Patent ID: 8435468
Filing Date: 2013-05-07
Classification: C01B,C01D,C01G,C01P,C22B,C25B

Abstract:
1. A method of producing highly pure lithium carbonate, the method comprising the steps of: feeding a first aqueous solution comprising a purified lithium chloride stream to an electrolyzer equipped with a membrane or a separator, wherein the first aqueous solution has a lithium chloride concentration of up to 40% by weight to form a second aqueous solution comprising at least 10% by weight lithium chloride; applying a current to the electrolyzer to produce a third aqueous solution in the cathode compartment that comprises greater than 4 wt % lithium hydroxide; optionally cooling the third aqueous solution; supplying the third aqueous solution and carbon dioxide to a carbonation reactor to produce a fourth aqueous solution comprising lithium bicarbonate; separating the fourth aqueous solution from the carbon dioxide and lithium carbonate solids formed using a gas-liquid-solid reactor; filtering the fourth aqueous solution to remove trace impurities; and feeding the filtered fourth aqueous solution to a precipitation reactor maintained at a temperature of at least about 95° C. to precipitate highly pure lithium carbonate.