Effects of MgO addition on Al2O3-SiC-C castable

To suppress cracking Al2O3 SiC-C castable refractories, a study was made on the addition of MgO. As a result, it was found that the addition MgO was effective for the suppression of cracking due to thermal shock. It is considered that the addition of MgO reduces the elastic modulus of castable by forming liquid phase in the vicinity of the hot face, improving the thermal shock resistance of castable. As the formation of the liquid phase is dependent upon the CaO and MgO contents of castable, it is possible to obtain castable with high resistance to corrosion and thermal shock by controlling the formation of such liquid phase through the adjustment of CaO and MgO content.