Statistical Optimization of Tungsten Carbide Synthesis Parameters

Commercial methods for synthesizing tungsten carbide require large energy inputs due to the high temperatures and grinding processes associated with production. In this study, tungsten carbide was synthesized by adsorbing tungstate anions from aqueous solutions onto an activated carbon matrix. The tungsten-loaded precursor was carburized under mixtures of hydrogen, methane, and carbon monoxide to produce tungsten carbide at temperatures significantly lower than most commercial operations. Tungsten carbide was synthesized at temperatures below 1000 °C with conversion to tungsten carbide exceeding 90%. The adsorption and carburization processes were modelled and optimized using experimental design techniques. The effects of time, temperature, initial tungsten concentration, and pH were considered for modelling adsorption behaviour, while carburization behaviour was modelled on the effects of time, temperature, carbon content, and reducing gas composition. Carburization products were characterized using X-ray diffraction and scanning election microscopy. The adsorption of tungstate anions was measured using inductively coupled plasma optical emission spectroscopy.