Carbon dioxide sequestration by conversion to carbonates has become a promising option for CO 2 storage. Experiments were conducted to determine the feasibility of CO 2 sequestration at ambient conditions using a Ca-rich industrial waste in a carbonate solution. The Ca-rich industrial waste used in this study was lignite fly ash. Fly ash was chosen because it is cheap, available near large CO 2 point sources, already in powder form, and reactive due to amorphous properties. In the experimental set-up, CO 2 absorption was inferred by monitoring feed and exhaust gas CO 2 concentrations. The addition of an alkali to a fly ash-distilled water solution provided a 50% increase in CO 2 absorption of the solution. Absorption time also increased by 50% compared to a fly ash-distilled water solution. TGA analysis was used to determine the extent of CO 2 sequestration in the carbonate form. At a liquid to solid ratio of 20:1, the conversion of "free" calcium to carbonates was 75%. A CO 2 balance on the system concluded that at the current operating conditions 42% of the total CO 2 fed to the system was sequestered in the carbonate form. SEM-EDS analysis of the fly ash particles before and after reaction with CO 2 indicated that the carbonate compound being formed was calcium carbonate. The analysis identified rhomboidal structures on the surface of the fly ash particles after reaction with CO 2,but not before. These rhomboids are characteristic of calcium carbonate formation and they had higher Ca, C, and O concentrations than the host spheres, suggesting calcium carbonate formation.