Original Article

Study on low-temperature fluidized hydrogen reduction treatment of red mud

¹ Chinalco Research Institute of Science and Technology Co., Ltd, 102209 Beijing, PR China
² State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, 100083 Beijing, PR China

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Received: 1 April 2026
Accepted: 1 June 2026

Abstract

To address the issues of pollution and resource waste associated with red mud stockpiling, this study proposes a high-temperature calcination and granulation modification technique. Through multidimensional low-temperature fluidized-bed hydrogen reduction experiments, it elucidates the mechanism by which high-temperature calcination and granulation modifies the reduction behavior of red mud. Results indicate that high-temperature calcination and granulation promotes the dissociation of Fe₂O₃ and Al₂O₃ in red mud, enhances hydrogen-Fe₂O₃ contact during fluidized reduction, and effectively lower the temperature required for red mud reduction. The metallization rate of the three types of red mud after calcination increased from <60% before calcination to over 80% after reduction, demonstrating that high-temperature calcination granulation significantly enhances the reduction efficiency of red mud. The study indicates that combining granulation with low-temperature hydrogen reduction technology can significantly improve the reduction efficiency of various red mud types, providing a feasible technical reference for the efficient and clean utilization of red mud resources.