Optimization of the Nickel Removal Process From Zinc Sulfate Solution Using Central Composite Design of Experiments

Nickel is one of the metallic impurities that should be removed from the electrolyte solution before the electrowinning of zinc. This study investigated the parameters affecting the process of nickel removal in an Iranian zinc smelter plant by the response surface methodology. According to the results of experiments, the optimum condition for removal of nickel was obtained at temperature of 85 °C, the residence time of 60 minutes, zinc powder of 2.5 g/l, mixing speed of 500 rpm, and pH of 5. With regards to the resulting model from the Design-Expert software, the significant parameters were concentration, residence time, and temperature, respectively.