Sixteenth International Conference on Environmental, Cultural, Economic & Social Sustainability

Abstract

The management of fine oil sands tailings is a major challenge for the oil industry in the north Alberta, Canada. The tailings have high water content and low permeability attributable to their significant clay content. Without treatment, consolidation and solidification of the tailings in tailings ponds will take decades. For the oil sand industry, effective and efficient technologies for effective and efficient dewatering of fine oil sand tailings are in urgent demand. In this paper, recent research and development on innovative technologies for dewatering and solidification of find oil sand tailings are introduced, including electrokinetic (EK) treatment, chemical treatment, and surcharge, vacuum, and EK combined treatment. EK dewatering treatment has shown to be very effective, mainly because of the favourable mineralogy and chemistry of the oil sand tailings. Extensive studies were conducted on the material characterization, system configuration, energy consumption and numerical simulation. The chemical treatment involves applications of chemicals to oil sand tailings to achieve specific management objectives. Quicklime, Portland cement, and various liquid silicates have been investigated in recent studies. The effectiveness of these stabilizers at different dosages and curing durations is assessed in terms of the undrained shear strength, solid content, plasticity, pore fluid chemistry, and microstructure. The study on combined surcharge, vacuum, and EK treatment is investigated to accelerate consolidation and dewatering of fine oil sand tailings. Preliminary results under conditions such as EK, vacuum, surcharge, and their combinations, are assessed and discussed.