Synthesis of silicon carbide from rice husk in a dc arc plasma reactor

SiC particles have been synthesized in the alpha-phase from a mixture of boiler-burnt rice husk and graphite powder in a de extended are plasma reactor on a 200-250 g scale. A SiC yield as high as 72% was achieved at a 3.03:1 carbon-to-silica ratio. 21R polytypism, which is rare to grow, was observed in the SiC. About 90% of the SiC particles produced were found to lie under 163 mu m, 50% under 90 mu m, and 10% under 28 mu m size. Very fine particles under 10 pm size occurred to the extent of 3%. XRD and SEM characterizations mere carried out to study the phase and morphology of the particles. Heterogeneous gas-phase reactions seem to be responsible for intermediate-size SiC particle growth in the multitemperature zone dc extended are plasma reactor.