Hydride Decomposition From Industrial-grade Lithium Carbonate Purified Preparation Of Battery Grade Lithium Carbonate

Lithium carbonate is a very important material for national economy, national defense construction and human daily life. It is the basical material, bing widely used in battery, ceramic, metallurgy, energy, medicine, et al, due to its excellent performance.In this paper, the applications and resource distribution of lithium carbonate were firstly presented. Then the categories, properties and preparations of Li2CO3 were introduced. Battery-grade Li2CO3 was prepared by carbonation-decomposition mothed using the industrial-grade Li2CO3. At the same time, ion exchange mothed was also studied in the removal of the impurities, such as Ca and Mg.The carbonation experiments were carried out in a three-phase mechanically agitated slurry-bed reactor. Battery-grade Li2CO3 could be basically obtained by carbonation-decomposition mothed using the industrial-grade Li2CO3. The effect of carbonation conditions, such as carbonation temperature, CO2 flow rate, carbonation time and the ratio of solid phase and liquid phase (S/L), on the purification was further investigated. The optimal carbonation conditions, i.e. the carbonation conditions being 25℃, the CO2 flow rate being 3L/min, the carbonation time being 40 min, the ratio of solid phase and liquid phase (S/L) being 1:30 were determined. The purity and the productivity of product were relatively high under above carbonation conditions.The effect of cycles of the mother liquor on purification was importantly investigated in this paper. Results showed that the process of cycles can improve the purity and productivity of Li2CO3. But 4 cycles were appropriate considering the decrease of the purity of product and the increase of impurities contents.The investigation of ion exchange mothed showed that it is necessary to combine ion-exchange method with carbonation-decomposition process for removing Ca and Mg deeply and improving purity largely. And Then, It was found that 15 ml/min of flowing speed was appropriate for the ion-exchange process after the flowing speed experiments.Purier Li2CO3 was obtained by combining carbonation-decomposition mothed and ion exchange mothed using above optimal conditions. This Li2CO3 has been up to the industrial standard of battery-grade Li2CO3 and used to prepare other material of lithium ion battery.