Characterization of a Fe-Cr residue with high C content by x-ray diffraction and scanning electron microscopy

Every metallurgical process is associated with the production of wastes. These, for environmental/economic reasons must be recycled. For example, the production of FeCr alloys, which are relevant for the stainless steel industry, results in a significant amount of fine sized particles containing significant quantities of Cr and C. A possible route for the recycling of such industrial waste consists in using combined pyro and hydrometallurgical processes for Cr extraction. The present work focuses on the characterization of the mentioned powder residue by X-ray diffraction (XRD) for phase determination (Rietveld Method), Scanning Electron Microscopy (SEM) for the study of particle morphology, as well as the semiquantitative evaluation of the major elements composition through Energy Dispersive Spectroscopy (EDS). Moreover, in order to illustrate the applicability of the diverse characterization techniques used for giving support to a pyro and hydrometallurgical Cr extraction process design, both intermediate, as well as final material produced were studied. The results give support to the high selectivity achieved during extraction, thereby resulting in a final product consisting almost entirely by Cr₂O₃ (>98%). (author)