Study on physicochemical properties of Al2O3SiC C castable for blast furnace

The physicochemical properties of a new Al O –SiC–C castable (ASCC) material were systematically investigated in this study. The results indicate that different heat treatment (HT) temperatures can lead to the formation of different phases, generating performance changes. A high HT temperature of 1773 K can create the mullite phase, serving as a strength-enhancer and shrinkage-compensator. The coexistence of carbon and corundum phases can effectively impede the corrosion caused by iron and slag, respectively, while the low carbon content in the ASCC can strengthen the iron attack resistance. The compressive strength of the ASCC showed a greater than 40% decrease after impurity element (K, Na, and Zn) corrosion experiments, which is greater than the change of the breaking strength. The larger atomic diameter of alkali metal could cause local relaxation and volume expansion of the aluminosilicate structure. The alkali metal scatters on the substrate; however, zinc exists in the form of ZnS and is primarily concentrated in the voids of the ASCC.