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Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, [1] is a surface mining technique that extracts rock or minerals from the earth. Open-pit mines are used when deposits of commercially useful ore or rocks are found near the surface where the overburden is relatively thin. In contrast, deeper mineral ...
Most open cast mines in the United States extract bituminous coal. In Canada, Australia, and South Africa, open cast mining is used for both thermal and metallurgical coals. In New South Wales open casting for steam coal and anthracite is practiced. Surface mining accounts for around 80 percent of production in Australia, while in the US it is ...
A 3D diagram of a modern underground mine with shaft access. Underground hard-rock mining refers to various underground mining techniques used to excavate "hard" minerals, usually those containing metals, [1] such as ore containing gold, silver, iron, copper, zinc, nickel, tin, and lead. It also involves the same techniques used to excavate ...
The Siilinjärvi carbonatite complex, [1] an open-pit mine owned by Yara International, in Siilinjärvi, Finland Coal strip mine in Wyoming. Surface mining, including strip mining, open-pit mining and mountaintop removal mining, is a broad category of mining in which soil and rock overlying the mineral deposit (the overburden) are removed, in contrast to underground mining, in which the ...
Environmental impact of mining can occur at local, regional, and global scales through direct and indirect mining practices. Mining can cause erosion, sinkholes, loss of biodiversity, or the contamination of soil, groundwater, and surface water by chemicals emitted from mining processes. These processes also affect the atmosphere through carbon ...
Fort Knox mine – gold mine in the Fairbanks mining district of Alaska. Hull–Rust–Mahoning Open Pit Iron Mine – largest open pit iron mine in the world, near Hibbing, Minnesota [7] Lavender Pit – copper mine in Cochise County, Arizona. Morenci Mine – copper mine in Greenlee County, Arizona.
Most of India's coal comes from Jharia. Jharia coal mines are India's most important storehouse [3] of prime coke coal used in blast furnaces, it consists of 23 large underground and nine large open cast mines. [4] ==History== mining activities in these coalfields started in 1894 and had really intensified in 1925.
Covering nearly 30 km 2, it is the second largest open-cast mine in the world. [9] The deepest part of the pit is 400 m lower than the surrounding plateau. Open-pit mining at Nchanga started in 1955, in the main Nchanga open pit. Subsequently, nine medium-sized open pits, called satellite pits, have also been mined at one time or the other.