PRODUCTION OF SILICON NITRIDE AND THE PRODUCT THEREBY OBTAINED

摘要

A process for the production of silicon nitride by the reaction of silicon and nitrogen, wherein, in the reaction step, silicon powder is reacted with nitrogen with continuous rolling round at a temperature of from 1000 to 1800.degree.C. and at a pressure of from 1.01 to 1.8 bar up to a nitrogen content of 1 to 39.5% by weight, and a silicon nitride which is produced by such process which is of porous form and has the following properties: a) grain size of 0.1 to 20 mm., b) nitrogen content of 1 to 39.5% by weight, c) oxygen content of <1%, d) ratio of .alpha.:.beta.-phase of 1:9 to 9:1.