Reduction of Wolframite Ore with Activated Charcoal to Produce Nano Tungsten Carbide

Tungsten carbide possesses exceptional high temperature hardness and corrosion resistance, which makes it suitable for its application in cutting and mining tools, wear resistance parts, dies and coatings. It is generally used as composite with cobalt as binder material. Conventionally, it is prepared by carburizing elemental tungsten at high temperature. The elemental tungsten is obtained from the two main ores of tungsten, Wolframite (FeWO₄) and Scheelite (CaWO₄). The extraction process involves digestion of the ore in alkali followed by purification and filtration and subsequently high temperature treatments with chemicals to finally get elemental tungsten. This paper presents the study of reduction/carburization of wolframite ore (FeWO₄) by activated charcoal through solid state reaction method to directly produce tungsten carbide. The wolframite ore was milled with activated charcoal for 50 h in planetary ball mill. Then powders were calcined at different temperatures. The results indicate the formation of tungsten carbide (W₂C) and iron tungsten carbide. The powders were characterized by X-ray diffraction and scanning electron micrograph.