Fluid tailings are common to all surface mining operations and are comprised of the water, clay, sand, and residual bitumen that is left over when the bitumen is separated from the sand. Tailings are stored in deposits that help separate the solids from the water, so the water may be reused. They also serve as storage facilities, allowing water to be stored for low flow periods when water availability is restricted.
At Kearl, Imperial’s oil sands mining operation, tailings from the bitumen extraction process are stored in a carefully engineered above-ground tailings area, located more than 29 kilometres (18 miles) away from the Athabasca River.
A key feature of Kearl’s tailings management is the use of thickener technology that intercepts the tailings produced by the extraction process and processes them into a paste prior to being placed in a deposit.
These thickened tailings are placed in thin layers and allowed to dry into a solid state. Eventually they will be covered by sand and topsoil to enable a reclaimable area containing both upland and wetland features.
Imperial has been an energy innovator for more than 140 years, investing in industry-leading research and development. Over the past 20 years, we’ve spent more than $2.1 billion in research and technology development – one of Canada’s largest R&D investments in any industry.
Learn more about some of our technologies we are working on to improve the treatment of tailings:
- Thickener technology intercepts the tailings produced by the extraction process and processes them into a paste prior to being placed in a deposit.
- Non-Aqueous Extraction (NAE) could reduce water use in the mining extraction process by more than 90 percent. With NAE, dry stackable tailings will be produced, eliminating the need for fluid tailings ponds and resulting in faster progressive reclamation.
Tailings management framework
In July 2016, the Alberta Energy Regulator (AER) released Directive 085 to implement the provincial government’s tailings management framework. Directive 085 sets project-specific limits for each operation to ensure fluid tailings are in a ready-to-reclaim state within 10 years of the end-of-mine life.
In 2018, Kearl received approval of its tailings management plan under Directive 085. In our application, Imperial committed to provide appropriate and timely information based on our continued technology and deposit performance evaluation, along with research and other information, which informs tailings management at Kearl.
Kearl’s tailings management plan leverages the technical collaboration from our participation in Canada’s Oil Sands Innovation Alliance (COSIA) and industry best practices, which reduce freshwater use, maximize water recycling and limit the accumulation of large volumes of fluid tailings, all while implementing progressive reclamation.
For more than 10 years, Imperial has been engaged with local Indigenous groups affected by our Kearl operation. We will continue to work with the affected Indigenous groups to develop specific and pertinent plans for ongoing dialogue regarding Kearl's tailings management plan and performance.
Imperial is the founding sponsor of the Institute for Oil Sands Innovation (IOSI) at the University of Alberta. Through the institute, university experts are conducting ground-breaking research to address a variety of environmental challenges associated with oil sands development, including tailings. To date, we have contributed $24M in funding to IOSI.