Extraction of metals by bis-(2-ethylhexyl) phosphoric acid in 2-ethylhexanoic acid as monomerizing diluent from an aqueous chloride phase: Am(III), Eu(III), Tm(III) and Y(III)

Abstract

The extraction of Am 3+, Eu 3+, Tm 3+ and Y 3+ from an aqueous chloride phase into a solution of bis 2-ethylhexyl phosphoric acid, (2-C 2H 5·C 6H 12O) 2PO(OH), HDEHP, in the monomerizing diluent 2-ethylhexanoic acid has been studied in terms of the concentration of hydrogen ion in the equilibrated aqueous phase and of HDEHP in the opposing equilibrated organic phase. The extraction stoichiometries, with the corresponding expression for K in terms of F (the formality of HDEHP in the organic phase), [H +](the concentration of hydrogen ion in the aqueous phase), and K S , for a 1.00 F(NaCl + HCl) aqueous phase are ▪ where HY represents the monomer of HDEHP and the formulations of extracted species are non-committal with respect to structure. With HZ representing the monomer of 2-ethylhexanoic acid, suggested formulations of the extracted species in terms of homogeneousand heterogeneous dimers are: for Am 3+, and Eu 3+, M(HYZ) 3; and for Tm 3+, Y 3+, M(HY 2) 2(HYZ). The K S values are: Am 3+(5 × 10 −3), Eu 3+(1 × 10 −2), (1 × 10 −2), Tm 3+(7) and Y 3+(2).