insights into Yttrium speciation in bauxite residue before and after unconventional leaching experiments

With a predicted world population of over 9 billion people in 2050 and rapid economic growth, the pressure on natural resources is exponentially increasing. It is the case for critical metals, including Rare Earth Elements (REEs), that are the heart of a number of strategic technologies for the environmental transition. In the context of a circular economy, this project aims at extracting REEs from a secondary source: bauxite residue produced from alumina extraction. This project proposes to develop environmentally sustainable extraction processes (soft physico-chemical and bio-inspired processes) with thorough characterization of the waste including metal speciation. We propose here to investigate bulk speciation of Yttrium (proxy for Heavy REEs) in bauxite residue samples formed from 2 bauxite sources (lateritic and karstic origins) as well as in the residue after partial leaching of Yttrium to better understand leaching mechanisms and how speciation affect leaching yield.