Study On Technologies Of Preparing Battery Grade Lithium Carbonate With Tibet Saline Lake Lithium Concentrate

Lithium mineral mainly exist in saline brine, spodumene as well as lepidolite which in China and its reserve is abundant. Zabuye Salt Lake is the third largest lithium salt lake in the world and the total reserves of 523 million tons, which have laid a solid foundation for self-development of lithium resources. Lithium carbonate is used in the production of industrial raw material. With the development of new energy materials technology, lithium carbonate application research in lithium ion batteries constantly deepened. The research may have on important guiding significance for the preparation of lithium carbonate.Based on the analysis of lithium carbonate resources, application and production process, this article based on fundamental of carbonation reaction take the salt lake lithium concentrate as the main study subject in Tibet, two types of salt lake lithium concentrate have been chosen as raw material, respectively. Focusing on the causticizing-carbonizing technique and carbonizing-ion exchange technique can be used to prepare battery grade lithium carbonate.This study investigates the relevant properties of Lithium carbonate in aqueous solutions and also optimizes the optimum washing conditions, causticizing method conditions, carbonization, ion exchange conditions and crystallization conditions by experiments. Eventually chooses the carbonizing-ion exchange technique, Optimum carbonization conditions: normal temperature; reaction time; liquid-solid ratio: 20: 1; the Li concentration of carbonization solution should be kept at 5g/L to 6g/L; the PH value of the reaction should be kept at 6 to 7. Solution purification selects the amino phosphonic acid chelating resin and meglumine chelating resin. Si purification conditions: use a rotary evaporator and keep the negative pressure at-0.6 to 0.07. Keep the temperature of water bath at 65 to 70℃ ℃.To engineering budget based on production practice, the environmental problems that exist in production process have been analyzed system. At the same time, a tentative idea for development of the recycling use of CO2 and solid-liquid separation methods is put forward.This process is economically viable and all according with environmental protection demand, which a direct recovery rate of 81.6% and the product specifications meet the YS/T 582-2006 standard. Research products of this paper have important directions to exploitation and utilization of salt lake lithium resources in Tibet.