Prediction of the chromium oxide oxidation rate from the equilibrium constants and the mass transfer coefficients at high temperatures

Previously published experimental data on the oxidation/volatilization of chromium oxide covering a wide range of oxygen pressure (10^–6 to 1 atm) and temperature (900 to 1385°C) were used to predict its oxidation rate from the equilibrium constants and the mass transfer coefficients using the kinetic model originally developed by Bartlett. The experimental data available were found to be either surface-reaction-controlled or volatile-product-controlled which are the limiting cases of the model. The availability of the dimensionless fluid correlations and the force constants for the diffusing species enabled the prediction of the mass transfer rate for the various sample shapes and hydrodynamic conditions. The good agreement between the experimental and predicted oxidation rates covered four orders of magnitude range.Prepared for the U.S. Department of Energy under contract No. W-7405-Eng-82.