Extraction of Rare Earth Elements(III) with Picrolonic Acid Mixtures with Phosphoryl-Substituted Aza Podands

Extraction of rare earth element(III) (REE) ions from chloride solutions with picrolonic acid mixtures with phosphoryl-substituted aza podands in chloroform has been studied. A considerable synergetic effect observed has been caused by the formation of hydrophobic mixed-ligand complexes of REE. The stoichiometry of extracted complexes has been determined and extraction constants have been calculated. The effect of aqueous phase composition, organic solvent nature, and the structure of phosphoryl-substituted aza podands on the efficiency of REE(III) recovery into organic phase have been considered.