A saltern is an area or installation for making
salt
Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...
. Salterns include modern salt-making works (saltworks), as well as
hypersaline
A hypersaline lake is a landlocked body of water that contains significant concentrations of sodium chloride, brines, and other salts, with saline levels surpassing that of ocean water (3.5%, i.e. ).
Specific microbial species can thrive in hi ...
waters that usually contain high concentrations of
halophilic
microorganisms
A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...
, primarily
haloarchaea
Haloarchaea (halophilic archaea, halophilic archaebacteria, halobacteria) are a class of the Euryarchaeota, found in water saturated or nearly saturated with salt. Halobacteria are now recognized as archaea rather than bacteria and are one of t ...
but also other halophiles including algae and bacteria.
Salterns usually begin with seawater as the initial source of
brine
Brine is a high-concentration solution of salt (NaCl) in water (H2O). In diverse contexts, ''brine'' may refer to the salt solutions ranging from about 3.5% (a typical concentration of seawater, on the lower end of that of solutions used for br ...
but may also use natural saltwater springs and streams. The water is evaporated, usually over a series of ponds, to the point where
sodium chloride
Sodium chloride , commonly known as salt (although sea salt also contains other chemical salts), is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35.45 g ...
and other salts precipitate out of the saturated brine, allowing pure salts to be harvested. Where complete evaporation in this fashion was not routinely achievable due to weather, salt was produced from the concentrated brine by boiling the brine.
Background
Earliest examples of pans used in the solution mining of salt date back to
prehistoric
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of ...
times and the pans were made of ceramics known as
briquetage
Briquetage or very coarse pottery (VCP) is a coarse ceramic material used to make evaporation vessels and supporting pillars used in extracting salt from brine or seawater. Thick-walled saltpans were filled with saltwater and heated from belo ...
. Later examples were made from
lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cu ...
and then
iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
. The change from lead to iron coincided with a change from wood to coal for the purpose of heating the brine. Brine would be pumped into the pans, and concentrated by the heat of the fire burning underneath. As crystals of salt formed these would be raked out and more brine added. In warmer climates no additional heat would be supplied, the sun's heat being sufficient to evaporate off the brine.
One of the earliest salterns for the harvesting of salt is argued to have taken place on
Xiechi Lake
Xiechi Lake (), also called Yuncheng yanchi (Yuncheng Salt Lake) is the largest natural lake in Shanxi in Northern China. It is a saline lake
used for production of salt.
In the summertime intense light and heat cause the algae ''Dunaliella sali ...
,
Shanxi
Shanxi (; ; formerly romanised as Shansi) is a landlocked province of the People's Republic of China and is part of the North China region. The capital and largest city of the province is Taiyuan, while its next most populated prefecture-lev ...
, China by
6000 BC
The 6th millennium BC spanned the years 6000 BC to 5001 BC (c. 8 ka to c. 7 ka). It is impossible to precisely date events that happened around the time of this millennium and all dates mentioned here are estimates mostly based on geological an ...
. Strong archaeological evidence of salt making dating to
2000 BC is found in the ruins of Zhongba at
Chongqing
Chongqing ( or ; ; Sichuanese dialects, Sichuanese pronunciation: , Standard Mandarin pronunciation: ), Postal Romanization, alternately romanized as Chungking (), is a Direct-administered municipalities of China, municipality in Southwes ...
.
See also
*
Sodium chloride
Sodium chloride , commonly known as salt (although sea salt also contains other chemical salts), is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35.45 g ...
*
Alberger process
The Alberger process is an industrial method of producing salt from rock salt.
Method
The Alberger process begins by heating brine under high pressure with a series of heaters. Impurities are removed using a tank filled with granite cubes called ...
*
Salt evaporation pond
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 large of size because it will be easier for sunlight to travel and reach the sea water. Natural sal ...
*
Seawater greenhouse
A seawater greenhouse is a greenhouse structure that enables the growth of crops and the production of fresh water in arid regions which constitute about one third of the earth's land area. This in response to the global water scarcity and peak ...
*
History of salt
Salt, also referred to as table salt or by its chemical formula NaCl (sodium chloride), 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 ...
*
Salt March
The Salt March, also known as the Salt Satyagraha, Dandi March and the Dandi Satyagraha, was an act of nonviolent civil disobedience in colonial India led by Mahatma Gandhi. The twenty-four day march lasted from 12 March to 6 April 1930 as a di ...
(
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
)
*
Red hill (salt making) Red Hill is an archaeological term in Britain for a small mound with a reddish colour found in the coastal and tidal river areas of East Anglia and Essex. Red Hills are formed as a result of generations of salt making, deriving their colour from the ...
References
External links
* ''This article incorporates text fro
Dawlish.com a site which allows free use of its content.''
* Archaeology, arable landscapes and drainage ...Excavations at the
Bourne–Morton Canal and the Roman saltern recorded.
Archaeology, arable landscapes and drainage in the Fenland of Eastern England.* A medieval saltern mound at Millfields Caravan Park, Bramber,Wes
Medieval (13th-16th century) saltern mound Definition of Saltern Mound
{{Salt topics
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