Conventionally, oil sands ores are mined using the Clark Hot Water Extraction (CHWE) process to extract bitumen. The by-product slurry (tailings) resulting from the extraction process is an aqueous suspension of coarse sands, fine solids, and clays with some fugitive residual bitumen at pH between 8 and 9. Effective dewatering of these tailings is of extreme importance to reduce the environmental pollution caused by the oil sands operations. Conventional technologies are mature in the treatment of domestic wastewater but they are not perfectly customized for treating the mature fine tailings (MFT). Our group is investigating the biopolymers to dewater the MFT and the underlying mechanism. Biopolymers are the suitable candidate as they can be made using natural raw materials hence; the dosage of such flocculants is of less significance as compared to the costlier synthetic flocculants. This work presents the chitosan-based flocculants to dewater the 5 wt % MFT. We measured the settling behavior of the tailings as a function of chitosan modification. Further, we report the quality of water recovered after the consolidation of the tailings. The ability of sediments to expel the water over the longer times was also measured using capillary suction time (CST). Overall, chitosan-based flocculants are promising candidates to effectively dewater the MFT.
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