Determination of the composition of complexes formed in europium extraction with tertiary amine nitrates

Extraction of 152Eu with solutions of tridodecylammonium nitrate in carbon tetrachloride has been studied at 20, 30 and 40 deg C. Non-linear dependence of the distribution coefficient on extragent concentration is shown. Solutions of tridodecyl ammonium nitrate have been studied ebulliometrically at 45 deg C in CCl4 containing europium nitrate. The activity coefficients have been calculated for amine nitrate and europium complex assuming the formation of the compound with 2 or 3 molecules of amine nitrate. It is shown that only in the second case the calculation results correspond to experimental dependence of the europium distribution coefficient on the extragent concentration. The conclusion has been made about the formation of the complex of the (R3NH)3M(NO3)6 type