Recovery of Iron and Alumina from Iron-Rich Bauxite, Red Mud, and Fly Ash by Reduction Smelting with Steel Slag

High iron bauxite (IRB), red mud (RM), and fly ash (FA) are resources rich in iron and alumina, yet there are no effective methods of recovering and utilizing them. In this paper, a new reduction smelting technology for the extraction of iron and alumina from IRB, RM, and FA is proposed based on the technology platform of “Slag Metallurgy, Mineral Recycling, and Resource Recovery”. For the first time, molten steel slag (SS) was used in the alumina extraction process, which not only recovered the heat resource and iron from SS but also recycled the activated calcium oxide. The phase evolution and composition during the reduction smelting process were analyzed based on the phase diagram of the CaO-Al₂O₃-SiO₂ system, and the composition triangle was determined to be C₂S-C₁₂A₇-CA. Experiments were carried out to test the raw materials and formulations supplied by different manufacturers, and the alumina extraction rate reached 85% in all cases, while the iron recovery rate reached 95%. This proposed method promotes the sustainable use of energy and resources and has a promising future for industrial applications.