0.13% CuEqii, while for transitional material it is 0.14% CuEqii. Material reporting to a stockpile has a slightly higher COG than direct mill feed material to account for rehandling costs.
Grade bins were established to aid in mine planning, including low-grade, medium-grade and high-grade bins. Low-grade material reports to stockpiles unless available throughput allows direct feed to the mill in that period. The grade bins are defined by percent copper for sulphide and transitional material (Table 7).
Table 7: Open Pit Grade Bin Application for Mine Schedule Optimization
| Grade Bin | Sulphide (% Copper) | Transitional (% Copper) |
| Low-grade | 0.13% – 0.25% | 0.14% – 0.27% |
| Medium-grade | 0.25% – 0.45% | 0.27% – 0.48% |
| High-grade | >=0.45% | >=0.48% |
Where possible, waste is proposed to be backfilled into depleted pits which allows for shorter haulage and reduced surface disturbance. Otherwise, waste would be sent to the external waste facility. The waste facilities would be designed to simplify closure and allow for progressive reclamation.
It is expected that mining at the Mammoth pit would commence during the pre-production period and continue through the entirety of surface mining, while satellite pits would be mined in a sequence driven by value and haulage efficiencies. Mineralized material above COG would be sent to either the run-of-mine pad directly south of the Old Reliable pit or to one of two low-grade stockpiles further to the west. Oxide material would be crushed immediately and conveyed to the heap leach facility adjacent to the processing plant.
Copper Prince would be the first satellite pit to be mined. Waste in the early periods would be sent east to the external storage facility. Once the Copper Prince and Globe pits are mined out in Year 3, the pits would be expected to serve as a backfill facility for waste rock from the Mammoth, Globe, and Rum pits. After Old Reliable is depleted in Year 4, it would serve as a backfill facility for Mammoth waste. By Year 5 and 6, Phases 2 and 3 of the Mammoth pit would be advancing along with the eastern satellite pits Marsha, Bald and Jailhouse (the latter two would be mined together). Waste from these phases would be sent to the adjacent external waste facility due to haulage efficiencies. Mineralized material from Marsha and Bald/Jailhouse would be hauled along in-pit haul roads in the Mammoth pit. The Rum pit (not shown in Figure 4) is a small pit located in the northwest of the project area and would be mined in Year 7. Open pit mining is expected to conclude in Year 8 when Bald is exhausted.
Underground Mine Design and Schedule
The Keel and American Eagle block cave footprints and production schedule were generated using Geovia's Footprint Finder software, an industry standard for cave optimization and scheduling, using the resource model. The economic parameters applied in the footprint finder optimization were maintained as per the resource constraints as part of the Reasonable Prospects for Eventual Economic Extraction (“RPEEE”) process, except for the maximum height of cave draw being set to 500 metres (“m”). The footprint finder outcome was then manually optimized to prioritize the higher-grade cave blocks whilst targeting the most practical footprint geometry for sequencing and productive capacity. This exercise culminated in a PEA underground mill feed inventory of 211 Mt.
Preliminary mine development design and scheduling were completed in Deswik Suite, encompassing detailed lateral and vertical development designs for all primary and secondary infrastructure. Excavation profiles were applied to each development type enabling discrete advance rates and costs to be applied, culminating in a practical integrated mine schedule.
The cave footprint(s) would be accessed via a twin decline system providing access and material conveying to surface. The mine plan for the underground block cave contemplates development of the twin declines commencing in Year 3 with initial cave production beginning six years after. Underground cave production would ramp up over approximately a 3-year period and would achieve a steady-state production rate of 30,000 tpd in Year 12. The Keel and American Eagle extraction horizons are located at approximately 900 m and 760 m below the portal elevation, respectively. The cave footprints are 300 m laterally offset. The average height of draw of the Keel and American Eagle domains is 375 m and 337 m, respectively. The maximum vertical height of draw was constrained to 500 m for the purpose of the PEA design.
Table 8: Underground Footprint Metrics (exclusive of development)
| Unit | Keel | American Eagle | Total | |
|---|---|---|---|---|
| Mineralized Material | Mt | 47.0 | 154.6 | 201.6 |
| Copper Grade | % | 0.55% | 0.49% | 0.51% |
| Molybdenum Grade | % | 0.014% | 0.007% | 0.008% |
| Silver Grade | g/t | 3.28 | 0.86 | 1.42 |
| CuEqii Grade | % | 0.60% | 0.52% | 0.54% |
| Footprint Area | m2 | 51,900 | 194,600 | 246,600 |
| Hydraulic Radius | m | 56 | 95 | N/A |
| Drawbells | # | 88 | 321 | 409 |
| Height of Draw (Average) | m | 375 | 337 | 346 |
Electric-drive loaders would deliver mill feed material to passes at the mid-point of each extraction level drive which connects to truck loading stations on the underlying haulage level. Trucks would haul mill feed material to one of three primary crushers, one servicing Keel and two servicing American Eagle. Following crushing, mill feed material would be conveyed 4.8 kilometres (“km”) to surface via the dedicated conveyor decline. At surface, the mill feed material would be transferred to the surface overland conveyor and transported directly to the process plant.
Table 9: Underground Production Schedule by source
| Source | Unit | Total | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16-20 | 21-25 | 26-29 |
| Keel | Mt | 47.0 | - | - | 0.85 | 2.94 | 5.17 | 6.80 | 7.39 | 6.90 | 5.60 | 3.84 | 7.48 | - | - |
| Cu % | 0.55 | - | - | 0.48 | 0.59 | 0.62 | 0.60 | 0.56 | 0.54 | 0.51 | 0.50 | 0.50 | - | - | |
| CuEq ii % | 0.60 | - | - | 0.54 | 0.65 | 0.68 | 0.65 | 0.62 | 0.60 | 0.57 | 0.55 | 0.53 | - | - | |
| American Eagle | Mt | 154.6 | - | - | - | - | - | 1.61 | 2.78 | 3.27 | 4.55 | 6.30 | 44.11 | 54.95 | 37.08 |
| Cu % | 0.49 | - | - | - | - | - | 0.39 | 0.40 | 0.45 | 0.49 | 0.49 | 0.53 | 0.53 | 0.40 | |
| CuEq ii % | 0.51 | - | - | - | - | - | 0.45 | 0.45 | 0.48 | 0.52 | 0.51 | 0.56 | 0.56 | 0.42 | |
| Development | Mt | 9.7 | 0.11 | 0.25 | 0.88 | 0.65 | 0.61 | 0.92 | 0.78 | 0.77 | 0.79 | 0.81 | 3.16 | - | - |
| Cu % | 0.39 | 0.30 | 0.37 | 0.39 | 0.56 | 0.36 | 0.35 | 0.34 | 0.31 | 0.32 | 0.35 | 0.43 | - | - | |
| CuEq ii % | 0.42 | 0.31 | 0.42 | 0.45 | 0.61 | 0.40 | 0.40 | 0.38 | 0.35 | 0.34 | 0.38 | 0.46 | - | - | |
| Total | Mt | 211.4 | 0.11 | 0.25 | 1.73 | 3.60 | 5.77 | 9.33 | 10.95 | 10.95 | 10.95 | 10.95 | 54.75 | 54.95 | 37.08 |
| Cu % | 0.50 | 0.30 | 0.37 | 0.44 | 0.59 | 0.59 | 0.54 | 0.50 | 0.49 | 0.49 | 0.48 | 0.52 | 0.53 | 0.40 | |
| CuEq ii % | 0.53 | 0.31 | 0.42 | 0.49 | 0.64 | 0.65 | 0.59 | 0.56 | 0.55 | 0.53 | 0.52 | 0.55 | 0.56 | 0.42 |
Figure 6 shows the underground footprint extraction sequence by period and the average recovered drawpoint grades.
Figure 6: Plan Views of Underground Footprint: Extraction Sequence by Period (left) and Mined and Recovered Grades (right).
Mine levels within and directly adjacent to the cave footprints comprise undercut, extraction, haulage and crushing and ventilation levels. Total pre-production lateral development requirements are estimated to be 24,900 m, plus associated drawbell establishment. Underground development activity generates 9.7 Mt of material above COG and contributes to economic mill feed. Total lateral development requirements have been generated based on the mine design and are estimated to be approximately 32,200 m and 31,850 m of capital and operating development, respectively. A raise system from surface supplies fresh air to the mine levels and is exhausted via the twin declines to the exhaust ventilation system. Total vertical development is estimated to be 6,400 m, comprised predominantly of fresh air raises, return air raises and material passes.
Figure 7: Underground Development Metres and Mill Feed by Period
Geotechnical
Geotechnical assessments of pit slope stability and underground caveability, including fragmentation analysis, subsidence and ground support requirements, were carried out by Call & Nicholas, Tucson (“CNI”). These assessments were based on geotechnical characterizations developed from geological assessments, core logging, downhole televiewing data and laboratory rock strength analysis from the Phase I exploration drilling program (holes drilled between February and June 2022). The geotechnical program was further supported by historical core logging data and prior geomechanical studies of the pit and underground deposits.
A geotechnical assessment of multiple methods was appraised for geotechnical parameters and suitability, shortlisted to open pit mining, block caving, sub-level caving and longhole open stoping. The outcomes of the geotechnical assessment supported the selection of open pit extraction for near surface deposits (predominantly breccia) and extraction of the underground resource (predominantly porphyry) via block caving methods. Underground mining interaction with the open pits was also assessed to ensure mine sequencing accounts for adequate phasing and realistic operability. Upon method selection for the PEA, a comprehensive geotechnical design parameter report was developed to guide an optimal and practical mine plan.
Key geotechnical assessment highlights from the PEA include:
Open Pit
- Rock strength and joint orientations allows for favourable interramp slope angle between 50-53 degrees and overall slope angle of 50 degrees supporting low strip ratios
- Assessment supports 24 m double bench height (12 m single bench height)
- Geotechnical domains defined by wall dip direction informed optimal ramp placement and haulage networks between pits and material destinations
Underground Block Caving
- Confirmed caveability of the rock mass with caving rate of 55 m/year (15 cm/day) with no requirement for preconditioning currently deemed necessary
- Productive capacity of the current underground resource footprint suggests 30 to 45 kilotonnes per day (11 to 16 Mtpa)
- Rock mass quality within the footprint domain offers favourable conditions for drawpoint spacing that optimizes capital development requirements. The extraction level layout is to employ a herringbone configuration with extraction drive spacing of 32 m by 20 m
- Thermistors located in vibrating-wire piezometers indicate in-situ rock temperatures between 25 – 44 degrees Celsius, confirming the underground operation will benefit from favourable ventilation requirements
Mineral Processing
The Company recently completed a metallurgical test work program utilizing samples from the Phase I drilling to complement the historical test work conducted by Mountain States R&D International (“MSRDI”) and METCON Research (“METCON”). Metallurgical testing was conducted by ALS Metallurgy, Kamloops, and tailings filtration testing completed by BaseMet, Kamloops, with oversight by Ausenco Engineering USA South Inc. (“Ausenco”), based in Tucson. This test work program was designed to accomplish the following key objectives on samples taken throughout the open pit:
- Develop process design criteria with test work results from spatially representative samples of the current mineral resource and grades
- Comminution test work to optimize grind size
- Confirm flotation recoveries for both open pit sulphide and transitional materials
- Mineralogical analyses to inform future performance by domain
- Solid–liquid separation test work to confirm dry stack tailings performance