Effect of Magnesium Slag-doping on the Microstructure and Properties of Corundum-mullite Multiphase Ceramic

The corundum-mullite multiphase ceramic was prepared by solid phase sintering method with the secondary bauxite as main raw material,manganese oxide powder and magnesia slag as sintering aids. The effect of magnesia slag-doping on the properties(i.e., bulk density, compressive strength and refractoriness under load) were investigated, and the microstructure was analyzed. The results show that the bulk density and refractoriness under load decreases after increasing first and compressive strength increases with increasing the amount of magnesium slagdoping. The sample added magnesium slag of 2% and sintered at 1350 ℃ for 3 h has bulk density of 3.04 g/cm3, apparent porosity of less than 1%, compressive strength of 180 MPa and the temperature T5 of refractoriness under load of 0.2 MPa is 1276 ℃, the phase of the multiphase ceramic includes corundum, mullite and anorthite.