碳化法因具有反应高效、工艺简单等特点,已成为电池级碳酸锂生产的主流工艺。但是,在以盐湖锂精矿为原料采用碳化法制备电池级碳酸锂的过程中,还存在碳化过程二氧化碳利用率低、碳化液杂质去除效果不好以及锂的收率低等问题。以盐湖锂精矿为原料,从碳化、净化、热解3个主要环节进行了工艺优化实验,即由常压碳化改为加压碳化、采用化学净化和离子交换树脂吸附相结合的方法去除碳化液中的杂质、由常规热解改为加压热解,可将碳化过程二氧化碳利用率提高到87.4%、净化过程钙镁去除率分别提高到97.92%和96.09% 、全流程锂的直收率提高到82.27%。

The carbonization method of lithium carbonate is characterized by its high reaction efficiency and simple process.It has become the mainstream process for battery-grade lithium carbonate production.However,in the process of preparing battery-grade lithium carbonate by carbonization method and with salt lake lithium concentrate as raw material,there are still problems such as low carbon dioxide utilization in the carbonization process,poor removal of impurities in the carbonized liquid and low lithium yield.With salt lake lithium concentrate as raw material,process optimization experiments were carried out from three main links：carbonization,purification and pyrolysis,that is,changing from atmospheric carbonization to pressurized carbonization,and using a combination of chemical purification and ion exchange resin adsorption to remove carbonization.Impurities in the liquid were changed from conventional pyrolysis to pressure pyrolysis,which can increase the carbon dioxide utilization rate in the carbonization processed to 87.4%,the removal rate of calcium and magnesium in the purification processed to 97.92% and 96.09%,and the direct yield of lithium in the whole processed to 82.27%.