MAXIMIZATION OF SIC WHISKER YIELD DURING THE PYROLYSIS OF BURNT RICE HUSKS

Studies have been made on the conversion of burnt rice husks to SiC over a wide temperature range. Four distinct processes (crystallization of silica and carbon, formation of SiC whiskers and particles) have been identified as occurring during the pyrolysis of burnt rice husks. The dependence of relative rates of these four reactions on the temperature has been ascertained through detailed X-ray diffraction, scanning electron microscopy, chemical analysis and marco structural study. It was also revealed that a multistep pyrolysis to 1310-degrees-C yields a higher SiC(w) than the single step pyrolysis. The yield of SiC(w) from burnt rice husks has been found to be lower than that from raw rice husks. A correlation between the amount of SiC(w) formed and the appearance of pyrolysed rice husks has been identified.