The J&L Property lies at the northern end of the Kootenay Arc which is known for its Irishtype carbonate hosted Zn-Pb, volcanogenic massive sulphide (VMS) and sedimentary exhalative (Sedex) deposits. The two deposits on the J&L Property are the Main Zone and the Yellowjacket Zone.

The Main Zone is a structurally-controlled precious metal and polymetallic base metal sheeted sulphide (Au-Ag-Pb-Zn-As) deposit. The deposit has quite a reliable and predictable geometry. The zone is sheet-like or tabular with an average dip of 55° to the northeast. The zone of sheeted massive and stringer sulphide veining has an average width of 2.5 m but the sheeted sulphide veining can reach 15 m in true thickness.

The Main Zone is composed of closely spaced bands of massive sulphides which frequently coalesce at its widest parts. Individual bands, which are generally tabular, may die out along strike over tens of metres but appear to resume in an adjacent band. Individual massive sulphide bands frequently range from 5 cm to 1 m thick. Sulphide minerals include pyrite, pyrrhotite, gold-bearing arsenopyrite, iron-rich sphalerite (blackjack), galena, tetrahedrite and trace chalcopyrite. There are also traces of silver-lead-antimony and lead-antimony sulphosalts. The banding ranges from predominantly arsenopyrite (high gold), to mixed arsenopyrite and massive sulphides, to massive sphalerite with no arsenic present.

An underground mine plan developed by Micon comprises 1.09 million tonnes of measured resources at an average grade of 6.32 g/t Au, 65.91 g/t Ag, 4.16% Zn, and 2.28% Pb; 1.05 million tonnes of indicated resources at an average grade of 7.10 g/t Au, 66.08 g/t Ag, 3.94% Zn, and 2.04% Pb; and 2.76 million tonnes from inferred mineral resources at an average grade of 6.20 g/t Au, 72.43 g/t Ag, 3.24% Zn, and 2.22% Pb. The mine plan includes provision for mining losses and dilution. The PEA is based on a 1,500 t/d underground bulk mining operation, using ramp access. The main mining method considered is mechanized, longhole stoping with truck haulage and stope backfill using waste rock and process tailings.

The ore is delivered by mine trucks to the plant and fed through a grizzly with 400 mm openings to the ROM feed hopper. The ore is extracted from the feed hopper by an apron feeder and fed to a jaw crusher with an opening of 18-20 mm.

HMS may be used to selectively remove non-sulphide gangue materials by applying an SG of 2.95-3.00. By removing the lower grade material prior to the grinding circuit, the HMS plant allows the mill feed tonnage to be increased without having to increase the grinding or flotation capacity.

The HMS concentrate reporting to the grinding circuit, comprises 60% of the feed to the HMS circuit or 900 t/d of coarse sink.

The lead flotation circuit is a conventional lead-zinc differential flotation circuit. The initial lead flotation tails are cycloned, with the oversize returning to the ball mill and the fines reporting as feed to the lead scavenger circuit.

Lead rougher tailing, lead-scavenger tails, and zinc spill returns are conditioned with copper sulphate and lime in a conditioner. The zinc rougher tailing is discarded from the circuit as final flotation tails. The final concentrate is pumped to the dewatering circuit.

For Option A, tails from lead flotation are run through bulk sulphide flotation to recover all remaining sulphides, including gold and silver bearing minerals, sphalerite, arsenopyrite, and pyrite.

The flotation concentrate is thickened, filtered, and sent to pressure oxidation.

For Option B, the same process is carried out on the zinc flotation tails.

The bulk sulphide concentrate is carried out in an autoclave, using oxygen produced in a dedicated plant on site. The resulting autoclave discharge slurry is neutralized using limestone. The PO residue is then filtered, to produce a solids feed to cyanidation.

A six-stage carbon-in-leach (CIL) circuit is designed based on a retention time of 6 hours and a new carbon concentration of 20 g/L. Solids from filtration of the PO residue are slurried and fed to the train of six CIL tanks in series, where the slurry is leached using sodium cyanide in the presence of activated carbon.

The loaded carbon is acid-washed and then fed to a pressurized Zadra circuit to strip gold and silver from the carbon. The pregnant solution is then sent to two electrowinning cells to recover the gold and silver. The stainless steel wool, containing the gold from the electrowinning cells, is fed to an induction furnace to produce gold doré bars for sale.