Adduct formation constant in the synergic extraction of several rare earth elements with acetylacetone and 1,10-phenanthroline in nonpolar organic solvents

Abstract

The synergic extraction of La(III), Nd(III), Sm(III), Tb(III) and Lu(III) with 0.1M acetylacetone (Hacac) and 1,10-phenanthroline (phen) in benzene was studied. The adduct formation constant, βs, for RE(acac)3 (phen) in benzene was determined. The βs decreases with inceasing atomic number of RE(III). The βs in different organic solvents can be predicted in connection with the activity coefficients of the solutes, and the validity of this prediction is confirmed by good agreement with the experimental values of βs in carbon tetrachloride and heptane.