Hydrogen-Based Reduction Boosts Sustainable Iron Production from Red Mud

Abstract

Extracting iron from red mud─a caustic waste formed during the refinement of bauxite into alumina─provides a promising pathway toward the sustainable treatment of the unwanted byproduct and the supply of an important resource, but existing approaches raise environmental concerns and are financially unattractive. Here, we describe a plasma-enhanced chemical vapor reduction process that allows for efficient extraction of iron from red mud by using hydrogen as the reducing agent. This process, powered by electricity, can generate iron at temperatures down to 900 °C, with a high grade up to 71% and an iron recovery rate of 88.1%, showing advantages over conventional hydrometallurgy and pyrometallurgy methods in terms of cost and environmental footprint. The achieved performance can be attributed to the energetic hydrogen radicals generated in situ that make the iron reduction thermodynamically favorable. Our results suggest a promising path for economically viable and emission-free extraction of iron from red mud.