Preparation and Characterization of Tungsten Carbide Using Products of Hard Metal Sludge Recycling Process

In this study, tungsten carbide (WC) powder was prepared using a novel recycling process for hard metal sludge that does not use ammonium paratungstate. Instead of ammonia, acid was used to remove the sodium and crystallized tungstate, resulting in the formation of tungstic acid (H 2 WO 4 ). The WC powder was successfully synthesized by the carbothermal reduction of tungstic during the sintering of the WC-Co composite; thus, a WC-Co composite with large WC grains was fabricated using the WC powder prepared from H 2 WO 4 . The large WC grains affected the mechanical properties of the WC-Co composite. Further, due to the large grain size, the WC-Co composite fabricated from H 2 WO 4 exhibited a higher toughness than that of the WC-Co composite prepared from commercial WC powder.