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.
