A thermogravimetric system is described for the determination of the total oxygen consumption, sample weight‐change, and vaporization rate during the oxidation of . The results show an increasing deviation from parabolic kinetics with increasing temperature at 250 mm oxygen pressure. The following equation is used to describe the total oxygen consumption in the temperature range of 800°–1500°C Because is oxidized stoichiometrically, this result can be converted to the recession of as follows