• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.537-541
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• 2001

For the development of reformation material of soft ground using the LD slag, the relation to the particle condition of LD slag and the pH behavior of slag dissolution water, extraction properties of slag, and origination of white water were investigated. When the LD slag is mixed with sea water, the pH of solution ranged between 9.47 and 10.0. On the other hand, when mixed with distilled water, the pH was about 10.4 to 12.1. For the as-received slag and the aged slag in sea water, a pH of 11.5 to 12.0 was observed when the particle size was less than 0.5mm. For the reoxidized slag in seawater, the pH of the solution was lower than 9.5 when the particle size was bigger than 0.075mm. For the aged slag and reoxidized slag, the pH of the solution remained constant when the addition ratio of sea water to the slag was higher than 500 times. The main elements dissolved from the slag were Ca and Mg ions. When the pH went over 9.0, the white water started to font which was caused by the CaCO$_3$and Mg(OH)$_2$.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.207-214
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• 2000

Sand Compaction Pile method is one of the widely used ground improvement techniques at loose sand or soft clay ground in Asian countries. However, due to environmental and economical problems concerning shortage of sand resources alternative materials are needed to substitute sand for SCP. This study is on the applicability of slag as an alternative material SCP. Consolidation and direct shear test are performed for the slag-clay composite specimens to find out the positive effects of consolidation rate and shear resistance of slag reinforced ground. The result shows that slag has similar effects with sand in consolidation and shear resistance behavior in composite ground, which says slag can be used as alternative material of sand for SCP.

• 한국안전학회지
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• 제27권2호
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• pp.25-32
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• 2012

In this study, the effect of blast furnace slag on precast concrete culvert was assessed by measuring the flexural strength using to full scaled box culvert. As a result, the initial cracking load and yield load of reinforced concrete box converts are increased in comparison with those of the normal concrete box culvert, but the ultimate load is decreased slightly. It can be concluded that use of blast furnace slag induce to flexural strength in precast concrete box culvert greatly improved the serviceability.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.526-531
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• 2001

LD slag, that is, a by-product of steel making process, has been mainly used as land construction materials. Recently, the seashore application of LD slag was tried in Japan and Korea tut the reaction between LD slag and seawater was not studied yet. We tried to clarify the leaching reaction and/or mechanism of LD slag and the reaction between seawater and LD slag. We tried to apply these results to the decarbonization of seawater for seawater magnesia process. At first, LD slag was milled and classified into 5 grades, that is, (ⅰ)45${\mu}{\textrm}{m}$ under, (ⅱ)0.25~0.5mm (ⅲ)0.5~1mm(ⅳ)1~2mm, (ⅴ)2.36~3.35mm. These slags were leached in the distilled water. In case of 45${\mu}{\textrm}{m}$ under, the pH of the leached solution was over 12. The chemical analysis of leached solution showed that the $Ca^{+}$$^2$was main component and the S $i^{+}$$^4$was very low. On the other hand, the content of S $i^{+}$$^4$in leached solution was decreased with the increase of pH of this solution. The nearly pure calcium solution was made and the ultra high purity MgO could be made with this calcium solution. The leaching behavior of LD slag was different between the fine particle and coarse particle. The calcium was leached by bulk dissolution in the coarse particle and by surface controlled reaction in fine particle. The leaching rate was slow in coarse particle and fast in fine particle. Therefore, the high pH solution, that is, over 12, was obtained in fine particle.cle.e.

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

• 콘크리트학회논문집
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• 제27권3호
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• pp.311-317
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• 2015

시멘트를 전혀 사용하지 않고 슬래그와 같은 산업 부산물과 알칼리 활성화제를 사용하여 콘크리트를 제조하면 천연자원 및 에너지 고갈 문제와 이산화탄소 배출에 의한 환경오염을 해결할 수 있을 것으로 판단된다. 현재까지 알칼리 활성화제를 사용한 무시멘트 콘크리트의 연구는 주로 재료적인 분야에 대해서만 수행되어지고 있는 실정이다. 그러나 무시멘트 콘크리트를 구조재료로 사용하기 위해서는 구조 부재 거동 등에 대한 연구가 필수적이다. 본 논문에서는 50 MPa급 알칼리 활성 슬래그 콘크리트를 사용한 철근콘크리트 보부 재 3개를 제작하여 휨실험을 수행하였다. 실험결과를 검증하기 위하여 알칼리 활성 슬래그 콘크리트의 탄성계수와 응력-변형률 관계를 이용한 비선형 해석 모델을 제안하였으며, 제안된 해석 모델을 이용하여 해석을 수행한 결과, 해석결과와 실험결과가 비교적 잘 일치하여 제안된 해석 모델은 적절한 것으로 판단된다.

• 자원리싸이클링
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• 제25권6호
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• pp.23-28
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• 2016

본 연구는 제강슬래그로부터 인성분을 추출하여 농업용 비료의 자원으로서 사용하기 위한 침출공정을 연구하였다. 일반적으로 제강 슬래그에 함유되어 있는 인성분은 $C_2S-C_3P$상에 고용되어 있고, 이 고용체는 슬래그 내의 free-CaO 다음으로, 다른 상들보다 수용해성이 크다. 본 실험에서는 다원계 슬래그를 이용하여, 다양한 원소들의 용해거동에 미치는 pH의 영향을 알아보았다. 낮은 pH에서 제강슬래그로부터 수용액 중 Ca, Si, P, Fe의 농도는 증가되었다. pH가 3인 경우, 수용액 중 P 이온의 농도는 시간에 따라 감소하였고, P이온과 Fe이온과의 침전 반응을 감소 원인으로 고찰하였다.

• 한국재료학회지
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• 제13권2호
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• pp.94-100
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• 2003

The interface between low carbon steel and blended cement pastes containing slag was investigated using impedance spectroscopy. In addition, the pastes were characterized by several analytical methods (XRD, EDX, electrode potential, pH and ICP). The electrical behavior of the interface in the blended slag systems is correlated to its corresponding pore solution chemistry and the products present in the interface. Passivation occurred at the paste/steel interfaces, in cement pastes up to containing from 0 to 75% slag content. 100% slag paste induced corrosion of the low carbon steel, which could be explained by the influence of sulfur on the system.

• Computers and Concrete
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• 제16권3호
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• pp.487-502
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• 2015

This study investigated particle expansion in basic oxygen furnace slag (BOF) and desulfurization slag (DSS) after heat curing by using the volume method. Concrete hydration was accelerated by heat curing. The compressive strength, ultrasonic pulse velocity, and resistivity of the concrete were analyzed. Maximum expansion occurred in the BOF and DSS samples containing 0.30-0.60 mm and 0.60-1.18 mm particles, respectively. Deterioration was more severe in the BOF samples. In the slag aggregates for the complete replacement of fine aggregate, severe fractures occurred in both the BOF and DSS samples. Scanning electron microscopy revealed excess CH after curing, which caused peripheral hydration products to become extruded, resulting in fracture.

• 한국재료학회지
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• 제20권1호
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• pp.42-46
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• 2010

Phosphorus exhibits considerable segregation in steelmaking slag. In order to recover phosphorus from slag to $K_3PO_4$ via molten iron, a carbothermic reaction using microwave heating was suggested recently. The carbothermic reduction of phosphorus from slag to molten iron using microwave heating was carried out at 2073K. However, at this temperature the thermodynamic properties of both slag and molten iron cannot be determined experimentally. Therefore, the computational approach of the so-called CALPHAD method is very useful to understand the transfer of phosphorus from slag to metal and to enhance this reaction. In the present investigation, a theoretical study of the reduction behavior of phosphorus in slag was carried out at much lower temperatures using the recently developed thermodynamic database in the FactSage program. The calculated results showed reasonable accordance with the experimental data; namely, the thermodynamic database could be applied successfully to higher temperature reactions. The current study found that higher temperature and high $SiO_2$ concentration are favorable for the recovery of phosphorus from slag.