ISSN:
0001-1541
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Carbothermal reduction kinetics to synthesize SiC is studied under conditions of high carbon/silica precursor heating rates (105 K/s) and minimized reaction times (s) over a wide temperature range (1,848≤T≤2,273 K). The reaction mechanism includes rapid formation of a gaseous SiO intermediate. Further carbon reduction of the SiO to SiC is reaction-rate-controlling. Carbon crystallite diameter, d, has a substantial influence on the rate of reaction and the size of synthesized SiC. Fractional oxide conversion, X, can be described by a contracting volume shrinking core model: \documentclass{article}\pagestyle{empty}\begin{document}$$ k = \frac{{1 - (1 - X)^{1/3} }}{t} = \frac{{k_o }}{d}\,\exp \,(- E/RT) $$\end{document} where k0 = 27.4 m/s and E = 382±34 kJ/mol.
Additional Material:
13 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aic.690390311
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