| Title |
Carnothermal Reduction of Oxide of WC/Co Hardmetal Scrap |
| Authors |
권철민(CheolMin Kwon); 이길근(Gil-Geun Lee); 하국현(Gook-Hyun Ha) |
| DOI |
https://doi.org/10.3365/KJMM.2016.54.10.743 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
powder; tungsten carbide; hardmetal; carbothermal reduction; phase transformation |
| Abstract |
This study conducted an analysis of the carbothermal reduction of oxidized WC/Co hardmetal scrap with solid carbon under an argon and hydrogen gas atmosphere. The WC/Co hardmetal scrap oxide consisted of WO₃ and CoWO₄. WO₃ was reduced before CoWO₄ by the solid carbon regardless of gas atmosphere. The simple oxide WO₃ transformed to a tungsten carbide phase without the formation of tungsten under argon atmosphere. However, WO₃ reduced to tungsten and then tungsten carbide was formed under the hydrogen atmosphere. Further, the complex oxide CoWO₄ transformed to tungsten carbide and cobalt phases via a Co-W-C system complex carbide phase under the argon atmosphere. However, in contrast to the reaction under the argon atmosphere, under the hydrogen atmosphere an additional phase transformation route was observed, i.e., the formation of tungsten carbide and cobalt phases from CoWO₄ through the formation of tungsten oxide and cobalt-tungsten alloy phases. The tungsten carbide formation under argon hydrogen atmospheres occurred at about 950°C and 850°C, respectively. |