公开(公告)号：US09994454B2

公开(公告)日：2018-06-12

申请号：US15075751

申请日：2016-03-21

Applicant: KOREA INSTITUTE OF SCIENCE AND TECHNOLOGY

Inventor： Sang Whan Park ,  Mi Rae Youm ,  Sung Il Youn ,  Gyoung Sun Cho

IPC: C01B31/36 ,  C01B32/956

CPC classification number: C01B32/956

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.

公开(公告)号：US10106423B2

公开(公告)日：2018-10-23

申请号：US15072724

申请日：2016-03-17

Applicant: KOREA INSTITUTE OF SCIENCE AND TECHNOLOGY

Inventor： Sang Whan Park ,  Mi Rae Youm ,  Sung Il Youn ,  Gyoung Sun Cho

IPC: C01B21/06 ,  C01B31/36

Abstract: The present invention relates to a method for preparing an ultrahigh-purity silicon carbide powder, more particularly to a method for preparing an ultrahigh-purity silicon carbide granular powder by preparing a gel wherein a silicon compound and a carbon compound are uniformly dispersed via a sol-gel process using a liquid state silicon compound and a solid or liquid state carbon compound of varying purities as raw materials, preparing a silicon dioxide-carbon (SiO2—C) composite by pyrolyzing the prepared gel, preparing a silicon carbide-silicon dioxide-carbon (SiC—SiO2—C) composite powder via two-step carbothermal reduction of the prepared silicon dioxide-carbon composite, adding a silicon metal and then conducting carbonization and carbothermal reduction at the same time by heat treating, thereby growing the synthesized silicon carbide particle with an increased yield of the silicon carbide.