• Morris, Christina
• Boxall, Naomi
• Ashton, Jake

Abstract

Biomining utilises the metabolic activity of microorganisms to extract (i.e., to bioleach) and recover (e.g., bioprecipitate, biosorb) metals from solid materials. Bioleaching has been applied for decades at an industrial scale for the extraction of copper from sulfidic ores; and biooxidation for the pre-treatment of refractory sulfidic gold ores to solubilise the sulfide matrix before cyanidation. There is also increasing interest in applying biomining to extract and recover resources from various mining and metallurgical wastes (e.g., slags, tailing, sludges, and ashes) and electronic wastes (e.g., batteries and printed circuit boards). Moreover, other potential applications of biomining are currently being explored, for example, targeting specific critical commodities, including rare earth elements and lithium, to meet growing demand. Biomining is especially attractive for low-grade and complex ores and wastes, which may not be economical to process through traditional metallurgical technologies and feedstocks containing penalty elements, such as arsenic. Biomining is typically carried out at ambient pressures and relatively low temperatures, providing opportunities to reduce energy consumption and the carbon footprint of processing as compared to hydrometallurgical pressure leaching and pyrometallurgical operations. Biomining can also reduce the consumption of chemical reagents, further reducing operating costs. In addition, biomining also has the potential to reduce the passivation of some minerals, such as chalcopyrite, thus improving resource extraction and recovery. This presentation provides an overview of biomining mechanisms and microbes suitable for various mineral types and commodities, and engineering applications for the implementation of microbial catalysts, including bioreactors, vats, heaps, and in situ leaching. Examples are given for some industrial-scale biomining operations across the globe. Finally, recent developments in the field and future research targets are highlighted.

Topics

• impedance spectroscopy
• mineral
• Carbon
• extraction
• gold
• copper
• leaching
• Lithium
• refractory
• Arsenic
• rare earth metal