Controllable preparation and slag corrosion resistance of novel MgO–MgAl2O4–ZrO2 refractory

Brine magnesia and fused Al2O3–ZrO2 powder were used as raw material to prepare MgO–Al2O3–ZrO2 (MAZ) refractory brick which was sintered at 1690 °C for 8 h in a tunnel kiln. Its resistance to slag corrosion of non-ferrous metallurgy was investigated. The phase and microstructure of the samples before and after corrosion were characterized by XRD, SEM and EDS. The results show that MAZ ternary metastable phase was formed during sintering, which then decomposes to finely dispersed MgO, MgAl2O4, and ZrO2. Thus, highly uniform distribution of ultra-fine MgAl2O4 and ZrO2 in the matrix was achieved. The non-ferrous metallurgical slag is mainly composed of FeO and SiO2. At high temperatures, when the material is subjected to slag corrosion, both (Mg, Fe)Al2O4 and 2MgO·SiO2 with high-temperature melt point were formed in the corrosion layer, effectively preventing further infiltration and corrosion of MAZ samples by slag. A model for the formation process of high dispersion of MAZ was explained, and a model for the corrosion mechanism between non-ferrous metallurgical slag and MAZ samples was established.