Porous silicon dioxide-carbon composite and method for preparing high-purity granular beta-phase silicon carbide powder with using the same

Abstract

The present disclosure relates to porous silicon dioxide-carbon composites and a method for preparing high-purity β-phase silicon carbide granular powders using the same. More particularly, it relates to a method for preparing high-purity β-phase silicon carbide granular powders in accordance with a first step of preparing gel wherein carbon compounds are uniformly dispersed in silicon dioxide network structures generated by a sol-gel process using a silicon compound and a carbon compound in a liquid state as raw materials, a second step of preparing porous silicon dioxide-carbon composites, in which the carbon compounds are solidified, dried and then thermally treated to have a high specific area, and a third step of conducting both of a direct reaction between carbon and metallic silicon and a carbothermal reduction between carbon and silicon dioxide through a two-step treatment process of the prepared porous silicon dioxide-carbon composites powders with the added metallic silicon, wherein the average particle size, particle size distribution and purity of the silicon carbide powder can be adjusted by controlling a heating rate, a heat treatment temperature and time during the heat treatment process.