Scientists using the Canadian Light Source are working to understand how current reclamation methods could shape the future of oil sands mine sites and how their surrounding environments may be affected over time.
Matt Lindsay is an Assistant Professor in the Department of Geological Sciences at the University of Saskatchewan and the NSERC/Syncrude Industrial Research Chair in Mine Closure Geochemistry. He says that based on his findings, there is both good news and bad news for mine reclamation in northern Alberta’s oil sands.
“When companies mine an area, they clear the forest and wetlands and underlying rocks, sometimes approaching 100 metres in depth, to access oil sands ore deposits” says Lindsay. “Once the ore is exhausted, these pits may be used to create end pit lakes, which contain fluid fine tailings stored beneath a water cover.”
Fine fluid tailings are a slurry of clay, silt, sand and process water, which contains salts and other chemicals. Over time, the tailings solids settle out of the slurry and release process water. Lindsay and his students are studying how microbes and minerals influence water chemistry during the settling process.
“These microbes survive by altering the forms iron, sulfur and carbon in fluid fine tailings. Some of these processes may have long-term beneficial impacts on water chemistry.”
Lindsay’s research indicates that there is hope water quality within these tailings deposits will improve over time. The big question though, according to Lindsay, is just how long such improvements may take to achieve.
“Pilot studies conducted by oil sands companies indicate that water quality does improve over time. But will these predictions hold true when we move to full-scale implementation?” he asks.
“It’s early! Certainly some of the predictions we can see: the tailings are settling and water is being released. But it is too early to determine whether the processes we are studying will produce significant long-term improvements in water quality.”
With more questions than answers, one thing is clear for Lindsay: there is much more research to be done.
.jpg)
For more information, contact:
Victoria Martinez
CLS Communications Coordinator
W: (306) 657-3771
victoria.martinez@lightsource.ca
Aug 10, 2016
Newsletter sign Up
How can we help?