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 4.24 % 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 mine plan is based on an annual production of 216,485 tonnes of concentrate (resulting in 214,579 tonnes of concentrate after 0.88 % in handling and transportation losses were accounted for). An initial starter pit was designed which will supply the majority of the run of mine ore for the first five (5) years of the operation. The purpose of the starter pit is to maximize the feed grade and minimize the strip ratio during the early years of the operation. The total material mined per year during the 20-year life of the open pit mine ranges from 1.0 Mt in pre-production to a maximum of 5.3 Mt in Year 10. The average annual grade of Li2O varies 1.44 % to 1.60 % during the 20-year period.

The mine equipment fleet for the open pit includes six (6) 55-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 97 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 21 of the operation. The duration of the underground mining is six (6) years and is scheduled to be in operation from the beginning of Year 21 to the end of Year 26. An underground mine production rampup period of 4 months is planned during the last months of Year 20 to reach the cruising production rate of 1.2 Mt of ROM at the beginning of Year 21. The duration period of the development of the underground mine is planned for 20 months starting at the beginning of Year 19.

The mining methodology selected is 30-metre high long-hole type stopes. Based on the favorable geotechnical and hydrogeological conditions, backfilling of the excavated stopes will not be required. However, in order to ensure the rock mass stability and work safety within the underground excavation zone, four (4) central stope pillars will be maintained until the last stages of the operation. The very last excavation phase consists of mining the 30-metre thick remaining crown pillar from the open pit floor.

The annual production requirement will be the same as during the open pit period with yearly lithium concentrate production ranging from 188 to 240 kt (1.2 to 1.4 Mt/y of ore). An overlapping underground mine ramp up production period of four (4) months with a target ROM production of 300 kt is planned with the open pit ore extraction finishing at the end of Year 20. This will ensure an uninterrupted ROM feed to the concentrator.

The contractor will supply and operate the underground mining fleet consisting of development jumbos (2), production drills (2), LHDs (3) and haulage trucks (4). 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.

The process design has been split in two (2) locations. The concentrator plant will be located at Whabouchi and the Hydrometallurgical Plant will be located Grand-Mère, near Shawinigan.

Concentrator:

The Whabouchi concentrator will be located near the open pit mine. The concentrator will be designed to produce a nominal 216,485 tonnes of spodumene concentrate per year. The Run-of-Mine (“ROM”) mineralized material will be transported to the primary jaw crusher and then conveyed to the secondary and tertiary cone crushers. The crushed mineralized material will be screened and the screen oversize will be upgraded in a dense media circuit to produce a coarse spodumene concentrate and a middlings product that will be further ground and treated by flotation. The DMS coarse spodumene concentrate will then be dried in a rotary dryer before being fed to the dry magnetic separation system. The magnetic particulates will be discarded with the tailings to produce a non-ferrous concentrate. The DMS middlings product will be combined with screen undersize, less than 0.5 mm material (fine), and will be further ground in a ball mill to a P80 of 174 microns. This ground product forms the feed for the flotation circuit. The flotation circuit consists of de-sliming and mica flotation followed by attrition magnetic separation and then followed by more de-sliming and finally spodumene flotation.

Mica concentrate, de-slimed and magnetic materials and spodumene rougher flotation tailings will be combined, thickened and filtered in a filter press to a moisture content of about 6 % and subsequently combined with DMS tailings and transported by haul truck to the mine waste dump. The spodumene flotation concentrate will be thickened and filtered by a pressure filter to about 8 % moisture and combined with the dry DMS concentrate for transport by road trucks to Chibougamau. The shipped concentrate will have moisture of less than five percent (5 %) to prevent freezing during the winter months. Here it will be transferred into railcars (93 net tonnes each) for transport to the Shawinigan hydrometallurgical plant for further processing.

Hydrometallurgical Plant:

The plant availability has been estimated at 93 %. The hydromet plant will be designed to produce a nominal 27,645 tonnes of lithium hydroxide monohydrate crystals per year and a nominal 3,267 tonnes of lithium carbonate powder per year. The overall lithium recovery of the hydromet circuit will be 88.4 %. The concentrate will be discharged from the railcar into a receiving hopper. A reclaim conveyor will transport the concentrate to the hydrometallurgical plant where it will feed the spodumene conversion kiln. The kiln will heat the spodumene to approximately 1,050 °C. The high temperature converts the spodumene concentrate from the alpha crystalline structure to the beta crystalline structure. A flash cooler will use ambient air to cool the converted spodumene to approximately 100 °C.

The beta-spodumene will be fed to the pug mill. Sulphuric acid will be sprayed and mixed with the beta-spodumene in the pug mill. The mixture will be acid-baked in a rotary dryer at 250°C. The resulting reaction produces solid lithium sulfate and aluminum silicates. The temperature in the dryer must be maintained above 175 °C.

The acid baked mixture will be fed with water into a concentrate leach tank. Lithium sulfate will dissolve into water. The discharge of the concentrate leach tank will be pumped to a downstream belt filter. The cake, which consists mainly of aluminum silicate, will be conveyed outside the plant building and stockpiled before being dispatched to potential end users.

The lithium sulfate solution will be pumped to the PIR tanks for purification. Precipitated impurities such as iron and aluminum are will be separated from the liquor using a thickener and three (3) filter presses. The residue will be sent to the tailings and the purified liquor will be pumped the second purification stage.

In the SIR tanks, the pH will be further increased to precipitate even more dissolved metals as solid hydroxides and carbonates. The discharge slurry will be pumped to the candle filters to remove the solid impurities from the lithium solution. The solid residue will be directed to the tailings. The solution will be stored in the IX feed tank before being pumped to the next cleaning process.

The final lithium sulfate solution cleaning step will be performed by three (3) ion exchange columns in a round-robin configuration. Solution will be fed to two (2) columns in series (the lead column and the lag column) while the third is being cleaned/stripped/regenerated. Clean lithium sulfate solution discharging from the columns will be stored in the lithium sulfate feed tank. Waste solutions from the acid strip and wash steps will be collected in the IX residue tank and pumped to the tailings tank for disposal.

An electrolysis process will be used to convert lithium sulfate (Li2SO4) to lithium hydroxide (LiOH).

The LiOH-H2O crystallization circuit consists of a single-stage mechanical vapor recompression falling film evaporator followed by a series of two (2) forced circulation crystallizers, the crude crystallizer and the pure crystallizer. The crystals will be separated from the mother liquor in a centrifuge where they reach a moisture content of about five (5) percent by weight (“% w/w”). The dewatered crystals will discharge to a fluid bed dryer before the final packaging step. The dried crystals will be stored in a bin located above the packaging system where crystals will be packaged in 1-tonne bags.

Lithium hydroxide remaining in the crystallization purge solution will be recovered in the lithium carbonate precipitation process. The Li2CO3 production process will be carried out in two (2) steps. The first step is called the lithium hydroxide carbonization (LC). The second step is called the lithium bicarbonate decomposition step (DC). In the LC step carbon dioxide will be injected at the bottom of the tank to react with lithium hydroxide and then with the precipitated lithium carbonate.

In the DC step, the lithium bicarbonate solution will be heated to 95ºC. The tanks will be jacketed and heated with steam. The DC decanter underflow joins the LC decanter underflow in the belt filter feed tank.

A vacuum belt filter will be used to dewater the lithium carbonate slurry to 70 % w/w solids. The belt filter cake will fall by gravity to the fluid bed dryer. The dried product will be transferred to the pulverization system. The jet mill will use high pressure air to pulverize the lithium carbonate to a P80 of about five (5) microns. The pulverized product will be transferred to a bin located above the packaging system. A robot operated system will be used to package the Li2CO3 into 25-kg bags.