The depositional environment for the mineralization at Lalor and the 1901 deposit are similar to present and past producing base metal deposits in felsic to mafic volcanic and volcaniclastic rocks in the Snow Lake mining camp. The deposits appear to have an extensive associated regional hydrothermal alteration.

The mineralized envelopes are shallow dipping, with zinc mineralization defined to date beginning at approximately 600 m from surface and extending to a depth of approximately 1,100 m. The mineralization trends about N320° to N340° azimuth and dips between 30° and 45° to the north. It has a lateral extent of about 1,400 m in the north-south direction and 800 m in the east-west direction.

Sulphide mineralization is dominated by pyrite and sphalerite. In the near solid (semi-massive) to solid (massive) sulphide sections, pyrite occurs as fine to coarse grained crystals ranging one to six millimetres and averages two to three millimetres in size. Sphalerite occurs interstitial to the pyrite. A crude bedding or lamination is locally discernable between these two sulphide minerals. Near solid coarse-grained sphalerite zones occur locally as bands or boudins that strongly suggest that remobilization took place during metamorphism.

Disseminated blebs and stringers of pyrrhotite and chalcopyrite occur locally within the massive sulphides, adjacent to and generally in the footwall of the massive sulphides. The hydrothermally altered rocks in the footwall commonly contain some very low concentrations of sulphide minerals. Some sections of massive pyrrhotite occur, but these tend to give way to pyrite-sphalerite-dominant zones.

The top two lenses of the stacked base metal zones at Lalor (referred to as Zone 10 and 11) and lenses 1 and 3 at the 1901 deposit have higher grade zinc and iron content. Lenses located lower in the stratigraphy and coded as Zones 20, 30, 31, 32, 40 and 42 at Lalor have moderate to high zinc grades hosted in near solid sulphides containing higher grade gold and locally appreciable amounts of copper.

The footwall gold mineralization is typical of any VMS footwall feeder zone with copper-rich, disseminated and vein style mineralization overlain by a massive, zinc-rich lens. The fact that the footwall zone is strongly enriched in gold suggests a copper-gold association which is comparable to other gold enriched VMS camps and deposits (Mercier-Langevin, 2009). Some of the footwall zones tend to be associated with silicification and the presence of gahnite. These zones are often characterized by copper-gold association and are currently interpreted as being associated with higher temperature fluids below a zone of lower temperature base-metal accumulations.

Gold and silver enriched zones occur near the margins of the zinc rich sulphide lenses and as lenses in local silicified alteration. Remobilization is illustrated in some of the gold-rich zones by late veining that is restricted to the massive lenses.

Some of the footwall zones tend to be associated with silicification and the presence of gahnite. These zones are often characterized by copper-gold association and are currently interpreted as being associated with higher temperature fluids below a zone of lower temperature base-metal accumulations.

General observations of the known gold zones indicate areas which are coarse-grained and porphyroblastic in nature are gold poor, while fine grain siliceous (± veins ± sulphide traces) and strained looking stratigraphy tend to be gold rich. However, the intensity and style of alteration can vary strongly over short distances and may suggest that the alteration was forming discordant stockwork like zones that are now strongly transposed in the main foliation (Mercier-Langevin, 2009).

Lalor mine is a ramp and shaft accessible mine.

At Lalor, lateral development is horizontal or near horizontal tunnelling, travelable by rubber tired mechanized equipment. Ramps are typically mined at up to +/- 15% grade to provide access between levels. Rounds are 4m long and typical dimensions are 6m wide by 5m high. Standard ground support, consists of resin grouted rebar and welded wire mesh across the back and to within 1.8m of the sill on the walls and face. Mine services, including compressed air, process water and discharge water pipelines, paste backfill pipeline, power cables, leaky feeder communications antenna and ventilation duct, are installed in main levels and stope entrances.

At Lalor, main ventilation raises and ore pass raises are developed by a mining contractor using a raisebore and/or Alimak climber. Ground support and ladder ways are installed as required. Longhole slot raises, transfer ore passes, and auxiliary ventilation raises are limited to approximately 35m long and are developed using longhole conventional drop raise techniques. Drain, paste backfill and electrical cable holes are drilled using longhole or raisebore drills and are reamed to designed diameter.

There are two mining methods used at Lalor mine: variations of cut and fill and longhole open stoping (predominantly transverse longhole mining with minor longitudinal retreat).

Cut and Fill Mining
Single pass overhand mechanized cut and fill mining is the preferred method where the ore is flatter than 35° and horizontal widths are less than 10m. The ore is accessed from a footwall drift by a crosscut developed at approximately -15%. Ore is mined in 5m high horizontal cuts. Unconsolidated backfill is placed tight to the back and the entrance crosscut is then back slashed to provide access to the next cut.

Where ore widths are greater than 14m wide, mining is conducted by overhand post pillar cut and fill. Post pillars provide ground support to allow for selective mining of wide stopes. Backfill is placed to within 1.8m of the back and the entrance crosscut is back slashed to provide access to the next cut. Drifts and crosscuts in stopes are typically 7m wide x 5m high, with 7m x 7m post pillars. Mining retreats towards the access to reduce risks associated with poor ground conditions.

Longhole Open Stope Mining
The minimum design height of a longhole stope is 17m. In shallower dipping areas of the ore the interval is typically 17 to 20m, and in steeper dipping areas the interval is 20 to 25m. Stope widths assume a minimum mining width of 5m. Maximum open stope length and width is determined considering the rock quality and hydraulic radius of the combined exposed hanging wall and back span of the stope. A 5m rib pillar is added when unconsolidated rock is used as backfill.

Backfill
All stopes at Lalor mine except uppers require backfill to maintain long term stability and to provide a floor to work from for subsequent mining. Backfill is either unconsolidated waste rock backfill (URF) or consolidated paste backfill. URF is used in stopes where pillar or wall confinement is not required and the value of the adjacent pillars does not warrant the added expenditure of paste backfill. Paste backfill is an engineered product comprised of mill tailings and a binder (3-5% cement by weight), mixed with water to provide a thickened paste that is delivered by borehole and pipes to stopes. Paste backfill presents several advantages over unconsolidated fill such as slurried mill tailings or loose waste rock including increased stability, better ventilation controls, higher mining recovery and lower mining dilution and it also eliminates potential flows of re-liquefied unconsolidated tails.

Ore handling
Ore is mucked by LHD, loaded to underground haul trucks and hauled to one of the two rock breaker/grizzlies on 910m level for sizing to less than 0.55m. A 40m bin below the grizzly provides approximately 1,200 tonnes of coarse ore storage. A chute at the bottom of the bin at 955m level feeds ore to a conveyor that loads a measuring flask with approximately 14 to 16 tonnes of ore. Ore is skipped to surface by two 16 tonne capacity bottom dump skips in balance. The ore enters the headframe chute from the skips and is deposited into the surface ore bin or to the exterior concrete bunker via gravity. From the surface bin or bunker, ore is truck hauled to a primary crusher at the Chisel North mine site, crushed to minus150mm, and then trucked to a concentrator to process.

Mine Ventilation
Lalor mine is a “push-pull” system primarily driven by pull. The exhaust shaft is equipped with two fans drawing 1.1 million cfm from the mine. Fresh air is supplied into the mine from the Chisel and Lalor downcast raises (0.6 million cfm). The Chisel and Lalor downcast raises are equipped with 600HP and 400HP fans respectively. An additional 0.6 million cfm is downcast via the Lalor production shaft, equipped with two 250HP fans. In the upper mine, ventilation raises and an internal ramp between 795mL to 755mL will provide ventilation to expanding stoping fronts. In the lower mine, an extension of the 810 to 1025mL raise is planned to connect 1025mL to 1090mL. An internal exhaust raise is planned from the 1000mL to the bottom of the exhaust shaft at 840mL. This will improve blast clearing times for the lower part of the mine. Individual mining faces are ventilated using 60 HP to 250 HP fans and 1.37 m ventilation duct. Three propane heaters heat air in the mine during the winter from Chisel, the access ramp and the production shaft.

The Stall mill, processes ore from the Lalor Mine, which began commercial operations in 2012. Initial capacity was 2,800 tonnes per day and through modifications and improvements, milling performance has increased to an average rate of 3,800 tonnes per day, although it has been demonstrated to reach peak throughput rates of up 4,500 tonnes per day.

From time to time, a portion of the ore mined from our Lalor mine is transported to the Flin Flon concentrator for processing.

New Britannia mill is currently being refurbished to process ores from the Lalor gold and copper-gold zones. The mill achieved first gold production on August 11, 2021.

The Stall mill consists of the following unit operations: crushing, grinding, talc flotation, copper flotation, zinc flotation, concentrate filtration and concentrate load-out.

Coarse ore from the mine is transported to a primary crushing plant located at the Chisel mine site and is operated by a third-party ........