The corrosion resistance of alumina-magnesia castable to a basic slag was evaluated to find the highly-resistive castable composition for steel processing. Stable solid phases were CA6, alumina and spinel after firing of the castable of Al2O3MgOCaOSiO2 system. The slag corrosion was simulated thermodynamically for CA6, alumina, spinel and castables. The solubility of each oxide component is expected in the order of MgAl2O4 > CA6 > Al2O3 at 1600°C because of the formation of CA2 on CA6 and the formation of CA2 and CA6 on alumina, suggesting the protection of castable from slag. However, CA2 and CA6 disappear at 1800°C and the solubility changes in the order of CA6 > Al2O3 > MgAl2O4. Although the protection of castable by CA6 is also expected, the CA6 disappears at a large amount of slag and a high temperature. The solubility of castable decreases with increasing MgO/CaO ratio owing to spinel formation. The practical immersion test demonstrated the high corrosion resistance of high MgO/CaO castable against slag, exhibiting the importance of spinel formation.
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry