Electrical Resistance Heating for Thawing of Frozen Uranium Tailings in a Uranium Tailing Management Facility

Abstract

The Rabbit Lake In-Pit Tailings Management Facility contains frozen layers of tailings due to sub-aerial deposition during successive winter operations. Thawing of the frozen layers is required to ensure full consolidation of the tailings prior to closure and to regain disposal space presently occupied by ice. Electric resistance heating (ERH), which has been used to heat soil for bitumen extraction and remediation of volatile contaminants, is being evaluated as a thawing mechanism. Two bench-scale experiments were performed in late 2009 and early 2010 wherein ERH was tested on about 0.3 cubic metres of frozen tailings. Thawing occurred in both experiments with negligible geochemical effects, demonstrating the viability of ERH as a tailings thawing mechanism. An in-pit field trial was performed from July 2010 until April 2011. Thermal and electric data collected throughout the trial indicate that thawing has occurred as was predicted based on the bench-scale experiment.