Acid mine drainage (AMD) mitigation strategies in cold regions should be able to take advantage of cold temperatures and permafrost conditions. The chemical reactions that cause AMD are slowed down at lower temperatures and frozen material has very low hydraulic conductivity. A review of the important physical and chemical processes that could affect AMD potential in permafrost environments is reviewed in MEND 1.61.2 (1996). This MEND report recognized that there is a lack of information available on the thermal properties of mine waste materials (waste rock and tailings). In order to provide some information that examines this issue, a laboratory research program was initiated at the University of Alberta and Norwest Mine Services Ltd. was contracted to manage the laboratory work, evaluate the data, and report on the results.
The main objective of this report is to present the results of laboratory research on the thermal properties of saturated mine tailings. The focus of the testing was for determining the thermal conductivity and unfrozen water content of saturated mine tailings samples. Additionally, the unfrozen hydraulic conductivity and the amount of unfrozen water provides an indication of the order of magnitude decrease in hydraulic conductivity that is realized after freezing. Estimates of frozen hydraulic conductivity are reviewed in this report.