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Characterization of Solids Isolated from Different Oil Sand Ores
- Author / Creator
- Adegoroye, Adebukola
Understanding mineralogy and surface properties of fine solids is vital in oil sands processing and tailings management. Fine solids in oil sands are often contaminated by tightly bound organic matter (OM) originally or during hydrocarbon removal, thereby increasing surface hydrophobicity and making its characterization problematic. The surface properties of solids affect the entire process cycle of obtaining synthetic crude oil from surface-mined oil sands using a water-based extraction process, and managing produced tailings.
In this study, low temperature ashing (LTA) was found to be a more suitable method than hydrogen peroxide (H2O2) for OM removal from clay sized minerals (CSM) because of its selectivity for decomposing only organics. The mineralogy and cation exchange capacity of the CSM remained unaffected after treatment with LTA as opposed to H2O2 treatment.
To comprehend the organo-mineral interactions in oil sands, solids isolated from weathered and oil sands having low- and high-fine solids content were examined. Low-fines ore possessed the lowest amount of organic coated solids and highest bitumen recovery. The solids in the bitumen froth from these ores were of less quartz, more carbonates, transition metals and carbon than the solids in the corresponding tailings. Infrared spectra showed a likely association between OM and carbonates in the organic coated solids isolated from bitumen froth. Weathered ores were found to contain more organic coated solids which were observed to reduce bitumen recovery from these oil sands ores.
A further study of weathered ores was undertaken to understand the reason for its poor processability from a mineralogical perspective. A higher amount of divalent cations was found in weathered ores than in high- and low-fines ores. The low-fines ore was found to exhibit the highest kaolinitic to illitic mineral ratio, while the high-fines ore displayed the lowest ratio. Siderite and pyrite were observed in the solids isolated from weathered and high-fines ores, but were absent in low-fines ores. In addition to wettability, the poor processability of weathered ores appeared to be related to the interactions between the divalent cations and illite, and the cementation effect of the siderite concretions on the oil sand grains, which inhibited bitumen liberation. Corrensite, a mixed-layer chlorite-vermiculite, was detected for the first time in weathered ores.
- Subjects / Keywords
- Graduation date
- Spring 2010
- Type of Item
- Doctor of Philosophy
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