탄소환원에 의한 Zircon으로 부터 고순도 Zirconia 제조에 관한 연구

Abstract

감압하에서 지르콘사를 탄소환원하므로 지르코니아의 고순도화에 대한 연구를 하였다.

지르콘과 탄소의 혼합물을 1 Torr의 진공로 중에서 가열함으로써, 지르콘 중의 SiO₂는 SiO(g)로 제거되었으며, 이 SiO(g)는 로의 낮은 온도 구역에서 미세한 백색 무정형 분말인 SiO(s)로 응축되었다.

생성된 지르코니아에는 미량의 탄소, ZrO 그리고 ZrC등이 존재하였으나, 공기중에서 산화 반응후에는 지르코니아 단일상으로 되었다.

단일상 지르코니아는 1500℃, C/SiO₂몰비 1.0 일때 SiO₂의 함유량이 가장 작았다.

이러한 공정의 반응 생성물은 XRD, SEM-EDX 및 습식방법 등에 의해서 분석하였으며,

지르코니아 분말의 순도는 99.8%이었고 결정구조는 단사정이었다.

A production technics of high-purity ZrO₂ powder from zircon (ZrO₂· SiO₂) were investigated by carbothermic reduction under reduced pressure.

The mixture of zircon and carbon was heated in the range of 1200℃ to 1500℃ in

vaccum furnace under the condition of 1 Torr. The reaction product for the process was examined by XRD, SEM-EDX, and chemical analysis.

By this techniques, the SiO₂ in zircon was removed as SiO(g). The generation of SiO(g) from a Zircon/Carbon mixture at high temperature to was greatly enchanced by reduction of pressure compared to atmospheric. Zirconia powder contaminated with a small amount of carbon, ZrO, and ZrC was obtained before oxidation reaction.

Single-phase ZrO₂ was obtained after oxidation reaction of Zirconia powder when the the C/SiO₂ mole ration in the Zircon/Carbon mixture was 0.5∼2.0. The SiO₂content in ZrO₂ powder was minimized at a C/SiO₂ ratio of about 1.0.

The monoclinic phase zirconia powder with a high purity of 99.8% and fine grain size was obtained.

The SiO(g) generated in the process condensed as a fine white amorphous powder in the low-temperature zone of the vaccum furnace, having an ultrafine grain size.

A production technics of high-purity ZrO₂ powder from zircon (ZrO₂· SiO₂) were investigated by carbothermic reduction under reduced pressure.

The mixture of zircon and carbon was heated in the range of 1200℃ to 1500℃ in

vaccum furnace under the condition of 1 Torr. The reaction product for the process was examined by XRD, SEM-EDX, and chemical analysis.

By this techniques, the SiO₂ in zircon was removed as SiO(g). The generation of SiO(g) from a Zircon/Carbon mixture at high temperature to was greatly enchanced by reduction of pressure compared to atmospheric. Zirconia powder contaminated with a small amount of carbon, ZrO, and ZrC was obtained before oxidation reaction.

Single-phase ZrO₂ was obtained after oxidation reaction of Zirconia powder when the the C/SiO₂ mole ration in the Zircon/Carbon mixture was 0.5∼2.0. The SiO₂content in ZrO₂ powder was minimized at a C/SiO₂ ratio of about 1.0.

The monoclinic phase zirconia powder with a high purity of 99.8% and fine grain size was obtained.

The SiO(g) generated in the process condensed as a fine white amorphous powder in the low-temperature zone of the vaccum furnace, having an ultrafine grain size.