Separation of Transplutonium and Rare-Earth Elements by Extraction with Di-isodecyl Phosphoric Acid from DTPA Solution

Abstract

The distribution ratio Df and the separation factor β for Nd(III) to Am(III) were studied in DIDPA-DTPA systems to determine optimum conditions for applying DIDPA to the TALSPEAK type extraction process to separate transplutonides from lanthanoids in the partitioning of high-level waste of nuclear fuel reprocessing. Extraction of lanthanoids from 0.05–0.1 M DTPA-1 M lactic acid (pH 3.0) aqueous solution into 0.2–0.3 M DIDPA in DIPB gives the separation factor of 20 revealing practicability of this system in the partitioning. The nature of diluent affects greatly Df, and DIPB proved to be the most appropriate one for the separation of transplutonides from lanthanoids. The presence of lactic acid in the aqueous phase improved the extraction kinetics in DIDPA-DTPA system.