This project is conceived as a need-led research focused on the concept that waste can become a valuable resource by providing metals that are extracted today by other processes, promoting recycling, minimising harmful waste, minimising the risk of hazards and minimising metal degradation. The selection of the minerals/metals of interest in the project takes into account the continuing need for the supply of such raw materials across European industries, anticipating cost efficiencies from the practical application of the expected research results. The main objective of the project is to find innovative methods and processes for the extraction of even weak traces of these elements. New microorganisms with potential applications in biosolubilisation, biomineralisation and bioaccumulation will be obtained and characterised. The consortium will assess the microbial biodiversity in tailings ponds located in different geological and climatic environments, where critical metals with high-tech potential (In, Ga, Te and W), and also relevant pollutants (As, Sb) may be present. In the last part of the project the isolates will be tested under macrocosm conditions. The final aim will be to apply the micro-organisms in the biosolubilisation extraction process and to recover minerals from the ore by biosolubilisation and bioaccumulation. A comparative environmental risk assessment will be carried out for tailings produced by biosolubilisation with and without nanoparticles.