MATHEMATIC MODEL OF DISTRIBUTION EQUILIBRIA IN THE EXTRACTION OF U(VI), U(IV), PU(IV), NP(VI), NP(IV), AND NITRIC-ACID BY 30-PERCENT TRIBUTYL-PHOSPHATE (TBP) IN ALIPHATIC DILUENTS

Empiric equations are suggested for the calculation of the distribution ratios of U(VI) (also in the presence of Pu(IV) or U(IV)), U(IV)), (also in the presence of U(VI)), Pu (IV) (also in the presence of U(VI)), Np(IV) and Np (VI) (also in the presence of U(VI) and HNO//3 (also in the presence of U(VI) and Pu(IV) in the extraction with 30% TBP in an individual or mixed aliphatic diluent from nitric acid solutions. The distribution ratios are calculated from concentrations of HNO//3, U(VI), and Pu(IV) (or some of them) in the equilibrium aqueous phase.