Feasibility of Red Mud Recycling via Hydrogen Plasma Smelting Reduction: Insights From Large‐Scale Laboratory Experiments

The transformation of the iron and steel industry to mitigate their 7%–9% share of global CO 2 emissions requires not only the modification of current technologies or research into new ones, but also the use of residual materials to recover valuable metals. Iron‐containing residues from various industries, which are deposited in large quantities, lead to the loss of valuable metals. The environmentally harmful red mud, which is still mainly deposited in landfills today, is generated during the primary route of aluminum production. This study assesses the feasibility of red mud recycling as an iron source through hydrogen plasma smelting reduction in 18 laboratory experiments using plasma, each processing more than one hundred grams of material. The aim is to identify conditions that maximize Fe yield and to identify first‐scale‐up challenges. Results demonstrate the recovery of iron from red mud and the elimination of environmentally harmful compounds, such as F and Cl, already in the early stages of the process. XRD analysis reveals the formation of different mineral phases and allows the quantitative determination of the phase fractions. This research takes the first steps to scale up development in sustainable red mud recycling via hydrogen plasma smelting reduction.