Summary of Research Progress on the Separation and Extraction of Iron from Bayer Red Mud

The Bayer method of alumina production generates highly alkaline solid waste known as red mud, which is challenging to utilize and can only be disposed of in stockpiles. This practice leads to environmental pollution and safety hazards, posing a significant barrier to the bauxite industry's transition towards green and sustainable development. In light of the diminishing availability of high-quality iron ore resources, Bayer red mud is increasingly viewed as a potential resource due to its high iron content. Consequently, utilizing red mud as a raw material for iron extraction presents both challenges and opportunities. This study systematically reviews the methods of iron extraction and recovery from red mud, categorizing them into physical sorting methods, wet leaching, pyrometallurgy method, and biometallurgy. This paper elaborate on the mechanisms of iron extraction from red mud in these processes, the transformation of mineral phases, and the challenges that exist. Additionally, it analyze and compare the characteristics, advantages, and disadvantages of the various technologies. It propose a novel low-carbon process for iron extraction from red mud-"calcified transformation-vortex reduction-cement preparation", achieving an iron recovery rate exceeding 95%. This recovered iron can be directly utilized in steel production, while the molten reduction slag can be modulated for the preparation of low-carbon cement clinker. This approach not only facilitates the reduction and high-value utilization of solid waste but also provides valuable insights into the recovery of iron and the effective use of red mud resources.