Method for producing manganese sulfate by manganese-rich slag through pressure leaching

The invention discloses a method for producing manganese sulfate by manganese-rich slag through pressure leaching. The method comprises the following steps of: (a) carrying out size mixing on the manganese-rich slag by sulfuric acid solution, so as to obtain mixed slurry; (b) placing the mixed slurry into a reaction container; (c) filling gas into the reaction container and maintaining the pressure of the reaction container to be the preset value for pressure acid leaching; in the reaction process, controlling the pH value of the solution, discharging after pressure acid leaching, so as to obtain acid leaching mixture; and (d) carrying out solid-liquid separation on the obtained acid leaching mixture, so as to obtain manganese sulfate solution. According to the embodiment of the invention, after the pressure leaching method is adopted, the leaching rate of manganese is high, and the manganese can be selectively and efficiently dissolved out. In addition, the method for producing the manganese sulfate by the manganese-rich slag through pressure leaching has the advantages of being simple in process flow, low in material price and production cost, short in processing time and natural-environment-friendly.