Bitumen recovery by the water-based extraction process produces waste streams known as tailings. When discharged into the tailing ponds, the coarse solids in the tailings stream settle out quickly, while the fine solids accumulate over years of settling to a solids content of 30-35% by weight. The formed fluid fine solids sludge, known as mature fine tailings (MFT), traps 1-3% by weight hydrocarbons within its stable slurry structure. The remediation of these mature fine tailings is one of the major challenges facing the oil sands industry. This study was intended to investigate the recovery of residual hydrocarbons in the MFT by froth flotation process. Using a laboratory Denver flotation cell operated in a batch mode, the effect of MFT dilution ratio by process water or tap water, the flotation hydrodynamics and aeration rate on hydrocarbon recovery kinetics was studied. It was found that at 1:2 dilution by weight of the MFT with process water, increasing aeration rate has a more favourable effect on recovering more than 85% of the hydrocarbons from the MFT. The hydrocarbon-rich froth produced was treated by naphtha and was found to produce a hydrocarbon product similar to diluted bitumen obtained in bitumen extraction process, suitable for upgrading. Similar approach was applied to the hydrocarbon-rich tailings from the Tailings Solvent Recovery Unit of paraffinic froth treatment. Satisfactory recovery of hydrocarbons from the MFT was obtained using a flotation column operated in a continuous mode, confirmed the results obtained from the batch tests. The tailings produced from the continuous flotation experiments were treated with polymer flocculants such as Magnafloc-1011 and Al-PAM to study the effect of hydrocarbon recovery on the remediation of the MFT. The results from initial tests showed that both flocculants were not as effective on flocculating MFT solids following the recovery of hydrocarbons by froth flotation. / in Chemical Engineering
Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:AEU.10048/1890 |
Date | 06 1900 |
Creators | Thomas, Tenny |
Contributors | Xu, Zhenghe (Chemical and Materials Engineering), Masliyah, Jacob (Chemical and Materials Engineering), Babadagli, Tayfun (Petroleum Engineering), Liu, Qi (Chemical and Materials Engineering), Xu, Zhenghe (Chemical and Materials Engineering), Masliyah, Jacob (Chemical and Materials Engineering) |
Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
Language | English |
Detected Language | English |
Type | Thesis |
Format | 1299353 bytes, application/pdf |
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