Utilization of Electrodeionization for Lithium Removal.

In this work, usage of a hybrid polymeric ion exchange resin and a polymeric ion exchange membrane in the same unit to remove Li from aqueous solutions was reported. The effects of the applied potential difference to the electrodes, the flow rate of the Li-containing solution, the presence of coexisting ions (Na, K, Ca, Ba, and Mg), and the influence of the electrolyte concentration in the anode and cathode chambers on Li removal were investigated. At 20 V, 99% of Li was removed from the Li-containing solution. In addition, a decrease in the flow rate of the Li-containing solution from 2 to 1 L/h resulted in a decrease in the removal rate from 99 to 94%. Similar results were obtained when the concentration of NaSO was decreased from 0.01 to 0.005 M. The selectivity test showed that the simultaneous presence of monovalent ions such as Na and K did not change the removal rate of Li. However, the presence of divalent ions, Ca, Mg, and Ba, reduced the removal rate of Li. Under optimal conditions, the mass transport coefficient of Li was found as 5.39 × 10 m/s, and the specific energy consumption was found as 106.2 W h/g LiCl. Electrodeionization provided stable performance in terms of the removal rate and transport of Li from the central compartment to the cathode compartment.