Luis Alberto MACIAS PEREZ - PhD Candidate - 2018 Class

Critical raw elements (CRE), including rare earths elements (REE) and platinoids, are at the heart of many emerging technologies such as smartphones, automobiles and low-carbon energy technologies. Nowadays, the main problem regarding CREs is a potential supply difficulty due to their low concentrations in ores as well as their unequal distribution in the world. The criticality of these materials is pushing industry and research to optimize recovery and recycle from secondary sources, including pre-consumer manufacturing residues; end-of-life products (urban mining); and landfilled mining of urban and industrial waste residues. Since classical recycling techniques involve the use of important quantities of acid and basic solvents, the project aims at developing bio-extraction processes alternative to more traditional pyro- and hydrometallurgy methods. To fulfill this objective, the first step of the project will be the fine characterization of two selected wastes and the speciation of the strategic elements present in them to better optimize the bio-extraction processes. The first waste to be studied will be red mud, a by-product of the alumina extraction that is produced in Gardanne. On the other hand, the second waste will be fly ashes from municipal solid waste coming from Marseille area. Based on these results, CREs will be recovered from wastes by either microbial fuel cells built on a library of bacterial strains able to extract CREs, or via phytoextraction processes by using root-associated bacteria that increase CREs uptake by plants.