Oil sands tailings have been produced for 50 years and now cover an area of 220 km 2. Join keith and rita in conversations that matter, a series of short videos about albertas oil sands the alberta energy regulators role. Depending on the fines content and solids content of oil sand tailings, the fines void ratio may have to be used instead of the total void ratio sorta et al. How to get oil out of canadas tar sands environment. Technical guide for fluid fine tailings management ostc companies august 30, 2012 page ix ostc companies following over two years of consultation and planning, the oil sands tailings consortium ostc was formally launched december 10, 2010 to facilitate cooperation with the. These ponds are temporary storage facilities and need to be reclaimed when no longer in use. The sands with the most accessible oil are up to 300ft deep and cover roughly 3,000 km sq of northern alberta. Some large tailings ponds are separated by earthen dikes from the. In run 1, the finesenriched sand tailings were assumed to be deposited at a rise rate of 5. Jan 10, 2017 the appropriate management of oil sand tailings requires a reduced environmental footprint of the waste containment facilities. Clay effects on geotechnical properties of tailings.
It was found when plotting the relationships for the atterberg limits, hydraulic conductivities, and shear strengths, that the fines void. The engineering characteristics of tailings are in most instances influenced by the degree of thickening and the method of deposition. The oil sands to water ratio is typically about 1to1 or 50% water in t. Geotechnical properties of mine tailings journal of. In the province of alberta, canada, the oil sands mining industry produces large volumes of tailings. Tailings are stored in basins called tailings ponds, which allow the solids in tailings to settle. Water management in oil sands mining facilities oil. With a consistency of thin yogurt, mft is unable to support. Oct 06, 2015 what are tailings and why are people talking about them. These tailings and associated effluent fluid fine tailings must be contained and cannot be. Allen wrote that typically tailings ponds consist of c. The role of clays in the performance of oilsands tailings. Rheology for deposition control of polymeramended oil.
Oil sands tailings are a mixture of water, sand, fine silts, clay, residual bitumen and lighter hydrocarbons, inorganic salts and watersoluble organic compounds. In the first step, at around t 350 c, relatively light organic substances are removed. It is therefore essential that while investigating the properties of tailings that the physical characteristics and material parameters e. Referencing this publication should be cited as follows. Naphtha, comprising low molecular weight aliphatics and aromatics c3. The values of c c of the coal wash tailings and the fine oil sand tailings are 0.
Oil sand tailings contain a mixture of salts, suspended solids and other dissolvable chemical compounds such as acids, benzene, hydrocarbons residual bitumen, fine silts and water. Oil sands are a mixture of sand, water, heavy oil and other minerals. Tailings ponds are massive earth structures used to store coarse and fine solids contained in the oil sands deposit and recover water back to the main processing plant. Environmental consequences of oil production from oil sands. The composition of this manmade material and its influence on the insitu state of tailings is of particular importance. To manage the volumes effectively, engineers must be able to predict a rate of compression of these tailings. Currently, these tailings are disposed of in large ponds, in which coarse particles settle out relatively quickly and fine particles remain suspended in water and settle very slowly. Numerous technologies are employed commercially to manage oil sands tailings. From that point on, further settling occurs only at a vastly reduced rate. Tailings directive 074 explained oil sands magazine. Whole oil sands tailings resulting from waterbased bitumen extraction processes can be coflocculated, after treatment with slaked lime, with low dosages of a high molecular weight anionic polyacrylamide. Fine solids from tailings streams tend to trap large volumes of water, making pond reclamation challenging at best. Under this new directive, oil sands mining operators are required by law to commit to the reduction of fine fluid tailings and reduce any current inventories. Dec 16, 2016 oil sands are a mixture of sand, water, heavy oil and other minerals.
Oil sands tailings oil sand is composed of 8085% mineral, 1015% bitumen and 34% water by weight. The course of the formation of the extract and the different fractions is illustrated in figure 7. The industry currently operates under a zero fluid discharge criteria. C14, is used as a diluent in processing of bitumen from oil sands. Shortterm dewatering of treated oil sand fine tailings. The comparison of c c for different tailings indicates that the oil sand tailings and coal wash tailings have a higher compressibility than the other metal tailings, and for the same type of tailings, the. Oil sands, tar sands, crude bitumen, or more technically bituminous sands, are a type of unconventional petroleum deposit.
If you pick up a handful of the oil sand, your hand will be black. Typically, surfacemined oilsands operations use the sand component of the tailings to create containment for the fluid fine tailings and the recycle water inventory mikula, 2008. This study models the shortterm dewatering behavior of a 10 m deep deposit. The tar sands leaking legacy from canadas environmental defence.
Advances in oil sands tailings research, alberta department of energy, oil sands research division, publisher includes bibliographic references and index 2 8 11 12 14 15 48. Suncor energy inc, canada abstract few studies have characterized the metal leaching and acid rock drainage mlard potential of tailings from oil sand production, and associated byproducts from bitumen upgrading. The hydrothermal pyrolysis of oil sand occurs in two steps. Some examples of surfactant applications in the petroleum industry gasliquid systems producing oilwell and wellhead foams oil flotation process froth distillation and fractionation tower foams. The mineral component of the oil sand contains both sand and fines. Dec 27, 2012 along with the 2030 wt% of solids sands and clays and slightly alkaline water ph7.
W aterfowl that land on oilsands tailings ponds can become coated in oil, causing them to sink to the bottom. However, it will fill a management gap by providing a framework in which to monitor and manage longterm fluid tailings accumulation and reclamation on the landscape in the lower athabasca region. In canadian oil sands mining operations, bitumen is extracted from oil sands using the hot water extraction process, which produces tremendous amounts of tailings. A research program was therefore initiated at the university of pretoria, to investigate the composition and state of south african gold tailings on the far west rand gold reefs.
What are tailings and why are people talking about them. Thermal properties of oil sands fluid fine tailings. Consolidation testing of oil sand fine tailings ubc library. Consolidation testing of oil sand fine tailings ubc. For hardrock metal mines, tailings are usually a very fine mud or powder, which is left over after ore is crushed and valuable minerals are extracted from it. Oil sands are either loose sands or partially consolidated sandstone containing a naturally occurring mixture of sand, clay, and water, saturated with a dense and extremely viscous form of petroleum technically referred to as bitumen or colloquially as tar due to its superficially similar appearance. Sulfur biogeochemistry of an oil sands composite tailings deposit. Sap based rapid dewatering of oil sands mature fine tailings. Calcined oil sands fine tailings as a supplementary. Oil sands mining facilities are fairly water intensive. The tailings problem in the oil sands industry in alberta is the worlds worst kept secret.
Flocculation of limetreated oil sands tailings sciencedirect. Nov 30, 2011 proceedings tailings and mine waste 2011 vancouver, bc, november 6 to 9, 2011 consolidation testing of oil sand fine tailings dobroslav znidarcic and robert miller university of colorado, boulder, usa dirk van zyl mining engineering, university of british columbia, vancouver, canada murray fredlund soilvision systems ltd. S reactivity of an oil sands composite tailings deposit undergoing reclamation wetland construction. Mamadou fall in partial fulfillment of the requirements for the degree of master of applied science in environmental engineering department of civil engineering university of ottawa ottawa, canada april, 20.
Along with the 2030 wt% of solids sands and clays and slightly alkaline water ph7. Sand is defined as having a particle size greater than 44 microns and fines have particle sizes less than 44 microns. Examples of consolidation model predictions for a finesenriched sand tailings deposit are shown in figure 16. May 23, 2017 sobkowicz jc 20 developments in treating and dewatering oil sand tailings. Jan 27, 2014 al hyndman is a principal consultant with magnus limited. Bitumen is separated from oil sand using the clark hot water. Geochemical characteristics of oil sand tailings and bitumen. Al hyndman is a principal consultant with magnus limited. The claydominated fine mineral solids contained in the water runoff from the mainly sand tailings discharged from the oil sands bitumen extraction process. For hardrock metal mines, tailings are usually a very fine mud or powder, which is left over. Requirements under the framework will be administered primarily through the oil sands conservation act and the environmental protection and.
A small fraction oil sand tailings or oil sands processaffected water ospw, have a highly variable composition and a complex mixture of compounds. Oil sand tailings or oil sands processaffected water ospw, have a highly variable composition and a complex mixture of compounds. Results indicated that inherent material properties along with hydraulic boundary conditions govern the rate and amount of consolidation. Federal study says oil sands toxins are leaching into. Tailings containment facilities are regarded as the worlds largest manmade objects. Sobkowicz jc 20 developments in treating and dewatering oil sand tailings. Technical guide for fluid fine tailings management ostc companies august 30, 2012 page ix ostc companies following over two years of consultation and planning, the oil sands tailings consortium ostc was formally launched december 10, 2010 to facilitate cooperation with the objective of accelerating. The tailings coarse and fine are pumped to the tailing management area, where the sand settles quickly, and a suspension of silt and clay flows into the tailings settling area in huge engineered earthstructure dams morgenstern et al. The resulting composite sandclay particles settle and dewater rapidly to a stackable product that can be handsqueezed to 4083 wt% solids. With regard to the occurrence of related colloidal systems in the petroleum industry, three recent books table 1. A blend of mft and sand used to dispose of fine tailings. Oil sands tailings ponds are engineered dam and dyke systems used to capture oil sand tailings. Oil sands tailings various mixtures of sand, fines, process affected water, and residual bitumen1, are produced by waterbased bitumen extraction processes, and are stored in the landscape behind dams and in mined out pits.
In northern alberta, canada, oil sands industries produce large volumes of tailings. Advances in oil sands tailings research internet archive. Nrcancetc devon facility and location of the oil sands tailings research facility the ostrf is a unique academic and industrial research facility dedicated to collaborative and multidisciplinary tailings research. Metabolism of btex and naphtha compounds to methane in oil. Tailings, a lasting oil sands legacy wwfcanada, october 2010 4 mature fine tailings or mft, is the term used to describe the mix of fine clay particles and water after the slurry has settled for several years. Oil sands tailings management natural resources canada.
The appropriate management of oil sand tailings requires a reduced environmental footprint of the waste containment facilities. In the second step, at temperatures of t 350500 c, the heavy organic substances begin to crack and the products are removed. Sulfur biogeochemistry of an oil sands composite tailings. Composite tailings ct, an engineered, alkaline, saline mixture of oil sands tailings fft, processed sand and gypsum caso 4. Microbial communities involved in methane production from.
We characterized the microbial communities involved in methanogenic biodegradation of whole naphtha a bitumen extraction solvent and its shortchain nalkane c 6 c 10 and btex benzene, toluene. These tailings and associated effluent fluid fine tailings must be. Nw, calgary, ab, canada t2l 2a6 2 university of calgary, dept. Ultraviolet light is an economical and simple way to clean up the residue, or tailings, left over from extracting oil from canadian tar sands. Proceedings tailings and mine waste 2011 vancouver, bc, november 6 to 9, 2011 consolidation testing of oil sand fine tailings dobroslav znidarcic and robert miller university of colorado, boulder, usa dirk van zyl mining engineering, university of british columbia, vancouver, canada murray fredlund soilvision systems ltd. In 2008, the former ercb alberta energy resources conservation board, now known as the alberta energy regulator introduced directive 074. Microbial metabolism of residual hydrocarbons, primarily shortchain nalkanes and certain monoaromatic hydrocarbons, in oil sands tailings ponds produces large volumes of ch 4 in situ. Gerrard marangoni3 1petroleum recovery institute, 100, 3512 33rd st.
These deposits cannot be tapped with standard production methods e. Oil sands are either loose sands or partially consolidated sandstone containing a naturally occurring mixture of sand, clay, and water, soaked with a dense and extremely viscous form of petroleum technically referred to as bitumen. Mine tailings size and composition depends on the mining method. How to get oil out of canadas tar sands environment the. Bitumen upgrading byproducts, alberta, canada bronwen forsyth1, stephen day1 and oladipo omotoso2 1. An investigation of the use of inline thickened tailings to create composite tailings at a sand to fines ratio, sfr, of 4. In this introduction to the oil sand industry presentations at the tailings and mine waste conference, al hyndman provides a succinct and. As the fluid fine tailings settle in the tailings pond, the resulting release water is recycled to the extraction process. The sand component of tailings settles out quickly, leaving the clay.
Oil sands tailings pond water tpw according to canadas oil sands innovation alliance cosia, an alliance of oil sands producers formed in 2012, who share research on. Oil sands are either loose sands or partially consolidated sandstone containing a naturally occurring mixture of sand, clay, and. Geochemical characteristics of oil sand tailings and. A good deal of the controversy about oil sands development centers around those tailings ponds, which cover more than square kilometers in northern alberta, according to the 2008 report 11 million litres a day. Jul 11, 2008 the sands with the most accessible oil are up to 300ft deep and cover roughly 3,000 km sq of northern alberta.
Oil sands mine operators have proposed the use of end pit lakes epls to contain soft tailings and syncrude canada ltd. Sap based rapid dewatering of oil sands mature fine tailings by aida farkish a thesis submitted under the supervision of dr. The insitu method of accessing oil sands resources does not produce tailings. The volume of fluid fine tailings fft stored in tailings ponds is approaching one billion cubic metres. Proceedings of the 16th international seminar on paste and thickened tailings, belo horizonte, brazil watson p, fenderson t, mahmoudkhani a, nair m, patel a, roberts g 2011 breakage and reformation of flocs in oil sands tailings. Since the beginning of oil sands mining in the 1960s huge volumes of tailings have been produced and are continuing to be produced. Effect of various treatments on consolidation of oil sands. Carbon and sulfur cycling by microbial communities in a gypsumtreated oil sands tailings pond. Large volumes of tailings are a byproduct of bitumen extraction from the oil sands and managing these tailings is one of the most difficult environmental challenges facing the oil sands industry.
Typically, surfacemined oil sands operations use the sand component of the tailings to create containment for the fluid fine tailings and the recycle water inventory mikula, 2008. The relatively dry oil sands deposit requires large volumes of water to produce an oil sands slurry that can be pumped and gravity separated throughout the process plant. Rheology for deposition control of polymeramended oil sands. Fluid fine tailings fft are soft tailings produced by the bitumen extraction process associated with openpit oil sands mining.
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