초록 ▼

본 연구 사업은 반도체용 실리콘 웨이퍼 절단 공정에서 부산물로 발생하는 실리콘 슬러지의 재활용 기술개발을 목적으로 2006년부터 2010년까지 3단계 연구가 진행되었으며 그 주요 연구 결과는 다음과 같음.
-실리콘 슬러지로부터 입자크기 30nm 이하의 고부가가치 소재인 실리카 나노분말의 제조를 위하여 파일롯 규모(50kg/일) 연구를 통해 실리콘화합물 합성장치, 실리콘화합물 정제장치, 실리카 나노분말 제조 장치 및 실리카 나노분말의 표면개질 장치 시작품들을 설치 한 후 시운전 및 현장 실험을 통해 최적 조업 조건을 도출하였음.

본 연구 사업은 반도체용 실리콘 웨이퍼 절단 공정에서 부산물로 발생하는 실리콘 슬러지의 재활용 기술개발을 목적으로 2006년부터 2010년까지 3단계 연구가 진행되었으며 그 주요 연구 결과는 다음과 같음.
-실리콘 슬러지로부터 입자크기 30nm 이하의 고부가가치 소재인 실리카 나노분말의 제조를 위하여 파일롯 규모(50kg/일) 연구를 통해 실리콘화합물 합성장치, 실리콘화합물 정제장치, 실리카 나노분말 제조 장치 및 실리카 나노분말의 표면개질 장치 시작품들을 설치 한 후 시운전 및 현장 실험을 통해 최적 조업 조건을 도출하였음.
-파일롯 규모 실험 장치를 통해 제조된 실리카 나노분말 시제품의 응용시험을 위해 실리카 나노 다공체의 약물방출 시험 및 고분자 수지의 표변 경도 향상을 위한 코팅시험을 수행하여 우수한 결과를 얻었음.
-실리카 나노분말 제조 반응에 대한 수치해석 연구를 국제 공동연구로 수행하여 반응기 설계자료를 확보하고 년간 500톤 규모의 실리콘을 처리하는 공정에 대한 장치설비를 검토한 후 따른 경제성 분석을 수행하였음.
-실리콘카바이드를 활용한 열 및 전기 전도성 다공성 복합소재 제조, 물성평가 및 응용실헝을 수행하였음(위탁)
(출처 : 보고서 요약서 5p)

Abstract ▼

IV. Results and Discussion
1. Synthesis of silica nanopowder from silicon sludge employed with pilot- scaled reactors
1) Basic criteria for designing the pilot-scaled reactors for the synthesis of silica nanopowder from silicon sludge
- The pilot-scaled reactors for the synthesis of silica

IV. Results and Discussion
1. Synthesis of silica nanopowder from silicon sludge employed with pilot- scaled reactors
1) Basic criteria for designing the pilot-scaled reactors for the synthesis of silica nanopowder from silicon sludge
- The pilot-scaled reactors for the synthesis of silica nanopowder less than 30 nm in diameter from silicon sludge were designed with a capacity of 50 kg per day.
- The flow diagram of the process for the synthesis of silica nanopowder from silicon sludge is as follow;
2) Synthesis and purification of TMOS from silicon sludge
- Potassium alkoxide, chemical catalyst of high boiling point, was prepared by chemical reaction with the pilot-scaled chemical reactors. Silicon alkoxides, tetramethylorthosilicate(TMOS), was synthesized by a reaction between silicon and methanol by using the catalyst.
- For the preparation of chemical catalyst, a reactor of 200 liter was installed and 99% of reaction recovery was obtained at the optimum reaction condition.
- In the presence of the catalyst, TMOS was synthesized by the reaction between silicon and methanol. The yield of reaction was 95% at the optimum condition. The synthesized silicon alkoxides were purified to 90% by distillation.
3) Synthesis of silica nanopowder from the TMOS
- Silica nanopowder was synthesized from the synthesized TMOS by the flame spray pyrolysis with a pilot-scaled reactor. The average particles dimeter was less than 30 nm with a flam reactor which has been installed with a capacity of 50 kg/day.
- Through a test operation, the flame reactor system was modified to improve the efficiency by changing couple of paπs such as the fabric of bag filter, electrical control valve and cooling jacket.
- Optimum condition for the synthesis of silica nanopowder of 20 nm in the average diameter was determined by changing process variables such as TMOS concentration and gas composition of the f1ame which has a capacity of 50kg/day.
4) Scale-Up Process Simulation, Nanopowder Production
- A mathematical model that computes the f1uid flow, flame temperature, chemical species concentrations, motion and vaporization of liquid droplets and silica particle size distribution at any position inside a f1ame reactor was developed. This model is based on the computational fluid dynamics (CFD) approach in which computers are used to solve complex multiphase fluid dynamics problems accompanied by heat and mass transfer and chemical reactions.
- A comprehensive CFD model for the flame synthesis process of silica nanopowder from volatile precursors was developed. The model was validated by comparing experimental and predicted average particle sizes for the flame reactors. As a result, the model is ready to be used in the design, optimization and scale-up of industrial-size flame reactors.
5) Surface treatrnent of silica nanopowder
- Modification of surface propeπy of silica nanopowder from hydrophilic to hydrophobic was conducted by aerosol drying process with a pilot-scaled reactor (10kg/day). As the best surface modifier, Trimethyl Chloro Silane (TMCS) was chosen as the best surface modifier and more than 40% of hyrdophobicity was obtained at the optimum process condition.
6) Application of silica nanopowder
- Nanoporous silica particles which have different pore size and volume were prepared from a colloidal mixture of the hydrophilic silica particles by a aerosol self assembly method. The prepared nanoporous silica particles were employed as a drug carrier to investigate the release behaviors of methylene blue (MB) as a model drug for a selected period of time. As pore volume of the nanoporous particles increased, the release rate of MB increased. The release of MB from the porous particles was maintained for 400 hours.
- Hydrophobic silica nanopowder was applied to additives of coating agent for polymer panel. The coating onto the polymer panel was conducted using a colloidal mixture of the silica particles, solvent and organic coating agent. The polymer panel coated with hydrophobic silica nanopowder exhibited a transparent film and enhanced surface hardness due to the well dispersion of the silica nanopowder in the coating solution.

2. Fabrication of SiC based ceramic composite
- Synthesis and characterization of SiC based porous ceramic composite was conducted from the waste SiC powder with a collaboration with professor Lee at Suncheonhyang University.
- Porous ceramic (Si3N4-SiC) composite materials were fabricated by fibrous mono-lithic method. A suitable sintering additive was developed for SiC based composite. The microstructure and materials propertiεs werε characterized for the optimum design.
- SiC-Si³N⁴/AIN and SiC-Si³N⁴/TiN composites which has high thermal and electrical conductivity were fabricated, respectively. Mechanical properties and microstructural characteristics were evaluated and optimized. Three dimensional porous or network structure with SiC/Si³N⁴ composites were fabricated. The pore surface of the channeled porous composites was coated with TîO² to impaπ photocatalytic activity. Detailed microstructural characterization and materials property evaluation along with their functional activity investigation were performed.

3. Feasibility Study of the process for silica nanopowder from silcon sludge
- A feasibility study of the process for the synthesis of silica nanopowder from silcon sludge was conducted with employing the optimum conditions of the pilot scaled experiments such as preparation of catalyst, synthesis and purification of TMOS, and synthesis of silica nanopowder. The study was referred on the treatrnent of 2000 tons of silicon sludge. The investment was calculated from the sum of invested capital and production cost. The analysis resulted in quite feasible for the profit if the silica nanopowder is successfully sold out in the market.

4. Evaluation of the technology for the synthesis of silica nanopowder from silcon sludge
- An evaluation of the technology for the synthesis of silica nanopowder from silcon sludge was conducted to find how much this technology is valuable for commercialization. This work was collaborated between research team of KIGAM and the welture company. The results was obtained by applying the income approach method.
- The evaluation informed that a value of the technology for the synthesis of silica nanopowder from silcon sludge was very dependant on how large amout of silicon sludge can be secured. The larger amount of silicon sludge can be secured, the higher value of the process can be generated.
(출처 : SUMMARY 14p)

목차 Contents

• 표지 ... 1
• 제 출 문 ... 3
• 보고서 요약서 ... 5
• 요 약 문 ... 7
• SUMMARY ... 13
• CONTENTS ... 19
• 목차 ... 21
• 제 1 장 연구개발과제의 개요 ... 23
• 1. 연구 개발의 현황과 목적 ... 23
• 2. 연구 개발의 내용 및 범위 ... 26
• 제 2 장 국내외 기술개발 현황 ... 28
• 1. 국내외 산업 환경 분석 ... 28
• 2. 연구사례 ... 28
• 3. 세부 기술사항의 검토 분석 ... 29
• 4. 특허 및 기술도입과의 중복여부에 대한 검토 · 분석 ... 31
• 5. 원재료에 대한 검토 분석 ... 31
• 6. 산업계 현황 ... 32
• 제 3 장 연구개발 수행내용 및 결과 ... 33
• 1. 실리콘 슬러지로부터 실리카 나노분말 제조 파일롯 플랜트 ... 33
• 2. 파일롯 규모 실리콘 화합물 제조 및 정제 ... 36
• 3. 파일롯 규모 실리카 나노분말 제조 ... 46
• 4. 실리카 나노분말 제조 수치해석 ... 58
• 5. 파일롯 규모 실리카 나노분말 표면처리 ... 90
• 6. 실리카 나노분말 응용시험 ... 97
• 7. SiC를 이용한 기능성 세라믹 복합 소재 제조 ... 103
• 8. 경제성 분석 ... 117
• 9. 기술과 가치평가 ... 122
• 제 4 장 목표달성도 및 관련분야에의 기여도 ... 130
• 1. 당초 계획 대비 최종목표 달성도 ... 130
• 2. 세부연구목표의 달성도 ... 130
• 3. 해외기술수준을 감안한 성취도 ... 131
• 4. 관련분야 기술발전에의 기여도 ... 131
• 5. 정성적 실적 ... 131
• 6 정량적 실적 ... 132
• 7. 연구개발의 부수적 효과 ... 132
• 제 5 장 연구개발결과의 활용계획 ... 133
• 1. 과학기술적 응용잠재력 ... 133
• 2. 국내외 시장 현황 및 전망 ... 133
• 3. 사업화 가능성 ... 134
• 4. 기대성과 ... 135
• 제 6 장 연구개발과정에서 수집한 해외과학기술정보 ... 136
• 제 7 장 참고문헌 ... 137
• 끝페이지 ... 142