The Whabouchi deposit is a lithium-bearing rare metal pegmatite. Emplacement of rare metal pegmatites is the last phase of the crystallization of a parent granite pluton. Highpressure residual fluids, with abundant water, silica, alumina, alkalis, and rich in rare elements and other volatiles from the crystallization of a pluton at modest depth, concentrate in the cupola or upper domed contact of the granite as it crystallizes. Under increasing pressure, this fluid dilates fractures in overlying rocks in a manner analogous to that of hydraulics in mechanical equipment, thereby providing feeder channels for emplacement of pegmatites at shallower depth. Progressive crystallization of the main rock-forming minerals out of this fluid enriches the final fluids in rare metals and the process culminates in the formation of rare metal pegmatites still under fluid pressure. A variety of types occur depending on the abundance and type of rare metals associated with the pluton and the physico-chemical conditions affecting the sequence of emplacement events.

The mineralization of economic interest at the Whabouchi site is found in spodumenebearing
rare metal bearing pegmatite dyke complexes. Spodumene is a lithium-bearing mineral, which contains 8 % Li2O when pure. Spodumene also contains minor amounts of niobium and tantalum. Assays for spodumene normally range between 7.6 % and 8.0 % Li2O depending on the degree of replacement by Na2O. Typically, the Whabouchi pegmatite sampled from drill core averages 1.62 % Li2O with values up to 4.59 % Li2O.

Rare metal bearing pegmatites are normally found in moderately metamorphosed terranes near vast granitic plutons: a possible parental source for the pegmatitic magmas. Pegmatites are associated with granitic intrusions and are generally zoned around these intrusive centers. Pegmatites tend to be more enriched in volatile elements further away from the intrusive centers. Pegmatites are thought to be derived from primary crystallization of highly differentiated volatile enriched granitic magmas. The host rocks of the intrusion also play a significant role in the final composition of the pegmatites due to the incorporation of host rock in the magma during the intrusive process.

Open Pit Mining:
The mining method selected for the Project will be a conventional open pit, truck and shovel, drill and blast operation. Vegetation, topsoil and overburden will be stripped and stockpiled for future reclamation use. The ore and waste rock will be mined with 10 m high benches, drilled, blasted and loaded into heavy duty off-road haul trucks with hydraulic excavators.

A topsoil and overburden stockpile has been designed 100 m to the east of the pit ramp exit, to the south of the concentrator. Material that will be placed in this stockpile will be used for future reclamation.

The waste rock excavated from the open pit will be hauled to and placed with the tailings in the codisposal storage facilities.

The mine plan is based on an annual production of 215,022 tonnes of concentrate, which is equivalent to a Run-of-Mine (“ROM”) production of 1.03 Mt/y. The total material mined per year during the 24-year life of the open pit mine ranges from 0.26 Mt in pre-production to a maximum of 5.3 Mt in Year 10. The average annual diluted grade of Li2O varies between 1.47 % to 1.59 % during the 24-year period.

The mine equipment fleet for the open pit includes six (6) 64-tonne haul trucks, two (2) hydraulic excavators with 6 m3 buckets, two (2) diesel powered down the hole track drills that will drill 114 mm (4.5") holes as well as a fleet of support and service equipment. Blasting will be carried out using bulk emulsion with an average powder factor of 0.37 kg/t. The mine workforce has been estimated to be approximately 109 employees.

Underground Mining:
The ore extraction will switch form an open pit operation to an underground mine located underneath the final pit floor in Year 24 of the operation. The duration of the underground mining is ten (10) years and is scheduled to be in operation from the beginning of Year 24 to the end of Year 33. An underground mine production ramp-up period of 14 months is planned during the last months of Year 23 to reach the cruising production rate of 1.3 Mt of ROM at the beginning of Year 25.

The mining methodology selected is 30-metre high long-hole type stopes. Based on the geotechnical and hydrogeological conditions, it is expected that backfilling of the excavated stopes will be required. The very last excavation phase consists of mining the 30 metre thick remaining crown pillar from the open pit floor.

Traverse Longhole stoping, followed by paste backfill, is the mining method selected for the ore extraction located underneath the crown pillar. The stope dimensions along the longitudinal axis are 30 m long and 30 m high. The stope width dimension varies between 6 m and 80 m depending on the thickness of the mineralized zone.

The main ramp is characterized by a sub-arch section design having an area of 5 m x 5 m with a maximum 15% inclination that connects the portal at elevation 167 m to the lowermost haulage drift located at elevation 2 m. The main ramp cross section area, present in Figure 16.19, has been designed to provide sufficient provision to accommodate the largest production equipment which is the 50-tonnes haul truck along with the roof suspended secondary ventilation ducting (diameter of 1.52 m). The overall length of the main ramp is 2,749 metres.

The annual production requirement is the same as the full regime of the open pit extraction period with yearly lithium concentrate production ranging from 201 to 221 k tonnes. An overlapping underground mine ramp-up production period of four (4) months with a target ROM production of 300 k tonnes is planned with the open pit ore extraction.

The contractor will supply and operate the underground mining fleet consisting of two (2) development jumbos, two (2) production drills, three (3) LHDs, and four (4) haulage trucks. The underground haulage trucks will haul the ore and waste up to the mine portal where it will be dumped into stockpiles to be reclaimed by the Owner and hauled out of the pit to the crusher or waste dump.

There is an accommodation for an 80,000 t mine ore stockpile at the crusher. The crushing is split in three (3) areas, primary crushing, ore sorting, and fine crushing.

The ROM ore, containing 17.5% spodumene with a moisture content of 2%, will be dumped into a hopper by front end loaders. The ore is transported via an apron feeder, underneath the hopper, into the jaw crusher. The primary crusher discharge will have a particle size of 80% less than (P80) 95 mm. The broken rock will be transported via conveyors to the double deck coarse ore crusher screen. The top deck has 80 mm screen openings and the bottom deck has ten (10) mm screen openings. The top deck oversize of this screen is returned to a smaller second jaw crusher. The discharge of the second jaw crusher, with a P80 of 72 mm, returns via the same conveyors to the same coarse ore screen in closed circuit. The bottom deck screen oversize will be transported to the ore sorters. The coarse ore crusher screen undersize is transported to fine crushing area.

The fine crushing facility is composed of screening and 2-stage crushing. The coarse ore screen fines and the sorter accepted material are combined and then screened on a double deck vibrating screen. The screen top deck opening is 20 mm, while the bottom deck opening is 9 mm. Both screen oversize discharges are transported to a coarse ore bin. This bin has two (2) compartments, -80 mm + 20 mm and -20 mm + 9 mm. The secondary cone crusher feed is deposited in the coarser section. There are two (2) secondary crushers and one tertiary crusher. The crushers operate in closed circuit with the double deck screen to produce a crushed product P80 of 5.8 mm will be conveyed to the fine ore stockpile near the concentrator building.

The secondary crushers will be standard cone crushers that crush the top deck oversize to a P80 of 21 mm. The tertiary crusher will be a short head cone crusher that crushes the bottom deck oversize to a P80 of 12.7 mm. All crusher discharges will be re-directed to the double deck vibrating screen via two (2) conveyors.

In Phase 2, the DMS concentrate will be crushed using an HPGR to facilitate the lithium refining at the electrochemical facility. This crushing circuit will include a buffer feed bin, several conveying systems, and HPGR and a dry screen. The material will be crushed to an F100 = 1.0 mm.

The DMS middlings need to be ground to liberate the finer spodumene particles. They enter the ball mill via the ball mill feeder conveyor from the Middlings storage bin. The ball mill discharge is pumped to the ball mill fine screen with apertures of 850 µm. The screen oversize reports back to the ball mill. The screen undersize, at a P80 of 640 µm, is pumped to the fine ore screen undersize to join the natural fines for fine muscovite removal stage.

The process design has been split in two (2) locations. The concentrator plant will be located 675 m north east of the Whabouchi mine open pit while the Electrochemical Plant will be located in Shawinigan.

Whabouchi Concentrator.
The crushed mineralized material will be screened on the fine ore screen and the oversize will be upgraded in a dense media circuit after a stage of mica hydroseparation removal to produce a coarse spodumene concentrate, a tailings product and a middlings product. The DMS coarse concentrate will then be dried in a rotary dryer before treatment by a dry magnetic separation system. The magnetic product will be discarded with the tailings and the non-magnetic product will be the first portion of the final spodumene concentrate.

The DMS middlings product will be ground to less than 0.85 mm and combined with fine ore screen undersize. This ground product feeds a fine stage of mica hydroseparation removal and then goes to flotation circ ........