Canadian Mining Journal

Feature

Charged Up

Rightly famous for its gold producers, Val d'Or, Que., has another hidden treasure. Forty years ago, lithium was mined 60 km to the north, and many readers will be unaware of this resource. Now Canada Lithium (CLQ) is redeveloping the former...



Rightly famous for its gold producers, Val d’Or, Que., has another hidden treasure. Forty years ago, lithium was mined 60 km to the north, and many readers will be unaware of this resource. Now Canada Lithium (CLQ) is redeveloping the former producer thanks to the growing demand for lithium by the electric vehicle market.

“We want to be an environmentally friendly company,” president and CEO Peter Secker told CMJ. “And we wanted to find a mineral that has application in the green energy sector.”

The Quebec Lithium project meets the major benchmarks that CLQ was looking for in a project. It is a previous producer; it is accessible; and hydro costs are reasonable.

“Hydro power is a green energy, and that fits again into what we are doing,” Secker added.

Quebec Lithium opened the original underground mine in 1955. It built a refinery to produce lithium carbonate, monohydrate hydroxide, lithium chloride and lithium hydroxide. Facing poor markets and falling prices, the owner suspended production in 1965.

The site was later rehabilitated. By 2001 the underground equipment, processing plant, headframe, railway line and all surface structures had been removed. The crown pillar was fenced off and other openings sealed.

CLQ acquired a 100% interest in the former producing property in 2008 and immediately launched an exploration and drilling program.

The greatest growth in lithium demand comes from the battery industry. The lithium ion battery has many advantages over older types. Lithium batteries have an energy density three times that of nickel hydride types, superior weight-to-power ratio, longer life and faster recharge, and lithium batteries remain functional to temperatures as low as -60°C.

Lithium has many uses in ceramics and glass, lubricants, refrigeration, the nuclear industry and the optical electrics, to name a few. The largest demand is from the lithium ion battery sector, and Canada Lithium is focused on supplying that sector with high purity lithium carbonate (Li2CO3), a product that commands a price premium for the makers of electric and hybrid vehicles.

By 2008, rising demand for lithium carbonate had driven prices up to approximately $6,000/t. The global financial collapse that followed sent prices spiralling downward, bottoming at US$4,750/t to US$5,500/t.

Recently, two of the world’s largest lithium carbonate producers announced price increases of up to 20%. In its projections based on approximately $6,000/t for lithium carbonate, CLQ anticipates annual revenues of $115 million and total operating costs of roughly US$3,160/t Li2CO3.

The demand for lithium carbonate has been growing 4% to 6% per year, based on growth in battery demand for cell phones and mobile computers. More recently, additional uses within the hybrid, plug-in hybrid and pure electric vehicle industry, in conjunction with new applications in the grid-storage industry, continue to spur world lithium consumption. With automotive battery demand for lithium carbonate alone predicted to be 53,500 tonnes in 2020, Canada Lithium’s output of 20,000 t/y would then represent a significant portion of world supply.

The Quebec Lithium project

Canada Lithium has embarked on a $202-million development program at the mine site. Construction is planned to begin in October 2011, with plant commissioning by the end of 2012.

Lithium is often produced from brine pumped to the surface at solution potash mines. The development of a hardrock producer will have a notable advantage: the speed with which lithium carbonate can be produced. Only five days are needed between the time the ore is mined and the final product is ready for shipment.

In countries such as Australia and Chile, brine evaporation can take between 18 and 24 months. That is a long time to have a product tied up in production or processing.

The Quebec Lithium mine plan calls for an open pit with one 10-m3 hydraulic shovel and three 90-tonne haul trucks to start. Five additional trucks will be purchased as the mining rate increases. Caterpillar dealer Hewitt Equipment of Montreal will supply the trucks. There will also be a 10-m3 front-end loader. A single blast hole drill as well as a tracked dozer, grader and water truck round out the pit equipment roster.

Before mining begins, 3.8 million tonnes of overburden will be removed from the pit area. An additional 108.8 million tonnes of waste rock will be removed as mining progresses. The waste rock will be stored initially in a pile southwest of the pit and south of the mill. A second waste rock pile will create a dike on the southwest side of the tailings pond. The dike will be reinforced with a 40-metre-wide rock berm about one-third the height of the dike.

The mine will operate with two 12-hour shifts, year-round. When mining starts it will be at a rate of 1,618 t/d of ore, ramping up over the first year so that in the second and following years 3,800 tonnes of ore are delivered to the mill every day. In order to maximize the net present value of the project, a cut-off grade of 0.90% Li2O will be used in the first two years and a cut-off of 0.60% in the third and remaining years.

Canada Lithium has identified proven and probable reserves of 17.1 million tonnes grading 0.94% Li2O, using a cut-off of 0.6%. That is enough ore to feed the mill at a rate of 3,800 t/d for 14.9 years.

One key to the success of the Quebec Lithium project will be the ability to create high-purity, battery-grade lithium carbonate; i.e. >99.5% Li2CO3. That will be accomplished in two steps. First a spodumene concentrate is made, and second it will pass through a hydrometallurgical facility to purify the lithium carbonate.

Run-of-mine ore will be reduced in a jaw and two stages of cone crushing, then it will be ground in a rod and a ball mill, and the slurry classified. The slurry is next deslimed and passed through an attrition scrubber ahead of flotation. The flotation circuit consists of roughing, scavenging and two stages of cleaning. After dewatering, the spodumene concentrate grades 5.7% Li2O.

Tailings generated from the scavenger circuit are thickened and impounded.

The spodumene concentrate is roasted at 1,025°C for 15 minutes, cooled and mixed with concentrated sulphide acid to produce lithium sulphate. Then it is mixed with water at ambient temperature to dissolve all the sulphates. Lime is added in the first purification stage to precipitate iron, aluminum hydroxide and insolubles, all of which are filtered out and treated as final tails.

The resulting lithium-rich pregnant solution undergoes a second purification with the addition of caustic soda and then soda ash to precipitate manganese and calcium carbonate. The solids are again filtered, washed and discarded as tails. The pregnant solution will pass through an iron exchange resin for final purification and clarification. The solution will be heated to 95°C and mixed with soda ash solution to precipitate lithium carbonate.

The precipitate is recovered by thickening, filtration and drying. It is then packaged for delivery to buyers.

Canada Lithium is also exploring the potential to sell up to 50,000 t/y of spodumene concentrate to the glass and ceramics industries.

Next steps

Canada Lithium’s next step is to begin construction at the mine site, generating 250 jobs during that phase. After two years of building, commissioning and the expenditure of $202 million, the company expects production employees to number about 198, roughly half in the mine and a third in the plant.

The final report card on the Quebec Lithium project will be written by growth in electric vehicle demand. Canada Lithium intends to be a supplier of choice for that market.


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