Mechanochemical reduction of lead sulphide by elemental iron

Metallic lead as well as cubic pyrrhotite were produced by the mechanochemical reduction of lead sulphide with elemental iron during milling in a planetary mill Pulverisette 6 (Fritsch, Germany) as a result of the reducing power of iron. The reaction kinetics has been examined by X-ray diffraction (XRD) and vibrating sample magnetometry (VSM). The surface properties have been characterized by transmission electron microscopy (TEM). The process of mechanochemical reduction of lead sulphide is quite more straightforward due to the monophase nature of the lead sulphide precursor. Both products are present in the form of Pb/FeS nanoparticles and the average grain size of the freshly formed lead is between 13-21 nm depending on the milling conditions. Unlike the conventional high-temperature reduction of lead sulphide, the mechanochemical reduction is very fast and ambient temperature and atmospheric pressure are sufficient for its propagation. (C) 2004 Kluwer Academic Publishers.