Method for preparing zinc sulfate heptahydrate from flotation lead tailings

The invention discloses a method for preparing zinc sulfate heptahydrate through flotation of lead tailings. The method comprises the steps of crushing and ore grinding, leaching, solid-liquid separation, removal of ferromanganese through oxidative hydrolysis, removal of cadmium through zinc powder replacement, removal of calcium and magnesium through a precipitation method, extraction and back extraction, evaporative crystallization and the like. According to the method, zinc is extracted from the flotation lead tailings and zinc sulfate heptahydrate is prepared through a wet metallurgy chemical method, valuable metal zinc is fully recycled, and the additional value is high compared with a physical beneficiation method, building material utilization and other methods. The method can well leach and purify the solid waste in the flotation lead tailings, and is more friendly to the ecological environment. Meanwhile, the method can be popularized to similar lead-zinc tailings and has a wide application prospect.