Extraction of Selected Lanthanoids and Scandium with Bis(2-ethylhexyl)hydrogenphosphate in 1,1,2,2-Tetrachlorodifluoroethane

Abstract

A study was made of the extraction of Ce, Pm, Eu, Tm and Sc(III) from aqueous into organic medium of 1,1,2,2-tetrachlorodifluoroethane (CFC-112) using bis(2-ethylhexyl)hydrogenphosphate (HDEHP) as extracting reagent. On the basis of earlier work which demonstrated the usefulness of using this type of solvent for extractions with dibutylhydrogenphosphate (HDBP) and also the possibility of using CFC-112 for converting the metal chelates formed to the solid phase, the work was concentrated particularly on the dependence of the extraction of selected lanthanoids on the analytical concentration of HDEHP and also on the [H+] concentration. In addition the dimerization and distribution constants were determined for this reagent in a mixture of CFC-112 with benzene and the extraction constants were determined for the individual metals.