Synergistic extraction of radium using 2-thenoyltrifluoroacetone and tributyl phosphate or trioctylphosphine oxide

The extraction of radium into a mixture of 2-thenoyltrifluoroacetone (HTTA) and tributyl phosphate (TBP) or trioctylphosphine oxide (TOPO) in n-hexane or cyclohexane has been investigated with regard to the dependence on pH, and TBP and TOPO concentrations. It has been found that the formation of mixed complexes of the type Ra(TTA)2 and Ra(TTA)2(TOPO)2 occurs and the overall extraction constants of both complexes were calculated. With the systems described, very high distribution ratios of radium have been attained; these may advantageously be used for the separation and concentration of traces of radium. (T.G.)