BMW Mining Deal, page-121

Brine Mining

Lithium is concentrated in salt deposits already in the ground, and brine mining, according to miningfeeds.com is a much easier technique than hard rock mining, “Brine, typically carrying 200–1,400 milligrams per liter of lithium, is pumped to the surface and concentrated by evaporation in a succession of ponds, each in the chain having a greater lithium concentration. After 9-12 months, depending on climate, a concentrate of 1 to 2% lithium is further processed in a chemical plant to yield various end products, such as lithium carbonate and lithium hydroxide.”
Using this mining process costs much less than hard rock mining, is faster, and researchers at the Lappeenranta University of Technology in Finland found that lithium mined from brine extraction can reach purity of up to 99.9%, an almost impossible purity level in the traditional hard rock mining method.

https://www.energyandcapital.com/re...rue-future-of-lithium-brine-vs-hard-rock/2157