Microbial synthesis of magnetic nanostructures for cobalt recovery from arsenic-rich tailings

Cobalt (Co) plays a crucial role in clean energy technologies, particularly batteries for electric vehicles and energy storage systems, making its supply essential to global markets. However, Co has a highly vulnerable supply chain and a growing supply deficit has been forecast to emerge by 2030. Significant Co resources remain unlocked as arsenic (As) polluted tailings from legacy sites and As-rich primary ores, referred to as 5-element deposits. Through the project BioMagiCo, I will develop a new low-cost, sustainable, biotechnology that can address European Co supply chain issues by unlocking these As-rich Co resources. The project focusses on bioleaching mineralogically complex polymetallic mine-waste, immobilising the As as Fe-arsenate phases, and then harness the ability of bacteria that can reduce ferric iron (Fe³⁺) and incorporate Co²⁺ ions under anaerobic conditions, forming Co-doped magnetite (Fe₃₋ₓCoₓO₄) nanostructures (NS). Co-doped magnetite NS have remarkable magnetic and chemical stability positioning these NS for selective Co recovery using low-cost, low-energy magnetic separation. I will develop this through four Research Objectives (1) Develop a functional microbial consortium will be developed to bioleach Co-bearing minerals from As-bearing mine wastes (2) Develop a protocol to overcome problems associated with the presence of As by precipitation of Fe-arsenates (3) Establish controls on Co doping levels in Co-doped magnetite NS during biosynthesis (4) Develop a conceptual process flowsheet at lab-scale for a techno-economically viable upscaled biosynthesis operation. Through BioMagiCo, I will be trained in mineralogical analytical workflows, geomicrobiology and bioleaching, synchrotron methods, developing techno-economic flowsheets, museum collection management, data archiving, public engagement and other professional skills that will establish me as a potential R&D Leader in sustainable, low-carbon energy solutions.