METHOD FOR SEPARATING TRIVALENT ACTINIDES FROM AT LEAST ONE TRIVALENT LANTHANIDE BY MEANS OF (BIS)ARYLDITHIOPHOSPHONIC ACID AS ORGANOPHOSPHATE AS SYNERGIST

摘要

The invention relates to a method for separating trivalent actinides from at least trivalent lanthanides, whereby said trivalent actinides are extracted from an aqueous solution containing a H+ concentration of 0.01 to 2 mol/1 by using an (aryl)dithiophosphonic acid of the general formula (4) = R1R2PS(SH), in which R1 = phenyl or naphthyl, R2 = phenyl or naphthyl, as well as rests of R1 and R2 substituted by methyl, ethyl, propyl, isopropyl, cyano, nitro or halogenyl, with addition of trioctylphosphate, tris-(2-propypentyl)-phosphate or tris-(2-ethylhexyl)-phosphate as synergist. The use of synergists according to the invention allows for a more selective extraction. In a more advantageous formulation, the aromatic solvent used is at least one component from the toluol, xylol, tert.-(butyl)-benzol, bis-(tert.-butyl)-benzol, bis-(tert.-butyl)-benzol, tris-(tert.-butyl)-benzol, bis-isopropylbenzol and tri-isopropylbenzol, resulting in increased selectivity An(III) and distribution coefficient DAn(III).