Our Icelandic partner Carbfix has demonstrated that over 95% of CO2 captured and injected at Hellisheidi Geothermal Power Plant is mineralized within two years. The remaining 5% turns into stone shortly thereafter.
Mineralization is so quick because dissolution of CO2 prior to or during injection ensures that chemical reactions between host rock and injected fluid begin to take place immediately after injection. The high reactivity and chemical composition of the basaltic host rock (lots of calcium, magnesium and iron that can combine with the injected CO2 to form stable carbonate minerals) play an even larger role in the efficiency of permanent mineral storage in basalts (see Carbfix FAQs for more info).