68th Canadian Geotechnical Conference and 7th Canadian Permafrost Conference

DESICCATON AND CONSOLIDATION MODELLING OF OIL SANDS FINE TAILINGS DEPOSITS

Session: Mining Geotechnique I / Géotechnique minière I

Paul Simms, Carleton University (Canada)
S. Soleimani, Carleton University (Canada)
L. Rozina, Carleton University (Canada)
S. Mizani, Carleton University (Canada)

Oil sands tailings deposition is regulated by enforcing reduction of the volume of fluid fine tailings over the life of an operation. Fluid fine tailings are defined by a 5 kPa undrained shear strength value. Operators are meeting these targets by improving dewatering and consolidation characteristics of fine tailings through various techniques, often involving addition of polymer or other flocculation-inducing treatment. Dewatering occurs through several mechanisms, including particle aggregation through application of the polymer, but also consolidation and desiccation through evaporation, drainage, or freeze-thaw. Understanding the relative contribution of each mechanism will assist in selecting optimal thickness, polymer dose, and rate of rise, to minimize and control impoundment footprints. In this paper, we examine the utility of consolidation and desiccation modelling to interpret laboratory experiments and field trials, to separate out the contribution of each mechanism, and to generalize these contributions to hypothetical deposition scenarios.