Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1913. / The entire thesis text is included in file. Typescript. Illustrated by authors. Title from title screen of thesis/dissertation PDF file (viewed March 31, 2009)

Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1914. / The entire thesis text is included in file. Typescript. Illustrated by authors. Mr. Dunn earned a Master of Science degree in General Science. Mr. McBride earned a Bachelor of Science degree in General Science. Title from title screen of thesis/dissertation PDF file (viewed April 6, 2009)

Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1914. / Two separate pages are numbered as "2". The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed April 24, 2009)

Thesis (M.Sc.) - University of Queensland, 2004. / Includes bibliographical references.

Oil sand processing to extract bitumen generates large volumes of slurry comprising water, silt, sand, clay, unrecovered bitumen, and residual chemical aides and solvents added during the extraction process. The by-product stream of the bitumen extraction is pumped into constructed tailings ponds. Managing these tailings is one of the most difficult environmental challenges for the oil sand industry. This study aims to develop a novel technique to assist in the assessment of the technologies for managing mature fine tailings (MFT) in oil sands. Innovative application of a superabsorbent polymer in the oil sands industry may provide a new method for tailings management. However, thus far, no study has addressed this research gap. In fact, fundamental knowledge of the behavior of MFTs pre-dewatered with the superabsorbent polymer could provide an important way to positively affect the speed of reclamation. To this end, comprehensive instrumentation, geo-environmental, and geotechnical analyses are carried out to obtain essential knowledge on the behavior of MFTs pre-dewatered with the polymer. The results of this study reveal that the mechanical, hydraulic, and thermal properties of the MFTs are related. Evaporation and drying shrinkage can affect the hydro-mechanical properties of the tailings and have a significant influence on the developed shear strength of the MFTs. In addition, the process-affected water includes a high concentration of the dissolved ions and organic chemicals that stem from ore extraction chemicals and tailings treatments, or that may be released from oil sands ores. Through the application of a superabsorbent polymer in the dewatering of oil sand MFTs, the chemical components are entrapped in the polymer chains, thus limiting the mobility of the major ions and trace metals in water bodies beneath the oil sand tailings pond. Results show that the application of the superabsorbent polymer considerably reduces the rate of drainage from the oil sand MFTs into water bodies, which can help mitigate the risk of seepage. The author believes that the superabsorbent polymer dewatering technique can be considered as an environmentally friendly promising approach for management of oil sands MFTs. This new technique can accelerate the pace of reclamation and thus minimize the footprint of the oil industry in Canada.

The relative effectiveness of anionic and nonionic polyacrylamide in enhancing the settling rate of flotation tailings was studied by performing batch settling tests. Anionic polyacrylamide was found to be more effective than nonionic polyacrylamide. A liquid flocculant was found to give lower settling rates than dry flocculants due to a lower polyacrylamide content. The aging of tailings resulted in increased settling rates. Residual polyacrylamide was detected in the supernatant water even at low flocculant addition rates and reached significant concentrations before the optimum addition rate was attained. The effect of polyacrylamide on flotation of a copper-molybdenum ore was investigated in a series of batch flotation tests. Flocculant concentrations up to 10 parts per million did not lower either concentrate grade or recovery. The presence of an oil phase from the liquid flocculant also had no noticeable effect on flotation. / Applied Science, Faculty of / Mining Engineering, Keevil Institute of / Graduate

No description available.

This research is an experimental, field and numerical study of the sedimentation and consolidation of in-line thickened oil sands fine tailings. In-line thickening is a process that adds flocculant and coagulant into a modified tailings pipeline in a multi stage fashion to improve the dewatering behaviour of oil sands fine tailings cyclone overflow. The parent untreated cyclone overflow, in-line thickened tailings and sheared in-line thickened tailings were investigated in the laboratory. In-line thickened tailings were produced in the laboratory using the same process as in the field project and sheared in-line thickened tailings were prepared by shearing the thickened tailings with a specified shearing effort to simulate tailings transportation. A combination of hindered sedimentation tests, compressibility standpipe tests and large strain consolidation tests with vane shear tests was then used to capture a full range of sedimentation, consolidation and shear strength characteristics for these materials. Results show that the in-line thickening process significantly improves hydraulic conductivity and undrained shear strength of the fine tails. Shearing damages some of the floc structure but does not cause the material to fully return to the original state of the cyclone overflow. The laboratory data of the in-line thickened tailings was compared with field performance at two in-line thickened tailings pilot scale ponds and with a validation standpipe test by utilizing a developed finite strain consolidation model. Good agreements were obtained between the field performance, the laboratory test results and the validation standpipe test. These good agreements confirmed the validity of the laboratory determined geotechnical parameters and of the developed numerical model and indicated that it is possible to model large scale field performance with small scale laboratory tests. Finally, composite tailings was made from the in-line thickened tailings and was found to have a similar segregation boundary to that of gypsum treated composite tailings made with mature fine tailings but had a much higher hydraulic conductivity and shear strength which were inherited from the flocculated fines. / Geotechnical Engineering

Oil sands operators are being faced with the challenge of reclaiming the large volumes of slurry tailings created during oil sands processing. New regulations mandate that operators must minimize fluid tailings by capturing fines in dedicated disposal areas, leading to a ‘trafficable’ or solid deposit. Adding a polyacrylamide polymer to the tailings and thinly spreading them over a sloped disposal area (a process developed by Shell Canada Energy known as the atmospheric fines drying or AFD process) has been shown to enhance the dewatering of tailings which leads to a dry deposit at a much faster rate than traditional methods. Hydroponic experiments using the emergent aquatic macrophytes cattail (Typha latifolia L.) and common reed (Phragmites australis (Cav.) Trin. ex Steud.) were conducted to investigate the phytotoxicity of waters formed during AFD processing. The phytotoxicity of AFD release waters was compared to the phytotoxicity of traditional mature fine tailings (MFT) reclaim water through the monitoring of plant water uptake and whole plant fresh weight over the course of the experiment. It was found that there are no significant differences between the phytotoxicity observed in the MFT and AFD treatments and it was also found that spring runoff melt water from the AFD deposits is less phytotoxic than the original release water. Two additional hydroponic studies using cattail and common reed were also conducted. The first examined the phytotoxic effects attributable solely to the naphthenic acids isolated from Shell’s Muskeg River Mine tailings, and the second evaluated the phytotoxic effects of amending mature fine tailings with gypsum. It was found that the gypsum amended tailings caused greater phytotoxicity in cattail and common reed than tailings without gypsum added. Furthermore, both species were tolerant to growing in nutrient media spiked with naphthenic acids (40 mg/L). The phytotoxicity experiments conducted also demonstrated that common reed is consistently more tolerant to growing in water associated with oil sands tailings and is therefore the more appropriate choice for use in reclamation strategies involving wetland plants. Mass spectrometry was used to determine the naphthenic acid molecular profiles for Shell oil sands tailings. Using low resolution mass spectrometry, no detectable features or changes to the composition of naphthenic acids attributable to Shell processing were found. High-resolution mass spectrometry provided insight into possible plant mediated changes and biodegradation of naphthenic acids. It appears as though, to some extent, cattail is able to dissipate naphthenic acids, which could explain the susceptibility of cattail to the phytotoxic effects of naphthenic acids. Further research is required to determine whether the changes observed in the naphthenic acid mixture are due to microbial degradation and/or a phytotoxic response of the plants studied.

The following is a thesis presented on the history, subsurface characterization and settlement analysis of the Conquista Tailings Impoundment located in Karnes City, TX. This research draws information from readily available sources at TCEQ in Austin, Texas. Documents included in this report date back to the mid-1980s and can be as recent as 2011. This thesis will focus on the eastern section of the Conquista Tailings Impoundment and will primarily observe and predict the settlement experienced in this portion of the site. The site has been analyzed using one-dimensional consolidation analysis, based on three (3) loading factors, and has been modeled using finite element analysis aided by the software PLAXIS. The research has justified the magnitude of settlement that has occurred in the area of concern and has provided just reasoning for the events. Further investigations into the subsurface conditions in the eastern portion of the Conquista Tailings Impoundment will be needed to confirm and refine the analysis presented. / text