Read More [+]
The production process is designed to use conventional and commonly-available equipment, arranged to take advantage of the distinctive qualities of the high-grade ore. The process comprises a series of steps to concentrate, separate and produce battery-grade Li2CO3.
First, ore from the mine will be crushed, screened and then transferred as a slurry to the leaching circuit where sulfuric acid will be added to attack the ore and liberate the lithium from the clay. The high-grade quality of the ore allows for leaching to occur in stirred reactors (vats), specifically designed to maximize speed and efficiency of lithium dissolution, while minimizing sulfuric acid consumption. Total leaching time is estimated at three hours.
The resulting lithium-bearing solution will then go through a pH-neutralization step. Neutralization will be achieved with ground limestone during start-up and sustained with recycled alkaline solids from an upstream precipitation process during normal operation. Next, the lithium solution will undergo a crystallization step using steam and electricity from the sulfuric acid production process. Water is removed for recycling, and magnesium sulfate (Epsom salt) is produced. Any magnesium remaining in solution is removed in a second step that involves the addition of reagents to precipitate magnesium hydroxide.
Finally, soda ash will be added to the lithium bearing solution to produce a high-quality, battery-grade Li2CO3. Much of the water contained in the lithium solution will be recovered and returned to the process. The total time projected to manufacture battery-grade Li2CO3 from the ore is less than 24 hours. The overall recovery of lithium from the ore is 83%.
The Company is advancing engineering to consider a 20,000 tpa lithium hydroxide chemical conversion plant to have flexibility to meet potential customer and partner needs.