Mechanochemical Reduction of Synthetic Sulphidic Copper-Bearing Minerals in an Industrial Scale

Matej  TEŠINSKÝ; Matej  BALÁŽ; Michal  RAJŇÁK; Mária KAŇUCHOVÁ; Peter  BALÁŽ

doi:10.29227/IM-2019-01-25

Matej TEŠINSKÝ Department of Mechanochemistry, Institute of Geotechnics SAS, Watsonova 45, 04004 Košice, Slovakia
Matej BALÁŽ Department of Mechanochemistry, Institute of Geotechnics SAS, Watsonova 45, 04004 Košice, Slovakia
Michal RAJŇÁK Department of Magnetism, Institute of Experimental Physics SAS, Watsonova 47, 04001 Košice, Slovakia
Mária KAŇUCHOVÁ Institute of Earth Resources, Technical University in Košice, Park Komenského 19, 04001 Košice, Slovakia
Peter BALÁŽ Department of Mechanochemistry, Institute of Geotechnics SAS, Watsonova 45, 04004 Košice, Slovakia

DOI: https://doi.org/10.29227/IM-2019-01-25

Keywords: mechanochemistry, mechanochemical reduction, high-energy milling, sulphides

Abstract

In this paper the mechanochemical reduction of binary sulphides chalcocite (Cu2S) and covellite (CuS) by elemental iron were
investigated. The composition and properties of nano-powders prepared by high-energy milling were analyzed by X-ray diffraction,
X-ray photoelectron spectroscopy and magnetic measurements. The XRD results showed that in case of chalcocite Cu2S the reaction
takes place until 360 minutes, as no elemental iron, could be identified afterwards. In case of covellite CuS, after 480 minutes of mechanochemical
reduction, a significant amount of non-reacted elemental iron could still be observed. The investigation of magnetic
properties reveals significant decrease of saturation magnetization as a result of milling. XPS results showed a significant surface
oxidation in both systems. Unlike the conventional high-temperature reduction of chalcocite and covellite, the mechanochemical
reduction is fast and ambient temperature and atmospheric pressure are sufficient for its propagation.