Modification of In-Situ Forming MgAl2O4 on Magnesia Surface

Fused magnesia, industrial corundum and aluminium sulfate was used as starting materials to form the MgAl2O4 on the surface of the magnesia. The phase compositions and the microstructures of the sintered samples were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The result shows that when the sintering temperatures reaches 1400 degrees C, the generation of spinel increases significantly, and when the sintering temperatures reaches 1600 degrees C, spinel crystal develops better, and the octahedral structure is formed. After samples sintering at 1500 degrees C for different holding time (1,3 and 5 h), with the increase of holding time, spinel crystal structure development is perfect. The increase of sintering temperature and holding time are beneficial to hydration resistance improving. In-situ spinel is obtained on the surface of magnesia and the performance of the magnesia is also improved.