Salt mining

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Inside a Polish salt mine, in Wieliczka, the site is inscribed on the World Heritage List.
Inside a salt mine, Slănic, Prahova, Romania. Note the size of the railing fence for scale.

A salt mine is a mining operation involved in the extraction of rock salt or halite from evaporite deposits.[1]

Occurrence

The crystal valley region of the Khewra Salt Mines in Pakistan. The mine is a major tourist attraction with around 250,000 visitors a year.
A small mosque made of salt bricks inside the Khewra salt mines complex

Areas known for their salt mines include Kilroot near Carrickfergus, Northern Ireland (over 100 years old with more than 25 km of passages); Khewra Salt Mines in Pakistan which are the world's second largest, spanning more than 300 km; Tuzla in Bosnia; Wieliczka and Bochnia in Poland (both established in the mid-13th century and still operating, mostly as museums); Hallstatt and Salzkammergut in Austria; Rheinberg in Germany; Slănic, Cacica, Ocnele Mari, Salina Turda, Târgu Ocna, Ocna Sibiului, and Praid in Romania; Provadiya in Bulgaria; Racalmuto, Realmonte and Petralia Soprana[2] within the production sites managed by Italkali in southern Italy; Avery Island in Louisiana, United States; Saltville, Virginia, which served as the site of one of the Confederacy's main saltworks; the wich towns of Cheshire and Worcestershire in England; and the Detroit Salt Company's 1,500-acre (10 km2) subterranean complex 1,100 feet (340 m) beneath the city of Detroit.[3] The Sifto Salt Mine in Goderich, Ontario, Canada is one of the largest salt mines in the world.[4] It measures 1.5 miles (2.4 km) wide and 2 miles (3.2 km) long.[5] In Morocco we find in Khemisset the JMS saltmine.

Solnitsata, an ancient town believed by Bulgarian archaeologists to be the oldest in Europe, was the site of a salt production facility approximately six millennia ago.[6]

History

Diorama of an underground salt mine in Europe

Before the advent of the internal combustion engine and earth moving equipment, mining salt was one of the most expensive and dangerous of operations, due to rapid dehydration caused by constant contact with the salt (both in the mine passages and scattered in the air as salt dust), among other problems borne of accidental excessive sodium intake. While salt is now plentiful, until the Industrial Revolution it was difficult to come by, and salt mining was often done by slave or prison labor. In ancient Rome, salt on the table was a mark of a rich patron; those who sat nearer the host were "above the salt," and those less favored were "below the salt". Roman prisoners were given the task of salt mining, and life expectancy among those sentenced was low. The Roman historian Pliny the Elder stated as an aside in his Natural History's discussion of sea water, that "[I]n Rome ... the soldier's pay was originally salt and the word "salary" derives from it ..."[7]

Modern rock salt mine near Mount Morris, New York

Even as recently as the 20th century, salt mining in the Soviet Union and Nazi Germany was performed by people being punished [citation needed].

Today salt mines are privately operated or operated by large multi-national companies like AkzoNobel, Cargill and Compass Minerals.

See also

References

  1. "Oilfield Glossary: Term 'evaporite'". Glossary.oilfield.slb.com. Retrieved 2012-02-13. 
  2. "Italkali Spa - Production Sites" (online). Retrieved 2011-05-09. 
  3. "The Detroit Salt Company --Explore the City under the City." (online). Retrieved 2008-02-08. 
  4. "CBC-TV - Geologic Journey - Goderich, Ontario and Detroit Michigan". CBC 2012. Retrieved 3 August 2012. 
  5. "Industries in Godrich". Retrieved 2008-02-08. 
  6. Maugh II, Thomas H. (1 November 2012). "Bulgarians find oldest European town, a salt production center". The Los Angeles Times. Retrieved 5 December 2012. 
  7. "''Plinius Naturalis Historia XXXI.''". Penelope.uchicago.edu. Retrieved 2012-02-13. 
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