EXTRACTION OF ACTINIDES AND LANTHANIDES WITH NEAT DIPHENYL(DIBUTYLCARBAMOYLMETHYL)PHOSPHINE OXIDE

Solid diphenyl(dibutylcarbamoylmethyl)phosphine oxide (Ph2Bu2) on cont act with nitric acid forms a liquid phase immiscible with the acid. Th is neat liquid effectively extracts lanthanides and actinides in vario us valence states. The composition of the liquid is Ph2Bu2. HNO3. nH(2 )O, where n = 2-3. The kinetics of formation of this compound and extr action of Am(III) were studied. Extraction of a series of actinides in various valence states and of Pr(III) was investigated. The complex o f the reagent with the acid exhibits redox properties, owing to which some actinides change valence state in the course of extraction. The o ccurrence of aryl strengthening in extraction of Am(III) with the neat complex was presumed. Similar formation of an extraction-active liqui d phase on contact with mineral acids is observed with many mono- and bidentate neutral organophosphorus compounds.