Microstructure and properties of hydratable alumina bonded bauxite–andalusite based castables

Roles of hydratable alumina and firing temperatures on the physical properties, hot modulus of rupture and thermal shock resistance of the bauxite–andalusite based castables were investigated. Cold strength, hot strength and thermal shock resistance of castables are improved with hydratable alumina content increasing from 2% to 6%, and also noticeably improved with the temperature rising from 1300 °C to 1450 °C, which can be ascribed to the increase in in-situ mullite content and its crystal size as well as the decrease in the silica-rich glass phase in the castables.