PREVENTION AND MITIGATION OF FUGITIVE DUST EMISSION FROM BAUXITE RESIDUES: AGGRAVATING ENVIRONMENTAL EFFECTS, FORECASTING AND RISK ASSESSMENT

Maurais, J., Dauphinais, E., Larivière-Loiselle, C., Beaumont, E., Morin, E., Royer, A., Bouchard, N.-A., Ayotte, P., Bourret, J.

Bauxite residue management is facing a plethora of environmental challenges, several of which arising from dust lift-off events. Unfortunately, our poor understanding of drying processes, and of their dependence on environmental conditions, require prevention and mitigation efforts that may unnecessarily exceed the risks of fugitive dust emissions. 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. These preliminary investigations constitute a methodological validation for further systematic studies of the effect of mud farming operations on their microstructure, 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.