Slag corrosion characteristics of MgO-based refractories under vacuum electromagnetic field

MgO-based refractories have been widely used in metallurgical processes. However, their service lives are limited by the corrosion and penetration effects of the molten slag. To figure out the slag resistance of various MgO-based refractories, MgO-MgAl2O4, MgO-CaO, and MgO-C refractories were chosen in this work, and their slag corrosion characteristics under vacuum electromagnetic fields were investigated using the static crucible method at 1873 K. Furthermore, the corroded interfaces of refractories were analyzed by x-ray diffractometer (XRD), scanning electron microscope (SEM), and energy dispersive spectrometer (EDS). It was found that in CaO-Al2O3-SiO2-MgO slag system, the refractories displayed different slag corrosion resistance, and their corrosion depths ranged from 3 to 10 mm. The corrosion depths of MgO-CaO refractories were more than 10 mm, which showed the worst slag resistance performance. Among them, MgO-C refractories were hardly corroded by the molten slag and its corrosion depth was less than 3 mm.