SOLVENT-EXTRACTION OF COPPER(II), NICKEL(II) AND COBALT(II) FROM HALIDE AND THIOCYANATE SOLUTIONS BY ALDOXIMES

The extraction of divalent copper, nickel and cobalt from acidic chloride solutions with solutions of heptaloxime, nonaloxime and 2-methyldekaloxime in toluene has been studied at 18-degrees-C. These metals were found to be extracted according to the following solvation reaction: M(aq)2+ + 2Cl(aq)2- + 40x(org) = MCl2Ox4(org) (M = Cu,Ni,Co) The influence of syn-anti isomerization of aldoximes on the extraction has been discussed. Taking into account association and syn - anti isomerization constants of aldoximes in organic phase, hydration of extracted complexes and activities of salts in aqueous phase, effective extraction constants have been calculated for chloride solutions. Separation of nickel and cobalt from acidic chloride, bromide and thiocyanate solutions by extraction with heptaloxime has been studied.