A Review of In Situ Manganese Bioleaching and Recovery Techniques

The rise in global consumption of manganese, largely due to its extensive use in the steel and battery industries, has increased the demand for sustainable manganese extraction methods. Conventional manganese extraction methods, such as open pit mining followed by pyrometallurgy and hydrometallurgy, are often costly and environmentally harmful due to their reliance on high energy and chemical reagents. The in situ bioleaching approach has the potential to replace conventional approaches, offering cost savings and environmental benefits. In situ bioleaching utilizes microorganisms and a source of nutrient media to directly dissolve manganese within ore bodies under natural environmental conditions. This review provides an in-depth discussion of the critical components of in situ bioleaching, including manganese dissolution mechanisms, manganese-reducing organisms, nutrient media for microbial growth, and manganese recovery options. This study also explores the challenges associated with scaling in situ bioleaching to a commercial level and provides insights into future directions to overcome challenges.