Co, Ni and V speciation in industrial waste: XAS study aimed at optimising recovery of precious metals from wastes.

This proposal is aimed at determining the speciation of Co, Ni and V in two petrolchemical spent catalysts based on alumina (Al2O3) with metal on surface. These samples, already well characterised by X-ray diffraction (XRD) and EDX analysis with Scanning Electron Microscopy (SEM), are currently under investigation to find a green process able to recover precious metals. We here propose to collect high resolution Co, Ni and V K-edge XANES and EXAFS to characterize their oxidation state and local structural environment. We propose the use of fluorescence detector system with a multielement high-purity Ge detector to guarantee successful data collection for the proposed experiment on diluted metals. Accurate information on the speciation is essential to optimize the recovery procedure or to find alternative ways to recover metals.