• 자원리싸이클링
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• 제33권2호
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• pp.46-53
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• 2024

전기로 제강공정에서 연속주조 조업 완료 후 ladle에 잔존하는 슬래그의 헌열과 슬래그 중 잔존 CaO를 활용하기 위해 전기로 출강 후 ladle 상부에 슬래그를 투입하여 Ladle Furnace(LF) 공정에서의 전력과 생석회의 사용량을 저감하는 공정이 연구되어 산업현장에서 활용되고 있다. 하지만 이러한 공정은 LF 공정과 연속주조 공정상 시점이 맞지 않으면 재활용율이 낮아진다. 슬래그 재활용율을 높이기 위해서 시점이 맞지 않는 경우 ladle의 슬래그를 슬래그 포트에 미리 부은 후 재활용하는 방법에 대해서 LF 조업 영향성을 분석하였다. Ladle 용융 슬래그를 재활용 방법에 대해 열역학 프로그램 Factsage 8.3에서 FSsteel(steel database)와 FToxid(oxide database)를 활용하여 슬래그 조성에 대한 액상화율을 계산하였고, 재활용 방법에 따라 각 10heats 조업 적용을 통해 슬래그 중 탈황능과 LF 조업성에 대해서 비교하였다. 그 결과 연속주조 조업 완료 후 바로 ladle에 슬래그를 재활용하는 방법에서 전력 사용량이 0.3MWh 낮고, LF 조업시간은 1.2분 단축되었으며, 탈황율은 5.8% 높은 결과를 얻었다.

• 자원리싸이클링
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• 제22권1호
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• pp.36-41
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• 2013

전기로 제강공정 중 LF 공정에서 슬래그는 전기로(EAF)에서 이월된 슬래그와 출강 중에 조재제인 생석회, 돌로마이트 등이 용강 중에 투입되어 생성된다. LF 조업이 끝나면 ladle은 연속주조 공정(CCM)으로 이송되며, ladle 하부의 노즐을 통해 tundish로 용강을 내보내어 연속 주조조업을 하게 된다. 일반적으로 연속 주조공정 후 ladle에 남는 슬래그와 잔강(殘鋼)은 슬래그 포트(Pot)에 받아 슬래그 야적장으로 이송되어 파쇄 후 처리된다. 본 연구에서는 연속 주조공정 후 ladle에 잔류한 용융슬래그(잔강(殘鋼) 포함)를 전기로 출강 후에 ladle 상부에 직접 투입하여 LF 공정 초기의 슬래그를 형성하는데 활용하고자 하였다. 그 결과 LF 공정 중에 사용되는 생석회의 원단위는 2.2 ~ 3.2 kg/steel-ton 저감되었으며, 용강의 생산회수율은 0.3 ~ 0.5% 증가되었다.

• 한국환경과학회지
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• 제26권8호
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• pp.955-966
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• 2017

Amendment of multi-binders was employed for the immobilization of metal(loid)s in field-contaminated soils to reduce the leaching potential. The effect of different types of multi-binders (lime/diammonium phosphate, diammonium phosphate/ladle slag and lime/ladle slag) on the solidification/stabilization of metal(loid)s (Pb, Zn, Cu and As) from the smelter soil and mine tailing soil were investigated. The amended soils were evaluated by measuring Toxicity Characterization Leaching Procedure (TCLP) leaching concentration of metal(loid)s. The results show that the leaching concentration of metal(loid)s decreased with the immobilization using multi-binders. In terms of TCLP extraction, the mixed binder was effective in the order of lime/ladle slag > diammonium phosphate/ladle slag > lime/diammonium phosphate. When the mixed binder amendment (0.15 g lime+0.15 g ladle slag for 1g smelter soil and 0.05 g lime+0.1 g ladle slag for 1 g mine tailing soil, respectively) was used, the leaching concentration of metal(loid)s decreased by 90%. However, As leaching concentration increased with diammonium phosphate/lime and diammonium phosphate/ladle slag amendment competitive anion exchange between arsenic ion and phosphate ion from diammonium phosphate. The Standard, Measurements and Testing programme (SM&T) analysis indicated that fraction 1 (F1, exchangeable fraction) decreased, while fraction 4 (F4, residual fraction) increased. The increased immobilization efficiency was attributed to the increase in the F4 of the SM&T extraction. From this work, it was possible to suggest that both arsenic and heavy metals can be simultaneously immobilized by the amendment of multi-binder such as lime/ladle slag.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 추계 학술논문 발표대회
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• pp.39-40
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• 2016

The aim of this research was evaluating strength characteristics of foamed concrete using Ladle Furnace slag with GGBFs. For all mixtures, because of the early setting and strength development, it was possible to deform the formwork and measure the compressive strength within 3 hours.

• 자원리싸이클링
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• 제30권1호
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• pp.83-91
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• 2021

조강 생산 시 발생되는 슬래그는 대부분 서냉 방식에 의해 처리되고 있다. 하지만 슬래그 중 일부는 속경성 광물을 포함하고 있음에도 불구하고, 서냉 방식에 의해 그 반응성을 상실하게 된다. 이에 본 연구에서는 제강환원슬래그를 SAT공법에 의하여 공기 급냉하여 선별 및 분급 후 분쇄한 CAC의 활용성 확대를 목적으로 석고 종류 및 혼입율에 따른 CAC의 특성에 관하여 고찰하였다. 그 결과, CAC는 3시간에서는 석고 용해도, 1일 이후에는 석고 함량비에 따라 특성이 나타나는 것을 확인하였다. 반수, 무수석고의 적정 혼입율은 30% 이내, 이수석고는 35% 이상인 것을 확인하였으며, 이수석고의 혼입율 및 특성 확인을 통하여 부산이수석고의 적용 가능성을 확인하였다.

• 자원리싸이클링
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• 제11권3호
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• pp.17-24
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• 2002

There has been an increasing demand over the years for steels with lower[s] content. For the purpose of improving the efficiency of desulphrization in the powder injection process of ladle, experimental studies were carried out by using cold model to optimize the lance configuration, gas flow rate, immersion depth of lance nozzle, position of lance nozzle relative to the ladle and the effect with slag, etc. As the results of this study, it was made clear that 2-hole nozzle lance (C, E type) placed in an asymmetric position gives the shortest mixing times.

• Geomechanics and Engineering
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• 제31권2호
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• pp.149-158
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• 2022

Ladle furnace (LF) slag, waste from the steel-making process, was incorporated to improve the compressive strength of soil cement. LF slag was mixed to replace the cement in the soil-cement samples with wt% ratio 20:0, 15:5, and 10:10 of cement and slag, respectively. LF slag in the range of 5, 10, and 20 wt% was also separately added to the 20-wt% cement-treated soil samples. The soil-cement mixed LF slag samples were incubated in a plastic wrapping for 7, 14, and 28 days. The strength of soil cement was highly developed to be higher than the standard acceptable value (0.6 MPa) after incorporating slag into soil cement. The mixing of LF slag resulted in more hydration products for bonding soil particles, and hence improved the strength of soil cement. With the LF slag mixing either a replacement or additive materials in soil cement, the LF slag to cement ratio is considered to be less than 1, while the cement content should be more than 10 wt%. This is to promote a predominant effect of cement hydration by preventing the partially absorbed water on slag particles and keeping sufficient water content for the cement hydration in soil cement.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권7호
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• pp.135-147
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• 2015

Remediation of metal(loid)s-contaminated sites is crucial to protect human and ecosystem. Solidification and stabilization of metal(loid)s by the binder amendment is one of the cost-effective technologies. In this study, metal (loid)s in various field-contaminated soils obtained from steel-making, metal refinery and mining tillage were immobilized by the application of single binders such as diammonium phosphate (DAP), lime, and ladle slag. The efficiency of solidification and stabilization was evaluated by Toxicity Characteristic Leaching Procedure (TCLP) and the Standard, Measurements and Testing programme of European Union (SM&T) extraction processes. In terms of TCLP extraction, the binder was effective in order of lime > DAP > ladle slag. All binders were highly effective in the immobilization of Pb, Zn, Cu, Ni, and Cd. The increased immobilization efficiency is attributed to the increase in the Step III and IV fractions of the SM&T extraction. Lime and ladle slag were highly effective in the immobilization of the metal(loid)s, however, As release increased with DAP due to competition between the phosphate originated from DAP and arsenate. A further study is needed for the better immobilization of multi metal(loid)s using binary binders.

• 한국세라믹학회지
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• 제36권10호
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• pp.1115-1122
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• 1999

• 대한금속재료학회지
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• 제46권10호
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• pp.662-671
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• 2008

The behavior of hydrogen in the steel making process was investigated. The relation between the composition of ladle slag and hydrogen concentration in molten steel was considered. The hydrogen distribution ratio between ladle slag and molten steel was increased with increasing basicity of the slag; it was about 20 when the basicity of slag was 15. Hydroxyl capacity measured from the hydrogen distribution ratio between slag and the molten steel was comparatively corresponding to the value of hydroxyl capacity measured by the equilibrium reaction of slag and $H_2O$ gas. However, it is considerably different from the value calculated by regular solution model. The influence of hydrogen on a sticking type breakout is considered. The effect of hydrogen and $H_2O$ gas on the crystallization behavior of mold powder was investigated by DHTT (Dual hot thermocouple technique). As a result, it was proved that mold powder could be crystallized by $H_2O$ gas in the atmosphere. Therefore, it is concluded that $H_2O$ gas in the atmosphere can be a possible cause of the sticking type breakout that occasionally occurs in the continuous casting process.