Separation of cobalt and nickel from ammoniacal solution by solvent extraction with β-hydroxyoxime N530 as extractant

The extractability of N530 (2-hydroxy-4-sec-octanoyl diphenyl ketoxime) in an ammoniacal (NH4)2SO4, NH4Cl or (NH4)2CO3 solution of Co(II) and Ni(II) and a method for separating the two elements with N530 as extractant have been studied. It is difficult to separate them at the extraction stage because the extractability of N530 is similar to that of Co(II) and Ni(II). The separation, however, can be easily achieved by selective stripping. Ni(II) is reextracted with dilute H2SO4(4)2S2O8 or air as oxidizer and Co(III) is not extractable by N530 in kerosine, nickel can thus be separated from cobalt by solvent extraction.