Patent ID: 8920763
Filing Date: 2014-12-30
Classification: C01D

Abstract:
1. A method for producing lithium carbonate, said method comprising: (i) thermally decomposing limestone to produce carbon dioxide (carbonate gas); (ii) adding ammonia to an aqueous solution containing lithium chloride; (iii) adding carbon dioxide to the resulting ammoniated aqueous solution containing lithium chloride of step (ii) to conduct a carbonation reaction to produce lithium carbonate; and (iv) thereafter, recovering the produced lithium carbonate by solid-liquid separation, wherein ammonia generated by reacting (a) ammonium chloride produced in step (iii) as a by-product with (b) burnt lime produced in step (i) as a by-product or hydrated product thereof is recycled as ammonia used in step (ii); and wherein the thermal decomposition of limestone is conducted in a field where the carbonation reaction is conducted.