Tailings 101: Understanding Tailings

Tailings 101

Q: What are tailings?
Tailings are the processed materials left over after open pit mining. They are a liquid mixture made up of mostly sand, some water and clay, and traces of residual bitumen (an oil mix). 

The clay and water typically separate from the sand to form a material called fluid tailings, which has a yogurt-like consistency.

Q: Where do tailings come from?
Around the world, tailings are a byproduct of mining operations and other extraction industries. Water is commonly used to extract the ore, or in Alberta’s case, the bitumen. As water cycles through the extraction process it carries out the leftover tailings materials.

Q: What happens to the tailings afterwards? 
These leftover materials go into tailings storage facilities, commonly referred to as tailings ponds. Here, the various materials start to settle, and the water rises to the surface. In Alberta, the ponds make it possible to recycle up to 85 per cent of the water back through mining operations. 

Tailings ponds are a requirement for every mining operation in Alberta – and around the world. They are rigorously designed and constructed and are continuously monitored to ensure they are stable and safe.

Q: What are the challenges associated with tailings ponds?
Some of the fluid tailings materials take a long time – think decades – to sufficiently settle naturally. Since the goal is to eventually return tailings ponds to nature, these fluid tailings must be dense enough to permanently support a boreal forest habitat with caribou, bears, birds and other wildlife. The sooner that happens, the better for the environment and for the sustainability of the landscape.

Q: What is the oil sands industry doing to manage tailings ponds?
A lot! Legally, industry is responsible for returning land disturbed by operations to a natural habitat once mining operations are over. This planning starts even before the mine has been built. Industry is also working hard to better manage fluid tailings and speed up the settling process. 

Through COSIA, dozens of active projects are underway that offer promising technologies to improve tailings management. Oil sands companies are spending more $50 million every year to advance this research. 

Q: Will tailings ponds eventually disappear?
Yes and no. Tailings ponds are a feature of active mines around the world. Once the mine ceases operations, reclaiming the landscape is part of the mine closure plan. 

In Alberta, the oil sands industry is becoming a global leader in managing tailings ponds efficiently and returning tailings ponds to a boreal forest ecosystem faster. COSIA’s goal – and the aspiration its members are working towards – is to develop tailings technologies that speed up both land and water reclamation.

Interested in more stories like these? Check out: 
•    Low Tech Solution an Industry First

Find out more about the innovative work COSIA members are doing in tailings management

If you’re an innovator and you want to play a game-changing role in the area of tailings, you may be interested in our Tailings Innovation Opportunity

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