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.
The Ranger Uranium Mine was a uranium mine in the Northern Territory of Australia. The site is surrounded by, but separate from Kakadu National Park, 230 km east of Darwin. The orebody was discovered in late 1969, and the mine commenced operation in 1980, reaching full production of uranium oxide in 1981 and ceased stockpile processing on 8 January 2021. Mining activities had ceased in 2012. It is owned and operated by Energy Resources of Australia (ERA), a public company 86.33% owned by Rio Tinto Group, the remainder held by the public. Uranium mined at Ranger was sold for use in nuclear power stations in Japan, South Korea, China, UK, France, Germany, Spain, Sweden and the United States.
Vale, formerly Companhia Vale do Rio Doce, is a Brazilian multinational corporation engaged in metals and mining and one of the largest logistics operators in Brazil. Vale is the largest producer of iron ore and nickel in the world. It also produces manganese, ferroalloys, copper, bauxite, potash, kaolin, and cobalt, currently operating nine hydroelectricity plants, and a large network of railroads, ships, and ports used to transport its products.
Brumadinho is a Brazilian municipality in the state of Minas Gerais. The city belongs to the Belo Horizonte metropolitan mesoregion and to the microregion of Belo Horizonte. Brumadinho is at an altitude of 880 m. In 2020 the population was 40,666. The municipality is on the Paraopeba River.
The Doñana Disaster, also known as the Aznalcollar Disaster or Guadiamar Disaster, was an industrial accident in Andalusia, southern Spain. On 25 April 1998, a holding dam burst at the Los Frailes mine, near Aznalcóllar, Seville, releasing 4–5 million cubic metres (3,200–4,100 acre⋅ft) of mine tailings. The acidic tailings, which contained dangerous levels of several heavy metals, quickly reached the nearby River Agrio, and then its parent river, the River Guadiamar, travelling about 40 kilometres (25 mi) along these waterways and covering an area of 4,600 hectares before they could be stopped. The Guadiamar is the main water source for the Doñana National Park, a UNESCO World Heritage Site and one of the largest national parks in Europe. The cleanup operation took three years, at an estimated cost of €240 million.
Ahtium was a Finnish mining company that operated the Talvivaara nickel mine from the company's establishment in 2004 until the mining business was sold to the state-owned Terrafame in 2015.
A tailings dam is typically an earth-fill embankment dam used to store byproducts of mining operations after separating the ore from the gangue. Tailings can be liquid, solid, or a slurry of fine particles, and are usually highly toxic and potentially radioactive. Solid tailings are often used as part of the structure itself.
The Merriespruit tailings dam disaster occurred on the night of 22 February 1994 when a tailings dam failed and flooded the suburb of Merriespruit, Virginia, Free State, South Africa. Seventeen people were killed as a result.
The Church Rock uranium mill spill occurred in the U.S. state of New Mexico on July 16, 1979, when United Nuclear Corporation's tailings disposal pond at its uranium mill in Church Rock breached its dam. The accident remains the largest release of radioactive material in U.S. history, having released more radioactivity than the Three Mile Island accident four months earlier.
The 2000 Baia Mare Cyanide spill was a leak of cyanide near Baia Mare, Romania, into the Someș River by the gold mining company Aurul, a joint-venture of the Australian company Esmeralda Exploration and the Romanian government.
The Omai Gold Mine is located in Guyana on the north coast of South America near the west bank of the Essequibo River in the interior of the country. Access to Omai is by road from the capital of Georgetown on the coast, and from the town of Linden approximately 60 km away. There is an operational airstrip on site which can accommodate aircraft from Georgetown. Gold mining at Omai is known from at least the 1880s, and when it was developed as a large scale mine in 1992 by Cambior, the mine was the largest gold mine in the Guiana Shield and a major source of income and employment in Guyana. During the period from 1992 – 2005, Omai produced 3.7 Moz of gold at an average grade of 1.5 g/t Au from the Fennell and the Wenot open pits.
Mount Polley mine is a Canadian gold and copper mine located in British Columbia near the towns of Williams Lake and Likely. It consists of two open-pit sites with an underground mining component and is owned and operated by the Mount Polley Mining Corporation, a wholly owned subsidiary of Imperial Metals. In 2013, the mine produced an output of 38,501,165 pounds (17,463,835 kg) of copper, 45,823 ounces of gold, and 123,999 of silver. The mill commenced operations in 1997 and was closed and placed on care and maintenance in 2019. The company owns 20,113 hectares (201.13 km2) of property near Quesnel Lake and Polley Lake where it has mining leases and operations on 2,007 hectares (20.07 km2) and mineral claims on 18,106 hectares (181.06 km2). Mineral concentrate is delivered by truck to the Port of Vancouver.
The 2015 Gold King Mine waste water spill was an environmental disaster that began at the Gold King Mine near Silverton, Colorado, when Environmental Protection Agency (EPA) personnel, along with workers for Environmental Restoration LLC, caused the release of toxic waste water into the Animas River watershed. They caused the accident by breaching a tailings dam while attempting to drain ponded water near the entrance of the mine on August 5. After the spill, the Silverton Board of Trustees and the San Juan County Commission approved a joint resolution seeking Superfund money.
The Mariana dam disaster, also known as the Bento Rodrigues or Samarco dam disaster, occurred on 5 November 2015, when the Fundão tailings dam at the Germano iron ore mine of the Samarco Mariana Mining Complex near Mariana, Minas Gerais, Brazil, suffered a catastrophic failure, resulting in flooding that devastated the downstream villages of Bento Rodrigues and Paracatu de Baixo, killing 19 people. The extent of the damage caused by the tailings dam collapse is the largest ever recorded with pollutants spread along 668 kilometres (415 mi) of watercourses.
The 1958 Mailuu-Suu tailings dam failure in the industrial town of Mailuu-Suu,, Jalal-Abad Region, southern Kyrgyzstan, caused the uncontrolled release of 600,000 cubic metres (21,000,000 cu ft) of radioactive waste.
The Padcal tailings spills of August–September 2012 were a series of mine tailings spills from Tailings Pond 3 of the Philex Mining Corporation's Padcal mine in Benguet Province, Philippines.
Sisson Mine is a proposed tungsten and molybdenum mine which would be sited near the town of Stanley, 60 km North-West of Fredericton, New Brunswick, Canada. The mine would be among the world's largest tungsten mines, with reserves equating to 227 kilotonnes of elemental tungsten (W). The claim owner, Sisson Mines Ltd., proposes to mine 30,000 tonnes per day of ore which contains on average 0.06 per cent tungsten trioxide (WO3) and smaller amounts of molybdenum. The tungsten component of the ore would be refined into an intermediate product ammonium paratungstate (APT) for shipment. Five hundred fifty seven thousand metric ton units (mtu) of APT would be produced per year, which equates to 4,457 tonnes of tungsten metal per year.
The Brumadinho dam disaster occurred on 25 January 2019 when a tailings dam at the Córrego do Feijão iron ore mine suffered a catastrophic failure. The dam, located 9 kilometres (5.6 mi) east of Brumadinho in Minas Gerais, Brazil, is owned by the mining company Vale, which was also involved in the Mariana dam disaster of 2015. The collapse of the dam released a mudflow that engulfed the mine's headquarters, including a cafeteria during lunchtime, along with houses, farms, inns, and roads downstream. 270 people died as a result of the collapse, of whom 259 were officially confirmed dead, in January 2019, and 11 others were reported as missing. As of January 2022 there were still 6 missing.
The Iron Quadrangle is a mineral-rich region covering about 7,000 square kilometres (2,700 sq mi) in the central-southern part of the Brazilian state Minas Gerais. The area is known for its extensive deposits of gold, diamonds, and iron ore, being the source of approximately 40% of all gold produced in Brazil between the years 1500 and 2000. The deposits themselves pertain to the Minas Supergroup, a sequence of meta-sedimentary rocks initially formed in the Paleoproterozoic, about 2.5 Ga. In the 2010s, there have been two collapses of large tailings dams, which caused extensive damage and loss of life.
