Defect study of MgO-CaO material doped with CeO

Abstract

MgO-CaO refractories were prepared using analytical reagent chemicals of Ca(OH)and Mg(OH)as starting materials and CeOas dopant, then sintered at 1650°C for 3 h. The effect of CeOpowders on the defect of MgO-CaO refractories was investigated. The sample characterizations were analyzed by the techniques of XRD and SEM. According to the results, with the addition of CeO the lattice constant of CaO increased, and the bulk density of the samples increased while apparent porosity decreased. The densification of MgO-CaO refractories was promoted obviously. In the sintering process, MgO grains grew faster than CaO, pores at the MgO-CaO grain boundaries decreased while pores in the MgO grains increased gradually, and no pores were observed in the CaO grains. The nature of the CeOpromoting densification lies in the substitution and solution with CaO. Ce4+ approaches into CaO lattices, which enlarges the vacancy concentration of Ca2+ and accelerates the diffusion of Ca2+. © 2013 Han Zhang et al.