氯化锂电解条件对氯离子迁移的影响

Influence of Lithium Chloride Electrolysis Factors on the Chloride Ion Migration

电解氯化锂溶液制备氢氧化锂的过程中,水分子伴随阳离子通过离子膜发生移动,从而使阳极液中的氯离子迁移到阴极液中,增加了阴极液中Cl-的含量,影响氢氧化锂产品纯度。采用自制的电解槽装置,用DF988膜进行了较为系统的实验研究,在阳极液初始浓度、阴极液初始浓度、电流密度、循环流量和温度等不同条件下,测定了阴极液中氯离子的含量。结果表明,电流密度和温度对氯离子迁移有明显的影响。随着电流密度的增加,氯离子迁移的速率明显降低;反应温度越高,电解中氯离子的迁移速率越大;阴、阳极液初始浓度对氯离子迁移影响明显;循环流量对氯离子迁移的影响较小。

In the process of lithium choloride electrocysis to lithium bhdroxide, along with the hydrated lithium passing through the ion-exchange membrame, the chloride ion in the anolyte was migrated to the cathode,increasing the Cl- content of eatholyte, thus affecting the purity of lithium hydroxide. The Cl- migration was investigated systematically using self-made electrolysis equipment and DF988 ion-exchange membrane. The chloride ion content in catholyte were determined under different conditions,including anolyte initial concentration, catholyte initial concentration, current density, circulation flow and temperature. The results show that Cl- migration was remarkably affected by the reaction temperature and current density. The speed of Cl- migration in electrolysis increased with the increasing of reaction temperature and decreased with the increasing of current density. The decreasing of anolyte concentration can increase the Cl- migration. The initial concentration of the electrolytes has an obvious influence on Cl- migration while the speed of Cl- migration being slightly affected by the increase of circular flow.