Salt mining


A salt mine is a mine from which salt is extracted. The mined salt is usually in the form of halite, and extracted from evaporite formations.

History

Before the advent of the modern internal combustion engine and earth-moving equipment, mining salt was one of the most expensive and dangerous of operations because of rapid dehydration caused by constant contact with the salt and of other problems caused by accidental excessive sodium intake. Salt is now plentiful, but until the Industrial Revolution, it was difficult to come by, and salt was often mined by slaves or prisoners. Life expectancy for the miners was low.
In ancient Rome, salt on the table was a mark of wealth; those who sat nearer the host were "above the salt", and those less favored were "below the salt".
Ancient China was among the earliest civilizations in the world with cultivation and trade in mined salt. They first discovered natural gas when they excavated rock salt. The Chinese writer, poet, and politician Zhang Hua of the Jin dynasty wrote in his book Bowuzhi how people in Zigong, Sichuan, excavated natural gas and used it to boil a rock salt solution. The ancient Chinese gradually mastered and advanced the techniques of producing salt. Salt mining was an arduous task for them, as they faced geographical and technological constraints. Salt was extracted mainly from the sea, and salt works in the coastal areas in late imperial China equated to more than 80 percent of national production. The Chinese made use of natural crystallization of salt lakes and constructed some artificial evaporation basins close to shore. In 1041, during the Song dynasty, a well with a diameter about the size of a bowl and several dozen feet deep was drilled for salt production. In Southwestern China, natural salt deposits were mined with bores that could reach to a depth of more than 1000 m, but the yields of ground and salt were relatively low. As salt is a necessity of life, salt mining played a pivotal role as one of the most important sources of Imperial Chinese government revenue and state development.
Most modern salt mines are privately operated or operated by large multinational companies such as K+S, AkzoNobel, Cargill, and Compass Minerals.

Mining regions around the world

Some notable salt mines include:
CountrySite------------------------------
AustriaHallstatt and Salzkammergut.
Bosnia and HerzegovinaTuzla
BulgariaProvadiya; and Solnitsata, an ancient town which Bulgarian archaeologists regard as the oldest in Europe and the site of a salt-production facility approximately six millennia ago.
CanadaSifto Salt Mine in Goderich, Ontario, which, at wide and long, is one of the largest salt mines in the world extending.
ColombiaZipaquirá
EnglandThe "-wich towns" of Cheshire and Worcestershire.
Ethiopia, Eritrea, DjiboutiDanakil Desert, where manual labor is used.
GermanyRheinberg, Berchtesgaden, Heilbronn
Republic of IrelandMountcharles
ItalyRacalmuto, Realmonte and Petralia Soprana within the production sites managed by Italkali.
MoroccoJMS salt mine in Khemisset.
Northern IrelandKilroot, near Carrickfergus, more than a century old and containing passages whose combined length exceeds 25 km.
PakistanKhewra Salt Mines, the world's second largest salt-mining operation, spanning over 300 km.
PolandWieliczka and Bochnia, both established in the mid-13th century and still operating, mostly as museums. Kłodawa Salt Mine.
RomaniaSlănic, Cacica, Ocnele Mari, Salina Turda, Târgu Ocna, Ocna Sibiului, Praid and Salina Ocna Dej.
Russia
United States
  • Hutchinson, Kansas, Underground mining began at Hutchinson in 1923. In 1990 the Hutchinson Salt Company formed, then purchased the mine.
  • Avery Island, Louisiana
  • Detroit, Michigan, beneath which the Detroit Salt Company's subterranean complex extends
  • Western New York and Central New York, location of American Rock Salt, the largest operating salt mine in the United States with a capacity for producing up to 18,000 tons each day.
  • Syracuse, New York earned the nickname "The Salt City" for its salt mining, an activity that continues in the region to the present day.
  • Houston, Texas, near Minute Maid Park is a newly discovered saltworks.
  • Grand Saline in East Texas has a Morton Salt mine. It is one of the largest in the world.
  • Saltville, Virginia, the site of one of the Confederacy's main saltworks.
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    Idiomatic use

    In slang, the term, and especially the phrase, refers ironically to one's workplace, or a dull or tedious task. This phrase originates from in reference to the Russian practice of sending prisoners to forced labor in Siberian salt mines.