• Resources Recycling
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• v.8 no.5
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• pp.44-50
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• 1999

The sbdy iwestlgaled ihc propa-ties of Lhe dust\ulcorner rrom fe~~oallomya ~~ufacturTeh. e chemical composition, cornpasitlon material, p d c l e sire md shapes of the bulk dust, sired dust and magnetically separated durl were mvesligaled. As the re\ulcornerulL, we suppose that the dust from &gh Carbon Fenama~~gunesMc anuiact~vingP rocess is not sufiicient as solulce material of Mn because of ale low Mn canlenl (13.5%) and complicaled composition mate~ial. The dust from Bug F!lter or AOD Proccss is mi~inlym ade up of 0.2-2 pm Mn30, (Hausmam~iu)p iutlde in spherical shape and thc Mn content is 63.190.The dust from Cooler of AOD Process is inninly made up of coarse Ca(O1-Or)zM. n,FeyO,, SiO, and fine Mn30d.

• Resources Recycling
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• v.30 no.1
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• pp.3-13
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• 2021

In the secondary refining process for the production of high-grade steel, the proper composition is maintained by alloying elements, and non-metallic inclusions are controlled for high cleanliness. Complex reactions occur simultaneously between the molten steel, slag, inclusions, refractories, and alloying elements during the secondary refining process. Previous works have reported simulation models based on kinetics to predict the compositional changes in molten steel, slag, and inclusions in actual processes. Analytical reviews are required for the models to predict the process accurately. In this study, we reviewed and analyzed simulation models based on the coupled reaction model for the secondary refining process.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2006.05a
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• pp.150-155
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• 2006

제강공정에서 발생되는 $CaO-Al_{2}O_{3}-SiO_{2}$계 조성을 갖는 2 차 정련슬래그 (래들 슬래그)를 이용하여 하수슬러지용 고화재개발 및 하수슬러지 고화체의 물성에 관한 연구를 수행하였다. 래들슬래그는 냉각과정에서 분화되는 성질이 있어 냉각후 분말상의 슬래그가 만들어진다. 분말상 슬래그의 주 결정상은 $12CaO{\cdot}7Al_{2}O_{3}$ 및 $2CaO{\cdot}SiO_{2}$로 구성되어 있다. $12CaO{\cdot}7Al_{2}O_{3}$ 상은 속경성 시멘트의 특징이 있다. 또한 $CaSO_{4}$와 혼합사용시 ettringite 상을 형성시켜 하수슬러지의 함수율 저감효과 및 강도발현 효과가 우수한 결과를 얻었다. $Cl^{-}$ 이온의 고정화면에서는 고화재중 래들슬래그의 혼합비가 높을수록 고화체 구조내에 $Cl^{-}$ 이온이 고정화되어 용출량은 감소하였다. 고화재로서 제강부산물을 사용하기 때문에 경제성이 있으며, $Cl^{-}$ 이온 함량이 높은 하수슬러지 고화재로서의 재활용이 기대된다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.116.1-116.1
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• 2007

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.43.2-43.2
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• 2010

In this study, metallurgical grade (MG) silicon with 99% purity produced by arc furnace process was systematically investigated for slag refining. The most problematic impurities to remove from MG silicon are boron (B) and phosphorus (P). To remove B and P from MG-silicon, we used synthetic slag in the molten state. MG-silicon with synthetic slag of CaO, $SiO_2$, and $CaF_2$ was melted using by high-frequency induction furnace with electrical output of 50kW. Specimens prepared by various refining process conditions(holding time, mixture ratio) were inspected by combined analysis of ICP-MS and XRF. With this approach, B has been reduced to <5ppm, P to <1ppm and other impurities to 0.1~0.2% except for Calcium. Calcium has been increased from 17ppm to 1500ppm. Problem of calcium contamination will be resolved by additional refining processes.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.154-154
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• 2003

고품질의 합금강 생산 시 가장 큰 영향을 미치는 레이들정련은 고온 하에서 반응 및 유동이 일어나므로 실제조업 직접관찰이나 측정이 대단히 어려울 뿐만 아니라, 수많은 조업인자와 상호 결합되어 있기 때문에 최적의 작업조건을 찾는데 많은 시행착오를 겪는다. 본 실험에서는 직접 조업하는 조건과 가장 부합하는 수모델 실험 및 Flow 3D를 이용한 수치해석 방법으로 비용의 절감 및 실험에 대한 위험부담 등 시행착오를 최소화하면서 최적의 작업조건을 도출하여 고품질 합금강 생산성과 process 효율성의 극대화를 찾을 수 있다. 따라서 본 연구에서는 슬래그의 물성(슬래그 양, 점도)을 고려한 gas bubbling 조건(가스유량, 유체높이, ladle 크기, 단공nozzle, porous plug 위치)에 따른 용강의 교반특성 및 용강의 슬래그 혼입 거동을 조사함으로써 고청정 용강 제조를 위한 최적 gas bubbling 조건을 설정하기 위한 수모델 실험과 수치해석 연구를 실시하였다. 수모델 실험을 통한 기포형성 거동과 용강의 교반특성에 대한 현상론적 연구와 병행하여, 유동장 측면에서 이상유동을 가정한 수치해석을 통해 실제 용강 래들 내에서의 거동을 정량화 하고자 한다.

• Resources Recycling
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• v.16 no.4
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• pp.33-39
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• 2007

Titanium scrap was re-melted and refined by using a DC-ESR (Direct Current Electro Slag Remelting) apparatus. A graphite rod was used as an anode. The used slag was $CaF_2-TiO_2-CaO$ slag system. The effect of slag composition on the shape and oxygen content of re-melted ingot was studied. The titanium ingot was produced very well from the $CaF_2-TiO_2$ slag system, and the oxygen content of the ingot was less than that of titanium scrap. The addition of CaO into $CaF_2-TiO_2$ slag system made the bad shape of titanium ingot. The oxygen content of the ingot was also higher than that of titanium scrap.

• Resources Recycling
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• v.21 no.5
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• pp.65-71
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• 2012

The equilibrium distribution of bismuth and lead between molten PbO-$SiO_2$ slag and bismuth phase was studied in the temperature range of $775^{\circ}C$ to $850^{\circ}C$ in a MgO crucible. The oxygen partial pressure of atmosphere was controlled by $P_{CO2}/P_{CO}$ ratio. The value of $(%PbO)_{slag}/[%Pb]_{metal}$ increased with increasing $SiO_2$ content of slag, and the value of $(%Bi_2O_3)_{slag}/[%Bi]_{metal}$ decreased with increasing $SiO_2$ content of slag. The concentration of Pb in metal increased with increasing temperature. These experimental results agreed well with the thermodynamic prediction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.1
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• pp.136-142
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• 2007

Recent publications have paid attention on the utilization of solid reagents for the removal of substances causing eutrophication, in particular $PO_4^{3-}$ ions. The adsorption of dissolved inorganic phosphate on slag produced by the refining process of iron ore was fundamentally studied for suppressing the liberation of phosphate from wastewater. This study has been conducted in order to find a possibility to improve the phosphate removal and to evaluate the phosphate removal variation to form hydroxyapatite, when the converter slag is used for phosphate removal. The result shows that the converter slag can be applied to remove phosphate using Freundlich isotherm. The size of converter slag, $2{\sim}0.425 mm$ was more efficient than $2{\sim}4.75mm$ to remove phosphate. In particular, 1 mg/L of phosphate can be removed up to 80% of the initial concentration for the continuous column experiment.

• Resources Recycling
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• v.24 no.2
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• pp.23-28
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• 2015

Most of the domestic need for tin rely on imports. In this work, a pyrometallurgical process was investigated to recover pure tin from the tin oxides in tin bath which results from the production of flat glass and LCD panel. From the results on the effect of reaction temperature, the highest recovery percentage of tin was obtained at $1350^{\circ}C$. The recovery percentage of tin was improved to 88% by employing the first and second smelting step. Electrorefining of the crude tin thus obtained led to pure tin with purity higher than 99.9%.