Extraction and Sorption Preconcentration of U(VI), Th(IV), and REE(III) from Nitric Acid Solutions Using Bis [2-(diphenylphosphinyl)phenoxymethyl]phosphinic Acid

摘要

Extraction of microamounts of U(VI) and Th(IV) from HNO_(3) solutions in the form of complexes with polyfunctional organophosphorus acids was studied. The influence of the extractant structure on the efficiency and selectivity of the extraction of U(VI) and Th(IV) was examined, and the stoichiometry of the extractable complexes was determined. The possibility of preconcentration of U(VI), Th(IV), and REE(III) from nitric acid solutions with a complexing sorbent prepared by noncovalent immobilization of bis[2-(diphenylphosphinyl)phenoxymethyl]phosphinic acid on a macroporous polymeric matrix was demonstrated.