Liquid Phase Formation Behavior and Regulation in High‐Alumina Sintered Ore

This study investigates the occurrence modes of aluminum in high‐alumina sinter and their influence on reduction behavior and liquid‐phase formation. Results indicate that aluminum is predominantly present as calcium ferrites and aluminosilicates. A moderate content of Al 2 O 3 promotes the formation of silico‐ferrite of calcium and aluminum (SFCA), thereby enhancing the strength of the bonding phase; however, excessive Al 2 O 3 leads to the precipitation of high‐melting‐point phases, reducing liquid‐phase fluidity. Adjusting MgO and SiO 2 contents can effectively improve liquid‐phase properties. In terms of ore blending, Australian ore fines—rich in limonite—facilitate a lower assimilation temperature and enhanced liquid‐phase fluidity, whereas Brazilian ore fines exhibit the opposite effect. Rational ore blending and compositional control can thus mitigate the performance degradation of high‐alumina sinter. The ore‐blending results should be interpreted as a high‐temperature characteristic evaluation rather than a complete optimization of sinter production. Among the tested blends, the 3:1 mass ratio of high‐silica limonite to medium–low‐silica hematite exhibited a relatively low minimum assimilation temperature and favorable liquid‐phase fluidity, indicating a promising direction for improving assimilation and melt spreading in a high‐alumina system. Its effects on sinter yield, tumble strength, productivity, fuel consumption, RI/RDI, and softening–melting behavior, however, require further confirmation by sinter‐pot or industrial trials.