Preparation of Tungsten Carbide by Gas Sparging Tungstate Melts.
Gomes-JM; Raddatz-AE; Carnahan-TG
Paper in Tungsten: 1985 :96-109
The Bureau of Mines has devised a new technique for the preparation of tungsten monocarbide (wc) directly from ore concentrates by a two step process. Wolframite or scheelite concentrates or mixtures of the two concentrates are decomposed in a nacl-na2sio3 melt at 1,050 deg. C. The melt forms two immiscible liquids. The upper halide- tungstate (nacl-na2wo4) phase contains 99% of the wo3. The lower silicate phase contains 90% to 96% of the iron, manganese, and calcium oxides. After separating the two phases by decantation, the halide-tungstate phase is methane sparged to yield granular tungsten carbide. The wc is recovered from the reactor by decanting excess salt, cooling, water leaching, and scraping. The paper discusses results of research to establish operating variables, carbide harvesting procedures, selection of materials of construction, estimated cost of production, and physical properties of the wc product.
Paper in Tungsten: 1985, Mpr Publ. Serv., Ltd., Shrewsbury, England, 1985, PP. 96-109