How sulfur is recovered
Most of the world's sulfur is now a by-product of cleaning up oil and gas, and it piles up in yellow stockpiles.
- stations
- 4
- things downstream
- 411
The short version
Sulfur is recovered in two main ways. Petroleum and natural gas, the main industrial sources, are stripped of sulfur compounds to meet fuel standards. Deep native deposits can be melted in place by pumping superheated water down a well, the Frasch process, and the liquid sulfur is brought up to cool into yellow solid.
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Strip it from oil and gas
Petroleum and natural gas carry sulfur compounds that must be removed before the fuel is used. The sulfur taken out is sold on, and since the late twentieth century this has been the main route.
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Melt it underground
In the Frasch process, three concentric pipes go down into a sulfur deposit. Superheated water at 165 °C goes down the outer pipe, melting the sulfur, which has a melting point of 115 °C.
165 °C water
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Lift the liquid sulfur
Compressed air in the inner pipe lifts the molten sulfur to the surface, where it is poured into tanks or vats to harden. The product is about 99.5% pure sulfur, light yellow.
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Mine the volcanic crust
Native sulfur is also found near hot springs and volcanic regions, along the Pacific Ring of Fire. Such volcanic deposits are mined in Indonesia, Chile and Japan.
Worth repeating
- In 1894 the chemist Herman Frasch devised his method to get sulfur out from under a layer of quicksand in Louisiana.
- The Frasch process can produce sulfur about 99.5% pure.
- Stockpiles of elemental sulfur from refining oil sands exist throughout Alberta, Canada.
Where it goes next
Sulfur feeds 12 lines directly and reaches 411 things in total.
Further down the line
Keep walking
Sources
Cite this page: "How sulfur is recovered." Assembly Line, 2026-11-03. https://assemblyline.org/make/sulfur