Extraction of Rare Earth Elements(III) from Nitric Acid Solutions with Binary Extractants Based on Dialkylamino Derivatives of Carbamoylmethylphosphine Oxides and Dinonylnaphthalenesulfonic Acid

Abstract

Interphase distribution of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y between aqueous HNO3 solutions and solutions of binary extractants obtained by reaction of equimolar amounts of dialkylamino derivatives of carbamoylmethylphosphine oxides and dinonylnaphthalenesulfonic acid in organic solvents has been studied. Stoichiometry of extracted complexes has been determined, effect of HNO3 concentration in aqueous phase and organic solvent nature on the efficiency of metal ion recovery into organic phase has been considered. On the formation of extractable REE(III) complexes, the cationic moiety of binary extractant provides coordination solvation of REE(III) ions, while anionic moiety offers their high hydrophobicity, which favors to the efficient transition of metal ions into organic phase.