Mining of metal materials is a continually rising activity, but high-grade and accessible mining deposits are running low, making low-grade contend and high-processing costs ores an alternative to meet the growing global demand for metals and reduce impacts on mining areas. Among the widely exploited metals is nickel, an extremely versatile metal due to its corrosion resistance, malleability and ductility. Associated with large nickel reserves are large deposits of 8% nickel-containing tailings, difficult-to-handle environmental liabilities with the potential risk of environmental disasters. The presented research project proposes to study new approaches of extraction and recovery of metals present in ore tailings piles, through autochthonous communities, using denitrifying microcosms for the solubilization of metals and sulfetogenic for their precipitation and separation of the suspension as metal sulfide in process known as bioleaching. Bioleaching is the controlled leaching mediated by iron and sulfur oxidizing bacteria to extract metals sulfide in small volumes, allowing to contain smaller volumes, which when subjected to anaerobic conditions promote the formation of biogenic sulfide, with the potential to precipitate metals. The aim of the present study is to identify and enhance the interactions between minerals and autoctone bacteria from nickel mines used as inoculum-cultivated for bioleaching, concurrently with the removal of nitrate, residual material from explosions in exploration operations, contributing to the mitigation of its deleterious effects on the environment. The proposed project is part of a comprehensive research program by the University of Toronto / Canada BioZone Group, a center of excellence for microorganism-mediated environmental pollutant mitigation research.
News published in Agência FAPESP Newsletter about the scholarship: