Coordinated global valorization of Pidgeon-process magnesium residues: Environmental risks, carbon capture, and electroconversion.

The silicothermic process for magnesium production generates a substantial amount of Pidgeon-process magnesium slag (MS). According to the International Magnesium Council, approximately 6 to 8 tons of magnesium slag are produced for every ton of metallic magnesium. This results in persistent stockpiling and landfilling pressures in major magnesium-producing regions, while also triggering a series of issues including alkaline pollution, dust dispersion, and long-term land occupation. Although research on the high-value utilization of magnesium slag as construction-related resources is gaining traction, most existing studies treat hazard control and performance utilization as two separate issues. This separation can easily lead to risk transfer across different utilization pathways and lifecycle stages. Unlike reviews centered on a single utilization route, this work links residue hazards, pathway-specific performance, carbon capture, electroconversion, and LCA-MCDA evaluation within one decision framework. It identifies the suitable conditions, main limitations, and possible risk transfer of each route, providing a clearer basis for regional pathway selection.