1. when magnesia carbon brick is heated, active metal aluminum in brick will firstly react with carbon, became high melting point carbide, then carbon will reunite, getting Al4C3 and Al2O3. Al4C3 will stay on the surface of MgO, to prevent the penetration of slag erosion. In this way, it will improve the bricks erosion resistance, slag resistance and spalling resistance.
2. When the magnesia carbon bricks under high temperature condition, active aluminum will be oxidized and become high melting product Al2O3. It is a phase change process from metal into nonmetal, the volume of oxidation Al2O3 will have a expansion, making the pores in brick be dense, increasing bricks bulk density and forming the ceramic combination, so as to improve the bricks high temperature rupture resistance.