Effects of process parameters on tungsten boride production from WO ₃ by self propagating high temperature synthesis

In the present study, the production parameters of tungsten boride compounds by self-propagating high-temperature synthesis (SHS) method and following leaching process were investigated. In the SHS stage, the products consisting of tungsten borides, magnesium oxide, magnesium borate, and also minor compounds were obtained by using different initial molar ratios of WO ₃, Mg and B₂O₃ as starting materials. In the leaching step, Mg containing byproducts, i.e. MgO and Mg₃B ₂O₆, existed in the selected SHS product synthesized at 1:8:2.5 initial molar ratio of WO₃:Mg:B₂O₃ were leached out by using aqueous HCl solution to obtain clean tungsten boride compounds at different experimental parameters which are time, acid concentration and temperature. The acid leaching experiments of the SHS product showed that optimum leaching conditions could be achieved by using 5.8 M HCl at 1/10 S/L ratio and the temperature of 80 °C for 60 min.