Patent ID: 8431005

Claim:
A method for recovering lithium, potassium and sodium compounds from a material containing a low concentration of lithium, which method comprises: (a) reducing the material to small particles having average diameter of about 150 microns or finer; (b) mixing the material with a solid source of sulfates and carbonates at ratios 0.1:1 to 0.9:1 (c) granulating the mix with an aqueous solvent in order to obtain granules of 1-10 mm (d) heating the granules at temperatures of 950-1100 degrees C. to form reaction products (e) slurrying the reaction products of step (d) with process water; (f) heating the slurry of step (e) at about 50 degree. to 100 degree. C. for about between about 0.2 to 2 hr; (g) separating the solids and liquid of step (f); (h) evaporating the liquid of step (g) to from a concentrated solution having a volume of about 30 to 50% of original and cooling to 0 degree to 35 degree C.; (i) treating the concentrated solution from (h) to remove glaserite by filtering the cool suspension to leave a liquid phase; (j) reacting of a first part of the liquid phase of step (i) with a sufficient aqueous alkali carbonate to precipitate lithium carbonate to form a slurry and heating the slurry to between about 60 degree. to 125 degree. C. for between about 0.5 and 10 hr; (k) separating the hot slurry of step (j) to recover a liquid and the lithium value as solid lithium carbonate (l) decomposing the glaserite of step (i) to produce solid potassium sulfate (m) reacting the liquid of step (k) with sufficient amount acid to remove carbonates (n) treating the liquid of part (m) to remove glauber salt by cooling crystallization (o) recovering of lithium hydroxide from a second part of the liquid phase of step (i) by electrolysis.