Mining
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.
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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.
- Open excavations
- Tunnel mines
- Tunnel mining
- Deep mining
- Drift mining
- Hard rock mining
Bioleaching is the application of bacteria to extract metals from an ore.
Some examples of environmental problems associated with mining operations are:
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. See also
References