Effect of Potassium Carbonate Addition on the Sintered Properties of Coal Fly Ash

Coal fly ash was transformed into ceramic materials by adding a certain amount of fusing agent. Ash samples were compacted and sintered with the addition of potassium carbonate (K2CO3 center dot 1/2H(2)O) under a suitable sintering temperature range. Mineralogy and microstructure of the obtained products were characterized by means of X-ray diffraction and field emission scanning electronic microscope techniques respectively. The results indicate that K2CO3 center dot 1/2H(2)Ofacilitates the transformation of mullite and quartz phases above 800 degrees C, and the mineralogy phases of the product areleucite (KAlSi2O6) and potassium aluminum silicate (KAlSiO4). In the process, K+ interacts with oxygen atom and destroys the original lattice. The regular morphology of the sintered samples was confirmed by the observation under SEM, which reveals the uniform dense ceramic was formed at 900 degrees C with the 40wt% addition of K2CO3 center dot 1/2H(2)O.