Wettability Characteristics of Nanoporous Carbon Bricks Incorporated with Al2O3 Phase and Molten Iron in Sustainable and Low‐Carbon Blast Furnace

Abstract

Analyzing the wetting behavior between carbon brick and molten iron in a blast furnace is crucial for understanding prolonging the furnace's lifespan. This study investigates the wetting behavior between microporous carbon brick and molten iron. The contact angle between the carbon brick and molten iron is measured at various temperatures and carbon saturation conditions, while the microscopic morphology of the reacted interface is examined. Furthermore, the wetting mechanism of molten iron on the carbon brick surface is elucidated. The findings reveal that both the microporous carbon brick and molten iron remain in a never‐wetting state within the furnace. As the temperature rises from 1150 to 1450 °C, the contact angle decreases from 138° to 128°, whereas the initial carbon content in the molten iron increases from 2.6 wt% to 4.1 wt%. Additionally, the initial contact angles gradually increase from 128.3° to 133.6°, with final equilibrium contact angles of 119.2° to 127.0°, indicating a nonwetting state. The carbon dissolution reaction occurs within the carbon matrix region of the microporous carbon brick prior to carbon saturation in the molten iron. Conversely, the presence of a ceramic phase in the ceramic area hampers both chemical erosion and physical penetration of the molten iron.