Big research moves sustainable mining forward

Tailings research at UAlberta

In 2013, then PhD candidate Nicholas Beier rolled up his sleeves to help get the NSERC/COSIA Industrial Research Chair in Oil Sands Geotechnique off the ground at the University of Alberta. His specialized knowledge in mine waste management and background in mine closure planning allowed him to pose some difficult challenges he thought the program could tackle to support industry’s quest to reclaim oil sands tailings*. These leftover materials from oil sands mining are uniquely fluid-like, a feature that makes them incompatible with dry land reclamation techniques.

Eight years on, the Chair has evolved into a world class research initiative that’s pioneering innovative technologies and methods to transform tailings into a reclamation resource – and restore oil sands mine sites in Alberta faster. Along the way it has put Canada – and industry – at the forefront of best practice in tailings management and mine reclamation techniques.

Sustainable mining goal

“The ultimate goal is to make sure that mining in Canada’s oil sands is sustainable and that we’re progressively reclaiming the sites. We don’t want to leave that legacy to our children and grandchildren to deal with,” says Beier, now associate professor in GeoEnvironmental Engineering. What that means on the ground is state-of-the-art reclamation practices while mines are operating to ‘remediate’ tailings as they go, he says, instead of waiting many decades until a mine is at the end of its life.

“One of the challenges we have is the clays and minerology of our tailings,” Beier explains. “Because of these properties they stay in a slurry form. They don’t want to settle into a solid.” Industry has pioneered many technologies to remove the water, with varying degrees of success. Chair programs like these push the boundaries of science to determine why and find other ways. 

Multi-pronged research approach

Chairholder, G. Ward Wilson, a Geotechnical and Geoenvironmental Engineering professor at the university, oversees the research, which takes a multi-pronged approach. One line of enquiry is studying how to better convert liquid tailings into a near solid material (dry stackable deposit) for use in land reclamation. Does that mean finding ways to take more water out? Or can it be achieved by putting dry material in?

Another avenue of exploration is how to incorporate tailings into an aquatic ecosystem, containing them safely under a water cap in the empty mine pit. The question is how the lake and tailings will evolve in the landscape over time. A thrust of investigative science is underway to better understand the behaviour of the tailings themselves, why their composition makes them act differently to tailings elsewhere and how to safely design dry land reclamation techniques. 

Practical knowledge and tools

Recently renewed for a second term, the Chair is delivering knowledge and tools that can be readily and cost-effectively implemented in mining operations. That’s because it combines researchers from different disciplines, each one bringing new ideas to the problem at hand. COSIA members have hands-on involvement and an advisory role to ensure research is informed by what’s going on in the field.

This broad kind of approach provides the science for best practice and gives regulators and the public the confidence that industry is managing the natural resource responsibly, Beier says. “When you’re trying to determine how to treat tailings, you don’t get results overnight. Some of the tests we do can take up to two years before we get any insights and understand what’s going on.”

Cutting edge facilities

The program’s cutting-edge lab facilities and instrumentation put researchers at the top of their game, and it produces dozens of high-quality graduates who take specialized knowledge into their energy careers. The new methods and tools it delivers can potentially be tapped for mining operations in other countries, providing environmental benefits there too.

Will there come a time when Alberta’s tailings ponds are gone forever? Beier thinks so. “That’s in the plans,” he says. “Novel technologies will help industry reduce the impact of tailings and going forward allow them to develop the oil sands with sustainable tailings planning and management.”

*Tailings are a liquid mixture of sand, clay, water and residual bitumen. They are the by-product of the hot water extraction process used to separate the oil from the sand and clay in oil sands surface mining and extraction.

Interested in other stories like these? See:
•    Tailings 101: Understanding tailings
•    Clay poses perplexing challenge
•    Bugs help vegetation grow on tailings

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