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. / Chemical Engineering

No description available.

[No abstract submitted] / Science, Faculty of / Chemistry, Department of / Graduate

[No abstract submitted] / Science, Faculty of / Chemistry, Department of / Graduate

An efficient undrained model for the deformations analysis of oil sand masses upon undrained loading is presented in this thesis. An analysis which couples the soil skeleton and pore fluids is used. The soil skeleton is modeled as a non-linear elastic-plastic isotropic material. In undrained conditions, the constitutive relationships for the pore fluids are formulated based on the ideal gas laws. The coupling between the soil skeleton and the pore fluids is based upon volume compatibility. The undrained model was verified with the experimental results and one dimensional expansion of soil sand cores. Comparisons between computed and measured responses are in good agreement and suggest that this model may prove useful as a tool in evaluating undrained response of oil sand. The response of a wellbore in oil sand upon unloading was analyzed using the developed model. Such analysis are important in the rational design of oil recovery systems in oil sand. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Thesis (Ph. D.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on June 11, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Chemical Engineering, [Department of] Chemical and Materials Engineering, University of Alberta. Includes bibliographical references.

No description available.

Oil sand mining operations in Alberta, Canada produce large quantities of process water and mature fine tailing (MFT) during the bitumen extraction process. Wet landscape reclamation is one of the reclamation strategies proposed to utilize process water and MFT in the creation of aquatic reclamation environments that are economically and environmentally acceptable. In the interest of utilizing nutrient enrichment and peat amendment to improve aquatic flora and fauna colonization in new oil sands aquatic reclamation, this microcosm study was designed to assess the phytoplankton and periphyton growth (summer 2008), as well as benthic invertebrate colonization (summer 2009). Peat amendment significantly increased the growth of phytoplankton and periphyton by providing sufficient nutrients (total nitrogen, total phosphorus and dissolved organic carbon) to the system. In reference wetland, benthic invertebrate colonization was significantly increased by utilizing sand as bottom substrate and decreased by MFT/Sand mixture as bottom substrate. In OSPM-affected wetland, benthic invertebrate colonization was not affected by utilizing MFT/Sand as bottom substrate. In comparison to OSPM-affected wetlands, reference wetland had larger number of benthic invertebrate families and higher total abundance. In this research, experimental microcosms were constructed in three reclamation wetlands with different types of reclamation materials as the bottom substrates (sand, MFT + sand) and amendments (nutrient and/or peat) added to optimize growing conditions for phytoplankton and periphyton, thus creating a biological detrital layer over unfavourable substrates to enhance benthic invertebrate colonization. The growth estimates of phytoplankton and periphyton on MFT + sand without amendment were low in comparison to the control (water only, no substrate). In comparison to sand, MFT + sand had higher growth estimates at OSPM-affected sites, but lower growth estimates at reference site. The growth estimates of phytoplankton and periphyton on MFT + sand were significantly increased with peat amendment. Nutrient (nitrogen and phosphorus) enrichment insignificantly improved the phytoplankton and periphyton growth. Peat amendments elevated the concentrations of nitrogen, phosphorus and dissolved organic carbon in the system and maintained these high concentrations throughout the experiment period. Nutrient enrichment only temporarily (less than 3 weeks) elevated nitrogen and phosphorus levels as the nutrients added were quickly utilized by the system. Benthic invertebrate colonization was assessed in the following year. Sand treatments had increased total abundance and numbers of families of benthic invertebrate compared to the mature sediments of the reference wetland. In oil sand process material (OSPM)-affected wetlands, sand treatments had slightly lower abundance and fewer numbers of families in comparison to the mature sediments. In comparison to sand treatments, MFT + sand treatments had decreased total abundance in the reference wetland but not in OSPM-affected wetlands that received MFT input during its construction. Peat amendment and nutrient enrichment had no impact on benthic invertebrate total abundance or composition.

An experimental investigation was conducted on the static liquefaction behaviour of very loose lightly cemented sands. Undrained and drained triaxial compression tests, one dimensional consolidation, high stress compression, and unconfined compression tests were performed on artificially prepared lightly cemented loose samples with cement-sand ratios of 2, 4 and 6%. Additional tests were also conducted on uncemented samples prepared at the same initial void ratio as the cemented samples. Besides the influence of degree of cementation, the effects of void ratio and confining pressure on the liquefaction potential of cemented sands were examined. The aim of this study is to make significant contribution to the understanding of static liquefaction failures in lightly cemented sands. It is shown that cementation could increase the initial stiffness and yield strength of cemented sands but its effect might decrease considerably after the peak strength because of destruction of the cementation bond. The response of cemented sands at lower cement contents was very similar to the response of loose sands and behaviour approached the response of medium to dense sands with increase in the degree of cementation. It is also shown that degree of cementation has a significant influence on liquefaction resistance. Even though the presence of small amounts of cementation did not prevent liquefaction failure, the liquefaction resistance of cemented sands generally increased for higher degrees of cementation. The consolidation, high stress compression and unconfined compression tests demonstrated the effect of cementation in increasing both the stiffness and strength of cemented sands. The unconfined compression strength increased approximately linearly with the increase in cement content. The rate of strength gain increased with an increase in the dry density of the compacted sample, indicating that the cementation was more for denser samples.

An experimental investigation was conducted on the static liquefaction behaviour of very loose lightly cemented sands. Undrained and drained triaxial compression tests, one dimensional consolidation, high stress compression, and unconfined compression tests were performed on artificially prepared lightly cemented loose samples with cement-sand ratios of 2, 4 and 6%. Additional tests were also conducted on uncemented samples prepared at the same initial void ratio as the cemented samples. Besides the influence of degree of cementation, the effects of void ratio and confining pressure on the liquefaction potential of cemented sands were examined. The aim of this study is to make significant contribution to the understanding of static liquefaction failures in lightly cemented sands. It is shown that cementation could increase the initial stiffness and yield strength of cemented sands but its effect might decrease considerably after the peak strength because of destruction of the cementation bond. The response of cemented sands at lower cement contents was very similar to the response of loose sands and behaviour approached the response of medium to dense sands with increase in the degree of cementation. It is also shown that degree of cementation has a significant influence on liquefaction resistance. Even though the presence of small amounts of cementation did not prevent liquefaction failure, the liquefaction resistance of cemented sands generally increased for higher degrees of cementation. The consolidation, high stress compression and unconfined compression tests demonstrated the effect of cementation in increasing both the stiffness and strength of cemented sands. The unconfined compression strength increased approximately linearly with the increase in cement content. The rate of strength gain increased with an increase in the dry density of the compacted sample, indicating that the cementation was more for denser samples.