Synthesis of MgO–MgAl2O4 refractory aggregates for application in MgO–C slide plate

Abstract

This work provides an effective method for synthesis of MgO–MgAl2O4 (MgO-MA) aggregates with good thermal shock resistance (TSR) using lightly calcined magnesia and α-Al2O3 micro-powder as the starting materials. The effect of α-Al2O3 micro-powder amount and calcination temperature on TSR and microstructure of the synthesized MgO-MA aggregates was investigated. The optimum amount of α-Al2O3 micro-powder was 15 wt%, and the obtained aggregates had the highest density after calcination at 1650 °C. The synthesized MgO-MA aggregates had excellent TSR which was attributed to the thermal mismatch of MgO and MA grains as well as the pinning effect of MA grains on the periclase grain boundaries. TSR of MgO–C slide plate materials was improved significantly by introducing appropriate amount of the synthesized MgO-MA aggregates.