Brief Project Description of the Lithium Carbonate Plant:

Based on “Technical Report NI 43-101 on the Pre-Feasibility Study for the Quebec Lithium Project” by Canada Lithium and BBA Inc, May 2010

• This is a simplified model of a Lithium Carbonate plant. The project is based on the proposed Rose Tantalum-Lithium Project in Canada, as described in “Technical Report and Preliminary Economic Assessment on the Rose Tantalum-Lithium Project”, by Genivar Inc, December 2011 (http://www.cecorp.ca/documents/en/pea_final_techreport.pdf).

In the past, the sulphuric acid leach process was used to extract the lithium from the spodumene, a lithium alumino-silicate mineral (LiAlSi2O6). However, that process also extracted much of the other minerals which were in the spodumene flotation concentrate, rendering the isolation and purification of the lithium carbonate difficult.

The Quebec based research organization CRM studied and piloted an alternate process which allowed for the isolation and purification of the lithium carbonate to be less complicated. This process was evaluated on the pilot scale at CRM research facilities and the process design parameters determined. The same process was used industrially at the plant of the Sullivan Mining Group (Quebec Lithium Corporation) in the 1960’s.

This process is based on the transformation of the α-spodumene to β-spodumene in a kiln followed by a leaching of the β -spodumene with sodium carbonate (Na2CO3). During the leaching process, lithium carbonate (Li2CO3) precipitates in the aqueous solution while the rest of the mineral react with the Na+ to form an hydrated aluminium sodium silicate (NaAlSi2O6•H2O) known as analcite (or analcime), a very stable mineral. To remove the precipitated lithium carbonate from the rest of the solid, it is reacted with carbon dioxide gas (CO2) under pressure to form lithium bicarbonate (LiHCO3) which is soluble in the aqueous solution. After this stage the slurry is filtered and washed to recover the lithium values in the liquor.

The lithium carbonate solid is finally recovered from the mother liquor by reducing the pressure to atmospheric pressure and heating the liquor to expel the carbon
dioxide. This results in the precipitation of the lithium carbonate which is filtered and dried. The spent liquor with lithium values remaining in is recycled back to the
lixiviation (leaching) section. The following description of the lithium carbonate plant is based on the CRM process. The process includes six (6) elementary steps, which are briefly outlined.