Freeze-thaw dewatering of oil sands fine tails

Abstract

Laboratory and field experiments demonstrate that substantial dewatering occurs when the waste clay from oil sands operations is subjected to one cycle of freeze-thaw. The enhanced permeability resulting from the freezing process causes further dewatering and accompanying strength increases during post-thaw consolidation. The findings presented here were guided by a number of different materials handling scenarios which take advantage of the freeze-thaw process and are driven by the appropriate geotechnical, geochemical, and geothermal input parameters. Different conceptual design scenarios are examined to demonstrate how this process might be feasibly implemented at the commercial scale. Emphasis is placed on the large-scale requirements, sensitivity to input parameters, and the coupling of the continuing applied research with the conceptual materials handling models. The latter point is of generic interest to those involved in mine waste management.Key words: mine wastes, freeze-thaw, volume reduction, disposal, large strain consolidation.