Effect of Binders on the Dynamic Slag and Iron Erosion Behavior of Taphole Clay

Dynamic slag and hot metal erosion tests were performed by the rotating cylinder method to evaluate the erosion resistance of taphole clay with different binder systems under high‐temperature flowing media. Macroscopic diameter changes, XRD phase analysis, and SEM–EDS observations before and after erosion were used to clarify the erosion behavior and degradation mechanisms. The results show that pore formation induced by binder volatilization and pyrolysis is the prerequisite for erosion initiation and propagation. Slag erosion is mainly characterized by penetration along pores and reactions with the ceramic skeleton to form new Ca–Mg–Al–Si‐based phases, accompanied by local structural instability. In contrast, hot metal erosion is dominated by preferential penetration through pores and attack on carbonaceous phases, resulting in local carburization and Fe–C reactions. After cardanol addition, the original structure became denser and more uniform, with fewer and smaller pores, leading to weaker interfacial defect evolution and less severe macroscopic damage during subsequent erosion. Cardanol may improve erosion resistance by enhancing binder flowability and compatibility and by optimizing the pore structure after pyrolysis. This work provides guidance for optimizing binder systems of taphole clay for blast furnaces with similar slag and hot metal compositions.