Editing Argon (section)

==Production==
Argon is extracted industrially by the [[fractional distillation]] of [[liquid air]] in a [[cryogenic]] [[air separation]] unit; a process that separates [[liquid nitrogen]], which boils at 77.3&nbsp;K, from argon, which boils at 87.3&nbsp;K, and [[liquid oxygen]], which boils at 90.2&nbsp;K. About 700,000 [[tonne]]s of argon are produced worldwide every year.<ref name="emsley" /><ref>
{{cite web
 |url=http://environmentalchemistry.com/yogi/periodic/Ar.html
 |title=Periodic Table of Elements: Argon – Ar
 |publisher=Environmentalchemistry.com
 |access-date=12 September 2008
}}</ref>