Oxidative hydrolysis of Fe(Ⅱ) in the process of hydrothermal synthesis of hematite

Iron removal is an important step in zinc hydrometallurgy, and hematite process not only can effectively remove iron, but also is environmentally friendly and has certain economic benefits, so it has great application potential in zinc hydrometallurgy. The oxidative hydrolysis of Fe(Ⅱ) was studied by the change of ions in solution with different initial ferrous ion concentration. Meanwhile, the oxidation rates of Fe(Ⅱ) at different initial Zn(Ⅱ) concentrations were also studied. The results show that temperature has an important influence on the oxidative hydrolysis of Fe(Ⅱ). Increasing the temperature can inhibit the formation of complex and make more Fe(Ⅱ) precipitate directly in the form of hematite, which is not limited by the hydrolysis rate of Fe(Ⅲ). The oxidation reaction of Fe(Ⅱ) approximately conforms to the second order reaction rate. Zinc sulfate can promote the oxidation of Fe(Ⅱ). When the initial Zn(Ⅱ) concentration was 20, 40, 60 and 80 g/L, the oxidation kinetic constants of Fe(Ⅱ) were 2.433, 4.492, 10.106 and 14.857 L·mol−1·min−1, respectively.