Sulphuric acid
The most produced industrial chemical: a cheap strong acid made mostly by burning sulphur, essential for phosphate fertiliser, metal leaching and battery materials.
Commodity chemicals · Acids & alkalis · No. 1
- Single chemical
- Feedstock: Minerals and salts
- about 230 Mt a year (2025, derived: about 90% of 84 Mt sulphur in all forms consumed as acid x 3.06 t acid per t S); IndexBox records 131 Mt from reported national data (2024), which under-counts China
- 0.1 t CO₂e per t
- HS 280700
The world makes more sulphuric acid than any other chemical, and in 2026 its price in Chile doubled within two months.
Chart: Illustration: Sulphuric acid
Where it comes from
Chart: Map of where it comes from
Nearly all acid comes from the contact process, turning SO2 from burnt sulphur or smelter fumes into SO3 over vanadium; about 90% of the sulphur behind it is recovered from gas and refining.
Three things to know
- Each tonne of sulphur yields about 3 t of acid, so when sulphur jumped from $46/t in 2024 to $740/t in May 2026, acid followed.
- Smelter acid is a by-product with almost no feedstock cost, so it can trade near zero, or even negative, at the smelter gate.
- Chile imports the most acid, 3.6 Mt in 2024, because its copper leach mines cannot run without it.
The journey
- 1 Sulphur sourcesRecovered from sour gas, refineries, smelters
- 2 Burning or captureSulphur burnt, or smelter SO2 captured
- 3 Contact processSO2 turned to SO3 over vanadium
- 4 AbsorptionSO3 absorbed in strong acid, steam exported
- 5 ShippingPipeline, rail and 10-40 kt tankers
- 6 End useFertiliser, copper and nickel leaching, chemicals