The effect of C-coated alumina particles on properties of MgO-C refractories

In this study, carbon-coated alpha-Al2O3 powder was prepared by two routes: a physical method and a chemical method. The obtained carbon-coated alpha-Al2O3 powders were adopted to prepare MgO-C refractory materials for the purpose of regulating the in-situ synthesis of MgAl2O4. The effect of the carbon-coating alpha-Al2O3 powder addition on the service behavior of MgO-C refractories was studied. The results show that both the physical and chemical methods for coating alpha-alumina particles could regulate the solid-phase formation of spinel in the magnesia carbon material, which weakened the solid-phase reaction of the spinel in the magnesia carbon material, thus reducing the volume expansion. Samples containing coated alpha Al2O3 micmpowder, prepared by the chemical method, presented the largest bulk density, the minimum apparent porosity, the largest cold and hot modulus of rupture, and the best thermal shock and corrosion resistance.