The effect of irradiation on hydrodynamic properties of extraction mixtures based on diamides of N-heterocyclic dicarboxylic acids in heavy fluorinated diluents

Abstract

Hydrodynamic properties have been investigated for promising extraction systems: 0.05 mol L−1 solutions of di(N-ethyl-4-ethylanilide) of 2,2′-bipyridine-6,6′-dicarboxylic acid, di(N-ethyl-4-fluoroanilide) of 2,6-pyridinedicarboxylic acid and di(N-ethyl-4-hexylanilide) of 2,2′-bipyridine-6,6′-dicarboxylic acid in meta-nitrobenzotrifluoride (F-3) or trifluoromethylphenyl sulfone (FS-13) diluents. To evaluate the perspectives for their use as extraction mixtures at the final stage of the nuclear fuel cycle, the change in density, viscosity, surface tension, and phase separation rate under irradiation with accelerated electrons was studied. The concentrations of extractants in the irradiated mixtures have been determined and the radiation-chemical yields have been calculated. Irradiation significantly decreases the phase separation rate at the stages of extraction and back extraction for all the studied systems. The viscosity of the DYP-7 solution in FS-13 increase above the values suitable for its use in extraction processes. Keywords: Diamides of dicarboxylic acids, Meta-nitrobenzotrifluoride, Trifluoromethylphenyl sulfone, Irradiation, Hydrodynamic stability