Lime
Burnt limestone: a cheap, reactive alkali that steelmakers, chemical plants, power stations and water works quietly depend on.
Construction · No. 82
- Not on a critical list
Burn limestone and you get lime, the quiet chemical that steel mills, water works and power stations cannot run without.
Chart: Illustration: Lime
Where it comes from
Chart: Map of where it comes from
Lime is made, not mined: pure limestone is crushed and burned in kilns, which drives off CO2 and leaves quicklime. World output was 420 million t in 2025.
Three things to know
- China produced about 310 million t of lime in 2025, roughly three-quarters of the world's 420 million t.
- US quicklime prices nearly doubled between 2021 and 2025, from $132.8 to about $260 per tonne.
- Burning limestone releases about 0.75-0.79 t of CO2 per tonne from the rock itself, before any kiln fuel.
The journey
- 1 LimestoneHigh-calcium limestone or dolomite
- 2 QuarryQuarried and crushed
- 3 KilnBurned to quicklime, releasing CO2
- 4 HydrationOptionally slaked to hydrated lime
- 5 IndustrySteel, scrubbers, water works, chemicals