A salt mine is a mine where halite, commonly known as rock salt, is extracted from evaporite formations.
Video Salt mining
Histori
Prior to the advent of modern internal combustion engines and ground transfer equipment, mining salt was one of the most expensive and dangerous operations, due to the rapid dehydration caused by constant contact with salt (both at the mine and scattered in the air as salt dust), among problems another is borne out of an unintentional intake of excessive sodium. While salt is now abundant, until the Industrial Revolution is hard to come by, and salt mining is often done by slaves or prison workers and life expectancy among those who are given low penalties.
In ancient Rome, salt on the table was a rich protective sign; those who sit closer to the host "above salt", and those less favored are "under salt". The Roman historian Pliny the Elder states as an exception to his Natural History's discussion of seawater, that "[I] n Rome... the salary of the soldier is essentially salt and the word 'salary' comes from him..."
Ancient China is one of the earliest civilizations in the world with the cultivation and trade of salt mining. They first discovered natural gas as they dug rock salt. Chinese writer, poet, and politician Zhang Hua of the Jin Dynasty wrote in his book Bowuzhi how people in Zigong, Sichuan dig natural gas and use it to boil a rock salt solution. The ancient Chinese gradually mastered and advanced the technique of producing salt. Salt mining is a tough task for ancient Chinese, facing geographical and technological constraints. Salt is mainly extracted from the sea, and salt works in the coastal areas of late imperial China that equate to more than 80 percent of national production. At the same time, the Chinese use the natural crystallisation of the salt lakes and build some artificial evaporation basins close to shore. In 1041, during the medieval Song dynasty, a well with a diameter of about the size of a bowl and a few dozen meters deep was drilled for salt production. In Southwest China, natural salt deposits are mined with holes that can reach depths of more than 1000 meters but soil and salt yields are relatively low. Because salt is a necessity of life for human civilization, salt mining plays an important role as one of the most important sources of Chinese Imperial government revenues and state development.
Most modern salt mines are privately operated or operated by major multinationals such as K S, AkzoNobel, Cargill, and Compass Minerals.
Maps Salt mining
Mining areas around the world
Areas known for their salt mines include:
See also
References
External links
- JMS Salt - production site
Source of the article : Wikipedia
0 Comments