8th International Congress on Science and Technology of Ironmaking - ICSTI 2018

Permeability at the cohesive and dripping zones in blast furnace is mainly controlled by the dripping behavior of molten slags in the cokes aggregates layer. Thus, wettability of cokes (graphite) which contains ash minerals should be one of the most important controlling factors on the dripping behavior. In the present study, the wettability of graphite-alumina composites with different alumina contents against molten CaO-SiO2-Al2O3-MgO slags was investigated at 1873K by sessile drop method. It was found that the composite with the larger alumina content had the better wettability, which is attributed to the intensive interfacial reaction against the molten slags. Moreover, the molten slags with the higher basicity revealed the smaller contact angles on the composite substrate, which is simply due to the higher surface tension of slag. Additionally, with increasing the alumina content in the composite, the longer holding time was required for the equilibrium in interfacial reactions.