Recovery of nickel,cobalt,copper and zinc in sulphate and chloride solutions using synergistic solvent extraction

A number of synergistic solvent extraction （SSX） systems have been developed to recover nickel, cobalt, zinc and copper from sulphuric and chloride leach solutions by the solvent extraction team of CSIRO, Australia. These in- clude （1） Versatic 10/CLXS0 system for the separation of Ni from Ca in sulphate solutions, （2） Versatic 10/4PC system for the separation of Ni and Co from Mn/Mg/Ca in sulphate solutions, （3） Cyanex 471X/HRJ-4277 system for the separation of Zn from Cd in sulphate solutions, （4） Versatic 10/LIX63 system for the separation of Co from Mn/Mg/Ca in sulphate solutions, （5） Versatic 10/LIX63/TBP system for separation of Ni and Co from Mn/Mg/Ca in sulphate solutions, （6） Versatic 10/LIX63 system for the separation of cobalt from nickel in sulphate solutions by difference in kinetics, （7） Cyanex 272/LIX84 system for the separation of Cu/Fe/Zn from Ni/Co in sulphate solutions, （8） Versatic 10/LIX63fFBP system to recover Cu/Ni from strong chloride solutions, and [9） Versatic 10/LIX63 system to separate Cu from Fe in strong chloride solutions. The synergistic effect on metal separation and efficiency is presented and possible industrial applications are demonstrated. The chemical stability of selected SSX systems is also reported.

Phase separation in solvent extraction of cobalt from acidic sulfate solution using synergistic mixture containing dinonylnaphthalene sulfonic acid and 2-ethylhexyl 4-pyridinecarboxylate ester

Phase separation rate is a critical character in determining the usefulness of a solvent extraction system in hydrometallurgy. A survey of the synergistic mixture containing dinonylnaphthalene sulfonic acid (HDNNS) and 2-ethylhexly 4-pyridinecarboxylate ester (4PC) for the extraction of cobalt from acidic single metal sulfate solution was carried out to suggest how the physicochemical properties and the morphology of the reverse micelles in the loaded organic phase affect the phase separation. The results show that effective parameters affecting the phase separation are the viscosity and the excess water uptake of the loaded organic phase. It is obvious that the specific settling rate (SSR) decreases with the apparent increase of these two parameters. The measurement of small angle X-ray scattering (SAXS) proves that the morphology of the reversed micelles in the loaded organic phase changes evidently with the change of the specific settling rate (SSR).