Thermal Cover Design for Mine Waste Facilities in Cold Regions

Christopher Stevens, Maritz Rykaart, Tia Shapka-Fels
Tuesday, October 2, 2018
First presented: 
Tailings and Mine Waste Conference 2018
Published paper
Mine Waste

Thermal covers have been widely adopted in northern Canada for freeze encapsulation of potentially reactive mine waste to limit acid rock drainage. A better understanding of the predicted and observed thermal performance of these cover systems is needed to improve design and gain regulatory and public acceptance of the strategy for long-term closure. This paper describes the design and dominant heat transfer mechanisms that impact thermal performance of thermal conduction, latent heat, and air convection covers. Thermal model results for each cover type is compared to demonstrate major differences in short and long-term thermal performance. Review of Canadian mining projects that have adopted the freeze encapsulation strategy indicate that the most common design is the thermal conduction cover which is generally performing as expected under contemporary climates. Thermal covers for freeze encapsulation of mine waste remain a viable approach for closure of some mine waste facilities located in cold regions.

Feature Author

Dr. Christopher Stevens
Christopher Stevens, PhD., is a geocryologist who specializes in permafrost and cold regions work. He has 8 years of project and research experience in both terrestrial and subsea permafrost, for mining, highway infrastructure, utility corridors, and oil and gas projects in USA and Canada. His experience includes thermal analysis, terrain and climate analysis, permafrost and ground ice characterization, talik delineation, permafrost-groundwater interactions, design and implementation of permafrost monitoring programs, and numerical thermal modeling to assess thermal performance of infrastructure and potential impacts to the environment. His experience also extends to the design and evaluation of permafrost mitigation techniques used to achieve infrastructure and site stabilization in areas with ice-rich permafrost, including passive thermosyphons, active ground freezing, air convection, and thermal covers. Christopher has developed several novel satellite and ground-based geophysical applications for mapping degrading permafrost conditions and characterizing related environmental changes.
Geocryology and Cold Regions Specialist
PhD. Geology and Geophysics
SRK Alaska
SRK Exploration Services