Recovery of cobalt(II) by the hybrid liquid membrane − electrodialysis − electrolysis process
A novel method for cobalt(II) recovery from acidic solutions is studied. The extraction of cobalt(II) ions using the bulk liquid membrane during a galvanostatic electrodialysis-electrolysis process was studied. Solutions of di (2-ethylhexyl) phosphoric acid (D2EHPA)with admixtures of tri-n-octylamine (TOA) in 1,2-dichloroethane were used as liquid membranes. Effects of current density, cobalt(II) concentration and acid concentration in the feed solution, carrier concentration in the liquid membrane, as well as the type and concentration of acid in the cathodic solution were studied, and optimal conditions were determined. Under the optimal conditions it was possible to extract > 99% of cobalt(II) from the acidic feed solution containing 0.01 mol∙L-1 CoSO4. A possibility of effective (> 75 %) transfer of cobalt(II) into dilute solutions of perchloric, sulphuric, hydrochloric and nitric acids was demonstrated. Adherent, compact cobalt electrodeposits with a fine-grained structure were obtained in the studied systems.
Date
01.07.2014.
Keywords
liquid membrane, cobalt, di(2-ethylhexyl)phosphoric acid, electrodialysis, electrodepositon
