• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 춘계학술대회 논문집
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• pp.404-404
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• 2004

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.1316-1321
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• 1990

Molten steel level information of ladle is very important for process control in steelmaking process. At secondary refining process, measuring lance and snokel have to keep constant thier depth from molten steel surfaces. But, there is much slag on the molten steel surface. Besides, not only the thickness of slag is varied with refining condition, but also molten steel level is largely affected by firebrick errosion. Then, optical measuring method and/or by human eyes cannot detect true molten steel surface, but slag surface. This slag thickness is 300mm at maximum, then huge diameter eddy current sensor will be needed if that type sensor is applied. In addition to, cooling system is necessary because the molten steel and slag temperature is high. This is not practically. To solve this problem, immersion type levelmeter is developed. This sensor is made up from primary and secondary cylindrical coils. High frequency current is applied to primary coil. Electro-motive force from secondary coil is measured, which is varied with molten steel level. This complete set is installed within stainless steel long capsule and attached to top of lance. This sensor is immersed into molten steel bath of ladle or tundish with protection of expendable paper sleeve.

• Environmental Engineering Research
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• 제25권3호
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• pp.356-365
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• 2020

The aqueous carbonation efficiencies of basic oxygen furnace (BOF) and ladle slags at various pressures, temperatures, and liquid-to-solid (L/S) ratios were investigated to determine optimum conditions. The maximum CO₂ carbonated concentrations in slag (0.584 mmol/g for BOF slag and 1.038 mmol/g for ladle slag) was obtained at 10 bars, 40℃, and L/S = 5 mL/g-dry. The L/S ratio was the most critical parameter for carbonation. The effect of carbonated slag amendment on the immobilization of heavy metals in two field-contaminated soils was also investigated. The immobilization efficiencies evaluated by using the toxicity characteristic leaching procedure (TCLP) and the Standards, Measurements and Testing Programme (SM&T) were above 90% for both raw and carbonated slags for all soils. The TCLP-extractable heavy metals concentrations were below the criteria (5.0, 1.0 and 5.0 g/L for Pb, Cd, and Cr, respectively) after immobilizations with both slags except for Pb in soil B. The SM&T analysis showed the decrease in the exchangeable phase but the increase in residual phase after immobilization with raw and carbonated slags. The results of this study imply the promising potential of the carbonated slags on the immobilization of heavy metals in the field-contaminated soils.

• 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.

• 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.

• 한국건설순환자원학회논문집
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• 제7권2호
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• pp.70-77
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• 2012

제강슬래그 중 15~20%를 차지하는 환원슬래그는 건설재료로서의 유익한 화학적 조성을 함유하고 있음에도 불구하고, 특별한 활용처가 없이 매립되어지고 있기 때문에 용도개발이 시급하다. 본 연구는 제강 환원슬래그를 고효율 재활용 용도 개발을 위한 연구로, 사전 연구결과 급냉을 통하여 분화가 없는 안정된 골재상 제조가 가능하고, 이를 분쇄하여 수화시 급결 특성과 자체 수화특성을 갖는 것을 확인하였다. 한편, 철강 제조 공정에서 부산되는 환원슬래그일지라도 생산 제품에 따라 슬래그의 특성도 큰 차이를 보이기 때문에, 각 생산 제품에 따른 10군데 플랜트에서 배출되는 환원슬래그를 채취하여 그 화학적 특성을 평가하였다. 분석된 화학적 특성을 바탕으로, 급냉 시 생성되어지는 광물을 예측하여 사전연구 되었던 급냉 환원슬래그와 같이 급결성 및 강도발현특성을 갖는 무기결합재로의 제조 가능성을 확인하고자 하였다. 그 결과 특수강 및 열연 제품 생산공정에서 배출되는 환원슬래그일수록 높은 $Al_2O_3$ 함량을 가짐에 따라, 급결성 광물인 $C_{12}A_7$을 다량 함유하고, 이로써 급냉을 통하여 특수용 무기결합재로서 적용이 가능할 것으로 판단된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 춘계학술대회 논문요약집
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• pp.281-281
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• 2004

본 논문에서는 레이들(ladle)에 실린 용강의 균일한 혼합을 위해 사용되는 저취 시스템의 버블 강도를 예측하기 위해 진동센서를 이용한 안착대를 설계하고 제작하였다 또한 무선 인터넷을 이용해 안착대로부터 진동 데이터를 수신하여 실시간으로 원격지에 위치한 서버에 저장하는 시스템을 구현하였다. 이와 함께 저취 시스템에 사용되는 유량제어밸브를 컨트롤하기 위해 기존에 사용되는 프로토콜 변환기를 변경한 데이터 처리장치를 설계하고 제작하였다. 데이터처리장치는 4개의 직렬 신호를 동시에 처리 가능하며 비구조화된 데이터를 보관하다록 하기 위해 플래쉬 메모리를 장착하였으며, CPU의 데이터 처리를 위해 SRAM을 장착하도록 구성하였다.(중략)

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1998년도 The Korea Society for Simulation 98 춘계학술대회 논문집
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• pp.70-73
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• 1998

본 연구에서는 광양제철소에서 철광석과 코크스를 이용하여 용선을 생산하는 고로공장과 이러한 용선을 용강으로 변화시키는 제강공장지역을 운행하는 기관차 및 TLC (Torpedo Ladle Car)의 용선 수성작업을 분석하여 기관차 및 TLC의 적정댓수를 산정하고, 운행 패턴의 변화에 따른 대안들을 검토하였다. 시뮬레이션은 AUTOMOD II를 이용하여 수행하였으며, 시뮬레이션에 이용되는 관련 기준 및 운행 패턴을 수집하여 확정하고, 실적치의 분포를 추정하였다. 시뮬레이션의 결과는 현장 전문가들의 이해를 높이기 위아여 Animation을 통하여 가시화하였다.

• 한국시뮬레이션학회논문지
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• 제7권2호
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• pp.17-32
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• 1998

The flow fields in Gas Bubble Driven Circulation Systems were numerically analyzed. In various gas flow rate and bubble size, the flow characteristics were predicted. Eulerian-Eulerian approach was used for the formulation of both the continuous and dispersed phases. The modification of the general purpose computer program PHOENICS code was employed to predict the mean flow fields, turbulent characteristics, gas dispersion, volume fraction. The predicted shows very satisfactory agreement with experimental results for all regions of ladle. The results are of interest in the design and operation of wide variety of material processing.

• Membrane and Water Treatment
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• 제9권3호
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• pp.181-188
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• 2018

A sidestream contains the filtrate or concentrate from the belt filter press, filter backwash and supernatant from sludge digesters. The sidestream flow, which heads back into the sewage treatment train, is about 1-3% less than the influent flow. However, the sidestream can increase the nutrient load since it contains high concentrations of phosphorus and nitrogen. In this study, the removal of PO4-P with organic matter characteristics and bacteriological changes during the sidestream treatment via ladle furnace (LF) slag was investigated. The sidestream used in this study consisted of 11-14% PO4-P and 3.2-3.6% soluble chemical oxygen demand in influent loading rates. LF slag, which had a relatively high $Ca^{2+}$ release compared to other slags, was used to remove $PO_4-P$ from the sidestream. The phosphate removal rates increased as the slag particle size decreased 19.1% (2.0-4.0 mm, 25.2% (1.0-2.0 mm) and 79.9% (0.5-1.0 mm). The removal rates of dissolved organic carbon, soluble chemical oxygen demand, color and aromatic organic matter ($UV_{254}$) were 17.6, 41.7, 90.2 and 77.3%, respectively. Fluorescence excitation-emission matrices and liquid chromatography-organic carbon detection demonstrated that the sidestream treatment via LF slag was effective in the removal of biopolymers. However, the removal of dissolved organic matter was not significant during the treatment. The intact bacterial biomass decreased from $1.64{\times}10^8cells/mL$ to $1.05{\times}10^8cells/mL$. The use of LF slag was effective for the removal of phosphate and the removal efficiency of phosphate was greater than 80% for up to 100 bed volumes.