Evaluation and Optimization of the Antifluctuation Ability of Slag Components Based on Critical Circles

Abstract

Traditional research has primarily focused on the performance of slag, but there is little research on the allowable composition fluctuation range of slag. In this study, an innovative approach, utilizing the critical circle radius to represent the slag composition range. The results show that as the Al₂O₃ content increases from 13 to 16 wt%, the proportion of the liquid-phase area expands from 25.9 to 28 wt%. Critical circle analysis reveals that at 1480 °C, when the MgO content reaches 8 wt%, the critical circle radius is maximized, indicating the largest composition fluctuation range. Under low Al₂O₃ conditions, basicity is the primary limiting factor for the inscribed circle radius. As Al₂O₃ content increases from 10 to 25 wt%, the optimal slag basicity initially rises and then declines. With the decrease of liquid-phase temperature from 1480 to 1440 °C, the slag's capacity to tolerate Al₂O₃ decreases, and the optimal critical Al₂O₃ content reduces. Increasing MgO content enhances the slag's tolerance to Al₂O₃. When the liquid-phase temperature is lowered to 1420 °C, the optimal critical Al₂O₃ content is 12.5 wt%, and the MgO content is controlled to be 5 wt%. The corresponding critical circle radius is the largest.