Editing Hall–Héroult process (section)

==History==

===Existing need===
Aluminium is the most abundant [[metal|metallic element]] in the Earth's crust, but it is rarely found in its [[Native aluminium|elemental state]]. It occurs in many minerals, but its primary commercial source is [[bauxite]], a mixture of hydrated aluminium oxides and compounds of other elements such as iron.

Prior to the Hall–Héroult process, elemental aluminium was made by heating ore along with elemental [[sodium]] or [[potassium]] in a [[vacuum]].{{citation needed|date=September 2022}} The method was complicated and consumed materials that were in themselves expensive at that time. This meant that the cost to produce the small amount of aluminium made in the early 19th century was very high, higher than for [[gold]] or [[platinum]].<ref>{{Cite web |last=Kean |first=Sam |date=2010-07-30 |title=Aluminum: It Used To Be More Precious Than Gold |url=http://www.slate.com/articles/health_and_science/elements/features/2010/blogging_the_periodic_table/aluminum_it_used_to_be_more_precious_than_gold.html |access-date=2024-02-23 |website=Slate Magazine}}</ref> Bars of aluminium were exhibited alongside the French [[crown jewels]] at the [[Exposition Universelle (1855)|Exposition Universelle of 1855]], and [[Napoleon III of France|Emperor Napoleon III]] of France was said to have reserved his few sets of aluminium dinner plates and eating utensils for his most honored guests.<ref>{{cite web | url=https://www.latimes.com/archives/la-xpm-2001-sep-05-fo-42149-story.html | title=When Aluminum Plates Were Cool | website=[[Los Angeles Times]] | date=5 September 2001 }}</ref><ref>{{cite web | url=https://www.hollymelody.com/history/9/did-napoleon-iii-reserve-a-special-set-of-aluminum-cutlery-for-special-guests | title=Did Napoleon III reserve a special set of aluminum cutlery for special guests? }}</ref><ref>https://www.alcirclebiz.com/blogs/from-emperors-table-to-the-moon-the-fascinating-history-of-aluminium</ref>

Production costs using older methods did come down, but when aluminium was selected as the material for the cap/lightning rod to sit atop the [[Washington Monument]] in [[Washington, D.C.]] upon its completion in 1884, it was still more expensive than [[silver]].<ref>{{cite journal|author = George J. Binczewski|title = The Point of a Monument: A History of the Aluminum Cap of the Washington Monument|journal = JOM|volume = 47|issue = 11|pages = 20–25|year = 1995|url = http://www.tms.org/pubs/journals/JOM/9511/Binczewski-9511.html|bibcode = 1995JOM....47k..20B|doi = 10.1007/BF03221302|s2cid = 111724924}}</ref>

===Independent discovery===
The Hall–Héroult process was invented independently and almost simultaneously in 1886 by the [[United States|American]] chemist [[Charles Martin Hall]]<ref name="Hall-patent">{{US patent reference|number = 400664|y = 1889|m=04|d=02|inventor=[[Charles Martin Hall]] |title=Process of Reducing Aluminium from its Fluoride Salts by Electrolysis}}</ref> and by the [[France|Frenchman]] [[Paul Héroult]]<ref>Héroult, Paul; French patent no. 175,711 (filed:  23 April 1886; issued:  1 September 1886).</ref>—both 22 years old. Some authors claim Hall was assisted by his sister [[Julia Brainerd Hall]];<ref name = "Kass">{{cite book|editor1-last=Kass-Simon |editor1-first= Gabrielle|editor2-last=Farnes|editor2-first=Patricia|editor3-last=Nash|editor3-first=Deborah |title=Women of Science: Righting the Record|url=https://books.google.com/books?id=Ez7DCJM57esC&q=%22Julia+Brainerd+Hall%22&pg=PA173|year=1990|publisher= Indiana University Press|isbn=0-253-20813-0|pages=173–176}}</ref> however, the extent to which she was involved has been disputed.<ref name= "Sheller">{{cite book|last1=Sheller|first1=Mimi|title=Aluminum dreams : the making of light modernity|date=2014|publisher=MIT Press |location=Cambridge, MA|isbn=978-0262026826|page=270|url=https://books.google.com/books?id=VOjaAgAAQBAJ&pg=PA270|access-date=19 April 2016}}</ref><ref name="Giddens">{{cite journal|last1=Giddens |first1=Paul H.|title=Alcoa, An. American Enterprise. By Charles C. Carr. (Book review)|journal=Pennsylvania History|date=1953|volume=20|issue=2|pages=209–210 |url=https://journals.psu.edu/phj/article/view/22279/22048}}</ref> In 1888, Hall opened the first large-scale aluminium production plant in [[Pittsburgh]]. It later became the [[Alcoa]] corporation.

In 1997, the Hall–Héroult process was designated a [[National Historic Chemical Landmarks|National Historic Chemical Landmark]] by the [[American Chemical Society]] in recognition of the importance of the process in the commercialization of aluminum.<ref>{{cite web | title = Production of Aluminum: The Hall–Héroult Process | work = National Historic Chemical Landmarks | publisher = American Chemical Society | url = http://www.acs.org/content/acs/en/education/whatischemistry/landmarks/aluminumprocess.html | access-date = 2014-02-21 }}</ref>

===Economic impact===
Aluminium produced via the Hall–Héroult process, in combination with cheaper [[electric power]], helped make aluminium (and incidentally [[magnesium]]) an inexpensive commodity rather than a precious metal.

This, in turn, helped make it possible for pioneers like [[Hugo Junkers]] to utilize aluminium and [[Magnesium alloy#Aluminium alloys with magnesium|aluminium-magnesium alloys]] to make items like metal airplanes by the thousands, or Howard Lund to make aluminium fishing boats.<ref>{{cite web|url= https://www.in-depthoutdoors.com/community/forums/topic/ftlgeneral_69525/|title= Lund Boat Company Founder Dies at 91|date =October 24, 2003|website = In-Depth Outdoors}}</ref> In 2012 it was estimated that 12.7 tons of CO<sub>2</sub> emissions are generated per ton of aluminium produced.<ref name= "Das2012">{{cite journal|last1=Das|first1=Subodh|title=Achieving Carbon Neutrality in the Global Aluminum Industry|journal=JOM|volume=64|issue=2|year=2012|pages=285–290|issn=1047-4838|doi= 10.1007/s11837-012-0237-0 |bibcode=2012JOM....64b.285D|s2cid=59383624}}</ref>

In the 20th and 21st century the aluminum industry due to its large-scale requirements for cheap electricity has often been sited in locations where such electricity is available. For example Iceland, a country with no notable bauxite reserves and [[demographics of Iceland|a population]] of less than half a million, is the world's [[List of countries by aluminium production|twelfth largest aluminum producer]] due to the availability of [[energy in Iceland|cheap and plentiful]] electricity, particularly [[hydropower in Iceland|hydropower]]. Similarly [[Aluminerie Alouette]] in [[Sept-Îles, Quebec]] is dependent for its electricity needs on the 5,428 MW [[Churchill Falls Generating Station]] operated by [[Churchill Falls (Labrador) Corporation Limited]]. The [[company town]] of [[Kitimat]] in [[British Columbia]] was built by [[Alcan]] to meet the growing demand for aluminum in the postwar era. It makes use of the [[Kenney Dam]] built to power the smelters. The [[Tiwai Point Aluminium Smelter]] on the South Island of [[New Zealand]] consumes some 570 MW of electricity, most of which is supplied by nearby [[Manapōuri Power Station]]. This amounts to around a third of the electricity demand of South Island and 13% of that of the entirety of New Zealand. [[Borssele Nuclear Power Station]] was built primarily to supply electricity to an aluminum smelter operated by French [[Pechiney]] at the time.