Abstract The high-temperature (900–1200 K) interaction of transition-metal carbides namely Cr7C3, Fe3C, TiC, ZrC, NbC, TaC, MoC, WC, VC and HfC with Na2SO4 has been studied in a stream of pure and dried oxygen gas. Thermogravimetric studies were carried out by measuring the weight change as a function of time and mole fraction of Na2SO4 in the reaction mixture. The presence of different constituents in the reaction products were identified by X-ray diffraction analysis and the morphologies of the reaction products were discussed on the basis of metallography, scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). The quantitative determination of soluble metal species in the aqueous solutions of Na2SO4-transition-metal carbide products was carried out by atomic absorption spectroscopy. At high temperatures, transition-metal carbides interact with Na2SO4, forming metal oxides. The resulting metal oxide interacts with Na2SO4 forming a soluble sodium metal oxide or a metal sulphide depending upon the local condition prevailing during the reaction.
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