Reaction Mechanism of Iron-Rich Magnesia-Corundum Composites at 1420°C

Specimens were prepared by using iron-rich magnesia and high-pure magnesia as the main starting materials, and introducing fused corundum of 3%(in mass), 6%, 9%, 12%, 15% respectively and sintered at 1420°C.The samples were characterized by XRD and SEM. The results show that in-situ synthesized composite spinel solid solution were formed in the reaction between iron-rich magnesia and fused corundum. Iron oxides play a key role on the formation of spinel solid solution. When fused corundum was added in a certain particle size, the material showed core-shell structure. Outer layer of core-shell structure were spinel solid solution and the inside were corundum. These core-shell structure make the synthesis of spinel solid solution bonded periclase material at low temperature happen.