Extraction and separation of manganese and iron from ferruginous manganese ores: A review

There are abundant ferruginous manganese ores (abbr. Fe-Mn ores) in many parts of the world. For example, almost half of the manganese ore resources in India are ferruginous and more than 73% of the manganese ores in China belong to Fe-Mn ores with a low Mn/Fe mass ratio (<3). With the depletion of high grade manganese ore resources, the Fe-Mn ores are becoming important substitution resources for extracting manganese. In general, the production of Mn alloy from manganese ores requires that the Mn grade is more than 30% and the Mn/Fe mass ratio is greater than 5. During the production of electrolytic manganese or manganese chemical products, the issue of co-leaching of Mn and Fe complicates the purification procedure for the MnSO4 solution if Fe-Mn ores are used as raw materials. Numerous approaches are reported to realize the selective extraction and separation of Mn and Fe from the Fe-Mn ores. The extraction and separation technologies cover physical beneficiation, chemical beneficiation (hydrometallurgy and pyrometallurgy) and physico-chemical combined processes. This present work reviews the technical principles, parameters and recovery efficiencies of diverse processes on the aspect of selective extraction and separation of Mn and Fe from Fe-Mn ores. This review can provide guidance for selecting appropriate methods to exploit Fe-Mn ores or other secondary resources containing Fe and Mn oxides. The authors also put forward a new route to produce manganese ferrite materials using Fe-Mn ores as the raw materials.