|
Mining is the extraction of valuable minerals from the ground, usually 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.
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
Bioleaching is the application of naturally available bacteria to extract
metals from their ore.
Environmental effects
Mining is often devastating to the environment of the local area. This is due to the massive scale of the rearrangement of
minerals and chemicals that are in the earth, causing unnatural concentrations of such elements. Combined with the effects of
water and the new 'channels' created for water to travel through, collect in, and its contact with these chemicals, a situation
is created where mass-scale contamination can occur.
Some examples of mine problems:
- 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.
This article is a stub. You can
help Wikipedia by expanding it .
See also
Further reading
|