Enrichment of iron from bauxite waste in chemical looping combustion

Abstract

AbstractThis work reports a method and findings related to the enrichment of iron from bauxite waste (red mud) using chemical looping combustion (CLC). According to the results from X‐ray Diffraction, X‐ray Fluorescence, and scanning electron microscope–energy‐dispersive X‐ray spectroscopy, uniformly distributed iron in the red mud particles migrated outward to the surface during the 148 redox cycles in a bubbling fluidized bed reactor, in which the size‐reduced iron‐oxide particles due to attrition are concentrated in filters. The concentrations of iron oxide in raw particles and attrition fines are 43 wt.% and 83–87 wt.%, respectively. Since the attrition in CLC is inevitable, this recycled iron oxide can be a valuable by‐product to compensate for the cost of CLC, whereas the bed materials continue to participate in the CLC process. Moreover, the abundant bauxite waste can be processed in an eco‐friendly manner for integrated power generation, carbon capture, and iron recovery by the proposed strategy in this work.