ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Maurais et al. .docx (2.38 MB)

A Thermal Imaging Methodology To Study Evaporation Kinetics in Mine Tailings

preprint
revised on 05.02.2020, 20:42 and posted on 07.02.2020, 05:55 by Josée Maurais, Étienne Beaumont, Joanick Bourret, Emrik Dauphinais, Nicolas-Alexandre Bouchard, Patrick Ayotte

Predicting why, how, and when mine tailings disposal sites become prone to dust scattering events is often hampered by our limited understanding of the factors that affect the drying rates from their surface layers. As a case study, thermal imaging is demonstrated here to be a valuable tool to study the evaporation mechanisms and rates from bauxite residues as a function of their thickness and physicochemical properties, as well as environmental conditions. These investigations reveal their that late stage drying rates are limited by gas phase diffusion through the interstitial air within their internal microporosity. The smallness of the effective diffusion coefficient indicates that water adsorption on bauxite residues surfaces is the dominant phenomenon responsible for their slow water vapour transport kinetics, a phenomenon that ultimately controls their late stage drying rates, that is when dust scattering is most likely to occur. As such, application of this thermal imaging methodology in the field may also contribute to improve the accuracy of risk assessment protocols, support intervention and mitigation strategies, underpin optimization efforts for mining residues management, and improve forecasting of fugitive dust emissions from mine tailings by enabling more accurate predictions of the evolution in their surface drying state.

Funding

Fonds de Recherche du Québec - Nature et technologies (FRQNT)

Conseil de Recherches des Sciences Naturelles et en Génie (CRSNG)

Ministère de l'Énergie et des Ressources naturelles (MERNS)

Rio Tinto

History

Email Address of Submitting Author

josee.maurais@usherbrooke.ca

Institution

Université de Sherbrooke

Country

Canada

ORCID For Submitting Author

0000-0003-1575-9637

Declaration of Conflict of Interest

No conflict of interest

Exports

Read the published paper

in Environmental Science: Water Research & Technology

Logo branding

Exports