Ibigawa Electric Industry Co., Ltd.

Takao Yokoyama

Ryo Enomoto

Mitihiro Yoshioka

Michihiro Yoshioka

.beta.-type silicon carbide having exceedingly high purity is stably and continuously produced in an apparatus comprising a vertical type reaction vessel having an inlet, a preheating zone, a heating zone, a cooling zone and a closable outlet which are sequentially communicated in this order in vertical direction, and a heat insulating layer composed essentially of fine powders of graphite and carbonaceous materials arranged on at least outside of the heating zone, the heating zone of the reaction vessel being made of graphite and having a heating means to indirectly and electrically heat charged materials, the preheating zone having a horizontal cross-sectional area larger than that of the heating zone at any level above an arbitrary position of the preheating zone.

Apparatus for producing silicon carbide consisting mainly of .beta.-type

An apparatus for producing silicon carbide consisting mainly of .beta.-type crystal are disclosed. The fine silicon carbide consisting mainly of .beta.-type crystal is produced by charging the starting material of silica and carbon with a mole ratio of C/SiO.sub.2 of 3.2-5.0 into a top portion of a vertical-type reaction vessel having a preheating zone, a heating zone and a cooling zone in this order, descending the starting material by gravity through the reaction vessel, heating the starting material in the heating zone at a temperature of 1,600.degree.-2,100.degree. C. by electrically indirect heating in horizontal direction to effect the formation of SiC, cooling the resulting reaction product in the cooling zone under a non-oxidizing atmosphere, and recovering the cooled product from the bottom portion of the reaction vessel to obtain a product having a composition ratio by weight of silicon carbide, silica and free carbon which lies within the area represented by the area ABCD shown in Fig. 1 of the accompanying drawings.

Apparatus for producing silicon carbide

A process and an apparatus for producing silicon carbide consisting mainly of .beta.-type crystal are disclosed. The fine silicon carbide consisting mainly of .beta.-type crystal is produced by charging the starting material of silica and carbon with a mole ratio of C/SiO.sub.2 of 3.2-5.0 into a top portion of a vertical-type reaction vessel having a preheating zone, a heating zone and a cooling zone in this order, descending the starting material by gravity through the reaction vessel, heating the starting material in the heating zone at a temperature of 1,600.degree.-2,100.degree. C. by electrically indirect heating in horizontal direction to effect the formation of SiC, cooling the resulting reaction product in the cooling zone under a non-oxidizing atmosphere, and recovering the cooled product from the bottom portion of the reaction vessel to obtain a product having a composition ratio by weight of silicon carbide, silica and free carbon which lies within the area represented by the area ABCD shown in FIG. 1 of the accompanying drawings.

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Ohgaki, Japan

Takao Yokoyama