• Journal of Welding and Joining
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• 제33권5호
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• pp.14-19
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• 2015

This study has been performed to investigate the adhesive slag at GTAW weld zone after FCAW multi-pass welding. The cause of adhesive slag formation was examined using optical microscope, field emission scanning electron microscope(FE-SEM) and XRD analysis. The results obtained in this experiment are summarized as follows. Slag of GTAW weld zone surface during welding were formed by mixing the presence of slag in FCAW weld zone. While the slag cools, Cr-spinel phase were formed due to reactions in slag/metal interface. Also, a Cr moves form the weld metal to the slag to strong affinity between oxide atoms and Cr atoms. Hence, detachability of slag was exacerbated by decreasing the interfacial tensions between slag and weld metal.

• 한국농공학회지
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• 제37권5호
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• pp.43-52
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• 1995

To examine the appicability of the converter slag to aggregate, tests were performed for the converter slag specimens which were aged with steam, and the stability of expansion was investigated. The strength of the converter slag was found to he lower than that of the natural aggregate. But the strength of the concrete mixed with the converter slag and the granular slag was increased with an increase of the content of the granular slag. The slump value was larger for the specimen of the converter slag than that for the natural aggregate. The specific weight of the converter slag was decreased with an increase of the aging peroid. The aging time for the converter slag was accessed to be about 48 hours to accommodate the full stability of the expansion. The amount of the steam needed to age one ton of converter slag to full expansion was accessed to be 60 kg. From the regression analysis for splitting tensile strength (t), and flexural strength (f), the compressive strength (c) based on the following formulas were proposed $\sigma$t=0.1506 $\sigma$c+4.5(kg/cm$^2$) (r=0.876) $\sigma$f=O.l537.~+30.5(kg/cm$^2$) (r=0.796)

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.542-546
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• 2001

Converter slag has some compositional similarities to portland cement. But it has no hydration properties due to it's quite high concentrations of FeO(20-35%), MnO(4-6.5%). So it is needed to reduce the concentrations of iron and manganese of converter slag to use as cement additives by enhancing it's hydration properties. In this study, converter slag was modified it's composition by mixing of silica, alumina and quenched BF slag and reduced in induction furnace and quenched in running water. The hydraulic properties and structures of modified and quenched converter slag are significantly changed depend on the amount and kinds of additives. The addition of alumina up to 10% and BFQ slag up to 20% by weight on converter slag was effective to enhance the hydraulic properties of modified and quenched slag. The addition of reduced and quenched converter slag up to 20% by weight in replacement of portland cement in mixing of concrete mortar were shown higher compressive strength than 100% cement concrete mortar.

• 연구논문집
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• 통권28호
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• pp.161-172
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• 1998

철강재생 공장내의 전기 용융로에서 발생된 먼지중의 아연 성분을 재생하는 공정인 Waelz 공정에서는 매년 많은 양의 slag가 발생되어진다. 표면이 유리질성인 이 slag의 물리적 특성이 매우 우수하며, 건축 현장에서 골재(모래나 자갈)의 대체물질로 사용 가능한 만큼 높은 안정성을 지니고 있다. 유럽공동체 과 제인 본 연구는 여러 종류의 slag에 대한 용출특성, 물리-화학적 특성조사 및 광물학적 특성 연구에 주안점을 두었다. 용출실험으로는 법규실험과 slag의 재사용 시나리오와 관련된 여러 주요인자에 대한 영향(pH, 산환원 전위, 용매의 화학적특성, L/S비 등)에 대하여 조사되어졌다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 추계 학술논문 발표대회
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• pp.67-71
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• 2008

Blast Furnace slag a pigiron waste that is produced more than 800 thousand tons per year, and micronized double quenching blast furnace slag improves flexibility of concrete, and even shows improvement effect of long-term intensity. However, the concrete that used micronized double quenching blast furnace slag is restricted in its use because of many problems to assure early intensity. Even micronized blast furnace slag can assure its early intensity of concrete when maximizing, and is considered that can be applied in high strength of blast furnace slag as an alternation material for Silica-fume that depends on overall import. Hereby this paper is revised activity index and fluidity of mortar that used Nano Slag that is produced by rotten Nano crush equipment to propose its size, and possible utility of Nano Slag that was produced by blast furnace slag made in Korea as an alternation material, with the conclusion as following. 1. To measure micronized Nano slag, it is judged that it should be in progress with BET method that is based on micronized Silica-fume for concrete. 2. As a result, the test based on KS L ISO 679 is shown to satisfy the basic additive size of KS F 2563 and of KS F 2567, and to determine new combination of stipulations. 3. The strength development of Nano Slag was shown excellent in the daily initial installment of 1, 3, 7 days against the basic additive. This is judged that contains CaO controlling initial strength against Silica-fume, and contributes to higher fineness than the basic blast furnace slag 1 type.

• 한국건축시공학회지
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• 제18권6호
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• pp.551-558
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• 2018

본 연구에서는 페로니켈슬래그 미분말의 시멘트 대체재로서의 가능성을 평가하기 위하여 페로니켈슬래그 미분말 사용 모르타르의 압축강도 및 건조수축특성을 비교 분석하였다. 연구결과 페로니켈슬래그 미분말을 사용한 배합의 경우 동일한 양의 고로슬래그 미분말 및 플라이애시를 사용한 배합에 비해 미소수화열량이 낮게 나타났으며 모르타르 플로우는 상대적으로 다소 높은 것으로 나타났다. 또한 페로니켈슬래그 미분말을 사용한 모르타르의 압축강도의 경우 초기 강도발현은 고로슬래그 미분말 및 플라이애시와 유사하게 나타났으나 재령 28일에서는 상대적으로 낮은 압축강도를 발현하였다. 건조수축의 경우 페로니켈슬래그 미분말을 사용한 배합에서 고로슬래그 미분말을 사용한 배합에 비해 낮은 건조수축값을 나타내었으며 플라이애시를 혼입한 배합의 건조수축과 유사하게 나타났다.

• 한국건축시공학회지
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• 제18권5호
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• pp.419-427
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• 2018

본 연구는 철 생산 공정 중에 발생되는 철강슬래그를 재활용하는 것으로 매립에 의존하는 철강 슬래그를 건설용 재료로 사용하는 것이다. 철강 슬래그는 물과 반응할 경우 팽창 붕괴되어지는 문제로 인하여 에이징 처리를 실시하고 있다. 이런 문제점을 해결하기 위하여 개발된 SAT 공법은 철강슬래그의 팽창 붕괴에 대한 안전성을 갖는다. 이에 본 연구에서는 SAT 공법에 의해 제조된 환원슬래그와 전기로 산화슬래그, 실리콘 망간 슬래그를 사용하여 도로용 긴급 보수모르타르에 관한 실험적 연구를 실시하였으며 다음과 같은 결론을 도출하였다. 환원슬래그는 초속경 시멘트에 대해 대체할 경우 속경성을 갖는 것으로 나타났으며, 대체율 15%까지는 동등하게 나타났다. 전기로 산화슬래그는 천연 골재에 대해 100% 대체하여도 동등한 특성을 갖는 것으로 나타났으며, 이런 전기로 산화슬래그에 대해서 실리콘 망간 슬래그를 대체할 경우 15-30%까지 대체가 가능한 것으로 나타났다. 이상의 배합으로 도로용 긴급 보수 모르타르의 배합 설계가 가능하였다. 이런 슬래그를 재활용은 시멘트와 천연 골재의 사용량을 저감시켜 이산화탄소 발생의 감소와 폐기물인 슬래그를 재활용으로 녹색 산업에 이바지가 가능하다.

• 방재기술
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• 통권11호
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• pp.5-8
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• 1991

This report is expressed on test results of incombustibility for slag-board according to test method in KSF2271 Two kinds of slag-board is tested, one is passed and the other is failed The object of this report is to introduce the meaning of incombustibility for slag-board.

• 환경영향평가
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• 제5권2호
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• pp.21-31
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• 1996

To assess the impact resulted from the slag dumping, we studied that the changes in the concentration of heavy metal were researched through the statistic analysis at 4 stations in Yongil bay, Korea from 1988 to 1995. And in order to clarify resulting from the changes in heavy metal concentration due to be leaked out from dumped slag, it was fulfilled experiments of the slag extraction. In the extracting experiment, Pb and As were only leaked out from slag aged during 10 days but all of heavy metals were not from it aged during 90 or 180 days. It was found that the concentrations of heavy metals in sea water of vincinity of slag dumping area were still remained in similar, comparing with it of control site(site 4) when they were by analysed statistic method, anova test and Mann-Whitney test. The slag recycling ratio of our country is lower than foreign country. While we need to apply a new process for phosphate treatment, foreign country already apply a slag to phosphorous removal. We suggest that slag dumping cannot putatively affected the changes in the concentration of heavy metal. And we thought that impact of heavy metal induced by slag dumping was not severe. So, it is necessary to utilize this process in phosphorous removal, like a foreign country.

• 한국건축시공학회지
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• 제9권2호
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• pp.77-83
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• 2009

In this study, a test has been carried out to solve the problem with ground granulated blast-furnace slag, low early strength & lack of supply and to find out a way to use as concrete admixture of the ultrafine blaine air cooling slag which is all disposed as the by product of air cooling slag and its test was conducted to the replacement rate of ultrafine blaine air cooling slag & mixing condition of every concrete admixtures by type for the purpose of obtaining later a basic data for practical use of the cement that used ultrafine blaine air cooling slag by conducting comparative analysis. If ultrafine-blaine air cooling slag is used to the concrete following the results, a high efficiency water reducing agent won't be needed much for flow acquisition due to a high increase in flow, and the stripping time of concrete form will be shortened thanks to the acquisition of early strength, And though, it has the problems with long term strength which is similar or a little lower than the 3 types of ground granulated blast-furnace slag, it's still applicable as the substitute materials for 3 types of ground granulated blast-furnace slag at 10, 15% replacement rate of ultrafine-blaine air cooling slag, at which it shows higher activation index than 3 types of ground granulated blast-furnace slag.