Abstract:Preparation of electronic grade manganese sulfate from ferromanganese slag, including grinding, leaching and purification, was studied. The impurities, such as Fe³⁺, Al³⁺, Ca²⁺, Mg²⁺, heavy metal ions and Na⁺, K⁺, were removed from leaching solution by neutralized-hydrolysis, fluorination precipitation, sulfuration precipitation and re-crystallization. Effects of pH of reaction, temperature and dosage of the different additives on removal rates of the metallic ions in leaching solution were investigated, and the suitable temperature, pH and the added amount of precipitating agent were obtained. The prepared manganese sulfate product, of which the mass fractions of Ca²⁺, Mg²⁺, Na⁺, K⁺ are all smaller than 0.005%, the mass fractions of Fe³⁺, Al³⁺ and heavy metal ions are smaller than 0.001%, and the mass fraction of Mn²⁺ is greater than 32%, can meet the demand of anode materials of lithium-ion batteries.

Key words: ferromanganese slag; leaching; purification; manganese sulfate; utilization of solid waste