Using microbes to recover rare earths with low environmental impact

Using Microbes to recover Rare Earths with low environmental impact Barbara Palumbo Roe, Simon Gregory, Antoni Milodowski, Julia West, Joanna Wragg British Geological Survey, Nicker Hill, Nottingham NG12 5GG, UK Steve Banwart, Maria Romero Gonzalez, Wei Huang, Emma Wharfe Kroto Research Institute, University of Sheffield, Sheffield S3 7HQ, UK John Harding, Colin Freeman, Shaun Hall Department of Materials Science and Engineering, University of Sheffield, Sheffield S1 3JD, UK Microbes play an important role in the fate and transport of rare earth elements (REE) in relation to the REE exploitation life cycle. A step change in understanding is needed for key mobilisation, concentration and fractionation processes such as bioleaching, biosorption and biomineralisation and how they can 1) be harnessed to recover REE in situ from low grade ores or secondary deposits, and 2) be quantified for reactive transport in environmental risk assessment and management of mining operations. Heap/in-situ leaching methods are relatively low impact mining technologies, requiring less energy (for comminution) and in the case of in-situ leaching have a minimal footprint. Furthermore, biologically-assisted leaching and separation processes represent a more sustainable alternative to chemical processes. We discuss the microbial potential to accelerate dissolution of REEs from source minerals, and how the natural selectivity of mineral and microbial surfaces as ligands for adsorption and biomineralisation of REE dissolved species could be exploited in the recovery of REEs from fluids.