Research progress of low-carbon Al₂O₃-C refractories for steelmaking and continuous casting

Al₂O₃-C refractories are widely used in sliding nozzles and continuous casting components due to their excellent thermal shock resistance and corrosion resistance. However, conventional high-carbon Al₂O₃-C materials suffer from issues such as carbon pickup in molten steel and CO₂emissions due to oxidation, as well as a loose microstructure that leads to performance degradation. These problems negatively affect clean steel production, environmental protection, and the service life of the materials. Therefore, there is an urgent demand to develop low-carbon Al₂O₃-C materials. However, key properties such as thermal shock resistance and corrosion resistance are insufficient to meet application requirements with carbon reduction. Optimizing carbon sources and additives is essential for improving the performance of low-carbon Al₂O₃-C materials. The effects of different carbon sources and additives on the composition, structure and properties of low-carbon Al₂O₃-C materials are reviewed in this paper, and the potential application of biochar as a green, renewable and highly reactive carbon source is prospected. The aim is to provide new ideas for the green preparation and performance improvement of low-carbon Al₂O₃-C materials.