Solvent extraction of europium and americium into phenyltrifluoromethyl sulfone by using synergistic mixture of hydrogen dicarbollylcobaltate and “classical” CMPO

Abstract

Extraction of microamounts of europium and americium by a phenyltrifluoromethyl sulfone (FS 13) solution of hydrogen dicarbollylcobaltate (H⁺B⁻) in the presence of octyl-phenyl-N,N-diisobutylcarbamoylmethyl phosphine oxide (“classical” CMPO, L) has been investigated. The equilibrium data have been explained assuming that the complexes ${\text{HL}}_{{}}^{ + }$, ${\text{HL}}_{2}^{ + }$, ${\text{ML}}_{ 2}^{3 + }$, ${\text{ML}}_{ 3}^{3 + }$ and ${\text{ML}}_{ 4}^{3 + }$ (M³⁺ = Eu³⁺, Am³⁺) are extracted into the organic phase. The values of extraction and stability constants of the cationic complex species in FS 13 saturated with water have been determined. It was found that the stability constants of the corresponding complexes ${\text{EuL}}_{n}^{3 + }$ and ${\text{AmL}}_{n}^{3 + }$, where n = 2, 3, 4 and L is “classical” CMPO, in water-saturated FS 13 are comparable.