Synergistic Extraction Studies of Thiocyanate Complexes of Gadolinium, Dysprosium and Erbium with Mixture of Tributyl Phosphate and Tricaprylmonomethylammonium Chloride

抄録

The synergistic extraction behavior of thiocyanate complexes of gadolinium, dysprosium and erbium has been studied for a mixed system: M³⁺/NH₄SCN/tributyl phosphate (TBP)+tricaprylmonomethylammonium chloride (Aliquat-336)+ xylene. The percentage extraction and distribution ratios were measured as a function of the pH as well as the NH₄SCN, Aliquat-336 and TBP concentrations, respectively. The percentage extraction of gadolinium, dysprosium and erbium increases with increase in pH. It was significant in the pH range 4 to 6 in a thiocyanate media. The composition of a binary synergistic extracted complex of lanthanides into the organic phase is probably M(SCN)₅^2-(L⁺)₂•2TBP_o under the conditions studied. The synergistic extraction sequence as a function of the atomic number of lanthanide elements is given.