Fugitive dust emissions emanating from bauxite residues can be a major environmental concern facing tailing storage facilities. These phenomena are a greater source of preoccupation in regions experiencing seasonal snow with the albedo being significantly modulated with bauxite residue content. Unfortunately, our poor understanding of drying processes, and of their dependence on environmental conditions is undermining prevention and mitigation efforts towards dust scattering events. In this work, new tools are brought to bear on the drying kinetics of bauxite residues and highlight their dependence on their microstructural and morphological properties. Thermal imaging was used to investigate the drying kinetics as a function of sample thickness and relative humidity suggesting that they are limited by gas phase diffusion through interstitial air within the bauxite residues internal microporosity. These preliminary results constitute a methodological validation for further systematic studies of the effect of mud farming operations on the microstructure of bauxite residues, and incidentally, on their drying kinetics with straightforward extension to Winter conditions. Along with efforts devoted to identifying aggravating environmental conditions based on detailed analyses of historical meteorological records that preceded past dust emission events, these enquiries will help develop predictive analytical and management tools that may improve forecasting of fugitive dust emissions. Furthermore, they may also contribute to establishing accurate risk assessment protocols, support interventions and mitigation strategies, and underpin optimisation efforts for bauxite residue management.

Thermal imaging: Novel approach to study evaporation kinetics in porous media

2019 Fall National Meeting

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