Separation factor of lanthanoids by solvent extraction of their ternary complexes

Abstract

The solvent extraction of praseodymium (III) and neodymium (III) (denoted by M 3+) with 2-thenoyltrifluoroacetone (Htta) into carbon tetrachloride was studied in the absence and presence of tetrabutylammonium ions (tba +). The extraction with Htta was greatly enhanced by the addition of tba +, and this fact was explained in terms of the formation of a ternary complex, M(tta) 4 −tba +. The neutral metal chelate was extracted into the organic phase and associated with ion pairs of the reagents, tta −tba +, in the organic phase. It was concluded that the degree of association of Pr(tta) 3 with tta −tba + (the ion pair) is slightly greater than that of Nd(tta) 3.