Synergistic extraction of cobalt and nickel ions by supported liquid membranes with a mixture of TIOA and TBP

Abstract

In this work, the selective separation of cobalt from acidic media, containing both equimolar and non-equimolar mixtures of cobalt and nickel by supported liquid membranes (SLMs), was investigated using Alamine 308 (tri-isooctylamine, TIOA) as the carrier. The liquid membrane consisted of the desired concentration of an extractant (Alamine 308), a modifier (TBP), and a diluent (chloroform). The membrane support was microporous hydrophobic polypropylene Celgard 2500. Parameters, such as the feed solution pH, modifier (TBP) concentration, temperature, stirring speeds, extractant (Alamine 308) concentration, stripping solution type, and the complexing reagent (NH4SCN) concentration were experimentally studied and the optimum conditions were determined. The permeation coefficients (P) and initial fluxes of cobalt were calculated. A separation factor of cobalt over nickel was calculated from the experimental measurements.