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Boldbaatar, Serdamba

University of British Columbia

Efficiently removing water from oil sands tailings remains a persistent challenge for the oil sands industry. Although substantial research has focused on flocculating these tailings, a direct link between rapid settling rates and effective filtration has not been fully established. This thesis investigates how major cations and anions in industrial process water affect both flocculation and subsequent vacuum filtration of a model blend (75% quartz, 25% kaolinite) that simulates mature fine tailings (MFT). In addition, it explores the potential to enhance flocculated sediment structure during vacuum filtration by introducing coagulants (specifically calcium and aluminum) after flocculation. Experimental findings revealed that measuring settling rates and turbidity in suspensions exceeding 20-25 wt% solids was challenging due to extremely slow settling, even when higher polymer dosages and prolonged settling times were employed. Consequently, all flocculation tests were performed at 10–15 wt% solids. Zeta potential analyses demonstrated the key role of calcium in reducing the negative surface charge on quartz and kaolinite, thus promoting the flocculation of model blends. Although introducing calcium improved supernatant clarity, it also yielded smaller flocs. In contrast, conditions that promoted the formation of larger flocs resulted in higher filtrate volumes, underscoring the importance of floc size for filtration performance. Post-flocculation additions of calcium or aluminum improved filtration under low vacuum conditions; however, excess aluminum was found to hinder performance by causing polymer chain collapse and reducing floc size.

Text

2025-06-23

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/91417

Mining Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/