Characterization of iron sulphides from ore mining rejects

Three (Fe,S)-rich samples were isolated from mining rejects of copper and coal ores of Cam aqua and Butia, RS, Brazil. Sulphides minerals were characterized by X-ray diffraction, scanning electron microscopy, Mossbauer spectroscopy and some aspects of their crystal structure are discussed. Mossbauer spectra at room temperature and 110 K showed characteristic patterns of ciialcopyrite or pyrite. For the chalcopyrite-rich sample, a magnetically ordered Mossbauer pattern suggests the existence of two non-equivalent sites for Fe which is confirmed by the Rietveld analysis of the corresponding XRD pattern.