Iron and Heavy Metal Removal from Bauxite Residues by Flash Joule Heating with Chlorination

Aluminum is one of the most produced metals worldwide. The Bayer process extracts aluminum from bauxite ores and generates bauxite residue as an environmentally hazardous waste with a low recycling rate and increasing accumulation. The high Fe content in the residue makes it cost prohibitive to extract the remaining aluminum. We present here a process using flash Joule heating combined with chlorination (FJH-Cl₂) to remove iron and heavy metals from bauxite residues. With one-step FJH-Cl₂ treatment in 1 min, >96% of the Fe can be removed as volatile FeCl₃ from bauxite residues while retaining ∼ 99% of the Al in the residue. The corundum-rich residue can be sintered into high-performing ceramics, underscoring the valorization of the bauxite residue. Life-cycle assessment and techno-economic analysis show that the FJH-Cl₂ process has far lower global warming emissions, energy consumption, and costs when compared to alternative processes. This highlights the potential of FJH-Cl₂ as an efficient method for upcycling bauxite residues into valuable Al resources and high-performance materials.