Hydrometallurgical Production of Electrolytic Manganese Dioxide (EMD) from Furnace Fines

The ferromanganese (FeMn) alloy is produced through the smelting-reduction of manganese ores in submerged arc furnaces. This process generates large amounts of furnace dust that is environmentally problematic for storage. Due to its fineness and high volatile content, this furnace dust cannot be recirculated through the process, either. Conventional MnO2 production requires the pre-reduction of low-grade ores at around 900 ◦C to convert the manganese oxides present in the ore into their respective acid-soluble forms; however, the furnace dust is a partly reduced by-product. In this study, a hydrometallurgical route is proposed to valorize the waste primarily by converting the furnace fines into electrolytic manganese dioxide (EMD), addressing both environmental concerns and enhancing resource efficiency. The methodology involves leaching and reduction processes that utilize environmentally friendly reagents to selectively extract manganese while minimizing secondary waste generation. The results indicate that the developed hydrometallurgical process is not only feasible but also sustainable, as it successfully transforms waste materials into valuable products. This approach opens new avenues for the recycling of furnace dust in the manganese industry.