Salt mining extracts natural salt deposits from underground. The mined salt is usually in the form of halite (commonly known as rock salt), and extracted from evaporite formations. [1]
Salt mining extracts natural salt deposits from underground. The mined salt is usually in the form of halite (commonly known as rock salt), and extracted from evaporite formations. [1]
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 (both in the mine passages and scattered in the air as salt dust) 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.
The earliest found salt mine was in Hallstatt, Austria where salt was mined, starting in 5000BC. [2]
As salt is a necessity of life, pre-industrial governments were usually keen to exercise stringent control over its production, often through direct ownership of the mines. Wheras the collection of most taxes generally required at least the grudging cooperation of the upper classes, ownership of salt mines could provide monarchs with a lucrative source of income for which they did not need to rely on the goodwill of other strata of society such as the nobility to remit to the monarch. For example, Polish king Casimir the Great relied on salt mines for over a third of his revenue in the 14th century.
Ancient China was among the earliest civilizations in the world with cultivation and trade in mined salt. [3] 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. [4] 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. [5] The Chinese made use of natural crystallization of salt lakes and constructed some artificial evaporation basins close to shore. [3] 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. [4] In Southwestern China, natural salt deposits were mined with bores that could reach to a depth of more than 1,000 m (3,300 ft), but the yields of salt were relatively low. [5] Salt mining played a pivotal role as one of the most important sources of the Imperial Chinese government's revenue and state development. [5]
Most modern salt mines are privately operated or operated by large multinational companies such as K+S, AkzoNobel, Cargill, and Compass Minerals.
Some notable salt mines include:
| Country | Site(s) |
|---|---|
| Austria | Hallstatt and Salzkammergut. |
| Bosnia and Herzegovina | Tuzla |
| Bulgaria | Provadiya; 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. [6] |
| Canada | Sifto Salt Mine [7] in Goderich, Ontario, which, at 1.5 miles (2.4 km ) wide and 2 miles (3.2 km) long, is one of the largest salt mines in the world extending 7 km2 (2.7 sq mi). [8] [9] [ need quotation to verify ] |
| Colombia | Zipaquirá |
| England | The "-wich towns" of Cheshire and Worcestershire. |
| Ethiopia, Eritrea, Djibouti | Danakil Desert, where manual labor is used. [10] |
| Germany | Rheinberg, Berchtesgaden, Heilbronn |
| Republic of Ireland | Mountcharles |
| Italy | Racalmuto, Realmonte and Petralia Soprana [11] within the production sites managed by Italkali. |
| Morocco | Société de Sel de Mohammedia (Mohammedia Rock Salt company) near Casablanca |
| Northern Ireland | Kilroot, near Carrickfergus, more than a century old and containing passages whose combined length exceeds 25 km. |
| Pakistan | Khewra Salt Mines, the world's second largest salt-mining operation, spanning over 300 km. It was first discovered by a horse of Alexander the Great. The mine is still operation till today. |
| Poland | Wieliczka and Bochnia, both established in the mid-13th century and still operating, mostly as museums. Kłodawa Salt Mine. |
| Romania | Slănic (with Salina Veche, Europe's largest salt mine), Cacica, Ocnele Mari, Salina Turda, Târgu Ocna, Ocna Sibiului, Praid and Salina Ocna Dej. |
| Russia |
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| Ukraine | Soledar Salt Mine in Soledar, Donetsk oblast. |
| United States |
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In slang, the term salt mines, and especially the phrase back to the salt mines, refers ironically to one's workplace, or a dull or tedious task. This phrase originates from c. 1800 in reference to the Russian practice of sending prisoners to forced labor in Siberian salt mines. [17] [18]
Potash includes various mined and manufactured salts that contain potassium in water-soluble form. The name derives from pot ash, plant ashes or wood ash soaked in water in a pot, the primary means of manufacturing potash before the Industrial Era. The word potassium is derived from potash.
An evaporite is a water-soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocean deposits, and non-marine, which are found in standing bodies of water such as lakes. Evaporites are considered sedimentary rocks and are formed by chemical sediments.
Halite, commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride (NaCl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, pink, red, orange, yellow or gray depending on inclusion of other materials, impurities, and structural or isotopic abnormalities in the crystals. It commonly occurs with other evaporite deposit minerals such as several of the sulfates, halides, and borates. The name halite is derived from the Ancient Greek word for "salt", ἅλς (háls).
Hallstatt is a small town in the district of Gmunden, in the Austrian state of Upper Austria. Situated between the southwestern shore of Hallstätter See and the steep slopes of the Dachstein massif, the town lies in the Salzkammergut region, on the national road linking Salzburg and Graz.
A salt evaporation pond is a shallow artificial salt pan designed to extract salts from sea water or other brines. The salt pans are shallow and expansive, allowing sunlight to penetrate and reach the seawater. Natural salt pans are formed through geologic processes, where evaporating water leaves behind salt deposits. Some salt evaporation ponds are only slightly modified from their natural version, such as the ponds on Great Inagua in the Bahamas, or the ponds in Jasiira, a few kilometres south of Mogadishu, where seawater is trapped and left to evaporate in the sun.
Goderich is a town in the Canadian province of Ontario and is the county seat of Huron County. The town was founded by John Galt and William "Tiger" Dunlop of the Canada Company in 1827. First laid out in 1828, the town is named after Frederick John Robinson, 1st Viscount Goderich, who was prime minister of the United Kingdom at the time. It was incorporated as a town in 1850.
Salt, also referred to as table salt or by its chemical formula NaCl, is an ionic compound made of sodium and chloride ions. All life depends on its chemical properties to survive. It has been used by humans for thousands of years, from food preservation to seasoning. Salt's ability to preserve food was a founding contributor to the development of civilization. It helped eliminate dependence on seasonal availability of food, and made it possible to transport food over large distances. However, salt was often difficult to obtain, so it was a highly valued trade item, and was considered a form of currency by many societies, including Rome. According to Pliny the Elder, Roman soldiers were paid in salt, from which the word salary is derived, although this is disputed by historians. Many salt roads, such as the Via Salaria in Italy, had been established by the Bronze Age.
In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as rock salt or halite. Salt is essential for life in general, and saltiness is one of the basic human tastes. Salt is one of the oldest and most ubiquitous food seasonings, and is known to uniformly improve the taste perception of food, including otherwise unpalatable food. Salting, brining, and pickling are ancient and important methods of food preservation.
Compass Minerals International, Inc is an American public company that, through its subsidiaries, is a leading producer of minerals, including salt, magnesium chloride and sulfate of potash. Based in Overland Park, Kansas; the company provides bulk treated and untreated highway deicing salt to customers in North America and the United Kingdom and plant nutrition products to growers worldwide. Compass Minerals also produces consumer deicing and water conditioning products, consumer and commercial culinary salt, and other mineral-based products for consumer, agricultural and industrial applications. In addition, Compass Minerals provides records management services to businesses throughout the United Kingdom.
A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen is created in surrounding rock by the presence of high heat and pressure in the Earth's crust.
The Khewra Salt Mine, also known as Mayo Salt Mine, is the world's second largest salt mine, located in Khewra, Punjab, Pakistan. The mine is in the Salt Range of the Potohar plateau, which rises from the Indus plain of the Punjab.
A saltern is an area or installation for making salt. Salterns include modern salt-making works (saltworks), as well as hypersaline waters that usually contain high concentrations of halophilic microorganisms, primarily haloarchaea but also other halophiles including algae and bacteria.
The Wieliczka Salt Mine is a salt mine in the town of Wieliczka, near Kraków in southern Poland.
Open-pan salt making is a method of salt production wherein salt is extracted from brine using open pans.
Room and pillar or pillar and stall is a variant of breast stoping. It is a mining system in which the mined material is extracted across a horizontal plane, creating horizontal arrays of rooms and pillars. To do this, "rooms" of ore are dug out while "pillars" of untouched material are left to support the roof – overburden. Calculating the size, shape, and position of pillars is a complicated procedure, and an area of active research. The technique is usually used for relatively flat-lying deposits, such as those that follow a particular stratum. Room and pillar mining can be advantageous because it reduces the risk of surface subsidence compared to other underground mining techniques. It is also advantageous because it can be mechanized, and is relatively simple. However, because significant portions of ore may have to be left behind, recovery and profits can be low. Room and pillar mining was one of the earliest methods used, although with significantly more manpower.
A salt well is used to mine salt from caverns or deposits. Water is used as a solution to dissolve the salt or halite deposits so that they can be extracted by pipe to an evaporation process, which results in either a brine or a dry product for sale or local use. In the United States during the 19th century, salt wells were a significant source of income for operators and the government. Locating underground salt deposits was usually based on locations of existing salt springs.
Mining is an important industry in Pakistan. Pakistan has deposits of several minerals including coal, copper, gold, chromite, mineral salt, bauxite and several other minerals. There are also a variety of precious and semi-precious minerals that are also mined. These include peridot, aquamarine, topaz, ruby, emerald, rare-earth minerals bastnaesite and xenotime, sphene, tourmaline, and many varieties and types of quartz.
Sifto Canada, Sifto Salt, or simply Sifto Salt Canada is a salt mining and marketing company based in Canada, with its primary products being table salt, fine evaporated salt, water conditioning salt, agricultural salt, and highway deicing salt. Sifto Canada is wholly owned by Compass Minerals.
The Prairie Evaporite Formation, also known as the Prairie Formation, is a geologic formation of Middle Devonian (Givetian) age that consists primarily of halite and other evaporite minerals. It is present beneath the plains of northern and eastern Alberta, southern Saskatchewan and southwestern Manitoba in Canada, and it extends into northwestern North Dakota and northeastern Montana in the United States.
The Whiskey Island mine is a salt mine in downtown Cleveland, Ohio owned by Cargill Deicing Technology. It is one of the largest salt mines in the world and one of two in the Cleveland area, the other being Morton Salt's Fairport Harbor mine to the east. It is also one of three mines in the United States owned by Cargill.
Sifto Canada Inc. [...] (Goderich Mine)
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