A study on the separation and concentration of Li from Li-containing waste solutions by electrodialysis

Electrodialysis was used to develop a highly efficient process for concentrating and recovering Li from the Li-containing waste solution that is generated after recovering Co and Ni from a leach solution of waste cathode materials of Li ion batteries. The optimum conditions were investigated by comparing the concentration of Li in the concentrated solution, water recovery rate, energy consumption and average flow rate. Limiting current density was also checked. The results showed that the concentration ratio of Li was enhanced up to 133.33% at an applied voltage of 10 V and volume ratio(V_D/V_C) of 4/1. In order to investigate the concentration ratio of Li based on large volume ratio, the total volume of the Li-containing solution was fixed, and the volume ratio of the dilute solution to the concentrate solution was adjusted to 1/1 to 10/1. The concentration ratio of lithium was increased in the initial stage and then decreased due to the osmotic phenomenon. Finally, an the analysis of the experimental results, including concentration ratio, average flux, and energy consumption, determined that the volume ratio(V_D/V_C) of 3/1 at 10 V of applied voltage was most efficient and the concentrate ratio of Li increased up to 160.61%.