View source for Potash

{{Short description|Salt mixture}}
{{distinguish|pottage}}
{{Other uses}}
[[File:PotashUSGOV.jpg|thumb|Polycrystalline potash, with a [[penny (United States coin)|U.S. penny]] for reference. (The coin is {{convert|19|mm|in|abbr=on}} in diameter and [[copper (color)|copper]] in color.)]]

'''Potash''' ({{IPAc-en|ˈ|p|ɒ|t|æ|ʃ}} {{respell|POT|ash}}) includes various mined and manufactured [[salt (chemistry)|salts]] that contain [[potassium]] in water-[[solute|soluble]] form.<ref name=usgs2>[http://minerals.usgs.gov/minerals/pubs/commodity/potash/myb1-2008-potas.pdf Potash], USGS 2008 Minerals Yearbook</ref> 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''.<ref>{{cite journal|first=Humphry|last=Davy|title=On some new phenomena of chemical changes produced by electricity, in particular the decomposition of the fixed alkalies, and the exhibition of the new substances that constitute their bases; and on the general nature of alkaline bodies|page=32|year=1808|volume=98|journal=Philosophical Transactions of the Royal Society of London|url=https://books.google.com/books?id=gpwEAAAAYAAJ&pg=PA32|doi=10.1098/rstl.1808.0001|doi-access=free}}</ref>

Potash is produced worldwide in amounts exceeding 71.9&nbsp;million [[tonne]]s (~45.4 million tonnes [[Potassium oxide|K<sub>2</sub>O]] equivalent{{Refn|Chemically pure KCl (96% of world potash capacity<ref>{{Cite web |title=Production and use of potassium chloride |url=https://www.ipipotash.org/uploads/udocs/Chap-1_potash_production.pdf |website=International Potash Institute |page=17}}</ref>) contains 63.17% K<sub>2</sub>O equivalent<ref>{{Cite journal |date=1998 |title=Production and Use of Potassium |url=http://www.ipni.net/publication/bettercrops.nsf/0/A529956F62A701F6852579800082035A/$FILE/Better%20Crops%201998-3%20p06.pdf |journal=Better Crops |volume=82 |issue=3 |pages=6 |via=International Plant Nutrition Institute}}</ref>}}) per year as of 2021, with Canada being the largest producer, mostly for use in [[fertilizer]].<ref>{{Cite web |date=2018-01-23 |title=Potash facts |url=https://natural-resources.canada.ca/our-natural-resources/minerals-mining/minerals-metals-facts/potash-facts/20521 |access-date=2023-09-06 |website=natural-resources.canada.ca}}</ref> Various kinds of fertilizer-potash constitute the single greatest industrial use of the element potassium in the world. Potassium was first derived in 1807 by [[electrolysis]] of caustic potash ([[potassium hydroxide]]).<ref>{{cite book|last1=Knight|first1=David|title=Humphry Davy: Science and Power|url=https://archive.org/details/isbn_9780631168164|url-access=registration|date=1992|publisher=Blackwell|location=Oxford|pages=[https://archive.org/details/isbn_9780631168164/page/66 66]|isbn=9780631168164}}</ref>

==Terminology==
Potash refers to potassium compounds and potassium-bearing materials, most commonly potassium carbonate. The word "potash" originates from the [[Middle Dutch]] {{Lang|dum|potaschen}}, denoting "pot ashes" in 1477.<ref name="Etyl">
{{cite web
|last1=van der Sijs i.a.|first1=Nicoline
|title=POTAS (SCHEIKUNDIG ELEMENT)
|url=http://etymologiebank.nl/trefwoord/potas|website=Etymologiebank
|access-date=14 August 2016
|language=nl
|date=2010
}}</ref>
The old method of making [[potassium carbonate]] ({{chem|K|2|CO|3}}) was by collecting or producing [[wood ash]] (the occupation of [[ash burner]]s), [[Leaching (chemistry)|leaching]] the ashes, and then evaporating the resulting solution in large iron pots, which left a white residue denominated "pot ash".<ref>{{OEtymD|potash}}</ref> Approximately 10% by weight of common [[wood ash]] can be recovered as potash.<ref name=usgs>{{cite news|url=http://minerals.usgs.gov/minerals/pubs/commodity/potash/|publisher=USGS|title=Potash|author=Stephen M. Jasinski}}</ref><ref name="ce">{{cite encyclopedia |title=Potash |encyclopedia=[[The Canadian Encyclopedia]] |url=https://www.thecanadianencyclopedia.ca/en/article/potash |access-date=August 31, 2019 |date=March 4, 2015}}</ref> Later, "potash" became widely applied to naturally occurring minerals that contained potassium salts and the commercial product derived from them.<ref>{{cite news|title=The World Potash Industry: Past, Present and Future|publisher=50th Anniversary Meeting The Fertilizer Industry Round Table|place=New Orleans, LA|year=2000|url=http://www.potashcorp.com/media/pdf/investor_relations/speeches/world_potash_industry.pdf}}{{dead link|date=March 2018 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

The following table lists a number of potassium compounds that have "potash" in their traditional names:
{| class="wikitable"
|-
! Common name !! Chemical name (Formula)
|-
|Potash fertilizer ||colspan="2"| Up to the early 20th century:[[potassium carbonate]] (K<sub>2</sub>CO<sub>3</sub>).
Beginning from the late 19th century: one or more of [[potassium chloride]] (KCl), [[potassium sulfate]] (K<sub>2</sub>SO<sub>4</sub>) or [[potassium nitrate]] (KNO<sub>3</sub>).<ref>{{cite book|title = 2005 Minerals Handbook|chapter = Potash|publisher = [[United States Geological Survey]]|date = September 2006|author = Dennis Kostick|page = 58.1|chapter-url = http://minerals.usgs.gov/minerals/pubs/commodity/potash/potasmyb05.pdf|access-date = 2011-01-29}}</ref><ref>{{cite journal|publisher = [[American Chemical Society]]|title = Composition of Potash Fertilizer Salts for Sale on the American Market|author = J. W. Turrentine|doi=10.1021/ie50299a022|journal = Industrial & Engineering Chemistry|year = 1934|volume = 26|issue = 11|pages = 1224–1225}}</ref> Does ''not'' contain [[potassium oxide]] (K<sub>2</sub>O), which plants do not take up;<ref>{{cite journal
 | title = Potash Terminology and Facts
 | author = Joseph R. Heckman
 | journal = Plant & Pest Advisory
 | date = January 17, 2002
 | publisher = [[Rutgers University]]
 | volume = 7
 | issue = 13
 | page = 3
 | url = http://njaes.rutgers.edu/pubs/plantandpestadvisory/2002/fc0117.pdf
 | access-date = January 29, 2011
 | archive-date = July 19, 2011
 | archive-url = https://web.archive.org/web/20110719054037/http://njaes.rutgers.edu/pubs/plantandpestadvisory/2002/fc0117.pdf
 | url-status = dead
 }} Reprinted from ''Agri-Briefs'', from the Agronomists of the Potash & Phosphate Institute, Winter 2001–2002, No.7</ref> the amount of potassium is often reported as K<sub>2</sub>O equivalent (that is, how much it would be if in K<sub>2</sub>O form), however, to allow apples-to-apples comparison between different fertilizers using different types of potash.
|-
|Caustic potash or potash lye ||[[potassium hydroxide]] (KOH)
|-
|{{nowrap|Carbonate of potash,}} {{nowrap|salts of tartar,}} or {{nowrap|pearl ash}} ||[[potassium carbonate]] (K<sub>2</sub>CO<sub>3</sub>)
|-
|Chlorate of potash ||[[potassium chlorate]] (KClO<sub>3</sub>)
|-
|Muriate of potash (MOP) ||[[potassium chloride]] (KCl:NaCl = 95:5 or higher)<ref name=usgs2/>
|-
|Nitrate of potash or saltpeter||[[potassium nitrate]] (KNO<sub>3</sub>)
|-
|Sulfate of potash (SOP) ||[[potassium sulfate]] (K<sub>2</sub>SO<sub>4</sub>)
|-
|{{nowrap|Permanganate of potash}} ||[[potassium permanganate]] (KMnO<sub>4</sub>)
|}

== History ==
[[File:FirstUSpatent.jpg|thumbnail|The first [[United States patent law|U.S. patent]] was issued for an improvement "in the making of Pot ash and Pearl ash by a new Apparatus and Process"; it was signed by then President [[George Washington]].]]
[[File:CoveredHopperForPotashBoltonON.jpg|thumb|A covered hopper car in a Canadian train for shipping potash by rail]]

=== Origin of potash ore ===
Most of the world reserves of potassium (K) were deposited as sea water in ancient [[inland ocean]]s. After the water evaporated, the potassium salts crystallized into beds of potash ore. These are the locations where potash is being mined today. The deposits are a naturally occurring mixture of potassium chloride (KCl) and sodium chloride (NaCl), more commonly known as [[table salt]]. Over time, as the surface of the earth changed, these deposits were covered by thousands of feet of earth.<ref name="digital.library.okstate.edu">Robert C. Fite [http://digital.library.okstate.edu/oas/oas_pdf/v32/p123_125.pdf Origin and occurrence of commercial potash deposits] {{Webarchive|url=https://web.archive.org/web/20100623234316/http://digital.library.okstate.edu/OAS/oas_pdf/v32/p123_125.pdf|date=2010-06-23}}, ''Academy of Sciences for 1951'', p. 123</ref>

=== Bronze Age ===
Potash (especially potassium carbonate) has been used in bleaching textiles, making [[glass]], ceramic, and making [[soap]], since the [[Bronze Age]].<ref>{{Cite web |title=Potash {{!}} Encyclopedia.com |url=https://www.encyclopedia.com/earth-and-environment/minerals-mining-and-metallurgy/mineralogy-and-crystallography/potash#:~:text=POTASH%20(potassium%20carbonate)%20and%20soda%20(sodium%20carbonate)%20have%20been%20used%20from%20the%20dawn%20of%20history%20in%20bleaching%20textiles,%20making%20glass,%20and,%20from%20about%20a.d.%20500,%20in%20making%20soap. |access-date=2022-04-25 |website=www.encyclopedia.com}}</ref> Potash was principally obtained by [[Leaching (chemistry)|leaching]] the ashes of land plants.

=== 14th–17th century ===

==== Potash mining ====
Beginning in the 14th century potash was mined in [[Ethiopia]]. One of the world's largest deposits, 140 to 150&nbsp;million tons, is located in the [[Dallol, Ethiopia|Dallol]] area of the [[Afar Region]].<ref name="Ethiopia Mining">[http://www.photius.com/countries/ethiopia/economy/ethiopia_economy_mining.html Ethiopia Mining]. Photius.com. Retrieved on 2013-06-21.</ref>

==== Wood-derived potash ====
Potash was one of the most important industrial chemicals. It was refined from the ashes of [[broad-leaved tree|broadleaved trees]] and produced primarily in the forested areas of Europe, [[Russia]], and [[North America]]. Although methods for producing artificial alkalis were invented in the late 18th century, these did not become economical until the late 19th century and so the dependence on organic sources of potash remained.

Potash became an important international trade commodity in Europe from at least the early 14th century. It is estimated that European imports of potash required 6 or more million cubic metres each year from the early 17th century.<ref name="Paul Warde 2018"/> Between 1420 and 1620, the primary exporting cities for [[wood ash|wood-derived potash]] were [[Gdańsk]], [[Königsberg]] and [[Riga]]. In the late 15th century, London was the lead importer due to its position as the centre of soft soap making while the Dutch dominated as suppliers and consumers in the 16th century.<ref name="Paul Warde 2018">Paul Warde, 'Trees, Trade and Textiles: Potash Imports and Ecological Dependency in British Industry, c. 1550–1770', Past & Present, 240, 1, 2018, 47–82</ref> From the 1640s, geopolitical disruptions (i.e. [[Russo-Polish War (1654–1667)]]) meant that the centres of export moved from the Baltic to [[Archangelsk]], Russia. In 1700, Russian ash was dominant though Gdańsk remained notable for the quality of its potash.

=== 18th century ===

==== Kelp ash ====
On the [[Orkney]] islands, [[kelp]] ash provided potash and [[soda ash]], production starting "possibly as early as 1719" and lasting for a century. The products were "eagerly sought after by the glass and soap industries of the time."<ref name="stkelp">{{cite news |title=Kelp Burning in Orkney |website=orkneyjar.com |publisher=Sigurd Towrie |url=http://orkneyjar.com/tradition/kelpburning.htm |access-date=2021-09-20 |archive-date=2023-05-14 |archive-url=https://web.archive.org/web/20230514013844/http://www.orkneyjar.com/tradition/kelpburning.htm |url-status=dead }}</ref>

==== North America ====
By the 18th century, higher quality American potash was increasingly exported to Britain. In the late 18th and early 19th centuries, potash production provided settlers in North America badly needed cash and credit as they cleared wooded land for crops. To make full use of their land, settlers needed to dispose of excess wood. The easiest way to accomplish this was to burn any wood not needed for fuel or construction. Ashes from [[hardwood]] trees could then be used to make [[Potassium hydroxide|lye]], which could either be used to make soap or boiled down to produce valuable potash. Hardwood could generate ashes at the rate of 60 to 100 [[bushel]]s per acre (500 to 900 m<sup>3</sup>/km<sup>2</sup>). In 1790, the sale of ashes could generate $3.25 to $6.25 per acre ($800 to $1,500/km<sup>2</sup>) in rural [[New York State]] – nearly the same rate as hiring a laborer to clear the same area. Potash making became a major industry in British North America. Great Britain was always the most important market. The American potash industry followed the woodsman's ax across the country.

====The first US patent====
The first [[United States patent law|US patent]] of any kind was issued in 1790 to [[Samuel Hopkins (inventor)|Samuel Hopkins]] for an improvement "in the making of Pot ash and Pearl ash by a new Apparatus and Process".<ref>[[wikisource:United States patent X1|Patent X1: the making of Pot ash and Pearl ash by a new Apparatus and Process (1790)]]. en.wikisource.org</ref> ''Pearl ash'' was a purer quality made by [[calcination]] of potash in a [[reverberatory furnace]] or kiln. [[Potash pit]]s were once used in [[England]] to produce potash that was used in making soap for the preparation of wool for yarn production.

=== 19th century ===
After about 1820, New York replaced New England as the most important source; by 1840 the center was in Ohio. Potash production was always a by-product industry, following from the need to clear land for [[agriculture]].<ref name="digital.library.okstate.edu" />

==== Canada ====
From 1767, potash from wood ashes was exported from Canada. By 1811, 70% of the total 19.6 million lbs of potash imports to Britain came from Canada.<ref name="Paul Warde 2018" /> Exports of potash and pearl ash reached 43,958 barrels in 1865. There were 519 [[Ashery|asheries]] in operation in 1871.

=== 20th century industrialization ===
[[File:International Exchange of Potash in 1937 - DPLA - 6e2d669a051158fe7afe1fc031988d4f.jpg|thumb|right|Global imports/exports of potash in 1937]]
The wood-ash industry declined in the late 19th century when large-scale production of [[:Category:Potassium minerals|potash from mineral]] salts was established in [[Germany]]. In the early 20th century, the potash industry was dominated by a cartel in which Germany had the dominant role.<ref name=":02" />{{Rp|page=147}} [[World War I|WWI]] saw a brief resurgence of American asheries, with their product typically consisting of 66% hydroxide, 17% carbonate, 16% sulfate and other impurities.<ref>{{Cite book |last=Bateman |first=Ernest |url=https://books.google.com/books?id=ksNWAAAAMAAJ&pg=PA15 |title=Wood Ashes and Production of Potash |date=1919 |publisher=U.S. Department of Agriculture, Forest Service, Forest Products Laboratory |language=en}}</ref> Later in the century, the cartel ended as new potash producers emerged in the USSR and Canada.<ref name=":02" />{{Rp|page=147}}

In 1943, potash was discovered in [[Saskatchewan]], Canada, during oil drilling. Active exploration began in 1951. In 1958, the Potash Company of America became the first potash producer in Canada with the commissioning of an underground potash mine at [[Patience Lake]].<ref name="ce" /> As numerous potash producers in Canada developed, the Saskatchewan government became increasingly involved in the industry, leading to the creation of [[Canpotex]] in the 1970s.<ref name=":02" />{{Rp|page=147}} 

[[File:Canadianpotashmine.jpg|thumbnail|A postcard of the Kalium Chemicals plant in [[Belle Plaine, Saskatchewan]]]]
In 1964 the Canadian company Kalium Chemicals established the first potash mine using the solution process. The discovery was made during oil reserve exploration. The mine was developed near Regina, Saskatchewan. The mine reached depths greater than 1500 meters. It is now the Mosaic Corporation's Belle Plaine unit.

The USSR's potash production had largely been for domestic use and use in the [[Council for Mutual Economic Assistance]] countries.<ref name=":02" />{{Rp|page=147}} After the [[Dissolution of the Soviet Union|dissolution of the USSR]], Russian and [[Mining in Belarus|Belarusian]] potash producers entered into direct competition with producers elsewhere in the world for the first time.<ref name=":02" />{{Rp|page=147}}

In the beginning of the 20th century, potash deposits were found in the [[Dallol, Ethiopia|Dallol Depression]] in the Musely and Crescent localities near the Ethiopean-[[Eritrea]]n border. The estimated reserves in Musely and Crescent are 173 and 12&nbsp;million tonnes respectively. The latter is particularly suitable for surface mining. It was explored in the 1960s but the works stopped due to flooding in 1967. Attempts to continue mining in the 1990s were halted by the [[Eritrean–Ethiopian War]] and have not resumed as of 2009.<ref name="industrialization1">{{cite news |title=Minerals for Agricultural Industrialization |publisher=Ministry of Mines and Energy of Ethiopia |url=http://www.mome.gov.et/industrial.html |url-status=dead |archive-url=https://web.archive.org/web/20110720153154/http://www.mome.gov.et/industrial.html |archive-date=2011-07-20}}</ref>[[Image:Potash evaporation ponds near Moab, UT, May 2013.jpg|thumb|Potash evaporation ponds at the [[Intrepid Potash]] mine near [[Moab, Utah]]]]

== Mining ==

=== Shaft mining and strip mining ===
All commercial potash deposits come originally from [[evaporite]] deposits and are often buried deep below the earth's surface. Potash ores are typically rich in potassium chloride (KCl), sodium chloride (NaCl) and other salts and clays, and are typically obtained by conventional shaft mining with the extracted ore ground into a powder.<ref>{{Cite book |last=Alikhan |first=Irfan |title=Management of Agricultural Inputs |publisher=Agrotech Publishing Academy |year=2014 |isbn=9789383101474}}</ref> Most potash mines today are deep shaft mines as much as 4,400 feet (1,400 m) underground. Others are mined as strip mines, having been laid down in horizontal layers as [[sedimentary rock]]. In above-ground processing plants, the KCl is separated from the mixture to produce a high-analysis potassium fertilizer. Other potassium salts can be separated by various procedures, resulting in potassium sulfate and potassium-magnesium sulfate.

=== Dissolution mining and evaporation methods ===
Other methods include dissolution mining and evaporation methods from brines. In the evaporation method, hot water is injected into the potash, which is dissolved and then pumped to the surface where it is concentrated by solar induced evaporation. [[Amine]] reagents are then added to either the mined or evaporated solutions. The amine coats the KCl but not NaCl. Air bubbles cling to the amine + KCl and float it to the surface while the NaCl and clay sink to the bottom. The surface is skimmed for the amine + KCl, which is then dried and packaged for use as a K rich fertilizer—KCl dissolves readily in water and is available quickly for [[plant nutrition]].<ref>[http://www.ipni.net/ipniweb/portal.nsf/0/68907f5d1e5922f8062577ce006ad872/$FILE/K%20Fert%20Prod%20&%20Tech%2011%2016%2010.pdf Potassium Fertilizer Production and Technology] {{Webarchive|url=https://web.archive.org/web/20121202150508/http://www.ipni.net/ipniweb/portal.nsf/0/68907f5d1e5922f8062577ce006ad872/%24FILE/K%20Fert%20Prod%20%26%20Tech%2011%2016%2010.pdf|date=2012-12-02}}. International Plant Nutrition Institute.</ref>

Recovery of potassium fertilizer salts from sea water has been studied in [[India]].<ref>[http://www.tifac.org.in/index.php?option=com_content&view=article&id=733&Itemid=205 Recovery of Potassium Fertiliser Salts from Sea Bittern] {{Webarchive|url=https://web.archive.org/web/20150610214622/http://www.tifac.org.in/index.php?option=com_content&view=article&id=733&Itemid=205|date=2015-06-10}}. Tifac.org.in. Retrieved on 2013-06-21.</ref> During extraction of salt from seawater by evaporation, potassium salts get concentrated in [[Bittern (salt)|bittern]], an effluent from the salt industry.

== Production ==
Potash deposits are distributed unevenly throughout the world.<ref name=":02" />{{Rp|page=147}} {{As of|2015}}, deposits are being mined in Canada, Russia, China, Belarus, Israel, Germany, Chile, the United States, Jordan, Spain, the United Kingdom, Uzbekistan and Brazil,<ref>Quick Guide to Potash. (2013, June 14). Retrieved September 29, 2015, from http://www.geoalcali.com/en/quick-guide-to-potash/ {{Webarchive|url=https://web.archive.org/web/20150930075527/http://www.geoalcali.com/en/quick-guide-to-potash/|date=2015-09-30}}</ref> with the most significant deposits present under the great depths of the [[Prairie Evaporite Formation]] in [[Saskatchewan]], Canada.<ref name="ce" /> Canada and Russia are the countries where the bulk of potash is produced; Belarus is also a major producer.<ref name=":02">{{Cite book |last=Massot |first=Pascale |title=China's Vulnerability Paradox: How the World's Largest Consumer Transformed Global Commodity Markets |date=2024 |publisher=[[Oxford University Press]] |isbn=978-0-19-777140-2 |location=New York, NY, United States of America |pages=}}</ref>{{Rp|page=12}}

The [[Permian Basin (North America)|Permian Basin]] deposit includes the major mines outside of [[Carlsbad, New Mexico|Carlsbad]], New Mexico, to the world's purest potash deposit in [[Lea County, New Mexico]] (near the Carlsbad deposits), which is believed to be roughly 80% pure. ([[Osceola County, Michigan]], has deposits 90+% pure; the only mine there was converted to salt production, however.) Canada is the largest producer, followed by Russia and Belarus. The most significant reserve of Canada's potash is located in the province of Saskatchewan and is mined by [[The Mosaic Company]], [[Nutrien]] and [[K+S]].<ref name="usgs2" />

In [[China]], most potash deposits are concentrated in the deserts and salt flats of the [[endorheic basins]] of its western provinces, particularly [[Qinghai]]. Geological expeditions discovered the reserves in the 1950s<ref name="jung">{{citation |last=Zheng |first=Mianping |title=An Introduction to Saline Lakes on the Qinghai–Tibet Plateau |date=1997 |url=https://books.google.com/books?id=hFz-CAAAQBAJ |page=[https://books.google.com/books?id=hFz-CAAAQBAJ&pg=PA3 3–5] |author-mask=Zheng Mianping |location=Dordrecht |publisher=Kluwer Academic Publishers |isbn=9789401154581}}.</ref> but commercial exploitation lagged until [[Deng Xiaoping]]'s [[Reform and Opening Up Policy]] in the 1980s. The 1989 opening of the Qinghai Potash Fertilizer Factory in the remote [[Qarhan Playa]] increased China's production of [[potassium chloride]] sixfold, from less than {{convert|40,000|MT|sp=us|abbr=on}} a year at [[Haixi Mongol and Tibetan Autonomous Prefecture|Haixi]] and [[Tanggu]] to just under {{convert|240,000|MT|sp=us|abbr=on}} a year.<ref name="factsoflife">{{citation |last=Garrett |first=Donald Everett |title=Potash: Deposits, Processing, Properties, and Uses |date=1996 |url=https://books.google.com/books?id=_MIjCQAAQBAJ |page=[https://books.google.com/books?id=_MIjCQAAQBAJ&pg=PA176 176–177] |location=London |publisher=Chapman & Hall |isbn=9789400915459}}.</ref>

In 2013, almost 70% of potash production was controlled by [[Canpotex]], an exporting and marketing firm, and the [[Belarusian Potash Company]]. The latter was a joint venture between [[Belaruskali]] and [[Uralkali]], but on July 30, 2013, Uralkali announced that it had ended the venture.<ref>{{cite news |date=2013-07-30 |title=Potash sector rocked as Russia's Uralkali quits cartel |work=Reuters |url=https://www.reuters.com/article/russia-uralkali-idUSL6N0G013H20130730 |url-status=live |access-date=2017-07-01 |archive-url=https://web.archive.org/web/20150924183441/http://www.reuters.com/article/2013/07/30/russia-uralkali-idUSL6N0G013H20130730 |archive-date=2015-09-24}}</ref>

Potash is [[Solubility|water soluble]] and transporting it requires special transportation infrastructure.<ref name=":02" />{{Rp|page=152}} 
{| class="wikitable sortable" style="text-align:right;"
|+List of countries by potash production
! rowspan="2" |Rank
! rowspan="2" |Country
! colspan="5" |Extraction in metric tons K<sub>2</sub>O equivalent
|-
!2016
!2017
!2018
!2019
!2020
|-
|1
| style="text-align:left;" |{{CAN}}
|10,789,662
|12,562,695
|14,023,931
|12,643,318
|13,881,665
|-
|2
| style="text-align:left;" |{{RUS}}
|6,480,000
|7,300,000
|7,055,000
|7,368,000
|8,167,300
|-
|3
| style="text-align:left;" |{{BLR}}
|6,180,100
|7,101,800
|7,346,096
|7,348,293
|7,562,153
|-
|4
| style="text-align:left;" |{{CHN}}
|5,783,000
|5,534,000
|5,452,000
|5,902,000
|5,530,000
|-
|5
| style="text-align:left;" |{{DEU}}
|2,750,841
|2,963,561
|2,754,085
|2,615,284
|2,874,026
|-
|6
| style="text-align:left;" |{{ISR}}
|2,093,100
|2,126,700
|2,149,300
|2,043,500
|2,415,600
|-
|7
| style="text-align:left;" |{{JOR}}
|1,222,140
|1,415,260
|1,485,960
|1,516,460
|1,598,200
|-
|8
| style="text-align:left;" |{{CHL}}
|1,303,840
|1,238,630
|991,180
|683,540
|966,680
|-
|9
| style="text-align:left;" |{{USA}}
|510,000
|480,000
|520,000
|510,000
|460,000
|-
|10
| style="text-align:left;" |{{ESP}}
|672,246
|557,468
|635,490
|547,100
|455,000
|-
|11
| style="text-align:left;" |{{LAO}}
|198,600
|307,600
|343,500
|286,900
|442,500
|-
|12
| style="text-align:left;" |{{BRA}}
|316,429
|306,296
|201,181
|269,300
|276,600
|-
|13
| style="text-align:left;" |{{UZB}}
|83,000
|114,900
|176,900
|198,400
|210,000
|-
|14
| style="text-align:left;" |{{GBR}}
|482,800
|297,400
|291,100
|84,000
|99,260
|-
|15
| style="text-align:left;" |{{IRN}}
|10,500
|15,300
|32,900
|37,200
|37,000
|-
|16
| style="text-align:left;" |{{TKM}}
|0
|0
|15,200
|11,100
|16,000
|-
|17
| style="text-align:left;" |{{BOL}}
|0
|0
|1,700
|17,800
|4,400
|- class="unsortable"
!
!Total
!38,876,258
!42,321,610
!43,475,523
!42,082,195
!44,996,384
|}

==Occupational hazards==
Excessive respiratory disease due to environmental hazards, such as [[radon]] and [[asbestos]], has been a concern for potash miners throughout history. Potash miners are liable to develop [[silicosis]]. Based on a study conducted between 1977 and 1987 of cardiovascular disease among potash workers, the overall mortality rates were low, but a noticeable difference in above-ground workers was documented.<ref>{{cite journal|title=Mortality from Cardiovascular Diseases among Potash Miners Exposed to Heat|first1=Pascal|last1=Wild|first2=Jean-Jacques|last2=Moulin|first3=François-Xavier|last3=Ley|first4=Paul|last4=Schaffer|date=16 April 1995|journal=Epidemiology|volume=6|issue=3|pages=243–247|jstor = 3702386|doi = 10.1097/00001648-199505000-00009|pmid=7619930|s2cid=40033328|doi-access=free}}</ref>

==Consumption==
{| class="wikitable sortable" style="float:right"
|+Production of potash and reserves at some current mines (being <2% of global reserves)<br/>(both in <chem>K2O</chem> equivalent)<br/>(2021, in million tonnes)<ref name=":0">{{Cite web |date=January 2023 |title=Potash Mineral Commodity Summaries 2023 |url=https://pubs.usgs.gov/periodicals/mcs2023/mcs2023-potash.pdf |access-date=6 September 2023 |website=[[United States Geological Survey]]}}</ref>
! Country
! Production
! Reserves
|-
|[[Canada]]
|align=right|   14.2 (28.57%)
|align=right| 1,100 (33.33%)
|-
|[[Russia]]
|align=right|    9.1 (17.14%)
|align=right| 400 (12.12%)
|-
|[[Belarus]]
|align=right|    7.6 (16.48%)
|align=right|  750 (22.73%)
|-
|[[China]]
| align="right" |    6.0 (14.76%)
| align="right" |  170 (5.15%)
|-
|[[Germany]]
| align="right" |    2.8 (6.90%)
| align="right" |  150 (4.55%)
|-
|[[Israel]]
|align=right|    2.4 (5.14%)
|align=right|   Large (?%)
|-
|[[Jordan]]
|align=right|    1.6 (3.37%)
|align=right|   Large (?%)
|-
|[[Chile]]
| align="right" |    0.9 (1.85%)
| align="right" |   100 (3.03%)
|-
|[[United States]]
| align="right" |    0.5 (1.04%)
| align="right" |  220 (6.67%)
|-
|[[Spain]]
| align="right" |    0.4 (0.79%)
| align="right" |   68 (2.06%)
|-
|[[Brazil]]
| align="right" |    0.3 (0.58%)
| align="right" |  2.3 (0.01%)
|-
|'''Other countries'''
| align="right" | 0.4 (0.76%)
| align="right" |   300 (9.09%)
|- class="sortbottom"
|'''World total'''
| align="right" |   46.3 (100.00%)
| align="right" | >3,300 (100.00%)
|}

===Fertilizers===
Potassium is the third major plant and crop nutrient after [[nitrogen]] and [[phosphorus]]. It has been used since [[Ancient history|antiquity]] as a [[soil]] [[fertilizer]] (about 90% of current use).<ref name=usgs/> Fertilizer use is the main driver behind potash consumption, especially for its use in fertilizing crops that contribute to high-protein diets.<ref name=":02" />{{Rp|page=23}} As of at least 2010, more than 95% of potash is mined for use in agricultural purposes.<ref name=":02" />{{Rp|page=24}}

Elemental potassium does not occur in nature because it reacts violently with water.<ref name="HollemanAF">{{cite book|publisher = Walter de Gruyter|year = 1985|edition = 91–100|isbn = 978-3-11-007511-3|title = Lehrbuch der Anorganischen Chemie|author = Arnold F. Holleman, Egon Wiberg and Nils Wiberg|chapter = Potassium| language = de}}</ref> As part of various compounds, potassium makes up about 2.6% of the [[Earth's crust]] by mass and is the seventh most abundant element, similar in abundance to sodium at approximately 1.8% of the crust.<ref name="Greenwood">{{cite book|last=Greenwood|first= Norman N|year=1997|title=Chemistry of the Elements |url=https://archive.org/details/chemistryelement00earn_612|url-access=limited|edition=2|place=Oxford|publisher= Butterworth-Heinemann|isbn=978-0-08-037941-8|page=[https://archive.org/details/chemistryelement00earn_612/page/n89 69]}}</ref> Potash is important for agriculture because it improves water retention, yield, nutrient value, taste, color, texture<ref name=":02" />{{Rp|page=24}} and disease resistance of food crops. It has wide application to fruit and vegetables, rice, wheat and other grains, sugar, corn, soybeans, [[palm oil]] and cotton, all of which benefit from the nutrient's quality-enhancing properties.<ref>[http://www.activex.com.au/reports/2008-09/AIV_20081114_ASX_Announ_Potash_Outlook.pdf Potash Price Close to all time highs – Future Outlook] {{webarchive|url=https://web.archive.org/web/20090918050005/http://www.activex.com.au/reports/2008-09/AIV_20081114_ASX_Announ_Potash_Outlook.pdf |date=2009-09-18 }}. ASX Release (14 November 2008). activex.com.au. Retrieved on 2013-06-21.</ref>

Demand for food and animal feed has been on the rise since 2000. The [[United States Department of Agriculture]]'s [[Economic Research Service]] (ERS) attributes the trend to average annual population increases of 75&nbsp;million people around the world. Geographically, economic growth in Asia and Latin America greatly contributed to the increased use of potash-based fertilizer. Rising incomes in developing countries also were a factor in the growing potash and fertilizer use. With more money in the household budget, consumers added more meat and dairy products to their diets. This shift in eating patterns required more acres to be planted, more fertilizer to be applied and more animals to be fed—all requiring more potash.

After years of trending upward, fertilizer use slowed in 2008. The worldwide economic downturn is the primary reason for the declining fertilizer use, dropping prices, and mounting inventories.<ref>[https://web.archive.org/web/20091008015109/http://southernstates.com/articles/ca/potash-global.aspx Potash Around the World]. southernstates.com</ref><ref>[http://www.indmin.com/Article/2188737/Channel/0/Potash-global-review-tunnel-vision.html "Potash global review: tunnel vision"] {{Webarchive|url=https://web.archive.org/web/20220331085627/https://www.indmin.com/Article/2188737/Channel/0/Potash-global-review-tunnel-vision.html |date=2022-03-31 }}, ''Industrial Minerals'', May 2009</ref>

The world's largest consumers of potash are China, the United States, Brazil, and India.<ref name="Potassio Do Brasil">[http://www.potassiodobrasil.com.br/index.php/pagina/view/9/supply-demand#x1 Supply and Demand] {{Webarchive|url=https://web.archive.org/web/20101210053902/http://www.potassiodobrasil.com.br/index.php/pagina/view/9/supply-demand#x1 |date=2010-12-10 }}. Potassiodobrasil.com.br. Retrieved on 2013-06-21.</ref>  Brazil imports 90% of the potash it needs.<ref name="Potassio Do Brasil"/> Potash consumption for fertilizers is expected to increase to about 37.8 million tonnes by 2022.<ref name="auto">{{Cite journal|last1=Rawashdeh|first1=Rami Al|last2=Xavier-Oliveira|first2=Emanuel|last3=Maxwell|first3=Philip|date=2016|title=The potash market and its future prospects|journal=Resources Policy|volume=47|pages=154–163|doi=10.1016/j.resourpol.2016.01.011|bibcode=2016RePol..47..154R |issn=0301-4207}}</ref>

Potash imports and exports are often reported in K<sub>2</sub>O ''equivalent'', although fertilizer never contains potassium oxide, per se, because potassium oxide is [[Causticity|caustic]] and [[hygroscopic]].

===Pricing===
At the beginning of 2008, potash prices started a meteoric climb from less than US$200 a tonne to a high of US$875 in February 2009.<ref>{{cite news|url=http://www.potashinvestingnews.com/354-potash-prices-at-record-high.html|date=February 5, 2009|title=Potash Prices Are Record High|publisher=Potash Investing news|access-date=October 18, 2009|archive-url=https://web.archive.org/web/20090316162444/http://www.potashinvestingnews.com/354-potash-prices-at-record-high.html|archive-date=March 16, 2009|url-status=dead}}</ref> These subsequently dropped dramatically to an April 2010 low of US$310 level, before recovering in 2011–12, and relapsing again in 2013. For reference, prices in November 2011 were about US$470 per tonne, but as of May 2013 were stable at US$393.<ref>[http://www.infomine.com/investment/metal-prices/potash/5-year/ 5 Year Potash Prices and Potash Price Charts – InvestmentMine]. Infomine.com (2013-05-31). Retrieved on 2013-06-21.</ref> After the surprise breakup of the world's largest potash cartel at the end of July 2013, potash prices were poised to drop some 20 percent.<ref>{{cite news|url=https://www.reuters.com/article/potash-prices-idUSL6N0H032X20130905|title=Potash prices head for 20 pct drop after cartel disintegrates|date=5 September 2013|access-date=16 April 2019|via=www.reuters.com|newspaper=Reuters}}</ref> At the end of December 2015, potash traded for US$295 a tonne. In April 2016 its price was US$269.<ref>{{cite web|title=Potash Prices and Potash Price Charts|url=http://www.infomine.com/investment/metal-prices/potash/|website=InfoMine|access-date=6 September 2016|date=2016-04-30}}</ref> In May 2017, prices had stabilised at around US$216 a tonne down 18% from the previous year. By January 2018, prices have been recovering to around US$225 a tonne.<ref>{{cite web|title=Potash Prices and Potash Price Charts|url=https://ycharts.com/indicators/potassium_chloride_muriate_of_potash_spot_price
|website=ycharts|access-date=18 October 2017|date=2017-06-05}}</ref> World potash demand tends to be price inelastic in the short-run and even in the long run.<ref name="auto"/>

===Other uses===
In addition to its use as a fertilizer, potassium chloride is important in many industrialized economies, where it is used in [[aluminium recycling]], by the [[chloralkali]] industry to produce potassium hydroxide, in metal [[electroplating]], oil-well [[drilling fluid]], snow and ice melting, steel heat-treating, in medicine as a treatment for [[hypokalemia]], and [[water softening]]. Potassium hydroxide is used for industrial water treatment and is the precursor of potassium carbonate, several forms of potassium phosphate, many other potassic chemicals, and soap manufacturing. Potassium carbonate is used to produce [[animal feed]] supplements, [[cement]], [[fire extinguishers]], food products, [[Photographic processing|photographic chemical]]s, and textiles. It is also used in [[brewing]] [[beer]], pharmaceutical preparations, and as a [[catalyst]] for [[synthetic rubber]] manufacturing. Also combined with [[silica sand]] to produce [[potassium silicate]], sometimes known as [[waterglass]], for use in [[paints]] and [[arc welding]] electrodes. These non-fertilizer uses have accounted for about 15% of annual potash consumption in the United States.<ref name=usgs2/>

=== Substitutes ===
No substitutes exist for potassium as an essential plant nutrient and as an essential nutritional requirement for animals and humans.<ref name=":02" />{{Rp|page=143}} [[Manure]] and [[glauconite]] (greensand) are low-potassium-content sources that can be profitably transported only short distances to crop fields.<ref name=":0" />

==See also==
* [[Bone ash]]
* [[Saltpeter]]
* [[Saltwater soap]]
* [[Sodium hydroxide]]

==References==
{{Reflist|30em}}
* {{USGS|title=Potash|url=http://minerals.usgs.gov/minerals/pubs/commodity/potash/myb1-2008-potas.pdf}}

==Further reading==
* Seaver, Frederick J. (1918) [http://www.reynoldstonnewyork.org/category/history-of-a-mill-and-logging-community-in-the-northern-new-york-state/history-of-reynoldston-ny/making-potash-in-reynoldston/ "Historical Sketches of Franklin County And Its Several Towns"], J.B Lyons Company, Albany, NY, Section "Making Potash" pp.&nbsp;27–29

==External links==
* [https://web.archive.org/web/20110309031121/http://www.mpaulkeeslerbooks.com/Potash.html They Burned the Woods and Sold the Ashes]
* [https://www.inventionandtech.com/content/first-u-s-patent-1 Henry M. Paynter, ''The First Patent'', Invention & Technology, Fall 1990]
* [http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.htm&r=1&p=1&f=G&l=50&d=PALL&S1=1790$.PD.&OS=ISD/$/$/1790&RS=ISD/1790$$ The First U.S. Patent] {{Webarchive|url=https://web.archive.org/web/20160415181250/http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.htm&r=1&p=1&f=G&l=50&d=PALL&S1=1790%24.PD.&OS=ISD%2F%24%2F%24%2F1790&RS=ISD%2F1790%24%24 |date=2016-04-15 }}, issued for a method of potash production
* [https://web.archive.org/web/20060107214307/http://www.potashcorp.com/media/flash/world_map/ World Agriculture and Fertilizer Markets Map]
* [https://web.archive.org/web/20071006195305/http://www.atimes.com/atimes/Central_Asia/IH01Ag01.html Russia reaps rich harvest with potash]

{{Wood products}}
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[[Category:Potash| ]]
[[Category:Agricultural chemicals]]
[[Category:Fertilizers]]
[[Category:Industrial minerals]]
[[Category:Potassium]]
[[Category:Salts]]
[[Category:Types of ash]]