Development of Mn recovery process from waste dry cell batteries

High-purity Mn is necessary for high strength steel production. However, the availability of metal Mn is limited to a few countries. Therefore, as an alternative to direct purchasing of metal Mn, a process for Mn recovery was investigated. Waste dry cell batteries are considered to be one of the most feasible Mn sources. We have developed a high efficiency chemical separation system. This system consists of a three-phase chemical treatment. In the first phase, the metal components of the waste dry cell batteries were dissolved by acid, along with a reducing agent. Afterward, the undissolved carbon particles were separated by filtration. In the second phase, the dissolved Mn was selectively precipitated as manganese oxide by O3 oxidation. Then, the precipitated manganese oxide was separated from the other metal components by filtration. Finally, in the third phase, the manganese oxide was reduced to high-purity Mn using an electric furnace.