选择性电渗析提锂技术的研究进展

Research and prospect of lithium extraction by selective electrodialysis

伴随电动汽车等新兴行业的快速发展,市场对锂及其化合物的需求高速增长。开展高储量、低品位的盐湖卤水、(浓)海水及油气资源生产水中溶存锂资源的高效提取具有重要意义。不少地区的溶存锂资源中镁锂比高,分离难度大,目前尚未实现充分开发利用。基于单价选择性离子交换膜的单价离子选择性电迁移特性,选择性电渗析(Selective Electrodialysis,S-ED)逐步应用于高镁锂比水体中镁锂间的预分离与锂的初步纯化。S-ED在保证较高锂回收率的条件下可获得低镁锂比的锂富集液,展现出较高的研究价值与应用前景。本文综述了S-ED用于盐湖卤水和(浓)海水中锂资源提取的研究现状,重点总结了主要操作参数和共存离子对S-ED提锂性能的影响规律,对目前高镁锂比水体选择性电渗析提锂技术存在的不足进行了总结,并对其未来发展趋势进行了展望。

With the rapid development of emerging industries such as electric vehicles,the market demand for lithium and its compounds is growing rapidly.It is of great significance to carry out the efficient extraction of dissolved lithium resources with high reserve and low-grade from salt lake brine,(concentrated)seawater,and oil and gas production water.In many areas,since the dissolved lithium resources have a high ratio of magnesium to lithium and the separation is difficult,it has not been fully developed and utilized.Based on the unique monovalent ion selective electromigration characteristics of monovalent selective ion exchange membrane,selective electrodialysis(S-ED)has gradually been applied to the pre-separation between magnesium and lithium and the preliminary purification of lithium from brine with a high magnesium-lithium ratio.Under the condition of ensuring high lithium recovery,a lithium enrichment solution with low magnesium-lithium ratio can be obtained,which shows its high research value and application prospect.This paper reviews the research status of S-ED in the lithium extraction from salt lake brine and(concentrated)seawater,and makes a special focus on the effects of main operating parameters and coexisting ions on the extraction of lithium.The shortcomings of the state of S-ED and its prospects of development trend for lithium extraction with high magnesium-lithium ratio was analyzed.