Effect of Ferric Oxide Addition on the Performance of MgO-Al<sub>2</sub>O<sub>3</sub> System Materials

Abstract

The MgO-Al2O3 system materials were prepared at 1600°C for 3h with magnesia powder and alumina powder as raw materials and with ferric oxide powder as additive. The effect of the ferric oxide additive on the sintering and thermal shock resistance of the composite materials was studied. The results showed that increasing the ferric oxide dosage could improve the densification of the MgO-Al2O3 system materials. In sample MAF-0, crystal phases all are spinel phase. With the ferric oxide dosage increased from 2% to 6% in MAF-2, MAF-4 and MAF-6, the MgAl2O4 (spinel) became the primary crystal phases, and less amount of sosoloid 20MgO•19Al2O3•Fe2O3. In comparison with samples MAF-0, MAF-2, MAF-6, sample MAF-4 has better structure compactness and thermal shock resistance, the optimum ferric oxide dosage was added in MgO-Al2O3 system material is equal to 4%. The MgO-Al2O3 system material is acceptable for application in cement rotary kiln linings and high temperature gas filter support.