Problem solving is critical to COSIA’s work in the oil sands. Organizations like Coanda—a western Canadian research and development corporation—work closely with members of COSIA’s Tailings Environmental Priority Area (EPA) to find solutions to tailings environmental challenges. With the ability to look at every stage in the lifecycle of oil sands operations, Coanda is helping to find ways to reduce the environmental footprint of mining operations by accelerating tailings dewatering and reducing tailings storage.
For over 20 years, Coanda has been using its expertise to help all types of industries solve challenging problems. From early concept and design stage to laboratory work to field-testing to operations, Coanda offers support throughout the lifecycle of a development project, all while focusing on the end goal. At COSIA, that goal is accelerating the pace of environmental performance improvement in the oil sands.
Coanda’s diverse, highly skilled staff, including mechanical, chemical, and geotechnical engineers and scientists, along with physicists, mathematicians, rheologists, technologists, and laboratory staff, are available to provide the right expertise depending on the challenge. Considering the complexity of oil sands operations, that breadth of expertise is necessary. It is not unusual for a single COSIA project to require an interdisciplinary approach to develop fit-for-purpose instrumentation and analytical methods, complex rheological analyses, detailed mathematical descriptions, and the design and execution of physical or computational testing programs.
In mining operations, much of the water remains with the fines and clay minerals that make up the tailings that have been produced by the oil sands extraction process. Some of the current tailings challenges include remediating legacy tailings ponds, treating tailings streams generated from current operations, and developing sustainable tailings management plans for upcoming projects. These challenges all look at how to manage and reclaim the water used, and how to manage the amount of tailings produced, which go hand-in-hand with defining an operator’s environmental footprint.
COSIA has been evaluating a number of process options for accelerating water removal from a tailings stream. One promising area has been the use of chemical additives to increase the rate of water removal. In this process, additives are used to enhance the settlement of clay. This settlement also occurs naturally by gravity in the field or is sped up with process equipment such as centrifuges or filters. Due to the time it takes for clay and water in a tailings stream to separate, it is important to understand how the treated tailings material changes over time.
In this accelerated dewatering process, it is challenging to find the optimum combination of chemical additives and physical treatment of tailings, to get adequate dispersion of the additive. As an example, Coanda can collect test data at bench or lab scale and use these results along with scale-up analysis and potentially pilot testing to guide the development of commercial processes.
By using these approaches, Coanda supported COSIA members in making significant achievements:
- Successfully scaling tailings flocculation treatment processes from bench scale up to commercial production scales spanning three orders of magnitude;
- Developing and demonstrating automated feedback control of a tailings treatment process utilizing online instrumentation; and,
- Developing techniques to measure and study the properties and behaviours of raw and treated tailings materials.
COSIA’s unique set-up allows Coanda’s research—new concepts, data and even equipment related to tailings research—to be shared between COSIA members. This collaboration has leveraged resources between members, to accelerate technology development and enhance the understanding of oil sands tailings behaviour. Given the challenges facing the industry with regards to tailings management, collaboration between Coanda and COSIA members has offered real, implementable solutions that are in operation today.
Coanda works with COSIA’s Tailings Environmental Priority Area (EPA) members: Canadian Natural, Imperial Oil, Shell Canada, Suncor, Syncrude and Teck Resources.
“Our relationship with COSIA and the Tailings EPA has provided Coanda the opportunity to contribute towards addressing tailings issues, which will ultimately have a lasting environmental and social impact,” says John Diep, research scientist at Coanda. “We have greatly appreciated that opportunity, and in particular the collaborative aspects that have brought together so many members of the oil sands community. We are proud of the positive contributions that we have made in this area over the past decade, and look forward to further opportunities to improve and optimize processes in tailings and other areas in the future.”