New grades of high-strength steel with high-Al contents are attractive materials for the automotive industry. However, in continuous casting, Al in the steel reacts with SiO₂ in the mould flux, leading to a change in flux composition and properties. Therefore, traditional CaO-SiO₂-based fluxes are not suitable for high-Al steel casting, and new CaO-Al₂O₃-based fluxes must be developed. The aim of this project is to study melting properties and viscosity of CaO-Al₂O₃-based fluxes, their crystallisation behaviour and heat transfer, flux-metal reaction, and flux stability and heat capacity. The outcomes of this project will provide a foundation for the development of mould fluxes for the continuous casting of high-Al steel at Baosteel.