二氟草酸硼酸锂的提纯工艺

Purification Process of Lithium Difluoro Oxalate Borate

二氟草酸硼酸锂(LiDFOB)生产过程的副产物四氟硼酸锂(LiBF4)难以去除,现有方案为多次结晶提高纯度,但产品收率低且成本高。研究了溶剂、溶剂用量、溶解温度、析晶方式对提纯效果的影响。结果表明:乙酸乙酯作为提纯溶剂,1.3倍添加量、溶解温度55℃、二氯甲烷作为析晶剂条件下,一次结晶即可得到纯度99.8%,收率为93.5%的LiDFOB。通过优化工艺,能够实现降本增效。

Lithium tetrafluoroborate,by-product of lithium difluorooxalate production process,is difficult to remove.Improvement of purity by multiple crystallization,but the yield is low and the cost is high.The effects of solvent,solvent amount,dissolution temperature and crystallization method on the purification effect are studied.The results show that:ethyl acetate is used as purification solvent,under the conditions of 1.3 times addition,55℃dissolution temperature and dichloromethane as crystallization agent.The purity of 99.8%and LiDFOB of 93.5%yield can be obtained by primary crystallization.By optimizing the process,it can achieve cost reduction and efficiency increase.