Oil sands tailings ponds (Canada)
Oil sands tailings ponds are engineered dam and dyke systems used to capture oil sand tailings. Oil sand tailings contain a mixture of salts, suspended solids and other dissolvable chemical compounds such as acids, benzene, hydrocarbons residual bitumen, fine silts and water. Large volumes of tailings are a byproduct of bitumen extraction from the oil sands and managing these tailings is one of the most difficult environmental challenges facing the oil sands industry. An October 2021 Alberta Energy Regulator (AER) report said that in 2020 the tailings ponds increased by another 90 million cubic meters and contained 1.36 billion cubic metres of fluids.
Oil sands tailings ponds
Syncrude tailings dam
Horizon tailings dam
In mining, tailings or tails are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore. Tailings are different from overburden, which is the waste rock or other material that overlies an ore or mineral body and is displaced during mining without being processed.
Yellow boy in a stream receiving acid mine drainage from surface coal mining
Phosphogypsum stack located near Fort Meade, Florida. These contain the waste byproducts of the phosphate fertilizer industry.
Red mud near Stade (Germany)
Bauxite, an aluminium ore (Hérault department, France). The reddish colour is due to iron oxides that make up the main part of the red mud.