By Sahar Pakzad - TechnoMine Manager - InfoMine

There are many challenges involved with tailings ponds. They cover large areas and are composed of sand, silt, clay, and oil. Getting the finer particles to sink is one challenge.

According to OilSandsToday.ca, a website started by the Canadian Association of Petroleum Producers (CAPP), “The tailings ponds required at mines are large and impact the landscape. Existing tailings ponds cover 176 km2 (67 mi2). … The bottom layer, a mixture of clay and water called fine tailings, takes a long time to settle and solidify. Even after many years it will still have the consistency of yogurt, and it can take up to 30 years to separate and dry out.”

A few different methods are used to deal with oil sands tailings. One method involves using thickeners to recapture water from the fine tailings prior to releasing into the pond.

Also, new methods are significantly reducing the amount of time it takes to dry the fine tailings. Suncor for example is using a process called TROTM that's expected to significantly improve the speed of tailings reclamation. See Suncor’s tailings management website for more details.

Syncrude Canada uses composite tailings technology to deal with what’s called fluid fine tailings, or FFT, and allow quicker reclamation of oil sands mining pits. According to Canada’s Oil Sands Innovation Alliance (COSIA), “The composite tailings (CT) process involves combining gypsum and sand with FFT, the clay, silt and water that remain following the bitumen mining and extraction process. The FFT is recovered from Syncrude’s tailings ponds and transported by pipeline to the CT plant. This reduces FFT inventories in the tailings ponds.”

Also take a look at the Tailings Technology Roadmap section of COSIA’s website. This roadmap is a collaboration of COSIA, Alberta Innovates - Energy and Environment Solutions, Alberta Energy, Natural Resources Canada, Alberta Environment & Sustainable Resource Development and the Alberta Energy Resources Conservation Board. You can download the technical guide and the five volumes of the roadmap from the above link on COSIA’s site.