2014 年 13 巻 6 号 p. 312-313
The refractory is used to protect the furnace and to improve the efficiency of a steel making process. Most of the refractories used in the Iron making process are the castable refractories that are primarily composed of Al2O3, MgO, or Cr2O3, etc. particles. By addition of Fumed Silica, which is amorphous silica micro-particle, to the castable, densification of the refractory is found at intermediate temperature range (e.g., 500 ˚C). However, the chemical principle of this densification is not known well yet. In this study, we aim to reveal qualitatively the chemical behavior of Fumed Silica in a castable refractory by using semi-empirical Molecular Orbital calculation. The result showed that Fumed Silica and Alumina does not react at room temperature, i.e., Al-O-Si bond is not formed. We also investigated the transition state of the Alumina-Silica reaction and its activation energy, and calculated the temperature corresponding to that energy.