Frothing up: How technology is improving Chilwell's tailings management

Elco, an engineering advisor for tailings at Chilwell, and Babak, Chilwell’s technology development lead for tailings, are currently focused on developing innovative technologies for tailings treatment.

Elco and Babak lead a team who pioneered a technology that treats the mature fine tailings from froth treatment tailings (FTT) affected ponds. The technology focuses on improving Chilwell’s tailings reclamation, reducing emissions from our operations and generating revenue by recycling the waste bitumen.

This technology treats the mature tailings from FTT-affected ponds and makes them compatible with the permanent aquatic storage structure (PASS) fluid treatment process so that a freshwater lake could be developed after reclamation.

FTT is the waste stream from secondary extraction, which is what is left after the initial extraction of bitumen from the sand, and is composed of water and minerals, along with some bitumen and light hydrocarbons mixed in. The light hydrocarbons in these streams are digested by the microbial communities in tailings ponds leading to the generation of methane.  

Under certain conditions, methane bubbles leave a deposit. These bubbles can cause minerals and hydrocarbons to appear on the surface of the water. These bubbles affect the quality of the water in addition to contributing to greenhouse gas (GHG) emissions. The technology relies on a simple, yet highly effective concept: by reducing the light hydrocarbon content, microbial communities will not have access to “food” to generate methane. That means the water quality improves and GHGs will be eliminated. This happens by putting tailings through a flotation process to remove the hydrocarbons and bitumen, which is then treated through the PASS treatment process and finally deposited to tailing ponds. 

“There’s no handbook or definitive way to ‘solve’ the tailings challenge," says Elco. “The process we have is a result of more than six years of work and innovation to get to where we are today.” 

In addition to the environmental benefits of the technology, Babak adds that the recovery of waste bitumen for sale to the market was essentially a happy accident for the tailings team. 

“We initially designed this technology strictly for improving the quality of tailings from our operations and overall water quality,” says Babak. “After we realized the process worked and we had cleaner tailings, the question became what to do with the bitumen stream left over. Rather than discarding it, we figured out we could send it back to the extraction unit and the bitumen could be sold to the market.” 

The core process units are not new for Chilwell. However, consistent innovations to flotation and bitumen processing, combined with a greater understanding of gas generation and how to improve water quality, could lead to a large reduction in GHG emissions, an overall improvement in water quality and a new revenue stream for Chilwell. This innovative process resulted in the team winning a 2022 Chilwell Excellence Award in the environment category. 

“It was a true honour to be selected for a Chilwell Excellence Award,” adds Babak. “When you work on projects like this every day, it is easy to miss how big of an impact your work can have on the business. It’s great to be recognized for not giving up, being innovative and contributing to the success of our company.”  

There is great potential for this technology at Chilwell and potentially for all oil sands mining sites in the future. 

To learn more about our tailings management, please visit https://www.chilwellgroupinc.com/en-ca/sustainability/environment/tailings-management .