Thermal-Hydrological-Chemical Modeling of a Covered Waste Rock Pile in a Permafrost Region
In order to reduce contaminant mass loadings, thermal cover systems may be incorporated in the design of waste rock piles located in regions of continuous permafrost. In this study, reactive transport modeling was used to improve the understanding of coupled thermo-hydrological and chemical processe...
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MDPI AG
2021-05-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/11/6/565 |
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| author | Xueying Yi Danyang Su Bruno Bussière K. Ulrich Mayer |
| author_facet | Xueying Yi Danyang Su Bruno Bussière K. Ulrich Mayer |
| author_sort | Xueying Yi |
| collection | DOAJ |
| description | In order to reduce contaminant mass loadings, thermal cover systems may be incorporated in the design of waste rock piles located in regions of continuous permafrost. In this study, reactive transport modeling was used to improve the understanding of coupled thermo-hydrological and chemical processes controlling the evolution of a covered waste rock pile located in Northern Canada. Material properties from previous field and laboratory tests were incorporated into the model to constrain the simulations. Good agreement between simulated and observational temperature data indicates that the model is capable of capturing the coupled thermo-hydrological processes occurring within the pile. Simulations were also useful for forecasting the pile’s long-term evolution with an emphasis on water flow and heat transport mechanisms, but also including geochemical weathering processes and sulfate mass loadings as an indicator for the release of contaminated drainage. An uncertainty analysis was carried out to address different scenarios of the cover’s performance as a function of the applied infiltration rate, accounting for the impacts of evaporation, runoff, and snow ablation. The model results indicate that the cover performance is insensitive to the magnitude of recharge rates, except for limited changes of the flow regime in the shallow active layer. The model was expanded by performing an additional sensitivity analysis to assess the role of cover thicknesses. The simulated results reveal that a cover design with an appropriate thickness can effectively minimize mass loadings in drainage by maintaining the active layer completely within the cover. |
| first_indexed | 2024-03-10T11:02:16Z |
| format | Article |
| id | doaj.art-341a0e7d634040e6a9eccddb720f4b33 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-10T11:02:16Z |
| publishDate | 2021-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-341a0e7d634040e6a9eccddb720f4b332023-11-21T21:25:07ZengMDPI AGMinerals2075-163X2021-05-0111656510.3390/min11060565Thermal-Hydrological-Chemical Modeling of a Covered Waste Rock Pile in a Permafrost RegionXueying Yi0Danyang Su1Bruno Bussière2K. Ulrich Mayer3Department of Earth, Ocean, and Atmospheric Sciences, The University of British Columbia, 2207 Main Mall, Vancouver, BC V6T 1Z4, CanadaDepartment of Earth, Ocean, and Atmospheric Sciences, The University of British Columbia, 2207 Main Mall, Vancouver, BC V6T 1Z4, CanadaInstitut de Recherche en Mines et en Environnement, Université du Québec en Abitibi-Témiscamingue, 445 Boulevard de l’Université, Rouyn-Noranda, QC J9X 5E4, CanadaDepartment of Earth, Ocean, and Atmospheric Sciences, The University of British Columbia, 2207 Main Mall, Vancouver, BC V6T 1Z4, CanadaIn order to reduce contaminant mass loadings, thermal cover systems may be incorporated in the design of waste rock piles located in regions of continuous permafrost. In this study, reactive transport modeling was used to improve the understanding of coupled thermo-hydrological and chemical processes controlling the evolution of a covered waste rock pile located in Northern Canada. Material properties from previous field and laboratory tests were incorporated into the model to constrain the simulations. Good agreement between simulated and observational temperature data indicates that the model is capable of capturing the coupled thermo-hydrological processes occurring within the pile. Simulations were also useful for forecasting the pile’s long-term evolution with an emphasis on water flow and heat transport mechanisms, but also including geochemical weathering processes and sulfate mass loadings as an indicator for the release of contaminated drainage. An uncertainty analysis was carried out to address different scenarios of the cover’s performance as a function of the applied infiltration rate, accounting for the impacts of evaporation, runoff, and snow ablation. The model results indicate that the cover performance is insensitive to the magnitude of recharge rates, except for limited changes of the flow regime in the shallow active layer. The model was expanded by performing an additional sensitivity analysis to assess the role of cover thicknesses. The simulated results reveal that a cover design with an appropriate thickness can effectively minimize mass loadings in drainage by maintaining the active layer completely within the cover.https://www.mdpi.com/2075-163X/11/6/565reactive transport modelingmine waste rockthermal coverfreeze-thaw cyclespermafrostcontaminated drainage |
| spellingShingle | Xueying Yi Danyang Su Bruno Bussière K. Ulrich Mayer Thermal-Hydrological-Chemical Modeling of a Covered Waste Rock Pile in a Permafrost Region Minerals reactive transport modeling mine waste rock thermal cover freeze-thaw cycles permafrost contaminated drainage |
| title | Thermal-Hydrological-Chemical Modeling of a Covered Waste Rock Pile in a Permafrost Region |
| title_full | Thermal-Hydrological-Chemical Modeling of a Covered Waste Rock Pile in a Permafrost Region |
| title_fullStr | Thermal-Hydrological-Chemical Modeling of a Covered Waste Rock Pile in a Permafrost Region |
| title_full_unstemmed | Thermal-Hydrological-Chemical Modeling of a Covered Waste Rock Pile in a Permafrost Region |
| title_short | Thermal-Hydrological-Chemical Modeling of a Covered Waste Rock Pile in a Permafrost Region |
| title_sort | thermal hydrological chemical modeling of a covered waste rock pile in a permafrost region |
| topic | reactive transport modeling mine waste rock thermal cover freeze-thaw cycles permafrost contaminated drainage |
| url | https://www.mdpi.com/2075-163X/11/6/565 |
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