PREPARATION OF LITHIUM CARBONATE

PURPOSE:To prepare high-purity Li2CO3 having large primary particle size, by the thermal reaction of an alkaline aqueous solution of a lithium compound with urea. CONSTITUTION:Urea is added to an alkaline aqueous solution of a lithium compound (e.g. an aqueous solution of LiOH), the mixed solution is hydrolyzed with heat, and the precipitated Li2CO3 is filtered with suction and dried to obtain Li2CO3 having large primary particle size. The conventional process comprising the direct reaction of an aqueous solution of an Li compound with CO2 gas, a bicarbonate and a carbonate, is liable to cause the rapid local ununiform reaction, and the nucleation is dominant in the precipitation of the Li2CO3, resulting in the insufficient crystal growth, the generation of fine particles, the tendency of forming secondary particles by the coagulation of the fine particles, and the tendency to entrap the impurities from the mother liquid. A desirable result can be achieved by feeding the carbonate ion into the reaction system by the hydrolysis of urea, and a high-purity product having large primary particle size can be obtained.