The Beaufor Mine is located within the Bourlamaque Pluton at the eastern contact with the Dubuisson Formation. The Bourlamaque Batholith is a major geological feature of the Val-d’Or mining camp. It is described as a quartziferous granodiorite cut by fine-grained dioritic dykes. The Bourlamaque Batholith is a massive, round syn-volcanic intrusion, 12 km across. The pluton cuts the mafic and ultramafic rocks of the Dubuisson and Jacola formations (Malartic Group), as well as the intermediate rocks of the Val-d’Or Formation (Louvicourt Group). The pluton hosts several past-producing mines, among them Belmoral, Wrightbar, Bussières (a.k.a. Old Cournor), Bras d’Or and Lac Herbin.

Gold mineralization occurs in veins associated with shear zones dipping moderately south. Mineralization is associated with quartz tourmaline veins resulting from the filling of shear and extension fractures. Gold-bearing veins show a close association with mafic dykes intruding the granodiorite. The dykes seem to have influenced the structural control of the gold-bearing veins. Sulphide content within the veins is generally less than 10%, and the principal mineral is pyrite with some minor chalcopyrite and pyrrhotite. Gold is associated with pyrite in native form, filling the void inside the pyrite crystals.

Veins strike at 115° azimuth and dips moderately to the south from 30° to 65°. The thickness of the veins varies from 5 cm to 5 m, but generally, the thickness of the quartz veining system is 30 cm to 120 cm. All the gold-bearing veins are contained in a strongly altered granodiorite in the form of chlorite silica forming anastomosing corridors of 5 m to 30 m in thickness. The veins at the Beaufor Mine sometimes form panels of more than 300 m long by 350 m high. The major zones like the C and Q zones could be traced along strike over 700 m and along dip over 400 m.

The multiple vein systems of the Beaufor deposit are cut and split apart by numerous steeply dipping discreet shear zones, striking 70° azimuth. The Beaufor Fault marks the limits of several major mineralized zones. The Beaufor Fault strikes roughly at 295° azimuth, with a steep dip of 60° to the north. The Beaufor Fault may have been one of the main conduits for mineralizing hydrothermal fluids at the Beaufor Mine. Several post-mineralization faults intersect and displace the quartz veins. Mafic dykes that predate mineralization are associated with shearhosted gold-bearing veins. Shallowly dipping extensional gold-bearing veins are commonly observed at the Beaufor Mine. The main gold-bearing quartz veins are intimately associated with dioritic dykes.

The long-hole method consists of drilling a series of holes in a stope from one level to another. Most of the long-hole drilling at Beaufor is performed upward. The maximum length for production drilling is approximately 18 m along the vein dip. Spacing between sublevels is planned accordingly. Conventional raises are excavated to initiate the stope opening. Long hole stopes are approximately 20 m wide and separated by 5-m-wide vertical pillars.

There are three types of stopes in Zone Q. The type of stope refers to the position of the vein regarding the dyke that crosses the zone and they are: upper, lower or hybrid. The type of stope must be identified before mining the stope because dilution and ground control differ from one type to another. The lower type will expose the dyke on the hanging wall and that dyke will fall and generate more dilution. For the other two types, the dyke is on the footwall or included and will generate less dilution.

Ore is blasted in vertical slices and the broken ore falls to the bottom of the hauling sublevel. Blasting is sequenced in a longitudinal retreating manner. Broken ore is mucked out by scoops that then fill the trucks.

The room-and-pillar mining method is adapted for shallow dipping structures. Prior to stoping, lateral development is carried out at the bottom of the orebody. Ore is then excavated using jack-legs and slusher-scrapers by mining upwards along dip. A certain amount of broken ore, ~15%, is kept in the stopes to provide a working surface for the miners. Rock pillars are left for ground stability in a general pattern of 6 m along strike by 5 m along dip. Pillars are generally square-shaped with an area of 6.25 m2.

The Beaufor ore has been processed at the Camflo Mill. The Camflo Mill has crushing and grinding circuits as well as a Merrill-Crow concentrating circuit that uses cyanidation and zinc powder precipitation for gold recovery. The mill capacity is 1,600 tpd. Gold recovery of the Beaufor ore is approximately 98%.

Ore is delivered by trucks and dumped on an assigned stock pile or directly fed to the crushing circuit if the mill is operating.

Ore from the stockpile and/or from trucking is fed to a jaw crusher operated by a contractor. The crushed material is conveyed to the coarse grained ore bin. A vibrating screen feeder separates the material; the fine-grained material (<1") is sent to the grinding circuit in the fine-grained ore bin while the coarse grained material passes through two cone crushers for size reduction to less than ¾", and that material finally goes to the fine grained ore bin.

Material from the fine-grained ore bin is sampled on Conveyor No. 8 before entering the rod mill. One sample of 2.0 to 2.5 kg is collected every half-hour at the discharge point. A total of six samples, representing three hours of operation, are mixed together to produce a composite sample of 12 to 15 kg. A total of eight (8) composites are collected each day.

Composites are sent to Actlabs in Val-d’Or for assaying. Composites are crushed in their entirety and split to obtain a subsample of 250 g to 300 g. The subsample is then pulverized in its entirety, and a 50 g pulp is assayed by fire assay method. The daily feed grade is obtained from the mean grade of the eight composites. When pulp duplicates are assayed, the composite grade is the mean grade of the original and duplicate assays. Assays with grades higher than 16.5 g/t are capped to 16.5 g/t. High-grade assays are rare.

The fine-grained material passes through the rod mill. Cyanide is added while the pulp leaves the rod mill. The pulp then passes through one hydro-cyclone. Material finer than 75 microns goes directly to the thickening circuit while the coarser pulp is sent to two parallel ball mills for further grinding, and then to hydro-cyclones.

The slurry that comes out of the grinding circuit is thickened to 55% solids in three parallel thickeners. The overflow, which is an enriched gold solution, is directly pumped to the rich-solution tank while the underflow slurry is pumped into the leaching circuit. The slurry is oxygenated and goes through three agitator tanks before passing into two parallel drum filters. The liquid solution is pumped back into the thickener tanks while the solid slurry is pumped into two agitator tanks and goes through two other parallel drum filters. Again, the liquid solution is pumped back into the thickener tanks, and the solid slurry is pumped into the final agitator tank. The slurry is filtered one last time in the two last drum filters. The liquid solution is pumped back into the thickener tanks and the solid slurry is rejected to the tailings dam.

The rich-solution is pumped into the clarifier and is then deoxygenated through a deaeration column. Zinc powder is then added to the de aerated solution which causes gold to precipitate. The precipitate is recovered in a filter press and the liquid is returned to the grinding circuit.

The precipitated gold is smelted to gold bullion bars by using an induction oven. The gold bars are then sent to the Canadian Royal Mint for further refining, and ultimately sold on the spot market.