Influence of rare earth elements on extraction of actinium with Di-(2-ethylhexyl)phosphoric acid from inorganic acid solutions

The extraction of actinium by HDEHP solutions in n-heptane as a function of mineral acids and some lanthanides (Ln) in the aqueous phase was studied. It was found that the actinium extraction coefficient in the absence of Ln decreased linearly with acid concentration with the slope of -3 in the whole investigated range of its concentration. In the presence of Ln the extraction coefficient decreased with a smaller slope than in the absence of Ln. This slope decreased with the Ln salt concentration. The extraction coefficient of Ac decreased with a slope of -3 at acid concentrations above 0.1N, regardless of the Ln concentration in the extraction system. (author) 7 refs.; 5 figs