Solvent extraction of copper(II) from sulfate media using neutral extractants, Cyanex-921 and Cyanex-923

Solvent extraction of copper(II) from sulfate media using neutral phosphine oxide extractants Cyanex-921 and Cyanex-923 in toluene has been performed. The extraction of Cu-II is quantitative in 0.8 and 0.1 M CH3COONa with 0.025 M Cyanex-921 and 0.25 M Cyanex-923 in toluene, respectively. The extracted Cu-II from the organic phases of both the extractants is stripped out with 4.0 M CH3COOH and determined spectrophotometrically. Effects of various parameters, such as sodium acetate concentration, reagent concentration, effect of various diluents and diverse ions on the extraction of copper are also studied. The extraction reactions proceed by solvation and their probable extracted species are [Cu(Ac)(2).2(Cyanex-921)] and [Cu(Ac)(2).2(Cyanex-921)].