Preparation and characterization of Al2O3-SiC-C castables using ferrotitanium slag: structural commonalities between titanium–alumina slag and calcium alumino-titanate

To promote sustainable development in the refractory industry, ferrotitanium slags, including titanium–alumina slag (TAS) and calcium alumino–titanate (CAT), were used in this study to prepare Al₂O₃-SiC-C (ASC) castables. In this study, low-cost ASC castables were prepared using TAS and compared with those prepared using CAT in different atmospheres. The results show that metallic inclusions and Ti-concentrated areas in TAS aggregates lead to lower cold mechanical strength in TAS-based castables when fired in air. The performance of the TAS-based castables was similar to that of the CAT-based castables in low-oxygen environments. In the TAS aggregates, titanium suboxide showed local enrichment at the crystal boundary of Al₂O₃ in the form of Ti₂O₃. Both CAT and TAS showed the structural commonalities that aggregates were damaged along the boundary of the main crystal phase after heat treatment in an oxidizing atmosphere.