Carbonation of lignite fly ash at ambient T and P in a semi-dry reaction system for CO2 sequestration

► The carbonation of lignite fly ash was achieved under semi dry conditions at low temperature and pressure conditions. ► Highest CO2-uptake was reached for intermediate liquid-to-solid ratios of 0.12-0.18 L kg−1. ► Increasing mixing intensity or pCO2 caused higher carbonation rates, suggesting limitation by CO2 supply. ► Up to 4.8 mmol CO2 g−1 were absorbed, corresponding to 53% of the theoretical CO2 binding capacity of the material. ► Both Ca and Mg containing phases were converted into carbonate minerals.