REACTION STOICHIOMETRY FOR COEXTRACTION OF TECHNETIUM(VII) WITH URANIUM(VI) BY CMPO

The coextraction equilibrium of technetium(VII) and uranium(VI) from n itric acid solution was studied in a system involving n-octyl(phenyl)- N,N-diisobutylcabamoylmethyl phosphine oxide (CMPO) in decalin. Stoich iometry of technetium, uranium and CMPO in the Tc-U-CMPO complex was o btained from the distribution data by slope analysis. The results indi cated that the enhanced extraction of technetium was caused by the for mation of UO2NO3TcO4 . nCMPO (where n=2 and/or 3), It was found that t his coextraction of technetium with uranium was well explained by usin g ion exchange reaction between UO2(NO3)(2) . 2CMPO complex and TcO4-.