Recent progress in biohydrometallurgy and microbial characterisation

Since the discovery of microbiological metal dissolution, numerous biohydrometallurgical approaches have been developed to use microbially assisted aqueous extractive metallurgy for the recovery of metals from ores, concentrates, and recycled or residual materials. Biohydrometallurgy has helped to alleviate the challenges related to continually declining ore grades by transforming uneconomic ore resources to reserves. Engineering techniques used for biohydrometallurgy span from above ground reactor, vat, pond, heap and dump leaching to underground in situ leaching. Traditionally biohydrometallurgy has been applied to the bioleaching of base metals and uranium from sulfides and biooxidation of sulfidic refractory gold ores and concentrates before cyanidation. More recently the interest in using bioleaching for oxide ore and waste processing, as well as extracting other commodities such as rare earth elements has been growing. Bioprospecting, adaptation, engineering and storing of microorganisms has increased the availability of suitable biocatalysts for biohydrometallurgical applications. Moreover, the advancement of microbial characterisation methods has increased the understanding of microbial communities and their capabilities in the processes. This paper reviews recent progress in biohydrometallurgy and microbial characterisatio

Prospective directions for biohydrometallurgy

Biohydrometallurgy has been commercially applied for the extraction of base metals from low-grade sulfidic ores and the pre-treatment of refractory sulfidic gold-containing minerals. Recent research explores its potential for other types of commodities, such as rare earth elements, and ores found in deep subsurface of the Earth, ocean floor and outer space. The application of biohydrometallurgy for extracting resources from waste streams is also gaining increasing interest to support the move towards a circular economy. The utilisation of complex feedstock is associated with new challenges, which may require the integration of various unit processes that combine biological approaches and/or electrochemistry, with physical or chemical processing. New biolixiviants are also being explored to mitigate harmful environmental impacts. The range of biocatalysts available for biohydrometallurgy can be increased through bioprospecting of novel biomining microbes, increasing the metabolic capability of microbes through adaptive evolution and engineering microbes through synthetic biology. New modelling and artificial intelligence tools are also expanding the opportunities for optimising biotechnical processes. This paper reviews recent trends and prospective directions for biohydrometallurgy