MICROWAVE SINTERING OF FLY-ASH

Class F flyash has been sintered by microwave and conventional process es. The sintering was carried out in a temperature range of 800 to 100 0 degrees C. Densities up to 2.2 g/cm(3), and diametral tensile streng th up to 26 MPa (corresponding diametral compressive strength 78 MPa) were achieved after sintering for 10-20 min. The microwave sintered sa mples were denser and thus stronger than the samples conventionally si ntered at the same temperature for the same time. The sintered bodies are glass-ceramic material, with mullite (Al6Si2O13) as the major crys talline phase.