Experimental and Modeling of Extraction of Lanthanides in System HNO3-TEDGA-{DMDOHEMA-HDEHP}

This paper presents the development of a model which calculates the composition of the organic phase for a system used to remove selectively americium from a PUREX raffinate. A phenomenological approach is performed to aggregate step by step the specificities of this complex extraction system. Modeling of the influence of TEDGA is complex because experiments have shown that the water-soluble ligand TEDGA is extracted by the diamide and that its extraction is enhanced in presence of lanthanides. The formation of mixed solvates lanthanides-TEDGA-DMDOHEMA is thus taken into account.