Liquid-liquid separation of Cd (II) from Cu-sulfide cake prepared from sulfate solution of Abu-Thor ore material, Southwestern, Sinai, Egypt

Abstract

The present work is concerned with the subsequent liquid-liquid separation of Cu, Zn, and Cd compounds from Cu- sulfide cake prepared from the sulfate solution of Abu-Thor Gibbsite-bearing shale ore material. This ore was found assaying 0.014% of Cd, 0.5% of Cu, and 0.55% of Zn as the elements of interest, by using 25% of H₂SO₄ solution at a solid/liquid ratio of 1/3 reaction time of 90 min at a temperature of 80 ◦C. About 96.5% of Cu (II), 99.3% of Cd (II), and 95.6% of Zn (II), respectively, were dissolved. After filtration, the prepared sulfate solution was treated with a suitable weight of Na₂S to prepare the working Cu-sulfide cake, which was then wholly re-dissolved in 10% of H₂SO₄ solution to prepare the working sulfate solution, which contained the elements of interest. This solution was gone out to the organic solvent process for complete separating between the Cu (II), Zn (II) ions in the organic phase, and Cd (II) ions in the aqueous phase. The effective extraction parameters such as pH value, LIX concentration, contact time, and organic/aqueous ratio were studied. The obtained data cleared that the pH value of 2.5 was found effective for separating Cd (II) in the aqueous phase and both Zn (II) and Cu (II) in the organic phase. Where Cd (II) ions were precipitated as CdS using Na₂S solution at pH 0.89, on the other side, both Zn (II) and Cu (II) were completely separated in the stripping process using Na₂CO₃ solution.