XAS investigation of heavy metals for precious metals recovery from industrial wastes

The aim of this in house research experiment is to evaluate the speciation and the local environment of Mo and Pd in petrolchemical spent catalysts based on alumina (Al2O3) with metal on surface, and W, Zn and Pb in pyrochlores treated with solutions containing heavy metals. These samples are under investigation to find a green process able to recover precious metals. We want to collect high-resolution Mo, Pd, Zn K-edge and W, Pb L-edge XANES and EXAFS in order to characterize the local structural environment and the oxidation states of those cations. We also propose to collect XRF maps. We will use transmission mode for the samples with high metals concentrations and fluorescence detector system with a multielement high-purity Ge detector for diluted metals. Accurate information on the local structure and the oxidation state are essential to find suitable recovery procedures to recover metals from industrial wastes and avoid their dispersion in the natural environment.