Method for preparing battery-grade manganese sulfate from low-grade manganese-containing material

The invention belongs to the technical field of non-ferrous metal hydrometallurgy, and discloses a method for preparing battery-grade manganese sulfate from a low-grade manganese-containing material, which comprises the following steps: adding the low-grade manganese-containing material into a reaction kettle, adding a reducing agent, and carrying out reduction leaching; after leaching is finished, purification and impurity removal are conducted, and purified liquid and purified residues are obtained; carrying out purification and copper removal treatment on the purified solution to obtain copper-removed slag and a copper-removed solution, and carrying out suction filtration on the copper-removed solution to obtain a relatively pure manganese sulfate solution; the manganese sulfate solution is subjected to first-stage extraction through unsaponified P204, and a raffinate manganese sulfate solution is obtained; performing freezing crystallization and impurity removal on the raffinate manganese sulfate solution