METHOD OF EXTRACTING LITHIUM FROM LOW CLAY MINERALS.

Abstract

The present invention relates to a method for extracting lithium from complex clay minerals whose mineral compositions fall within the ranges of: orthoclase (20-60%), quartz (4-60%), and calcite (4-65%), with lithium-containing clays (2-35%). The invention comprises the following steps: (1) A particle reduction and sieving process. (2) A dry mixing process of the sieved mineral with sodium sulfate, Na₂SO₄, in a mineral-to-Na₂SO₄ ratio ranging from 5:1 to 5:3. (3) A roasting process at temperatures between 700 and 900°C for a period of between 30 and 120 minutes. (4) Two processes of leaching the calcined mineral with an additive in water and collecting the lithium-containing liquor by filtration. Depending on the composition of the clay mineral, this process produces yields between 50 and 85% of lithium extraction from the rock to the liquor.