Patent ID: 6843917

Claim:
Process for separating lanthanides from one another and/or lanthanides from actinides and/or actinides from one another and/or from other transition metals in an aqueous medium, comprising the steps of: a) treating of the aqueous medium with at least one ligand selected from the group consisting of ethylenediamine-tetraacetic acid, linear polyamino acids and cyclic polyamino acids; b) (nano)filtering the aqueous solution treated with the at least one ligand through a membrane, under a transmembrane pressure greater than or equal to 0.01 MPa, so as to collect a retentate enriched in at least one species of lanthanide, actinide or other transition metal which is at least partially complexed with the ligand, and a permeate impoverished in said species; and c) optionally recovering the ligand/species complexes to be separated from the retentate, and treating the complexes with at least one decomplexing agent so as to separate the at least one ligand from the species.