This feasibility study assesses the proposed development of the Wasamac deposit as an underground gold mine and processing plant in Rouyn-Noranda, Quebec.
Report context
The NI 43-101 Technical Report for the Wasamac Project, a feasibility study prepared for Monarques Gold Corporation, has an effective date of December 1, 2018 and a signature date of December 3, 2018. The project is an advanced stage gold exploration project located 15 km west of Rouyn-Noranda in the Abitibi gold mining camp of Quebec, Canada. The study incorporates advanced mining designs integrating Rail-Veyor technologies and a paste backfill system, and investigates processing options, tailings and water management facilities. All monetary units in the feasibility study are in Canadian dollars based on fourth quarter 2018 dollars.
Processing route
Process plant design
The proposed carbon-in-pulp (CIP) process plant is designed to have a capacity of 6,900 tpd. The process plant is located some 2 km from the mine site, with neutral dry-stacked tailings disposal located some 5 km further to minimize the project footprint locally. The simplified process flow diagram is provided in the original report as Figure 17-1.
Crushing and grinding
Ore is transported from the underground mine to surface via the Rail-Veyor system to a discharge bin and crusher feed conveyor. The crushing building processes ore, which is then conveyed to a crushed ore stockpile and mill feed conveyor. Grinding is performed in the grinding area of the process plant.
Gold recovery
The process flowsheet includes a CIP circuit, an elution circuit, and a carbon regeneration area. The gold room handles final gold recovery. A reagent tank and park supplies process reagents. The proposed gold recovery method involves cyanidation within the CIP circuit. Average gold metallurgical recovery is 88.2% over the life of mine.
Metallurgical testwork
Metallurgical testwork was conducted on samples from the Main Zone and Zones 1, 2, and 3. Testwork sample maps for each zone are provided in the original report as Figures 13-1 through 13-4. The testwork included comminution testing measuring Axb (resistance to impact breakage) for each zone, with frequency curves presented in Figures 13-5 through 13-8 of the original report. Gravity Recoverable Gold (GRG) testing, Bond work index (BWi) testing, and leach variability testing were conducted on samples designated with Z_X_-GRIND-_Y_ and Z_X_-VAR-_Y_ naming conventions.
Tailings management
Tailings are processed through press filters in the tailings filtration area to produce filtered tailings for dry stack deposition. The tailings management facility uses a dry stack deposition plan with progressive reclamation sequencing. Tailings production operates in two modes: paste production mode and tailings production mode, as illustrated in flux diagrams (Figures 18-26 and 18-27 of the original report). The tailings storage facility designed capacity accommodates the years of production and produced tailings volumes as shown in Figure 18-15 of the original report.
Water management
The site water management design includes a concentrator retention basin and a TSF retention basin with specified design volumes. Sub-watersheds of the concentrator area and TSF area in undeveloped conditions were analyzed (Figures 18-24 and 18-25 of the original report). The water treatment plant design includes capital and operating costs.
Backfill system
A paste backfill plant is proposed to supply backfill to the underground mine. The paste backfill and slurry tailings distribution systems were designed with associated capital and operating costs.
Key reported parameters
| Parameter | Value | Basis |
|---|---|---|
| Process plant capacity | 6,900 tpd | Design |
| Mine production rate | 6,000 tpd | Design |
| Life of mine ore processed | 21.5 Mt | Design |
| Average diluted feed grade | 2.56 g/t Au | Design |
| Average gold recovery | 88.2% | Design (supported by testwork) |
| LOM payable gold production | 1,556,800 oz | Design |
| Peak annual gold production | 195,600 oz | Design |
| Average annual payable gold | ~142,000 oz | Design |
| Historical ore treated (1965-1971) | ~1.9 Mt | Historical operating data |
| Historical grade (Main Zone surface pillar, Karpoff 1986) | 740,000 t at 3.39 g/t Au | Historical estimate |
| Historical grade (Main Zone, Karpoff 1986) | 814,000 t at 5.83 g/t Au | Historical estimate |
| Historical grade (Zone 1, Karpoff 1986) | 88,000 t at 5.14 g/t Au | Historical estimate |
| Historical grade (Zone 2, Karpoff 1986) | 25,000 t at 5.79 g/t Au | Historical estimate |
| Historical grade (Zone MacWin, Karpoff 1986) | 92,000 t at 4.94 g/t Au | Historical estimate |
| Comminution test parameters | Axb frequency curves per zone | Testwork |
Project website: https://iaac-aeic.gc.ca/050/evaluations/exploration?projDocs=80879&culture=en-CA
Project website: https://wasamac-eng.agnicoeagle.com/project-description-2
Technical qualifications
The processing sections of this report are based on metallurgical testwork and process plant design completed for the feasibility study. The report notes that the qualified person responsible for chapters 13 (metallurgical testwork) and 17 (process plant) did not personally visit the property. The process plant design is presented at a feasibility study level of accuracy and is supported by laboratory testwork on samples from the Main Zone and Zones 1, 2, and 3. The report specifies that operating costs for the process were developed at a feasibility study level. Capital costs include contingency of $31.2 million and indirect costs of $52.4 million. The report does not provide actual plant operating data as the project is not in production.
Source: NI 43-101 Technical Report, Wasamac Project – Feasibility Study, Monarques Gold Corporation, effective December 1, 2018, signature date December 3, 2018. Relevant sections: 1 (Summary), 13 (Mineral Processing and Metallurgical Testing), 17 (Process Plant), 18 (Infrastructure).
