Abstract: This paper introduces purified treatment of the industrial -grade lithium carbonate (99.0 %) bycarbonate -decomposition method. The experiment mainly introduces the process of purifying of LithiumCarbonate by carbonation -decomposition method, influencing factors of purity and the rate of recovery oflithium carbonate, such as carbonization temperature, the ratio of solid phase and liquid phase, andcarbonization time; and works out the best process conditions: carbonization temperature 28 ℃, the ratio ofsolid phase and liquid phase 1/40, and carbonization time2.0 h, mixing rate of carbonation 300 r/min. Underthese conditions, the purity of prepared lithium carbonate can reach more than 99.60 %, and the rate ofrecovery can reach 70.0 %, with which the requirements of battery grade lithium carbonate are met.