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Elemental iron is virtually absent on the Earth's surface except as iron-nickel alloys from meteorites and very rare forms of deep mantle xenoliths.Although iron is the fourth most abundant element in Earth's crust, composing about 5% by weight, [4] the vast majority is bound in silicate or, more rarely, carbonate minerals, and smelting pure iron from these minerals would require a prohibitive ...
An open pit mine began operation in 1882, and moved to underground mining by 1900 for safety reasons. From 1901 until the end of active mining in 1962, the Soudan Mine was owned by the United States Steel Corporation's Oliver Iron Mining division. By 1912 the mine was at a depth of 1,250 feet (381 m). [4]
Iron ore mining pollutes water through metal contamination and heightened sediment levels in streams. [27] The risk of contamination increases when iron ore mining exposes metal-bearing ores rather than exposing ore bodies naturally through erosion and when mined ores are placed on earth surfaces in mineral dressing processes. [ 28 ]
The deepest mines in the world are the Mponeng and TauTona (Western Deep Levels) gold mines in the Witwatersrand region of South Africa, which are currently working at depths exceeding 3,900 m (12,800 ft). [13] The deepest inactive mine in Asia is the Kolar in the Karnataka region of India. Closed in 2001, the main shaft had reached a depth of ...
Gilbert (pop. 1,799) is the location of Lake Ore-be-gone, an artificial lake created by flooding three open-pit iron ore mines. Hibbing (pop. 16,361) is the largest city by area in the state of Minnesota. It is home to the Hull–Rust–Mahoning Open Pit Iron Mine, one of the world's largest open pit iron mines.
Iron ore is currently mined only from open pits, although some mines operated underground early on. [10] Much of the softer ore was formed close to the surface, allowing mining operations to be conducted via open pit mines. The world's largest open pit iron ore mine is the Hull–Rust–Mahoning Open Pit Iron Mine in Hibbing. In the early years ...
In the beginning, surface mining was used, but the mine has been mined with the sublevel caving mining method since the 1960s. In 1985 reserves for the Kiruna Mine were 1,800 million tonnes grading 60–65% iron and 0.2% phosphorus. [26] [1] As of 2018 the Kiruna Mine had Proven and Probable Reserves of 683 million tonnes grading 43.8% iron. [27]
US iron ore made up 2.5 percent of the total mined worldwide in 2015. Employment as of 2014 was 5,750 in iron mines and iron ore treatment plants. [3] US iron ore mining is dominated by the Precambrian banded iron formation deposits around Lake Superior, in Minnesota and Michigan; such deposits were also formerly mined in Wisconsin. For the ...