Solvent extraction of lanthanide ions with 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 (HPMBP), II. Extraction of erbium(III), ytterbium(III) and lutetium(III) by HPMBP from aqueous-methanol solutions

Abstract

The solvent extraction of lanthanides(III) (Ln=Er, Yb, Lu) by 1-phenyl-3-methyl-4-benzoylpyrazolone-5 (HL) in carbon tetrachloride from aqueous-methanol phase was investigated. The equilibrium constants for the extraction from aqueous −50% (v/v) methanol phase (K ex ), two-phase stability constants of the complexesLnL3 (β 3 * ) and stability constants of complexesLnL2+,LnL 2 + ,LnL3 (β n ) (Ln=Yb, Lu) were calculated. It was confirmed that the addition of methanol to the aqueous phase causes a synergistic effect. The influence of methanol on the dissociation constant of HPMBP (K a ) and the distribution constant of HPMBP (pHL) between carbon tetrachloride and water-methanol solutions was investigated.