Synergistic extraction of yttrium using mixtures of organophosphorus extractants

Abstract

The synergistic solvent extraction of yttrium from acidic nitric solution was carried out using organophosphorus mixed extractants of di(-2-ethyl hexyl) phosphoric acid – tri-n-octyl phosphine oxide and Cyanex 572 – tributyl phosphate in kerosene diluent. The effect of the concentration ratio between each of the extractants on the synergism phenomenon of the yttrium extraction process was investigated. This experiment was performed by dissolving yttrium concentrate in aqueous HNO3 then it is extracted using D2EHPA, TOPO, a mixture of D2EHPA - TOPO, Cyanex 572, TBP, and also a mixture of Cyanex 572 - TBP in kerosene diluent, at various concentrations with the ratio aqueous phase: organic phase=1: 1 until the equilibrium conditions. The result showed that a slight synergism phenomenon occurs in extraction using a mixture of di(-2-ethyl hexyl) phosphoric acid - tri-n-octyl phosphine oxide extractants as indicated by a range of synergistic coefficient (S) values between 1.0179 - 1.7047. The stronger synergism phenomenon is given by the extraction process using a mixture of Cyanex 572 - tributyl phosphate with susceptible synergistic coefficient (S) values of 3.4646 to infinity.