| The main objective of this investigation was to study and improve the precipitation characteristics of Ni(OH)2 in a sulphate system at various temperatures and pHs. Solubility tests were performed by dissolving crystalline Ni(OH)2 at constant pH and temperature for various test conditions. These results were then utilised to design alternative precipitation strategies with the objective of producing clean and easily filterable nickel hydroxide. Homogeneous Ni(OH)2 precipitation was performed using NaOH solution and MgO slurry at various temperatures and pHs in pure and impure aqueous systems. Ni(OH)2 was also produced by using controlled supersaturation technique in order to improve product quality. The use of supersaturation control improved particle morphology, crystallinity, settling rates and % solids density; however, sulphate and magnesium uptake was not eliminated by this precipitation technique. |
