Thermal Cover Design for Mine Waste Facilities in Cold Regions

Author(s): 
Christopher Stevens, Maritz Rykaart, Tia Shapka-Fels
Date: 
Tuesday, October 2, 2018
First presented: 
Tailings and Mine Waste Conference 2018
Type: 
Published paper
Category: 
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
Dr. Maritz Rykaart

Maritz has undergraduate and Masters degrees in Civil Engineering, a PhD in Geotechnical engineering and 21 years of experience in mine management and applied research. His experience includes geotechnical field investigations; geotechnical analysis; environmental audits; landfill siting and design; siting design, construction, operation and monitoring of pollution control systems, water supply dams, tailings impoundments and river diversions; optimization of mine water balances; permafrost engineering; and mine closure planning, design and cost estimating; construction management, quality assurance and quality control, including managing EPCM contacts.

 

Geotechnical Engineering Specialist
PhD, PEng
SRK Vancouver
SRK Africa