Separation of Cobalt by Liquid Surfactant Membranes

Abstract

An experimental study is presented on the separation of cobalt(II) cations from an aqueous solution by means of liquid surfactant membranes containing the ion exchanger di(2-ethylhexyl)phosphoric acid. The process was studied at various emulsifier (Span 80) concentrations, membrane viscosities, pHs, and rates of stirring as well as at various KNO₃ and cobalt concentrations. Cobalt recovery over 99% was achieved with up to tenfold enrichment. A substantial difference of the process course for cobalt and copper was found which allowed for their effective separation.