A Review of Low Grade Manganese Ore Upgradation Processes

Increased demand for manganese alloys and compounds for various industries created a dire need of Manganese (Mn) ore beneficiation technology. Significant variability in ore grades and mineralogical characteristics impose challenges during selection of a proper beneficiation process to upgrade the low-grade manganese ores. In the present review paper, an attempt has been made to summarize the various kinds of beneficiation practices used to upgrade the low-grade manganese ores. A detailed analysis of Mn ore types, genesis processes, mineralogical characteristics, and beneficiation practices including process flowsheet of operational plants are presented in this article. World manganese resources are classified into three major categories, i.e., oxide, siliceous, and carbonate ores considering the beneficiation characteristics. Selection of the appropriate beneficiation process depends on the gangue minerals and their association. Gravity separation methods are applied on the siliceous ores and these are in industrial practice at India and Brazil. The iron minerals are always found as an impurity in all kinds of manganese ores; however, these are successfully removed using variety of magnetic separation processes. Carbonate ores are mainly found in Ukraine, China, and South Africa and these ores are upgraded primarily by gravity and magnetic separation process. Ore type plays a vital role during alloy production process also. Studies tell that demand for high grade ores is expected to grow and beneficiation of low grade ores will be imperative in the future. The overlooked hydrometallurgical methods which can produce valuable products at high Mn recovery are expected to be popular in the future.