Tailings ponds are a fact of life in the Alberta oil sands, but that doesn’t mean the industry is becoming complacent about the reclamation of those sites.
A group of oil sands producers with surface mining operations – Suncor Energy, Syncrude Canada, Shell Canada, Canadian Natural Resources (CNRL), Imperial Oil, Total E&P Canada and Teck Resources – were brought together about two years ago under the banner of a Tailings Technology Roadmap and Action Plan project to share the technologies they use in their tailings reclamation efforts, all in the interest of improving tailings management in the oil sands.
The results were released at the end of August.
“Tailings is an environmental issue that’s been around for a fair bit of time,” said Dr. Eddy Isaacs, CEO of Alberta Innovates-Energy and Environmental Solutions (AI-EES), which partnered with the Oil Sands Tailings Consortium (OSTC) to lead the project.
Alberta Energy and Alberta Environment and Sustainable Resource Development (ESRD) also participated, along with the Alberta’s oil and gas industry regulator, the Energy Resources Conservation Board (ERCB), and Natural Resources Canada (NRCan).
“Different companies have been working together – separately and together – on a number of technologies to try to solve the problems, reclaim the land, and so on,” Isaacs continued. “And, of course, some reclamation has already taken place. Actually, a fair bit of reclamation has.”
The goal of the project was to review all existing and developing technologies in one place in order to determine all the potential pathways for reclaiming oil sands tailings ponds.
“In some cases, they have been collaborating, but it’s been one-on-one as opposed to the entire industry,” said Isaacs.
“Syncrude and Suncor have been working on this problem for a long time and so they have a lot of very good information that they can make available,” he continued. “And so part of the deal was that companies would start to share all of the past information, but also future information.”
It is a legal requirement that companies reclaim their tailings ponds, which can be a long and tricky process because of the oil and organic substances associated with the water.
Water in a tailings pond is also used for oil extraction throughout the life of the associated mine.
“When the water separates, it’s used in the process itself,” said Isaacs, noting that about 85 per cent of that water is recycled.
“But, in the meantime, you do have fine clays that have not settled and take a long time to settle,” he continued. “So, in order to reclaim these ponds, and in order to re-vegetate the soil and so on, you need to resettle these clays. And so a large part of what was looked at with this roadmap was to look at what are the key technologies to be able to do that from a practical perspective – an economic and technical perspective – and what [does] the consolidation look like if this is done properly.
“And what are the gaps that there are that need to be filled so that reclamation can be done and advance the rate at which reclamation can be done.”
The project identified nine pathways for tailings reclamation, each featuring a set of technologies specific to the characteristics of the operation.
“Some of them really require a lot more finesse and work in parts of it,” Isaacs explained. “So, a pathway could consist of a number of different technologies. The key technologies will remain the use of polymers for quicker settlement of the ponds [and] the use of things like centrifuges, which Syncrude has adopted to some degree.
“There are no silver bullets,” he continued. “Different companies have different ore bodies, they have different licenses for their settling areas. Some of them don’t have as much room to use for tailings ponds.”
The pathways also identify innovations that could improve tailings reclamation from an economic perspective.
“But the key aspects of these is how can these pathways be accelerated and what are the missing links to technologies that can do that,” said Isaacs.
“We also want to deal with the water issue,” he added. “Just because the clays get settled, we still have to clean up the water. And so some of the technologies deal with that as well.”
The pathways were developed with the help of nine consulting and engineering companies that work with oil sands producers.
“Really critical to this project’s success,” said Isaacs.
Overall, the team assessed over 500 technologies used in tailings ponds reclamations.
“The beauty is that all of this is in one place as opposed to being scattered in different places,” said Isaacs.
“The team we have within our own organization … is to now go through these and start to prioritize the work that needs to be done to firm up some of these pathways to make sure that the technologies that are already being demonstrated are being shared,” he continued.
“And to know where the gaps are. The roadmap itself has identified these gaps. And so the question is to follow up and make sure we actually start to address the gaps and to implement the roadmap.”
Demonstrations of these pathways are expected to begin in early 2013.