Editing Hall–Héroult process (section)

===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>