Extraction of Rare Earth Elements(III) from HNO3 and HCl Solutions with Mixtures of Carbamoylmethylphosphine Oxides and Picrolonic Acid

Extraction of REE(III) microamounts from HNO3 and HCl solutions with mixtures of mono- and bis-carbamoylmethylphosphine oxides with picrolonic acid in 1,2-dichloroethane was studied. The strong synergistic effect observed is due to increased hydrophobicity of the extractable complexes. The influence of the structure of carbamoylmethylphosphine oxides on the REE(III) extraction efficiency was considered, and the stoichiometry of the extractable complexes was determined. The possibility of REE(III) recovery and preconcentration from nitric acid solutions with a complexing sorbent prepared by noncovalent immobilization of the reagent mixture on the surface of a macroporous polymeric sorbent was demonstrated.