PROGRAMME

This work focuses on the local alkaline wastes of Estonia where different waste streams were studied for the performance testing of the fly ash based building blocks. Fly ash from oil shale direct combustion and wood fly ash from district heating plant were considered in the applications for utilizing both CO2 and combustion residues. These types of ashes contain Ca/Mg-oxides, silicates, or other metal oxides as candidate precursor materials for CO2 mineralization. Based on the results obtained from the performance testing of all compacted and carbonated (both with model flue gas and 100%CO2) samples, it can be concluded that flue gas curing can be an effective method for direct mineral carbonation of compacted fly ash blocks. The formation of carbonate phases in compact bodies lead to an increase in compressive strength. The rate limiting impact due to the low CO2 concentration in flue gas curing was negligible on the CO2 uptake level when elevated curing pressures were applied to the fly ash based compacts.