COEXTRACTION BEHAVIOR OF TC(VII) AND U(VI) BY CMPO

The coextraction behavior of technetium(VII) and uranium(VI) from nitr ic acid solution by tyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) in the absence or presence of tributyl phosphate (TBP) w as investigated. The extraction of technetium was remarkably enhanced in the presence of uranium at less than 0.1M nitric acid concentration , and with the initial concentration ratio of [U]/[Tc] = 50 in the aqu eous phase, the distribution coefficient of Tc(VII) at 0.01M nitric ac id was about one hundred times greater than that obtained in the absen ce of uranium. The coextraction of technetium and uranium was presumed to occur due to the same ion exchange mechanism as reported in the Tc -U-TBP system. However, the effect of TBP on this coextraction was not observed in the present study.