Solvent extraction of nickel(II) by combinations of aliphatic diamines and carboxylic acids

Abstract

Extraction of nickel(II) into methyl isobutyl ketone by aromatic carboxylic acids is enhanced in the presence of N- and C- methyl substituted diamines. In diamine/salicylic acid systems the extracted species are mono and/or bis-diamine complexes in which charge-reduction is effected by coordination of the bisalicylate anion. There is evidence that the monoammines are solvated by methyl isobutyl ketone whereas the bis-ammines are coordinately-saturated by direct coordination of bisalicylate ions of the nickel(II). The effect of diamines on the extraction of nickel(II) by aliphatic carboxylic acids is relatively small because these acids are effective extractants in their own right.