Single step synthesis of tungsten carbide (WC) nanoparticles from scheelite ore

To prepare tungsten carbide (WC) nanoparticles high purity precursors like W, WO3, WCl4, WCl6 and W(CO)6 are used. Moreover, these precursors are obtained after high temperature and multistage processing of the ore. In this article a single step synthesis method is reported to get tungsten carbide (WC) nanoparticles directly from scheelite ore. The mixture of scheelite, activated charcoal and magnesium was heated for 20 h at 800 °C in an autoclave which led to the direct conversion of scheelite to nanocrystalline WC. The undesired reaction products and impurities (CaO, MgO and SiO2) were washed firstly with dilute HCl (1:1) and then with base (0.25 M NaOH). The obtained powders were characterized by high resolution scanning electron microscopy (HRSEM), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction.