Nanostructural Characterization of the Porous Network in Bauxite Residues at Ambient and Sub-Zero Temperatures

Red mud, a byproduct of aluminum oxide extraction, often poses dust emission risks due to open-air storage. To predict the dust wind dispersal and apply adequate mitigation procedures, it is crucial to understand the bauxite residue material drying kinetics, which strongly depends on its nanoporous structure. We thus plan to achieve phase contrast nanotomography of this material using ID16B beamline, which offers a unique opportunity to achieve reliable porosity analysis. We thus aim to: (i) distinguish material phases from water\air; (ii) quantify pore size distribution and capillary length; (iii) identify and characterize porous networks and isolated pockets; (iv) examine the structural differences between on-site and lab-synthesized samples; (v) evaluate the impact of water phase transitions on pore structures. This will improve fundamental knowledge of water transport mechanisms in porous media, contributing to predictive models for dust scattering events and residue management.