Enhancement in erosion resistance of Al2O3–SiC–C refractories for high scrap steel ratio ladles: role of MgAl2O4 spinel
摘要
To resolve severe slag penetration and erosion in Al2O3–SiC–C refractories during high scrap ratio iron ladle operation, a novel strategy utilizing exogenous MgAl2O4 spinel as a sacrificial FeOx scavenger was proposed. Al2O3–SiC–C refractories produced with plate-like corundum, silicon carbide, and flake graphite incorporating MgAl2O4 additives were cured at 1400 °C in the condition of carbon embedding. The impacts of additives on phase composition, microscopic morphology, and performance of materials were studied. The results indicated that Al2O3–SiC–C refractories with the addition of 2 wt.% MgAl2O4 exhibited a smaller oxidation area after oxidation tests compared to samples without MgAl2O4, resulting in 28% improvement in oxidation resistance compared to blank samples. In the erosion test, the results informed that adding 4 wt.% MgAl2O4 induced significant interfacial slag modification: MgAl2O4 dynamically dissolved FeOx to form protective Mg(Fe, Al)2O4 solid solution on the slag–refractory interface. This sacrificial dissolution effectively immobilized FeOx, elevated local slag viscosity, and fundamentally inhibited slag penetration and matrix dissolution. The erosion index decreased from 50% in the blank group to 27.4%.