The Mining reference article from the English Wikipedia on 24-Jul-2004
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Mining

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The El Chino Mine located near [[Silver City, New MexicoEnlarge

The El Chino Mine located near [[Silver City, New Mexico

is an open-pit copper mine]] Mining is the extraction of valuable minerals or other geological materials from the earth, usually (but not always) from an ore body or vein. Materials commonly recovered by mining include bauxite, coal, copper, diamonds, iron (from haematite and limonite), gold, lead, manganese, magnesium, nickel, phosphate, platinum, salt, silver, tin, titanium, uranium, and zinc. Other highly useful materials that are mined include clay, sand, cinder, gravel, granite, and limestone.

Table of contents
1 History
2 Mining techniques
3 Environmental effects
4 See also
5 References

History

The first mining operation on Earth may have been the turquoise mine operated by the ancient Egyptians at Wady Maghareh on the Sinai Peninsula. Turquoise was also mined in pre-Columbian America in the Cerillos Mining District in New Mexico, where a mass of rock 200 feet in depth and 300 feet in width was removed with stone tools; the mine dump covers 20 acres.

Mining techniques

Mining techniques can be divided into two basic excavation types: 1) open-cast or open-pit mining and 2) tunneling by shafts into the earth.

Bioleaching is the application of bacteria to extract metals from an ore.

Environmental effects

Mining can have devastating impacts on the environment due to the massive rearrangement of minerals within the earth. The result can be unnatural high concentrations of some chemical elements over a significantly wider area of surface. Combined with the effects of water and the new 'channels' created for water to travel through, collect in, and contact with these chemicals, a situation is created where mass-scale contamination can occur.

Some examples of environmental problems associated with mining operations are:

Tar Creek, an abandoned mine in Northeastern Oklahoma that is now an Environmental Protection Agency superfund site. Water in the mine has leaked through into local groundwater, contaminating it with metals such as lead and cadmium. [1]

Scouriotissa, a copper mine in Cyprus that has been abandoned. Contaminated dust blows off this site.

Berkeley Lake, an abandoned pit mine in Butte, Montana that has filled with water which is now acidic and poisonous.

See also

References