MgCl2-YCl3 혼합 용융염 중 Mg을 이용한 Off-grade Ti 스펀지의 탈산 거동 = Deoxidation of Off-grade sponge in YCl3-MgCl2 Molten Salt by Molten Mg

다국어 초록 (Multilingual Abstract)

Ti has high specific strength and relatively low density compared to other metals and it also has excellent corrosion resistance. so, It is used in many fields including aerospace, chemical plant. However, A large amount of off-grade Ti sponge with high oxygen contnet is generated During smelting and processing. So it is necessary to carry out the deoxidation research in order to improve the utilization of off-grade Ti sponge.
In this work, off-grade Ti sponge was deoxidized using Mg and a chloride mixture as the reductant and flux, respectively. the effects of the reaction time, reaction temperature, quantitiy of Mg, chloride ratio and pickling condition on deoxidation were investigated. Notably, when YCl3 is used as the flux to react with MgO, it is possible to reduce the activity of MgO. Therefore Ti can be deoxidized using Mg.
When the mole fraction of YCl3 in chloride was 0.8, the oxygen concentration of the Ti sponge was deoxideized to 0.085 wt% at 1,073 K, 15 hours.
Since Ti deoxidation limit is lower at low temperature through thermodynamic calculations, Lower oxygen content in Ti was obtained at low temperature. The oxygen content in Ti was deoxidized to 0.082 wt% at 15 h, =0.22, 973 K, . At high temperature, on the other hand, the deoxidation limit is high. So the oxygen contnent in Ti was 0.499 wt%, similar to the initial oxygen content, because by-products were trapped in Ti particles due to sintering and could not be removed during the water and pickling process.

목차 (Table of Contents)

• Ⅰ. 서론 1
• Ⅱ. 문헌 고찰 6
• 2.1 Ti 내 O의 확산 6
• 2.2 Ti-O 고용체의 열역학적 특성 9
• 2.3 금속 Ti의 탈산 11
• 2.3.1 칼슘을 이용한 Ti의 탈산 11
• 2.3.2 마그네슘을 이용한 Ti의 탈산 14
• 2.3.3 희토류 금속을 이용한 Ti의 탈산 17
• 2.3.4 전해 탈산 21
• 2.4 반응 생성물 제거를 위한 수,산세 22
• Ⅲ. 실험 방법 24
• 3.1. 시료 24
• 3.2. 실험 장치 29
• 3.3. 실험 절차 31
• Ⅳ. 결과 및 고찰
• 34
• 4.1 탈산 반응에 대한 열역학적 해석 34
• 4.1.1 Ti 탈산에 사용될 수 있는 금속의 종류 34
• 4.1.2 Mg을 이용한 Ti의 탈산 원리 38
• 4.2 탈산에 미치는 반응 조건의 영향 47
• 4.2.1 탈산에 미치는 반응 온도의 영향 47
• 4.2.2 부산물 제거를 위한 수, 산세의 영향 50
• 4.2.3 탈산에 미치는 Mg의 영향 58
• 4.2.4 탈산에 미치는 YCl3의 영향 64
• 4.2.5 탈산에 미치는 반응 온도의 영향 70
• Ⅴ. 결론 75
• 참고문헌 77
• 영문초록 85