Mechanochemistry synthesis of high purity lithium carbonate

Abstract

A technique for preparing high purity Li₂CO₃ powders has been developed through mechanochemical process coupled with the dissolution-filtration process. The first step as mechanochemical reaction of both Na₂CO₃ and LiCl mixtures was designed to obtain the primary Li₂CO₃ powders using a ball mill. The second step as the dissolution- filtration process was performed to obtain high purity Li₂CO₃ powders. Experimental results indicate that the three parameters of milling time, rotation speed, and ball-to-sample mass ratio can closely relate with purity of primary Li₂CO₃ powders. The XRD patterns of primary Li₂CO₃ powders indicate that mechanochemical reaction of both Na₂CO₃ and LiCl can be completed in 15 min under optimal conditions at rotation speed as 600 rpm, ball-to-sample mass ratio as 5/1, and molar ratio of Na₂CO₃ to LiCl as 1/2. The target products of Li₂CO₃ powders contain impurity of Na⁺ less than 0.1 mass% with the minimum values as 0.073 mass%. Two shapes of massive particles and smaller grains less than 1 μm in nano scale can be observed in the target products of Li₂CO₃ powders.