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.

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.

Thesis (M. Sc.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on June 30, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Chemical and Materials Engineering, University of Alberta. Includes bibliographical references.

Syncrude Canada’s Base Mine Lake (BML), is the first oil sands pit lake and is being used to evaluate water-capped tailings technology for fluid fine tailings (FFT) management. To be successful, pit lakes must achieve the ecological role of a natural lake, requiring the development of oxygenated water cap capable of supporting macrofauna. Due to the reductive nature of the FFT stored at the bottom, oxygen-consuming constituents (OCC) such as methane, sulfide and ammonium can be mobilized into the water cap of oil sands pit lakes, posing a threat to the success of the reclamation. Results from BML are vital to inform successful pit lake design with a further 10+ pit lakes projected for collective waste reclamation required in the region, currently awaiting permitting. This field study established BML water cap depth dependent oxygen consumption rates (OCR), identified the key OCC driving those rates and modeled the roles of biogeochemical oxygen consumption and physical mixing in establishing water cap oxygen profiles during early stage development (< 5 years post commissioning). The balance between these two discrete processes underpins the likely viability of this management strategy for oil sands FFT. Results identify high OCR, in the range of highly productive eutrophic to hyper eutrophic lakes, in the vicinity of the FFT water interface, i.e. where concentrations of OCC are highest. Observed OCR rates decreased away from the FFT water interface, as concentrations of OCC decreased. The important OCC associated with high OCR were methane and ammonium. While the OCR values in the hypolimnion were extremely high, a minimally oxic FFT water interface persisted (<10 μM O2) contrasting the anoxic hypolimnetic waters typically observed in highly productive systems. Water cap oxygen mass balance modeling revealed physical mixing of oxygen into the hypolimnion from the metalimnetic region of the BML water cap currently slightly exceeds the oxygen being consumed through biogeochemical redox cycling, explaining the persistence of low levels of oxygen to the FFT water interface in the BML water cap (~ 10 m in depth). However, higher mobilization of OCC from the FFT as FFT consolidates, and/or higher rates of microbial biogeochemical cycling as microbial communities continue to establish and grow within BML, and/or decreased physical vertical transport of O2 into the hypolimnion, would all shift the oxygen balance towards greater consumption and thus would result in the migration of the oxic-anoxic boundary and OCC higher up into the water cap where they would directly impact the surface zone oxygen concentrations. Modeling results here identify that without the physical injection of oxygen into the hypolimnion, currently observed, OCR rates would generate anoxic conditions that would reach the middle of the metalimnion within this system within 24 hours. The development of an anoxic zone would facilitate greater generation of OCC directly within the water cap through anaerobic microbial biogeochemical cycling, the high levels of sulfate (~ 2 mM) observed within the BML water cap, which exceeds water cap oxygen concentrations by 3 orders of magnitude, indicate that generation of ΣH2S within this pit lake water cap would be a substantive risk to the development of a stable surface oxic zone that can support macro fauna. In addition, the emergence of nitrification, as one of the main oxygen-consuming reactions, was assessed experimentally to determine the potential effects on the oxygen depletion in BML water. Experimental results identified active nitrification with rates in the comparative range of marine to eutrophic estuary environments, with BML water collected from the metalimnion-hypolimnion interface, i.e. where the highest conversion of ammonia to nitrate was observed in field results. However, a comparison of oxygen consumption due to nitrification based on experimental, nitrification only results versus results from the field where nitrification as well as methanotrophy and other oxygen consuming processes are possible indicate oxygen consumption due to nitrification alone in the field is six times lower than the experimental oxygen consumption observed. These results highlight the competition for oxygen by multiple processes within BML, which suppress nitrification below levels observed under ideal experimental conditions. Characterization and modelling results of BML water cap oxygen concentrations carried out in this doctoral research reveal a new understanding of the important processes driving observed oxygen concentrations. These new insights delineate the potential effects of mobilized reduced constituents in the water cap from FFT and processes that may mitigate or exacerbate these impacts. Thus these results are of significant relevance to both the oil sands industry as well as other natural or anthropogenically impacted environments with high oxygen demand. / Thesis / Doctor of Philosophy (PhD)

Thesis (M. Sc.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on Jan. 18, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Chemical Engineering, Department of Chemical & Materials Engineering, University of Alberta. Includes bibliographical references.

Several oil sands tailings from Suncor Energy Inc. were analysed with respect to the mobility and solubility of the petroleum hydrocarbon (PHC) contaminants. At sites where oil sands tailings materials have been disposed of and are covered with a growing medium, the PHCs from the tailings may slowly migrate into the reclamation cover, increasing their availability to the plants in the cover system, which could be detrimental to the development and establishment of the plant cover system. This study characterized the PHC content of the tailings and quantified the desorption and diffusion coefficients for F2 and F3 fraction PHCs. All tailings materials collected from Suncor were characterized for initial PHC content. Desorption coefficients were experimentally determined using batch tests for 9 tailings materials (MFT, LG MFT, PT MFT, Tailings Sand, P4 UB Surface, P4 UB Auger, 2:1 CT, 4:1 CT and 6:1 CT). The experimental results from the batch tests were fitted to a Langmuir hyperbolic isotherm model. Diffusion coefficients were determined by fitting the experimental results from a radial diffusion 1-dimensional experiment to a Finite Difference Model. Diffusion coefficients for F2 and F3 Fraction PHCs were developed for 7 tailings materials (MFT, LG MFT, PT MFT, Tailings Sand, 2:1 CT, 4:1 CT and 6:1 CT). The diffusion coefficients (D*) and the Langmuir desorption constants ( and ) developed from these experiments are included in Table A.1. The desorption coefficients resulting from this study are similar to those reported for the desorption of asphaltene, which is one of the components in oil sands tailings. The Langmuir isotherm model was found to be the best fit for the experimental desorption data; the Langmuir isotherm model is commonly used in sorption isotherms of organic chemicals. The results of the radial diffusion experiments agree with diffusion rates found by other researchers in similar porous media. More research may be needed to verify both of these preliminary results for the desorptive and diffusive transport of F2 and F3 PHC fractions in tailings. Tailings composition will continue to change as new technologies for fines settling and bitumen extraction are developed. The diffusion of PHCs from these new materials will need to be examined as it is probable that these changes will affect the transport and mobility of the contaminants.