CO2 mineralization

Permanently storing carbon dioxide by reacting it with calcium or magnesium to form stable carbonate minerals.

• CO2 plus calcium or magnesium yields carbonates such as limestone; nature does this through slow rock weathering.
• Injected into fresh concrete, CO2 reacts with the cement to form nanoscale calcium carbonate that stays locked in the structure and can add strength.
• The CO2 stored per cubic metre is small; the larger benefit is using less cement, which causes about 7–8% of global CO2 emissions.
• In Iceland, Carbfix injects CO2 dissolved in water into basalt, where most of it turns to stone within about two years.