Characterisation of nickel(II) extraction by 2-hydroxy-5-nonylacetophenone oxime (LIX 84) in a micellar phase

Abstract

The properties of the nickel(II)/2-hydroxy-5-nonylacetophenone oxime (HNAPO), an active ingredient in LIX 84, extraction system were characterised in a micellar system. The extinction coefficient, λmax of HNAPO (316nm) and the Ni2+ complex (387nm) in a neutral micellar system, poly dispersed octa-ethyleneglycol mono-n-dodecyl ether (G 12A8) were determined as 3100 and 3500M -1cm-1, respectively. HNAPO was found to have a neutral micellar phase and bulk aqueous phase pKa of 11.5 and 12.5, respectively. The extraction equilibrium constant, Kex, was determined to be 10-8.0, and the deviation from theory observed at high pH can be accounted for by consideration of the competition for nickel(II) ..