In May 2024, the Company completed a Feasibility Study that supports a long life, large scale, 50,000 tonnes per day (“tpd”) open-pit mining operation; a project in a tier-one mining jurisdiction that stands out in the Quebec and Canadian mining landscapes. Read the press release HERE.
*Assuming a US$:C$ exchange of $0.74.
The Troilus Project is comprised of four main zones of mineralization, which are located on a NE-SW trend covering approximately seven kilometres. These deposits will be mined using conventional open pit mining methods over a 22-year period. Ore will be processed in a flotation mill to produce gold-rich copper concentrate for sale to a smelter, with provision for gravity gold recovery to produce doré after Year 1.
The projected payable gold production averages 256,200 oz per year over the first 5 years, 241,200 oz per year for the remaining 17 years, for a LOM average of 244,600 oz per year. Copper payable annual production averages 16.1 million pounds per year for the first five years, 17.7 million pounds per year for the remaining 17 years and 17.3 million pounds for the life of mine average. Silver payable annual production is 475,200 oz per year for the first five years, 438,300 oz per year for the remaining 17 years with a life of mine annual average of 446,700 oz per year. The production profile is shown in Figure 1.
Total payable metal over the 22-year mine life is estimated at 5.4 million ounces of gold, 381.8 million pounds of copper, and 9.5 million ounces of silver.
The Troilus Project’s estimated Base Case after-tax NPV (5%) is $884 million and IRR is 14%, assuming metal prices of $1,975 per ounce gold, $4.05 per pound copper, $23 per ounce silver and a USD:CAD foreign exchange rate of $0.74:1. Payback on initial capital is expected to be achieved in 5.7 years under the base case scenario.
Table 1: Troilus Project NPV and IRR Sensitivity to Metal Prices
Under the base case scenario, the Project generates cumulative cash flow of $2.2 billion on a post-tax basis, based on a throughput of 50,000 tpd over 22 years (see Figure 2).
Figure 2: Cumulative After-Tax Free Cash Flow After Repayment of Capital at Base Case
The initial CAPEX for the Troilus Project is $1,075 million, net of existing infrastructure that includes all-weather access roads, power lines and a 50MW substation, a tailings facility, water treatment plants and site roads. Sustaining CAPEX over the life of the mine is an additional $276.6 million. A breakdown of the capital requirements is presented in Table 2.
Table 2: Troilus Project Capital Expenditure Estimates Breakdown (US$)
*Net of existing infrastructure (access road, power line, substation, tailings facility, water treatment plant, site roads)
Total all-in-sustaining costs of $1,109 per ounce. Total operating costs are expected to average $19.06 per tonne of ore processed. A breakdown of the operating costs is presented in Table 3.
Table 3: Troilus Project Operating Cost Estimates (US$)
The Study considers a conventional open pit mining operation using a 100% owner-operated equipment fleet peaking at 41–227 tonne trucks, electric hydraulic shovels, wheel loaders and drills. The mine has been designed to deliver 18.3 million tonnes per year (50,000 tonnes per day) of mill feed. The FS contemplates a mine that delivers 379.5 million tonnes with an average head grade of 0.49 g/t Au, 0.058% Cu, 1.0 g/t Ag.
The process plant is expected to have three months of commissioning in pre-production, followed by nine months of production ramp-up during the first year of production.
The project will mine four areas: Z87, J Zone, Southwest (SW) Zone and X22. Mining commences in the Z87 pit area in the pre-production period and will be mined continuously until Year 8. The final phase of the 87 Zone pit area will be mined from Year 12 until Year 19. The SW Zone pit area starts production in Year 1 and is mined continuously until completion in Year 9 and will then be used for deposition of tailings from year 10 to 16. The J Zone pit area starts production in Year 5 and is mined continuously until early Year 15. The X22 pit will be mined from Year 18 to 21. Waste from the Z87 and X22 open pits will be backfilled over the SW tails from Year 16 onward. When Z87 pit area is completed in Year 19, waste is also backfilled into it from the X22 pit area, reducing the overall size of the waste storage facilities.
The average strip ratio for the open pit life of the mine is estimated at 3.1:1. Material movement averages 86 million tonnes (feed and waste) in the first 5 years with the peak at 86 million tonnes in Year 5. The open pit will provide 379.5 million tonnes of feed to the process plant over the 22-year mine life. Open pit bench heights of 10 metres will be mined and ore hauled with 227-tonne haul trucks and matching loading equipment including electric hydraulic shovels. The open pit mining fleet will be leased. Best practice grade control drilling will be done with reverse circulation drilling and rock sampling on mine benches prior to blasting. This provides the greatest flexibility for grade control during operations while maintaining reasonable mine operating costs and production capability.
During the mining operation a stockpile will be maintained adjacent to the primary crushing plant to be used as supplemental feed as required to meet production targets, weather events, and as mill feed in the later years of the operation. Waste rock will be hauled to dedicated waste management facilities near the open pits, backfilled into the 87 Zone pit, placed in lifts over the tails in SW Zone pit, and also used for lifts of the tailings management facility. Concurrent reclamation of the waste management facilities is planned.
The flowsheet, similar to the original Troilus Mill operated by Inmet, has been developed based on testwork completed at Eriez, FLS/Knelson, Base Met and Kappes Cassidy. The process plant consists of primary and secondary crushing, HPGR and ball milling, copper/gold flotation with a regrind circuit, concentrate filtration and tailings thickening and disposal. Copper concentrate, enriched with gold, will be sent to a smelter for refining. Provision has been made to install gravity gold concentration for the primary and regrind circuit in Year 1 where gold dorés will be produced. Overall recovery is estimated to be 92.7% for gold, 91.8% for silver, and 91.9% for copper based on the LOM average head grades.
Figure 3: Troilus Project Process Flowsheet
The Troilus Gold Project is located in Quebec, Canada, approximately 120 kilometres north of Chibougamau, where Inmet Mining Corporation operated a large mine/concentrator complex from 1996 to 2010. Access to the mine site from Chibougamau is by the Route du Nord.
The Troilus Project benefits greatly from the upgraded, and substantial infrastructure on site, which includes:
As part of the design, it is proposed to develop the tailings dyke as a downstream raise constructed containment from the existing tailings management facility which will limit the overall footprint disturbance. This structure will have the capacity to accommodate the first 10.5-year life of mine production and then from years 11-22, the tailings will be disposed subsequently into the mined-out SW pit, J pit and 87 pit as described in this FS. Waste rock from the mine operation placed along the tailings facility’s containment dyke will enhance the facility’s stability and safety and will also limit the footprint disturbance.
Figure 4: Troilus Project Location
Figure 5: Troilus Project Mine Site Layout (Year 22)
Mineral Reserve Estimate
The FS is based on an inaugural Probable Mineral Reserve estimate totaling 380 million tonnes, grading 0.59g/t AuEq (0.49 g/t Au, 0.058 % Cu and 1.0 g/t Ag) and containing 7.26 million ounces of gold equivalent (6.02 Moz Au, 484 Mlb Cu and 12.15 Moz Ag), reflecting the successful conversion of Indicated and Inferred Mineral Resources (see Table 4).
Table 4: Troilus Project Mineral Reserve Estimate
Note: This mineral reserve estimate has an effective date of January 15, 2024, and is based on the mineral resource estimate dated October 2, 2023, for Troilus Gold by AGP Mining Consultants Inc. The Mineral Reserve estimate was completed under the supervision of Willie Hamilton, P.Eng. of AGP, who is a Qualified Person as defined under NI 43-101. Mineral Reserves are stated within the final pit designs based on a US$1,550/oz gold price, US$20.00/oz silver price and US$3.50/lb copper price. An NSR cut-off of C$9.96/t was used to define reserves. The life-of-mine mining cost averaged C$3.99/t mined, preliminary processing costs were C$8.02/t ore and G&A was C$1.94/t ore placed. The metallurgical recoveries were varied according to gold head grade and concentrate grades. 87 pit recoveries for equivalent grades were 95.5%, 94.7% and 98.2% for gold, copper, and silver respectively. J pit recoveries for equivalent grades were 93.1%, 89.3% and 88.9% for gold, copper, and silver respectively. X22 pit recoveries for equivalent grades were 95.5%, 94.7% and 98.2% for gold, copper, and silver respectively. SW pit recoveries for equivalent grades were 85.7%, 91.5% and 85.6% for gold, copper, and silver respectively. The formulas used to calculate equivalent values are as follows, for 87 Pit AuEq = Au + 1.5361*Cu +0.0133 *Ag, for J Pit AuEq = Au + 1.4849*Cu +0.0123 *Ag, for SW Pit AuEq = Au + 1.6535*Cu +0.0129 *Ag, for X22 Pit AuEq = Au + 1.5361*Cu +0.0133 *Ag. Please refer to the identified risks in the Company’s Annual Information Form available under the Company’s profile at www.sedarplus.ca for known legal, political, environmental, and other risks that could materially affect the potential development of the mineral resources and mineral reserves.
The completed NI 43-101 technical report associated with the Troilus Project FS will be available on SEDAR+ at www.sedarplus.ca under the Company’s issuer profile, as well as the Company’s website at www.troilusgold.com within 45 calendar days.
1 AuEq was calculated using metal prices of $1,550/oz Au; $3.50/lb Cu and $20.00/oz Ag.
2 See Non-IFRS Measures at the end of this news release.