,6-TRISDIALKYL(DIARYL)PHOSPHORYL!-1,3,5-TRIAZINES AS EXTRACTANTS FORTRANSPLUTONIUM AND RARE-EARTH ELEMENTS

The extraction ability and selectivity of ,6-trisdialkyl(diaryl)phosp horyl!-1,3,5-triazines with various substituents on the P atoms for tr ivalent transplutonium (TPE) and rare-earth (REE) elements are studied . The most effective reagent is the toluene-substituted one. The TPE a nd REE are extracted much more effectively from SCN-HCL solutions than from HNO3 solutions. IR spectroscopy using Nd as an example demonstra ted that two phosphoryl groups and not the nitrogens form a chelate co mplex with the elements. The basicity of the reagents is determined. I R spectroscopy can detect the hydrolysis products of the reagents, cya nuric acid, after contact with 0.1 M HNO3 but not after contact with 3 M acid. The reagents exhibit selectivity for the TPE during extractio n from HNO3 and especially from SCN solutions. The intergroup separati on factor, defined as the ratio of the distribution coefficients of Cm and Ce, reaches approximately 10 on extraction from SCN solutions.