COSIA's first Tailings Challenge, widening the circle for solutions

Since 2014, COSIA has issued nearly 20 challenges to draw on outside expertise to help fill identified gaps in knowledge and technology across four Environmental Priority Areas (EPAs). Recently, COSIA’s Tailings EPA issued its first-ever challenge, aimed at finding outside-the-box solutions to a longstanding knowledge gap — how to effectively and cost-efficiently cap soft tailings deposits, accelerating environmental performance in Canada’s Oil Sands.

As with previous challenges, anyone who believes they have a potential solution is invited to submit their proposals through COSIA’s online E-TAP portal. That includes representatives of external companies and industries, academic researchers, other research institutes, consultants, entrepreneurs or inventors.

“Everybody likes a good idea and a good idea can come from anywhere,” says Paul Cavanagh, a Senior Technical Advisor with Imperial and Chair of COSIA’s Deep Deposit Working Group. “We are looking for answers wherever we can find them.”

“Everybody likes a good idea and a good idea can come from anywhere,” says Paul Cavanagh. “We are looking for answers wherever we can find them.”

Dealing with soft tailings is one of the most complex challenges facing the oil sands industry. Bitumen is extracted from mined sands ore by mixing it with warm water. Once the bitumen has been removed, what’s left are the tailings — a mixture of water, sand, clay silt and trace bitumen. The sandy deposits settle relatively quickly and the industry has had considerable success with reclaiming these deposits. Additionally, the sandy deposits are used as a cap to separate other tailings deposits from the overlying soil and allow for machinery to re-seed at a later stage of reclamation.

While members have successful commercial-scale experience in capping sand-dominated deposits, there has been limited experience with capping of soft, fines-dominated tailings materials placed in relatively thick deposits which are subject to substantial post-placement settlement and associated water release. The oil sands industry has pursued several possible solutions, but many of the options are not commercially viable, or are not practical to all operators equally.

For example, Suncor has used petroleum coke, a by-product from its upgrading process, to help create a trafficable surface on one of its tailings ponds. The coke cap design, known as the SAFE cover, is light enough to float on the tailings and yet strong enough to allow access for trucks and other equipment.

The COSIA Soft Tailings Capping Technology Challenge is designed to see if people outside the industry might have some potential solutions. Suncor’s Elco Hollander, Senior Technical Advisor, Tailings, co-wrote the challenge. A key element, he says, was to provide enough context so that people unfamiliar with the oil sands industry could understand the particulars of the challenge at hand.

“There are a lot of potential technologies that might work fine if you are operating in Florida, where it’s always warm, and you’re dealing with relatively small tailings deposits,” says Elco. “It’s something else to find solutions to deal with tailings on the scale of the oil sands, that will work in conditions where temperatures drop to -40 degrees Celsius.”

All the same, Elco sees clear value in reaching outside the industry.

“The language in the challenge statement is very much designed to encourage outside-of-the-box thinking,” he says. “We’re also asking people to think not in terms of incremental improvement but step-changes in performance. What we need are creative alternatives, rather than hitting the same nail with the same hammer all the time.”

All forms of mining — whether coal, gold, uranium or potash — produce tailings. So one potential source of fresh ideas are other mining industry operators. For this reason, it made sense for Jennifer Haverhals to launch the COSIA Soft Tailings Capping Technology Challenge at the Tailings and Mine Waste Conference in Banff in November 2017.

“You never know what someone else has discovered that perhaps could be applied to this kind of challenge,” says Jennifer, Senior Advisor and Imperial’s representative on the Tailings EPA steering committee. “You always hope there are parallels that be drawn that will serve to advance knowledge and innovation.”

About the same time, Paul Cavanagh hosted a well-attended, COSIA-led workshop on soft tailings capping. The workshop included outside experts and representatives from mining and other industries that undertake capping of tailings and sediments.

“The goal of the workshop was to present a snapshot of what we know to date about soft tailings capping,” says Paul. “It turned out there were about 45 case histories that Syncrude, Suncor, CNRL and Shell had done over the years. We wanted to share that knowledge and also have some outside experts help us understand the lessons learned.”

Paul shared the results of the workshop during a COSIA webinar in April 2018 where Jennifer presented the Soft Tailings Capping Technology Challenge and further widened the circle of participants.

As challenge submissions are received, they will be reviewed and evaluated by the Tailings EPA steering committee for potential research funding. Among the criteria submissions will be judged upon: the overall scientific and technical merit of the proposal; the respondent’s capabilities and related experience; and the realism of the proposed plan and cost estimates.

Contributors

Paul Cavanagh, M.Eng., P.Eng., Senior Technical Advisor, Imperial Oil and Chair of COSIA’s Deep Deposit Working Group

Jennifer Haverhals, Senior Regulatory Advisor, Policy and Advocacy, Imperial Oil

Elco Hollander, Ph.D, Senior Technical Advisor, Tailings, Suncor Energy