Classification and froth flotation of fly ash for producing high-quality pozzolan

Comparison of High-Unburned-Carbon Fly Ashes from Different Combustor Types and Their Steam Activated Products

“…The LOI values reported here are higher than those reported in previous studies that are typically <15 wt %. [10][11][12][15][16] However, this work focuses on the characterization of high-carbon fly ashes for their subsequent use as feedstock for activated carbons, and therefore, samples with high LOI contents were intentionally selected. Previous studies conducted by the authors have shown that the LOI values of fly ashes change significantly within the hoppers of the same unit at a power plant, where fly ashes from cool-side hoppers have generally higher LOI values (∼35-50 wt %) than those from the hot-side hoppers (∼10-15 wt %).…”

“…Applications in the cement and concrete industries utilized over 50% of the total ash marketed, followed by structural fills and waste stabilization applications. − An increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of these carbonaceous waste products from coal combustion. There are already various commercial technologies to separate the unburned carbon from the ash. , These separation techniques can generate ashes with carbon contents below 6% that are suitable for use in the cement industry, as well as concentrate the unburned carbon that could subsequently be used as feedstock for the production of AC. However, there are only a few studies that have looked into the activation of unburned carbon from coal-fired fly ash. − The treatment of flue gases by activated carbon from fly ash has been previously reported .…”

“…There are already various commercial technologies to separate the unburned carbon from the ash. 15,16 These separation techniques can generate ashes with carbon contents below 6% that are suitable for use in the cement industry, as well as concentrate the unburned carbon that could subsequently be used as feedstock for the production of AC. However, there are only a few studies that have looked into the activation of unburned carbon from coal-fired fly ash.…”