초록 ▼

개발 목적 및 필요성
현재 연간 200만톤 이상 발생될 것으로 추정되는 제강 환원슬래그는 높은 free-CaO로 인한 자체분화로 처리가 곤란하며 재활용에 어려움이 있는 실정임.
제강환원슬래그는 건설재료 중 하나인 속경성 시멘트와 유사한 산화물 조성을 가지고 있지만, 서냉과정에서 반응성을 상실하여 결합재로의 활용되지 못하고 있음.
이러한 제강 환원슬래그를 SAT(Slag Atomizing Technology)를 적용한 결과분화되지 않는 안정상의 비정질 비드로 생산이 가능하면 급결성을 가지는 C₁₂A

개발 목적 및 필요성
현재 연간 200만톤 이상 발생될 것으로 추정되는 제강 환원슬래그는 높은 free-CaO로 인한 자체분화로 처리가 곤란하며 재활용에 어려움이 있는 실정임.
제강환원슬래그는 건설재료 중 하나인 속경성 시멘트와 유사한 산화물 조성을 가지고 있지만, 서냉과정에서 반응성을 상실하여 결합재로의 활용되지 못하고 있음.
이러한 제강 환원슬래그를 SAT(Slag Atomizing Technology)를 적용한 결과분화되지 않는 안정상의 비정질 비드로 생산이 가능하면 급결성을 가지는 C₁₂A₇과 장기강도 발현성을 갖는 β-C₂S를 함유하고 있는 것으로 확인됨.
이를 바탕으로 현재 재활용에 많은 어려움을 가지고 있는 제강환원슬래그를 급냉안정화 기술인 SAT를 적용하여 고부가가치를 지닌 친환경 건설재료로 활용하기 위하여 연구를 추진하게 됨.

연구개발결과
제강 환원슬래그의 고효율 급냉 재활용 기술개발과제의 1단계 연구결과
1. 급냉 제강 환원슬래그의 골재로써의 활용 연구
1) 제강 환원슬래그에 SAT기술을 적용하여 분화가 발생하지 않는 안정한 기능성 골재 개발완료
2) 중금속 용출 및 방사능 유출시험결과 유해물질이 배출되지 않는 안정한 골재로 확인함
3) 다양한 내구성 시험결과 일반 표준사 대비 안정적인 것으로 나타났으며,폴리머 콘크리트 골재로 적용 시 고가의 폴리머 수지량을 약 6% 정도 감소시키는 결과를 확인함
4) 다양한 폴리머 콘크리트에 골재로 적용한 결과, 탁월한 수지저감 효과와 강도발현 등의 이점들을 바탕으로 적용 가능성 확인함

2. 급냉 제강 환원슬래그의 저탄소 급결 결합재로써의 활용연구
1) 급냉 기술을 적용한 반응성이 높은 저탄소 급결 무기결합재의 개발 완료
2) 개발제품의 다양한 수화특성 시험결과 현재 상용중인 속경성시멘트 대비동등이상의 품질특성을 확인 및 품질안정화 방안을 확립함
3) 개발제품인 저탄소 급결 무기결합재를 활용한 다양한 용도개발 및 현장 시험적용을 완료함
4) 급냉 환원슬래그 저탄소 결합재 제품의 용도개발 및 제품화 완료
5) 저탄소 급결 무기결합재의 환경성 평가 결과, 사용중인 속경성시멘트 대비 약 85%의 자원저감효과 및 CO₂ 배출저감효과를 확인함

3. 국내 Pilot plant 운영 및 해외 실증화
1) 5,000톤/월 규모의 제강 환원슬래그 공기급냉 처리용 Pilot Plant 설치 및 안정적 운영
2) 1,000톤/월 규모의 급냉 환원슬래그를 이용한 저탄소 급결 무기결합재 제조용 Pilot Plant 설치
3) 국내 급냉 환원슬래그 무기결합재 제조용 Pilot Plant 운전최적화 및 품질 안정화
4) 해외 실증화 국가인 인도에 제강 환원슬래그 공기급냉 처리용 Pilot Plant 설치·운영
5) 해외 실증화 국가인 인도에 급냉 환원슬래그를 이용한 저탄소 급결 무기결합재 제조용 Pilot Plant 설치·운영

활용계획
본 연구과제를 통하여 취득한 특허 제 10-1460628호 (급냉 제강 환원슬래그 분말을 포함하는 숏크리트용 급결제 조성물)과, 제 10-1460632호 (급냉 제강환원슬래그 분말을 결합재로 이용한 속경성 도로보수용 콘크리트 조성물 및 이를 이용한 도로보수 방법)을 이용하여 국내 도로보수 현장 및 숏크리트 타설 적용 현장을 확대할 계획임.
콘크리트 2차 제품 제조 현장 적용 결과, 충분한 가능성을 확인함에 따라 국내에서 생산되는 다양한 습식 콘크리트 2차 제픔 생산 현장에 급냉 제강 환원슬래그를 이용한 결합재를 적용하여 생산량을 증대할 예정임.
급냉 제강 환원슬래그를 이용한 급결제에 유동성 증진을 위하여 구형 급냉제강 환원슬래그 골재를 잔골재로 넣고 초속경 그라우트재를 개발할 계획이며, 이를 활주로 및 도로 보수의 빠른 보수를 위한 기층재 재료로 활용할 계획이며, 이를 위한 연구를 현재 진행중임.
그 외에도 다양한 용도를 개발하여 제강 환원슬래그의 활용도를 높이고자함.

( 출처 : 요약서 7p )

Abstract ▼

Ⅳ. Results
1. Contents of Carrying out 1st Stage Research and Development and the Result
1-1 Research for utilizing quenched LFS as aggregate
A. Optimization of LFS treatment technology
(1) SAT optimizes the atomization process for oxidizing slag. LFS has relatively high viscosity. When

Ⅳ. Results
1. Contents of Carrying out 1st Stage Research and Development and the Result
1-1 Research for utilizing quenched LFS as aggregate
A. Optimization of LFS treatment technology
(1) SAT optimizes the atomization process for oxidizing slag. LFS has relatively high viscosity. When SAT was applied to LFS, approximately 90% of the LFS volume was shown to be fibrous. Consequently, Slag Atomizing Plant (SAP) was designed and applied to LFS. SAP is optimized for LFS instead of oxidizing slag. Thus, optimization for SAP operating conditions, which fits the formation condition of LFS, was actualized.

B. Stability assessment of quenched LFS aggregate
(1) Slag is utilized by its form according to the following: 1) high amorphous fiber and irregular aggregate are grinded and utilized as binders; 2) round aggregate are utilized as concrete aggregate due to it being round and dry.
(2) Results from leach tests for heavy metals and radiation leak tests show that LFS aggregate is a stable aggregate that is harmless to humans and does not emit any hazardous materials.
(3) Results from sodium sulfate solution immersion test and test to quicken autoclave curing showed that, LFS aggregate is stable in comparison to standard sand. This observation is based on low absorption rates. However, acid and basicity tests long-term immersion test show that LFS aggregate produces precipitate in CaO elution. Consequently, LFS aggregate is judged to be suitable as a polymer concrete aggregate which has no contact with moisture.

C. Applying quenched LFS aggregate as polymer concrete
(1) Generally for polymer concrete, high-cost resin content is about 11%. However,using round LFS aggregate, this percentage was identified to be cut down to 6.8%.Consequently, when making polymer concrete piles, the overall cut in resin use was checked to be by 22.2%.
(2) Additionally, it was possible to produce polymer concrete which manifests optimized strength level at 1:1 mixture with quenched oxidizing slag. Unlike with oxidizing slag that has high ratio (within 3.5), LFS (within 3.0) did not show any mixture segregation.

D. Development of uses for the polymer concrete with quenched LFS aggregate
(1) Quenched LFS was applied as aggregate to various types of polymer concrete. The use of LFS as aggregate showed significant cuts in resin and increase in strength development. With these merits, LFS aggregate has much potential for application.

1-2 Research for utilizing quenched LFS as low-carbon quick setting binder
A. Characteristics of quenched LFS
(1) Unlike annealed LFS, quenched LFS is high in content of the highly reactive C₁₂A₇ and β-C₂S which has long-term strength development.
(2) Vitrification rate evaluation showed that while annealed LFS had a vitrification rate of only 6.5%, quenched LFS revealed to possess over 90% of amorphous material.

B. Hydration properties of quenched LFS (CAC, Calcium Aluminate Composite)
- Due to its content of fast-hardening minerals, quenched LFS particles show rapid response when in contact with water and harden quickly. Thus, the particles may control work time and act as a retarder.
- The hydration heat of over 100°C within the first hour signifies high responsiveness. However, when used as structural concrete, the high temperature can lead to cracks. Thus, temperature control is required.
- Even in the initial three hours of hydration, LFS show high strength of over 5 MPa.However, it showed low levels in long-term strength development. Therefore, improvement in long-term strength is required.
- Production of C3AH6(Hydrogarnet) following hydration of CA minerals and the fast bonding of the hydrogarnets lead to contraction. Consequently, LFS shows high contraction rates.

C. Hydration properties of Acement(low-carbon quick setting inorganic binder: quenched LFS + admixture)
- Mixed plaster to improve the various shortcomings of LFS
(LFS alone: C₁₂A₇+33H₂O→4C₃AH₆+6Al(OH)₃)
(LFS + plaster: C₁₂A₇+12CaSO₄+137H₂O→4(C₃A·3CaSO₄·32H2O)+6Al(OH)₃)
- Through testing on different types and mix percentage of plaster, the optimum mix percentage was selected. With the selected percentage, the hydration heat of binders went down (110°C → 60°C).
- Initial and long-term strengths both improved (initial three hours: 20 MPa, 28-day strength: 46.9 MPa, 129% hydration activity in contrast with OPC)
- With mixing of plaster, expansive ettringite is formed leading to shrinkage compensation. Consequently, volumetric stability is secured.

D. Development of uses for the low-carbon quick setting inorganic binder
(1) Confirmed the potential for various uses of CAC (Calcium Aluminate Composite, quenched LFS particles) and Acement (low-carbon quick setting inorganic binder: CAC + admixture)
(2) CAC (quenched LFS particles)
: Stabilizer for industrial by-products (stabilizing effect for by-products checked - when using under 5%, stabilization completed within one hour)
: Shotcrete accelerator (Rebound under 15%, compression strength ratio over 75%)
(3) Acement
: As substitute for fast hardening cement (LFS 70 + HG 30%, Add LFS 56 + HG 22% to commercial cement, Add LFS 42 + HG 22% to commercial cement; in test specimen with substitute material, strength that is equal to or above commercial CA was developed.)
: Road maintenance concrete (Passing scores in two application sites, 21 MPa for over 4 hours, 28-day strength: over 40 MPa)

E. Environmental assessment for the low-carbon quick setting inorganic binder
(1) Environmental assessment done in comparison to commercial ultra rapid hardening cement. Assessment done in areas of resource depletion and energy efficiency.
(2) In terms of resource depletion, inorganic binder showed 12.3% in comparison to the commercial ultra-rapid hardening cement (87.7% decrease).
(3) In terms of global warming (CO₂emission), binder showed 13% environmental loading in comparison to ultra-rapid hardening cement (87% decrease).
(4) When used as cement substitute, one ton of inorganic binder will result in cutting 0.7 ton CO₂ carbon emission.
(5) In 2011, 2 million tons of LFS was produced. If that amount substitutes cement, then CO₂emission could be decreased annually by 1.4 million.
(6) When 1,000 tons of quenched LFS is used monthly as substitute for ultra-rapid hardening cement, then 68,000 KRW could be saved per a ton substituted, resulting in an annual monetary savings of 680 million KRW.
(7) Treatment cost for slag is 10,000 KRW per ton; however, with the technology presented in this research, the cost is reduced to 7,000 KRW per ton. Thus, for treating 2 million tons, the slag produced in 2011, cut in costs would amount to 14 billion KRW per year.

1-3. Air quenching of LFS and a Pilot Plant which produces binders that use air quenched LFS
A. Optimization of treatment technology for LFS
(1) As mentioned above, SAT optimizes the atomizing of oxidizing slag. Process variables in Pilot Plant are to be improved to apply SAT to LFS.
(2) Optimal design for turn dish angle, nozzle angle, air volume, and wind speed of Pilot Plant

B. Build Pilot Plant for air quenching of LFS
(1) Design Pilot Plant that can process air quenching of 5,000 tons of LFS per month
(2) Build such plant in at steelmaking site
(3) Set optimal operation conditions for producing quenched LFS
(4) Create optimized test product
(5) Inspect quality changes in test products created by different mixes

C. Material balance of Pilot Plant for air quenching of LFS
(1) Payback rate: 22.72%
(2) Payback rates of valuables with atomizing are as follows: LF Ball 45.45%, small capital 9.09%, large capital 22.72% - together, the total payback rate amounts to 77.28%.

D. Design and building of pilot plant for manufacturing low-carbon quick setting inorganic binders
(1) Design Pilot Plant for manufacturing low-carbon quick setting inorganic binders
(2) Construct and build Pilot Plant for manufacturing low-carbon quick setting inorganic binders
(3) In the midst of setting optimal operation conditions

2. Contents of Carrying out 2^nd Stage Research and Development and the Result
2-1 Optimization of operation of the Pilot Plant for manufacture of low-carbon quick-setting inorganic binding material
A. Optimization of operation of Pilot Plant
(1) Ball Mill optimization: Attainment of production efficiency 4.5ton/hr(based on the fineness 6,000cm²/g)
(2) Separator optimization: Realization of performance classifier efficiency 4.5ton/hr
(3) Back filter optimization: Completion of optimization with intake flow 450m³/min
(4) Blending process operation optimization: Optimum blending ability is set to be 6~7 ton per hour

B. Pilot Plant Trial Run and Demonstration
(1) Completion of stabilization of putting raw material, grinding, transfer, mixing and storage operating under load
(2) Completion of stabilization of quality of product
(3) Hosting of Pilot Plant demonstration: Bestwestern Gunsan Hotel and Pilot Plant Site(Mar 2015)
(4) Contents of study outcome reported by numerous media in and outside the country

2-2 Stabilization of quality of the product of Pilot plant for manufacture of domestic reduction slag inorganic binding material
A. Making of quality standard and manual of low-carbon quick-setting binding material product produced in the domestic pilot plant
(1) Purpose
(A) Stabilization of quality of CAC and Acment product
(B) Establishment of the quality database of CAC and Acment product
(C) Regulation of test method for quality control of CAC and Acment product

(2) Object of quality test
(A) RC-LFS produced in Gunsan pilot plant
(B) CAC produced in Gunsan pilot plant
(C) Acement manufactured by mixing CAC with a certain amount of plaster

B. Monitoring of low-carbon quick-setting binding material product produced in the domestic pilot plant
(1) Collection of data and monitoring by periodical evaluation of product
(2) In case of occurrence of problem, you can trace cause, and by seeking solution immediately you can contribute to stabilization of quality of the product
(3) As a result of evaluation through statistical management of data and management graph, they are in stable management condition in physical and chemical characteristics.

2-3 Development of use of product using foreign and domestic rapidly cooled reduction slag low-carbon binding material and aggregate and evaluation of durability performance
A. Evaluation of long-term durability of rapidly cooled reduction slag aggregate and polymer concrete product using it
(1) According to the increase of rate of substitution of atomizing ladle furnace slag, compressive strength and bending strength decrease somewhat.
(2) As a result of analysis of microstructure of the combination between polymer binding material and atomizing ladle furnace slag aggregate, it can be observed that they are solidly bound.

B. Development of urgent road repair material
(1) It has a purpose of carrying out prompt construction using road repair concrete made from fast-hardening binding material and developing concrete for road repair which can be used for a long time by increasing durability.
(2) Mixing CAC 10% with other materials is the best in the aspect of performance and price.
(3) Satisfies all of quality standard for urgent road repair material and obtained certification test record of quality of road construction with securement of quality that meets or exceeds that of the existing product
(4) As a result of indoor experiment of fast-hardening concrete for road repair using rapidly cooled reduction slag and on-site application experiment it appeared to satisfy quality standard in all items.
(5) Progression of the test of accelerated carbonation, resistance against freezing-thawing, durability of RCPT: all satisfactory

C. Development of ultra rapid hardening polymer repair mortar
(1) Major use: Repair and reinforcement of damaged part of concrete of constructional and civil structure
(2) As a result of characteristic experiment and on-site application experiment of repair mortar, it satisfied all of standards.

D) Development of accelerating agent for shotcrete (Power-Crete)
(1) Use of accelerating agent is essential for carrying out prompt construction on cutting surface and slope on site so that following work can be smoothly progressed.
(2) As a result of on-site tunnel application experiment, the result exceeded the standard value of KS F 2782 regulation.

2-4 Global demonstration of technology making rapidly cooled reduction slag into resources
A. Selection of object country and analysis of marketability
(1) Trend of India-related industry
(a) Trend of Steel Industry
① Because of increase in demand of automobile, engineering and construction, India’s steel production and consumption rapidly increased.
② As India produced 72.2 million tons, it rose to the world 5th. It increased to 76.7 million tons in 2012.
③ India’s steel consumption recorded annual growth rate of 7.7% for the past 10 years.
④ It is expected that production of steel will continuously increase with investment by virtue of easy money of the government in the year 2015~ 2016 as well.

(b)Trend of Cement Industry
① India is the world 2^nd cement production country next to China.
② It recorded the annual average growth rate of 8.3% of cement industry production in 2007~2013 and while continuous increase is expected, the prospect of annual average growth rate in 2017 is 10.1%.

(2) Review of India’s Cement Marketability
(a) Production and Consumption (The world 2^nd market)
① Production Capa: 350 million ton/year (will increase to 550 million ton/year by 2020)
② Production and Consumption: 260 million ton/year (190kg/person)
(b) Major enterprises: 8 companies such as UltraTech, Holcim(Lafarge+ACC+Ambuja), Jaypee, India
(c) Price: 260 rupee/50kg (about 100 won/kg), tax 60% (manufacturing cost is comparatively low)
(d) Present situation of cement used: OPC(28%) : F/A CE(65%) : S/C(7%)
(e) Import and export of cement are in a very insufficient level.
(f) Ultra rapid hardening cement: used for tunnel construction, and road repair in cities(use insufficient)

(3) India Cement Manufacturers Association
(a) Cement enterprises of about 75% of India’s cement production joined the association
(b) Detailed consultation about entry into Indian market with India Cement Manufactures Association and business agreement with India Slag Cement Manufacturer Jindal

B. Analysis of the Characteristics of reduction slag of each of the enterprises of the object country
(1) Analysis of engineering characteristics
(a) Physical and chemical property of various enterprises’ reduction slag produced in India is evaluated
(b) Rapid cooling of air is progressed with the object of 3 enterprises’ slag suitable for chemical construct and hydration characteristic
(c) 3 enterprises’ rapid0 air cooled reduction slag shows high reactivity and long-term strength compared to those before rapid cooling
(d) In oxide construct, all of slag samples generated in India show high Al₂O₃ content of 15% or more, and as a result of XRD analysis, it appeared that they contain mineral similar to CAC domestically produced, so it was confirmed that they could be used as reactive binding material

(2) Review of hydration characteristics
(a) As a result of setting test, it is judged that JR3 which showed the highest reactivity is suitable for application of rapid cooling process.
(b) The manifestation rate of compressive strength of rapid air-cooled reduction slag was remarkably high compared to slow-cooled Indian reduction slag, so efficiency of rapid cooling was confirmed.

C. Establishment of local facilities for reduction slag air rapid cooling treatment
(1) JSPL, JSW companies both can produce rapid cooling reduction slag
(2) JSPL, JSW companies’ reduction slag can be used as special cement raw material when they are atomized.
(3) With atomizing treatment, slag waste generation decreased by big quantity.

D. Construction of overseas demonstration Pilot Plant
(1) Completion of design of process for Pilot plant for overseas demonstration
(2) Production capacity: 1,000 ton / month
(3) Completion of Construction of overseas demonstration Pilot Plant
(a) Location : Site within 16 Kharsia Road, Raigarh, Chhattisgarh – 496001 Jindal Cement
(4) Site inspection of overseas demonstration Pilot Plant

E. Establishment of Plan of Operation for overseas demonstration Pilot Plant
(1) Use of the Existing Process
(a) For efficient use of plant facilities, construction of production line for not only ladle furnace slag but also for product of high-added value of various slags including blast furnace slag by connecting Jindal cement’s blast furnace slag manufacture process line
(b) By mixing blast furnace slag with fast-hardening cement based on reduction slag in the plant process, progression of development of very competitive products of new concept that can realize fast-hardness and high strength

(2) Continuous development of technology
(a) Steady development of technology of low-carbon fast hardening inorganic binding material suitable for the property of ingredients of local reduction slag
(b) Strengthening of market competitiveness of high-efficiency rapid cooling recycling technology through development of new use suitable for local environment and law standard and accelerating agent for road repair which is the use of low-carbon fast-hardening inorganic binding material, fast-hardening repair mortar as well as development of more diverse uses for prompt repair material for airport runway, material for construction and repair of defense stronghold and for 1-day open pedestrian passage

(3) MOU Conclusion
(a) It is expected that there will be many difficulties in commercialization of Acement which has relatively high price in India that is the world cement production country but in which cement consumption (125kg (the world average 275kg)) per person is still insufficient.
(b) Targeting the market with method of joint investment with local enterprises for stable establishment of market network and efficient investment in facilities in early stage of commercialization
(c) For facilities to be extended progress joint investment through conclusion of MOU, and the local enterprises take charge of targeting the market such as sales and promotion to alleviate repulsion against other country’s enterprise.

( 출처 : SUMMARY 47p )

목차 Contents

• 표지 ... 1
• 제 출 문 ... 2
• 요 약 서 ... 7
• 요 약 문 ... 13
• SUMMARY ... 40
• 목차 ... 71
• 그림목차 ... 73
• 표목차 ... 90
• 1. 연구개발과제의 개요 ... 99
• 1-1. 연구개발 목적 및 필요성 ... 99
• 1-2. 연구개발 대상기술의 차별성 ... 115
• 2. 국내외 기술개발 현황 ... 118
• 2-1. 해외 기술개발 동향 ... 118
• 2-2 국내 기술개발 동향 ... 119
• 3. 연구수행 내용 및 결과 ... 121
• 3-1. 연구개발의 내용(범위) 및 최종목표 ... 121
• 3-2. 연구개발 결과 및 토의 ... 133
• 3-3. 연구개발 결과 요약 ... 672
• 4. 목표달성도 및 관련분야 기여도 ... 691
• 4-1. 목표달성도 ... 691
• 4-2. 관련분야 기여도 ... 695
• 5. 연구결과의 활용계획 ... 700
• 6. 연구과정에서 수집한 해외과학기술정보 ... 707
• 7. 연구개발결과의 보안등급 ... 708
• 8. 국가과학기술종합정보시스템(NTIS)에 등록한 연구시설·장비 현황 ... 708
• 9. 연구개발과제 수행에 따른 연구실 등의 안전조치 이행실적 ... 708
• 10. 연구개발과제의 대표적 연구실적 ... 709
• 11. 기타사항 ... 713
• 12. 참고문헌 ... 713
• 부 록 ... 715
• 끝페이지 ... 731