Tailings Technology Roadmap project releases nine development roadmaps for treatment of oil sands fine tailings
A collaboration of Alberta Innovates – Energy and Environment Solutions (AI-EES) and the Oil Sands Tailing Consortium (OSTC), in partnership with Alberta Energy, Natural Resources Canada, Alberta Environment and Sustainable Resource Development and the Alberta Energy Resources Conservation Board, released the report from The Tailings Technology Roadmap and Action Plan project. (Earlier post.)
The report provides nine different Tailings Technology Deployment (TDD) Roadmaps to accelerate the implementation of oil sands tailings solutions in Alberta. Each roadmap is made up of a suite of technologies that provide options for unique operating leases and mine characteristics. The roadmaps for the tailings technology suites include:
- Centrifuging MFT with conveyor/stacking
- Composite Tailings
- In-line thickening with accelerated dewatering
- In-line thickening with thin lift evaporative drying
- Water capped end pit lake
- Improvement to Water-Based Extraction
- Non-Aqueous Solvent Extraction, Retort Based Extraction, Parallel High/Low Fines Suite
- In-Pit Tailings Stream
Background. After oil sands ore is excavated from the ground (surface mining operations, not in situ production), warm water is added to wash the bitumen off the sand and clay. The water and solids that remain are the tailings, and consist of water, coarse sand, silt and clay particles and small amounts of bitumen and asphaltenes. These tailings are held in massive “ponds”.
While coarse solids settle rapidly, fine solids remain in a suspension called fluid fine tailings. The fluid fine tailings concentrate to about 30% mass solids in two to three years but only very slowly thereafter. This material, termed mature fine tailings (MFT), is impounded in the early years of a project in an external pond and in-pit when the mine advance makes space available in-pit. MFT is a concern because it may have to be impounded indefinitely and because there is currently no demonstrated means to reclaim it without further processing.
Tailings ponds contain toxic contaminants such as heavy metals, polycyclic aromatic hydrocarbons (PAHs) and naphthenic acids. Naphthenic acids in particular break down very slowly and pose a long-term threat to the groundwater of the region.
In 2009, the Alberta Energy Resources Conservation Board (ERCB) issued Directive 74 (D074); a new tailings directive, designed to reduce the amount of MFT and optimize the timing of reclamation. The OSTC was formed in 2010. The member companies agreed to remove monetary and intellectual property barriers with regard to tailings research and development and share knowledge, research and technologies in order to work in a unified effort to find solutions which meet the tailings challenges and accelerate the pace of reclamation.
In 2011, AI-EES, in partnership with the OSTC), awarded a contract to the Consortium of Tailings Management Consultants (CTMC) to undertake an integrated project called “The Technology Deployment Roadmap and Action Plan for ‘End-to- End’ Solutions for Oil Sands Tailings”. The project objective was “...to create a technology deployment roadmap and action plan that will assist regulators and industry to create and implement technology solutions that will meet the goals of Alberta Environment’s (AEW’s) Draft Tailings Management Framework and ERCB’s Directive 074”.
This project provides us with a full view of the suite of tailings technologies for application to oil sands reclamation. By evaluating each of them and understanding what works in different circumstances, this project will help us determine what demonstration technologies we can test to speed reclamation efforts.—Dr. Eddy Isaacs, CEO, AI-EES
The project. For the project, Alberta oil sands operators—Suncor Energy, Syncrude Canada Ltd., Shell Canada, Canadian Natural Resources Limited, Imperial Oil, Total E&P Canada and Teck Resources—shared openly their in-development tailings technologies.
This, together with public literature review and significant input from third party developers, led to the evaluation of more than 500 tailings and related technologies. From there, nine detailed tailings technology development roadmaps for the treatment of oil sands fine tailings were identified.
Each of the nine roadmaps contains a suite of technologies that would allow an oil sands operator to convert its fluid fine tailings inventory into a reclamation-ready deposit, depending on the individual characteristics of the mine operation.
The roadmaps range from passive technology options such as end-pit lakes, to more engineered options such as thin lift drying and centrifuging. The technology options used by a company will ultimately be dependent on specific mine characteristics. An added feature of each roadmap is identification of a series of innovations that have the potential to improve the effectiveness and economics of the technological solutions.
Member companies of the OSTC have used many of these technologies at one time or another and are actively developing others. The roadmap project has helped us identify where there are gaps—oil sands “missing links”—and will help operators apply technologies that close gaps and ultimately improve tailings management performance.—Alan Fair, Executive Director of the OSTC
The status of development of individual technologies has been plotted on a detailed generic model graphic, to map out the steps required in their future research and development.
Main conclusions. The main conclusions of the report are:
There is still no “silver bullet” tailings technology—i.e., a single technology or suite of technologies, which will solve all the Oil Sands tailings challenges with a single effort.
The TDD Roadmaps consider improvements to existing technology suites and contributions to potentially new suites, and identify technologies with a high priority for Research and Development (R&D) to effect these changes.
There are major opportunities to increase the performance and decrease the cost of existing commercial tailings technologies and suites employed at the oil sands operations.
The typical time frame required to progress a technology through the Research stage is from 2 to 3 years, and through the Development stage from 2 to 5 years. Additional time may be required after initial commercial implementation to bring the technology to a mature state—in the order of from 1 to 5+ years.
Timelines for bringing potential tailings technologies to full commercial implementation are thus quite long (from 5 to more than 10 years); this fact must be recognized when planning tailings management improvements (to reach desired reclamation and closure objectives, or in responding to regulatory changes).
Main recommendations. The report also made a number of major recommendations
The TDD Roadmaps should be assessed by individual operators for applicability to their specific site(s), mining practices, and tailings inventories, so that company priorities for R&D can be set. In addition, more detailed R&D plans should be generated from the selected Roadmaps and specific R&D technologies. There is a role for both operators and regulators to play in this process.
The TTD Roadmaps and related information should be regularly revised, so that they do not become dated.
The Roadmaps given in this report have focussed largely on Tailings Processing and Tailings Deposition & Capping technologies. More focussed study and attention should be given to potential technologies from the other mining life cycle categories (Mining, Extraction and Reclamation) that could contribute to better tailings management.
The full potential of chemical amendments as technology enhancers has only begun to be addressed. Greater R&D focus should be brought to bear on this issue, particularly by leveraging the knowledge of vendors who are active in industries outside of oil sands, but which has not been tapped to date.
A more flexible regulatory approach that places more emphasis on achieving Tailings Management and Reclamation (TMR) Objectives, and less emphasis on short-term goals, would result in more effective and less costly tailings reclamation efforts. Government regulators should give serious consideration to updating current regulations.
Issues of water balance and water chemistry are becoming critical and need attention. Initial efforts at defining water treatment needs were addressed in the Project, but this issue is larger than just water treatment. A similar focus should be directed, in the future, at addressing water storage and water release issues as was given to tailings management issues herein, with a similar definition of objectives for surface and ground water, and means of achieving those objectives.
Oil sands operators, together with AI-EES will be examining the recommendations of the roadmap project over the following months and will be planning and implementing demonstrations of these suites of technologies beginning in early 2013.
Alberta Innovates – Energy and Environment Solutions (AI-EES), a provincial corporation, is the lead agency for energy and environmental research in Alberta.
The Oil Sands Tailings Consortium (OSTC) was founded in December 2010 when seven of Canada’s oil sands companies (Suncor Energy, Syncrude Canada Ltd., Shell Canada, Canadian Natural Resources Limited, Imperial Oil, Total E&P Canada and Teck Resources) came together to share tailings research and technology in a unified effort to rapidly advance tailings management.
The Consortium is in the process of being integrated into Canada’s Oil Sands Innovation Alliance (COSIA)—an alliance with the mandate to accelerate the pace of environmental performance improvement in the oil sands, through collaborative action and innovation. COSIA has four environmental priority areas, water, land, tailings and greenhouse gases.