Selective Extraction of Americium from Curium and the Lanthanides by the Lipophilic Ligand CyMe₄BTPhen Dissolved in Aliquat-336 Nitrate Ionic Liquid

Abstract

The feasibility of separating americium from curium and the lanthanides was studied in batch solvent extraction experiments using an organic solvent composed of 0.01 mol L−1 2,9-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-1,10-phenanthroline (CyMe4BTPhen) in the ionic liquid Aliquat-336 nitrate [A336][NO3] from feed solutions containing N,N,N’,N’-tetraethyl diglycolamide (TEDGA), stable lanthanide ions and tracers of 241Am, 244Cm, and 152Eu. The combined use of a lipophilic and a hydrophilic ligand with opposite selectivity for Am(III) vs. Cm(III) and Ln(III) allowed the separation of Am(III) from Cm(III) and Ln(III) from moderate acidic feed solutions (1 mol L−1 HNO3, SFAm/Cm = 3.1–3.9, SFAm/La > 75, SFAm/Eu ≥ 3000).