Optimization of the Slag Composition in Ladle Treatment of Steel for Increasing the Resistance of Refractories and Promoting Slag Reuse

Abstract

Methods of ladle furnace slag stabilization are analyzed. It is shown that increasing the Al₂O₃ content of slag to higher than 18% results in chemical stabilization of slag. It is revealed that if the Al₂O₃ content is less than 30 wt.%, the refining properties of the slag do not degrade. When that content is exceeded, Al₂O₃ behaves similarly to SiO₂, i.e., reduces the desulfurization ability of slag and makes it more corrosion aggressive. The most favorable content of Al₂O₃ in slag is from 12 to 25%, the properties of slag varying from basic to acidic. If the Al₂O₃ content is higher than 14%, the probability of formation of MgO–Al₂O₃ refractory spinel on the surface of refractory products increases, thereby increasing the durability of ladles and vacuum chambers.