Abstract:This paper studies the process feasibility and optimum conditions of removing impurities such as iron, cobalt, calcium and magnesium from the crude nickel sulfate by using ozone and sodium fluoride as the impurity removal reagent, and using the process of "dissolving -- removing iron and cobalt by strong oxidation -- removing calcium and magnesium by fluoridation -- crystallization precipitation" as the main process. The experimental results show that iron and cobalt impurities in crude nickel sulfate can be deeply removed by using ozone as strong oxidant, the optimum reaction conditions are as follows: Reaction Temperature 80 °C, Reaction Time 8 h, end-point pH 4.5~5.0, the concentration of iron and cobalt in the solution at the end of the reaction is less than 0.005g/L; And the calcium and magnesium impurities in crude nickel sulfate can be deeply removed with sodium fluoride as additive, the optimum reaction conditions are as follows: Reaction Temperature is 90 °C, Reaction Time is 2 h, pH 5.5, and the addition coefficient of sodium fluoride 1.5, the calcium concentration in the solution at the end of the reaction is 0.007g/L, and the magnesium concentration is 0.005g/L; Combining the process of "removing iron and cobalt by strong oxidation" and "removing calcium and magnesium by sodium fluoride", a better effect of removing impurities can be obtained.