The invention discloses a method for preparing electrolytic
manganese by using
pyrolusite, and the method comprises the following steps of leaching
manganese ore: crushing
pyrolusite, mixing a
mixed solution containing
ammonium sulfate,
manganese sulfate and
ferrous sulfate with
pyrolusite particles to obtain
slurry, and leaching; neutralizing and precipitating iron: adding
calcium-based neutralizer into the
slurry, adjusting pH value, adding oxidant to enable Fe<2+> concentration in the solution to be lower than 1 mg / L, and filtering to obtain manganese sulfate solution and iron
hydroxide filter residue; carrying out heavy
metal removal: adding a vulcanizing agent into the manganese sulfate solution to enable the concentration of heavy
metal ions in the solution to be lower than 1 mg / L, and then filtering to obtain vulcanized
slag and
electrolyte; and carrying out electrolytic
recovery of manganese
metal: electrolyzing the obtained
electrolyte to prepare electrolytic manganese and electrolytic manganese anolyte containing
sulfuric acid. The method can effectively solve the problem that
dithionate is generated in the pyrolusite
sulfur dioxide leaching method, thereby causing the problems of high
electrolysis energy consumption, high
sulfur content of electrolytic manganese and large amount of iron-containing waste residue generated in the pyrolusite
ferrous sulfate leaching method.