Thermogravimetric analysis on Kapar coal power plant fly ashes / Nur Nazirah Ramlan

Increasing amount of municipal solid waste from coal residues such as fly ash and bottom ash has caused environmental issues and affecting human's health. Researchers came out with an idea of manufacturing concrete using fly ash because of its pozzolan characteristics. However, the unburned carbon in fly ash absorbs air entraining agents that are used to stabilize air bubbles in concrete formulation. Determining the amount of unburned carbon in fly ash helps in maintaining the workability and cohesion mixing of concrete by adding correct amount of air entraining agent. Thermal analysis on 45 um and 100 um fly ashes were carried out using thermogravimetric analysis to obtain accurate data of unburned carbon in fly ash. Fly ashes were burned in three different conditions and each condition was observed in order to identify which method can be used to determine the amount of unburned carbon precisely. Burning of fly ash in (i) oxidising atmosphere determine the weight loss due to water evaporation and carbon reaction with oxygen which produced carbon dioxide and in (ii) nitrogen gas, carbon is consumed in iron reduction reaction at elevated temperature and lastly (iii) proximate condition showed 1.08 % unburned carbon in 45 um and 3.66% in 100 um which can be concluded that bigger fraction of fly ash consist higher content of unburned carbon and proximate condition is the most reliable method to determine the amount of unburned carbon.