초록 ▼

최종목표:
- Mg 용융염전해 제련 상용화 기반기술 확립 : 99% Mg 잉곳트 연속 제조 semi-pilot 설치 및 시운전
- 마그네슘 빌렛 연속주조 기술 개발 및 사업화 준비
개발내용 및 결과:
- 마그네사이트 광석을 처리하여 720oC 고온에서 용융염전기분해해서 순도 99.5%의 Mg 금속을 제조하였으며, 스케일업 연구를 통해서 상용화 기반기술을 확립함
- 전자기교반 용해주조기술을 이용하여 6“-12”의 Mg 빌렛을 연속주조하는 기술을 개발하고 양산 사업화를 준비함
기술개발배경:
자동차

최종목표:
- Mg 용융염전해 제련 상용화 기반기술 확립 : 99% Mg 잉곳트 연속 제조 semi-pilot 설치 및 시운전
- 마그네슘 빌렛 연속주조 기술 개발 및 사업화 준비
개발내용 및 결과:
- 마그네사이트 광석을 처리하여 720oC 고온에서 용융염전기분해해서 순도 99.5%의 Mg 금속을 제조하였으며, 스케일업 연구를 통해서 상용화 기반기술을 확립함
- 전자기교반 용해주조기술을 이용하여 6“-12”의 Mg 빌렛을 연속주조하는 기술을 개발하고 양산 사업화를 준비함
기술개발배경:
자동차 산업과 IT 부품산업에서 경량화 재료에 요구로서 마그네슘의 대한 수요가 증가를 대비하고, 남북경협시 북한자원의 활용방안을 마련함
핵심개발기술의 의의:
국내 최초로 마그네슘 제련기술과 Mg 빌렛 제조기술 개발이며, 향후 남북 자원개발 협력시에 활용방안 제시가 가능함
적용분야:
비철금속제련, 자동차, IT용 경량합금 소재부품산업, 스포츠레져산업 등

Abstract ▼

Results and Achievements
1. Magnesite Ore Processing
Composition of MgO in the raw ore was 44.9% with small amount of impurities such as SiO₂ 1.24%, Al₂O₃ 0.08%, Fe₂O₃ 0.23%, CaO 1.3% K₂O 0.06%, Na₂O 0.03%. Those impu

Results and Achievements
1. Magnesite Ore Processing
Composition of MgO in the raw ore was 44.9% with small amount of impurities such as SiO₂ 1.24%, Al₂O₃ 0.08%, Fe₂O₃ 0.23%, CaO 1.3% K₂O 0.06%, Na₂O 0.03%. Those impurities were originated as gangue minerals such as dolomite, clinochlore, talk and quartz. The ore was crushed by pulverizer at first, and ground to smaller size followed by classification by use of ball mill and pin mill. The pin mill was more effective than the ball mill. Productivity of concentrate of the ore over 39㎛ size was 49.1% with 47.1% MgO concentration under 13,000rpm of the crushing media of the pin mill. This result shows that up-grade of the magnesite ore could be possible through simple grinding and classification of the size.
The crushed ore powder was clacined to make it into magnesium oxide. The ore started to decompose at 350oC and finished at near 700oC. Magnesium oxide with 98.5% MgO could be prepared through the optimum calcining at 750oC for 30 minutes.
2. Preparation of Anhydrous Magnesium Chloride
Concentrated magnesite was dissolved at the hydrochloric acid solution to form aqueous magnesium chloride solution. Some undissolved impurities could be removed by precipitation through pH adjustment and filtration. At this step, ammonium chloride was charged to make ammonium magnesium chloride hydrate(NH₄MgCl₃․nH₂O) instead of magnesium chloride hydrate(MgCl₂․nH₂O). The dissolved solution was concentrated by heating and drying, and then dehydrated to anhydrous magnesium chloride(MgCl₂).
Anhydrous magnesium chloride with 99% purity could be prepared through dehydration of MgCl₂․nH₂O with heating at 500℃ for 30 minutes under hydro chloride gas atmosphere. In case of dehydration of NH₄MgCl₃․nH₂O, anhydrous magnesium chloride with 99% purity could be also prepared through dehydration of it with heating at 300℃ for 90 minutes under air atmosphere.
3. Preparation of Magnesium through Fused Salt Electrolysis
Metallic magnesium was prepared by fused salt electrolysis of the anhydrous magnesium chloride at about 750oC. It was formed at the surface of cathod and floated at the free surface of the molten salt, and chlorine gas was generated at the anode. The optimum composition of electrolyte was NaCl 50~60%, CaCl₂ 15~25%, MgCl₂ 20~25%. The KIGAM cell was originally designed in consideration of current efficiency and convenience of the operation. Metallic magnesium with 99.5% purity could be prepared for 24 hours operation by use of the mono-polar type KIGAM cell with 150A. 89% of current efficiency could be achieved and power consumption was 17.2 kWh/kg-Mg. Those results showed good agreement to that of the reported commercial operations.
4. Scale-Up Test for the Overall Process
The unit processes such as preparation of magnesium chloride hydrate, anhydrous magnesium chloride, fused salt electrolysis was scaled up five times to confirm the laboratoy test results. The scaled up equipments were originally designed and manufactured. In the scale up test, the ammonium magnesium chloride(NH₄MgCl₃․2H₂O) was prepared instead of MgCl₂․6H₂O for making anhydrous magnesium chloride. Molten magnesium with 99% purity could be prepared for 24 hours operation by use of the mono-polar type KIGAM cell with 300A. 85% of current efficiency could be achieved at the scale-up test. The result showed good agreement with the lab scale experiments.
5. Preparation of Magnesium Ingot and Alloying
The composition of magnesium clod produced by electrolysis of molten salt was quantitatively evaluated by using ICP. Production technology of magnesium ingot using magnesium clod produced by electrolysis of molten salt was developed and the refining technologies were also developed in order to improve the quality of magnesium ingot through addition of additives and Ar gas bubbling. The stability of magnesium melt surface was evaluated under various conditions. Rapid ignition or combustion was not occurred but localized ignition was occurred when the amount of SF₆ gas was small or melt temperature was high. The optimum melt protection condition with small use of SF₆ shield gas was determined on the basis of experimental results and the discharge of green house gas was reduced more than 5 times.
Also, the control technology of the amount of non-metallic inclusions was developed through Ar gas bubbling into the magnesium melt. Amount of non-metallic inclusions and casting defect in the gravity cast magnesium treated by Ar gas bubbling was dramatically reduced.
6. Technology Development for Continuous Casting of Magnesium Alloy Billet
Light, functional and nonflammable magnesium alloy billets and energy-saving components using this magnesium billets were developed. In order to improve the resistance to flame of magnesium melts, calcium element was added to magneisum melts and ignition wassuccessfully retarded. Mechanical properties of this alloy was characterized and its strength and elongation is fully satisfied as a wrought alloy. We developed lab-scale magnesium billet continuous casting apparatus and magnesium billets were successfully fabricated. Electromagnetic casting and stirring technique was applied to improve the surface and internal quality of billets. Electromagnetic casting uses high frequency electromagnetic wave to induce induction heating and non-contact casting. Electromagnetic stirring casting used low frequency electromanetic wave to induce circulation of melts. The apparatus such as melting furnace, tundish, cooling water system, casting speed control system and so on were also adopted to integrate continuous casting equipment. In order to scale up this technology, automatic billet cutting and transferring system was developed. The experimental condition for sound magnesium billets was obtained from lab-scale equipment and proved that it can be applied to pilot-scale process. Using magnesium billets, we applied extrusion and forging technique to produce prototype magnesium products. The pully for automotive engine blocks, seamless pipe, sunroof guide-rail, and automotive door hinge were fabricated and estimated for commercial use. In phase 2, this technology will be commercialized by participant company.

목차 Contents

• 표지 ... 1
• 제출문 ... 3
• 최종보고서 초록 ... 4
• 연구개발사업 주요 연구성과 ... 7
• 요약문 ... 10
• SUMMARY ... 15
• Contents ... 21
• 목차 ... 22
• 제 1 장 서론 ... 23
• 제 1 절 개발기술의 중요성 및 필요성 ... 23
• 제 2 절 국내․외 관련 기술의 현황 ... 26
• 제 3 절 기술개발시 예상되는 파급 효과 ... 36
• 제 2 장 기술개발 내용 및 방법 ... 38
• 제 1 절 최종 목표 및 평가 방법 ... 38
• 제 2 절 단계 목표 및 평가 방법 ... 40
• 제 3 절 년차별 개발 내용 및 개발 범위 ... 42
• 제 3 장 결과 및 사업화 계획 ... 46
• 제 1 절 연구개발 최종 결과 ... 46
• 1. 연구개발 추진 일정 ... 46
• 2. 연구개발 추진 실적 ... 50
• 3. 기술개발 유무형 성과 ... 53
• 제 2 절 연구개발 추진 체계 ... 58
• 제 3 절 시장 현황 및 사업화 전망 ... 61
• 참고문헌 ... 67
• 끝페이지 ... 67