Characterization of Clay Minerals in the Athabasca Oil Sands in Water Extraction and Nonaqueous Solvent Extraction Processes

• Author / Creator

  Hooshiar Fard, Mohammad Ali

• Production of oil from the second largest oil deposit in the world, i.e., the Alberta oil sands containing approximately 13% of total proven oil reserves in the world (169.9 billion barrels), has been shown to be significantly influenced by clay minerals. Clay minerals in particular play a key role in the settling behaviour of massive amounts of aqueous tailings resulting from water-based bitumen extraction. A nonaqueous extraction process is of special interest to extract bitumen from oil sands due to its potential advantages, such as high bitumen recovery even from low grade oil sands ores and the elimination of slow settling, sludge tailings ponds with stable suspensions. While clay minerals have been characterized in water-based bitumen extraction from the oil sands to some extent, the gap of knowledge in the characterization of clay minerals in a nonaqueous bitumen extraction process has led to the current research.

  A nonaqueous bitumen extraction process was established where only toluene and heptane, with no water additions, were used to extract bitumen from oil sands ore samples. Bitumen recovery and product quality were studied under different process conditions, such as the ratio of toluene to heptane and settling time. Bitumen recovery was found to be insensitive to the characteristics of the oil sands ores, such as processability and fines content, although the high fines ore sample was more sensitive to the extraction conditions. A product with high purity, containing more than 99.5 wt% bitumen on a solvent-free basis, was produced at room temperature under the optimum extraction conditions tested.

  Quantitative x-ray diffraction (XRD) analysis revealed an enrichment of kaolinite in the extraction products (froth stream in water-based extraction and supernatant in nonaqueous extraction) when compared with the ore. High resolution transmission electron microscopy (HRTEM) investigations showed the presence of monolayer discrete smectitic clay minerals (not detectable by XRD). Illite-smectite expandability results calculated from HRTEM data have made it possible to explain the extraordinarily high surface activity in the primary froth stream. Scanning electron microscopy (SEM) observations showed some important features (clay-organic aggregates) which affect the settling behaviour of the solids after nonaqueous extraction.

• Subjects / Keywords

  • Oil Sands
  • Clay Minerals
  • XRD
  • TEM

• Graduation date

  Fall 2011

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3WM04

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.