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

摘要

To prepare tungsten carbide (WC) nanoparticles high purity precursors like W, WO_3, WCl_4, WCl_6 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℃ in an autoclave which led to the direct conversion of scheelite to nanocrystalline WC. The undesired reaction products and impurities (CaO, MgO and SiO_2) were washed firstly with dilute HC1 (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.