Production method of zinc sulfate heptahydrate

The invention provides a production method of zinc sulfate heptahydrate, which comprises the following steps: adding zinc oxide into a solution containing 15-35% sulfuric acid, starting steam to sufficiently heat and stir according to the mass ratio of zinc oxide to the solution of 1: (6-8), starting stirring and steam heating, adding lime milk to adjust the PH value to be acidic, heating the mixture to 70-80 DEG C, controlling the temperature for reaction for 30 min-1 h, adding hydrogen peroxide with the concentration of 30% into the solution, carrying out a reaction process for 1 h, and feeding the filtrate and the washing liquid into evaporation equipment together, heating and evaporating under the condition of slow stirring until a small amount of crystals are separated out, stopping heating, cooling, preserving heat, filtering or centrifugally separating to obtain crystals, namely zinc sulfate heptahydrate and a clear liquid. The production method of zinc sulfate heptahydrate disclosed by the invention i