In Situ Determination of Thermal Conductivity of Waste Rock Dump Material

In situ determinations of thermal conductivity of waste rock dumps at three mine sites: Aitik, Sweden; Kelian, Indonesia; and Heath Steele, Canada are described. Measurements were carried out at various locations and depths at each site. The estimated thermal conductivities range from 0.62 to 1.63 W m-1K-1 with an average of 1.21±0.27 W m-1K-1 for the waste rock pile at the Aitik site, 1.04 to 1.25 W m-1K-1 with an average value of 1.17(0.11 W m-1K-1 for the Heath Steele site, and 1.57 to 2.08 W m-1K-1 with an average value of 1.89±0.21 W m-1K-1 for the Kelian site. The higher average thermal conductivity at the Kelian site could be attributed to higher moisture content in the waste rock pile because of high rainfall at this site. Thermal diffusivity was also evaluated at a region of the Aitik waste rock dump where the thermal conductivity was also determined using measured temperature profiles. The thermal diffusivity value determined this way was (5.75 ± 0.75) × 10-7 m2s-1, consistent with that calculated from the thermal conductivity values determined for the same location.