How argon is separated from air
Argon is the third most abundant gas in the air we breathe, more than twice as plentiful as water vapor.
- stations
- 5
- things upstream
- 1
- raw source
- 1
- step from the ground
- 1
The short version
Argon makes up 0.934 percent of the atmosphere, and plants get it by liquefying air and distilling it. Air is filtered, compressed, cooled until liquid and then fed to tall cold columns where each gas boils off at its own temperature. Argon is drawn off along with oxygen and nitrogen.
-
Filter and compress the air
Air is pre-filtered for dust and compressed. Water condenses out between the compression stages.
Goes in -
Chill it to a liquid
Heat exchangers inside an insulated cold box cool the compressed air until it liquefies. Letting part of the compressed stream expand supplies the cold.
-
Boil it apart in columns
Liquid air is distilled so each component boils off at its own temperature. Nitrogen and oxygen leave at opposite ends of the column.
-
Draw off a side stream
Argon boils between nitrogen and oxygen, so it is drawn from the middle of the column. It is a side product of a plant that mainly makes the other two gases.
-
Polish and bottle the liquid
The crude side stream is purified again for demanding users such as semiconductor plants, then stored as liquid and filled into cylinders or tankers.
Worth repeating
- Argon's name comes from the Greek for lazy or inactive.
- Lord Rayleigh and Sir William Ramsay first isolated it from air in 1894.
- Argon shields welds and graphite furnaces from oxygen.
Back to the ground
Follow every input upstream and argon starts as these 1 raw source.
Open the whole family tree
Where it goes next
Argon feeds 7 lines directly and reaches 188 things in total.
Further down the line
Keep walking
Sources
Cite this page: "How argon is separated from air." Assembly Line, 2026-11-03. https://assemblyline.org/make/argon