<  Back to the Polytechnique Montréal portal

Effective oxygen diffusion coefficient of till and green liquor dregs (GLD) mixes used in sealing layer in mine waste covers

Anna Virolainen, Christian Maurice and Thomas Pabst

Article (2020)

Open Access document in PolyPublie
[img]
Preview
Open Access to the full text of this document
Accepted Version
Terms of Use: All rights reserved
Download (1MB)
Show abstract
Hide abstract

Abstract

Cover systems can efficiently limit acid mine drainage generation from sulfidic mine wastes by controlling oxygen diffusion. Their performance relies on their high degree of saturation, as oxygen diffusion is substantially reduced in water or saturated medium. However, natural soils available in the mine vicinities do not necessarily have the hydrogeological properties required for the construction of sealing layers. A common strategy is to improve the characteristics of local soils using bentonite amendment, but this usually induces high costs and environmental footprint. An alternative is to reuse (or valorise) waste materials, such as mine wastes or industrial wastes like green liquor dregs (GLD). Blends of till and GLD can have advantageous properties regarding water retention capacity and hydraulic conductivity. In this study, the effective oxygen diffusion coefficient De of till-GLD blends was evaluated using 81 diffusion tests. Various quantities and different types of GLD were tested. The diffusion coefficient was found to vary greatly depending on the degree of saturation. Even though the GLD contained naturally a substantial amount of water, a high water content of the till was still required to reach a low De. Measurements were also compared with modified Millington-Shearer predictive model which could generally predict the diffusion coefficient within an acceptable range. Results also indicated that the till-GLD mixes should not be exposed to evaporation as significant performance loss may rapidly occur upon drying. Main experimental results are presented in this paper together with recommendations in terms of cover design using till-GLD mixes.

Uncontrolled Keywords

Oxygen diffusion; Green liquor dregs (GLD); Mine wastes; Covers; Sealing layers; Acid mine drainage; Reclamation

Subjects: 1400 Mining and mineral processing > 1402 Mineral processing
1500 Environmental engineering > 1500 Environmental engineering
1500 Environmental engineering > 1504 Solid waste management (including Radioactivity)
Department: Department of Civil, Geological and Mining Engineering
Research Center: Other
Funders: Mistra "Closing the loop" (project GLAD), Horizon 2020 research and innovation (project Paperchain), GeoRes Marie Skłodowska-Curie Research and Innovation Staff Exchange (RISE) project
Grant number: 730305, H2020-MSCA-RISE-2017, 778120
PolyPublie URL: https://publications.polymtl.ca/5323/
Journal Title: Water, Air, & Soil Pollution (vol. 231, no. 2)
Publisher: Springer
DOI: 10.1007/s11270-020-4431-3
Official URL: https://doi.org/10.1007/s11270-020-4431-3
Date Deposited: 20 Jul 2020 16:31
Last Modified: 08 Apr 2024 12:58
Cite in APA 7: Virolainen, A., Maurice, C., & Pabst, T. (2020). Effective oxygen diffusion coefficient of till and green liquor dregs (GLD) mixes used in sealing layer in mine waste covers. Water, Air, & Soil Pollution, 231(2). https://doi.org/10.1007/s11270-020-4431-3

Statistics

Total downloads

Downloads per month in the last year

Origin of downloads

Dimensions

Repository Staff Only

View Item View Item