Our strategy to reclaim tailings combines the innovation of new technologies with the search for emerging solutions through collaboration with industry, academia and the broader scientific community.
full-scale centrifuge plant starts operation.
Construction of 85-hectare
wetland in former tailings area underway.
Over 3.5 million cubic metres
of soil material produced from tailings centrifuge project.
Through the use of tailings ponds, we maintain a highly efficient water recycling system, which minimizes withdrawal of water from the Athabasca River. However, the storage of tailings also creates a potential long-term liability because of the volume that must be managed responsibly and cost-effectively before reclamation can occur.
Tailings management is a priority across the organization. Our strategy to reclaim tailings currently incorporates three technologies – centrifuged tails, composite tails and water capping – in addition to working actively with industry partners and the scientific community towards developing further solutions. We are committed to meeting government regulation and the expectations of Albertans towards responsibly managing this environmental challenge.
To learn more about tailings and how they are stored, click here.
Following the 2014 Mount Polley tailings dam failure in British Columbia, the Mining Association of Canada (MAC) established an independent multi-interest task force which spent six months in 2015 reviewing its Towards Sustainable Mining tailings management protocol and related guides to ensure they met best practice. The task force submitted a final report to MAC’s Board of Directors, which contained 29 recommendations. All were accepted. Syncrude is currently reviewing the recommendations to identify opportunities toward integrating them into our own management system. More information on the work of the task force can be found here.
We are reclaiming tailings through an investment of approximately $3 billion in three main technologies:
A full-scale tailings centrifuge plant started operation in 2015. The $1.9 billion plant accelerates the reclamation process by centrifuging fluid fine tailings (FFT) to create a clay soil material that can be used in post-mining reclamation landform construction. The technology involves putting tailings through equipment where a spinning action, or centrifuging, separates out the water. Released water can be recycled back into plant operations. The resulting clay material will initially be used to reclaim portions of our North Mine, where it will be capped with soil and re-vegetated. In 2015, 3.5 million cubic metres of material was produced from 4.1 million cubic metres of FFT.
Syncrude contributed the centrifuge technology to the members of Canada’s Oil Sands Innovation Alliance (COSIA). In 2012, Shell Canada adopted the technology and used our findings to further develop centrifuge for use in its own operations. Shell will contribute its findings back to COSIA to allow other members to continue to develop the technology.
Composite Tails (CT) technology combines FFT with gypsum and sand to create a mixture that is deposited in mined-out areas where the tailings release water and quickly settle. The area can then be capped with sand and soil, enabling the development of landscapes that support forests and wetlands. CT is being used in our former East and West mines, as well as a portion of our North Mine which is still in operation.
CT placement in the East mine began in 2000 and was complete in 2011. Sand capping to establish closure drainage is ongoing. A 54-hectare fen wetland research project was constructed at the northwest end of this area. We are also beginning reclamation activities on the 85-hectare Kingfisher wetland. More information on these reclamation projects can be found in the Land chapter.
We continue to work towards improving the efficiency of this technology through a low-energy process borrowed from the concrete and construction industries which places CT underwater using a tremie deposition technique. A key advantage is the ability to create reclaimed uplands by initially placing material underwater. Essentially the landform is built from the bottom up. As an additional benefit, water is released from the deposit upon placement and recycled back into plant operations. We completed commercial-scale testing in 2015 and anticipate implementing this technology in the future. Listen to an interview with Syncrude tailings advisor Eric Leneve about the tremie process here.
One of the most extensively researched tailings management techniques is the capping of FFT with water to form a lake environment. Research and testing dates back to the 1980s, and culminated with the commissioning of the industry's first commercial-scale demonstration in late 2012 in one of our former mine pits. A comprehensive research and monitoring program is underway to study the performance of the lake as it evolves into an aquatic ecosystem. Research and monitoring focuses on water quality, impacts of the underlying FFT layer, performance of the littoral (shallow shoreline) zone, interaction of biological communities, consolidation of the tailings, development of the shoreline, and the establishment of plants and insects.
Monitoring since 2013 indicates progress on key performance factors such as shoreline stability, consolidation and stability of the underlying fluid tailings layer, improving water chemistry and decreasing naphthenic acids. We have noted the presence of hydrocarbon on the water surface and shore, and are investigating options for skimming and shoreline cleaning. Waterfowl deterrents continue to be in place throughout this period.
We are currently researching additional technologies that could be used to supplement existing tailings remediation methods. These include:
Also referred to as rim ditching, accelerated dewatering is based on methods successfully used in the Florida phosphate industry. This technology mixes FFT with an organic compound called flocculent, which is then placed in a shallow deposit. The flocculent is the same material used by municipal water treatment systems. Flocculent molecules wrap around the clay mineral particles in the FFT, forcing them to settle faster. Initial tests have shown a reduction in FFT volume by 50 per cent in three to five years. If tests continue to be successful, accelerated dewatering could be an energy- and cost-efficient enhancement to our tailings management activities.
This method, studied since the late 1980s, mixes FFT with overburden to create a fully functional surface that can be walked or driven on. A demonstration pilot plant began operation in 2014 and results have shown the mixed product can be used to build roads and berms, or as a base for reclamation soils.
The thickener technology process involves taking the tailings stream and running it through a cyclone separator. This sends the fines and water to the top. Coarser material sinks to the bottom and is then used as landform construction material. The fines-water overflow goes to a thickener, which adds an organic flocculent that binds the fines together into bigger particles that are the size of a grain of sand. Once dried, the resulting clay material can be used directly in reclamation. Water, forced out of the fines as they are bound together, is recycled back to the plant.
We operate one of the largest private sector research facilities in Western Canada and participate in Canada’s Oil Sands Innovation Alliance (COSIA), which exchanges findings among industry operators. COSIA is currently coordinating over 60 active tailings management projects with its members, including Syncrude. Further information is available by downloading a PDF (2MB) of the COSIA 2015 Performance Update.
We are also a member of the Petroleum Environmental Research Forum (PERF), which shares knowledge on health, safety and environmental-related technology development. Projects are jointly funded, helping reduce research costs and enhance access to industry expertise.
|Fluid tailings volumes1 (Mm3)||-||-||-||469.6||476.3|
|Fines capture, annual (thousand tonnes)||3,115||1,932||3,605||5,391||6,427|
|Fines capture, annual (%)||18.8||12.3||25.7||47.8||51|
|Fines capture, cumulative (thousand tonnes)||4,503||6,435||10,040||15,431||21,858|
|Fluid tailings volumes1 (Mm3)||-||-||-||113||127.9|
|Fines capture, annual (thousand tonnes)||0||0||0||4,058||9,549|
|Fines capture, annual (%)||0||0||0||25||53.5|
|Fines capture, cumulative (thousand tonnes)||0||0||0||4,058||13,607|
|Fluid tailings volumes1 (Mm3)||-||-||-||582.6||604.2|
|Fines capture, annual (million tonnes)||3.1||1.9||3.6||9.5||16.0|
|Fines capture, cumulative (million tonnes)||4.5||6.4||10.0||19.5||35.5|