An Innovative Process for the Separation of Iron and Aluminum from High-Iron Red Mud Using Fluidized Pre-reduction and Electric Furnace Smelting
摘要
The resourceful utilization and harmless disposal of high-iron red mud remain a global challenge. An innovative process for separating iron and aluminum from high-iron red mud via fluidized pre-reduction and electric furnace smelting is proposed. Iron in high-iron red mud from the Bayer process mainly exists as goethite and hematite, while aluminum is primarily present as alumogoethite due to isomorphic Fe substitution, with part of the aluminum as gibbsite. While conventional magnetization roasting converts hematite and goethite into magnetite, it cannot disrupt the isomorphic aluminum-iron lattice, resulting in residual aluminum in the magnetic concentrate that still requires further separation. Building on this, the innovative fluidized pre-reduction and electric furnace smelting process developed in this study effectively breaks the aluminum-iron substitution, disrupting their symbiotic structure and enabling the decoupling of aluminum and iron phases. This process produces high-quality pig iron (TFe > 92 wt%) that meets steelmaking standards, along with an aluminum-rich slag suitable for aluminate cement clinker production. It achieves a high iron recovery rate (> 95%) while ensuring the comprehensive recovery of aluminum resources. These results address the environmental and resource challenges associated with high-iron red mud and offer a technically robust and economically viable solution for its large-scale valorization.