Effect of cerium oxide on preparation of high-density sintered magnesia from crystal magnesite

Abstract Sintered MgO was prepared by using MgO powder with different particle sizes by calcination of by crystal magnesite as the raw material and CeO2 powder as an additive. In addition, the effect of the CeO2 addition on the performance of the sintered MgO was investigated. The results showed that (i) the densification of the sintered MgO with a small amount of CeO2 addition appreciably promoted, (ii) the maximum bulk density reached 3.48 g cm−3, and (iii) the apparent porosity was 0.35%. In the sintering process, the Ca2+ could approach into CeO2 lattices, forming O2− vacancy at CeO2 grains, which resulted in promoting the growth of CeO2 grains filling the pores between the MgO grains, and enhanced the densification of sintered MgO. In addition, the solid solution reaction limited the formation of silicate phase in MgO, improving the bonding degree between the MgO grains.