• 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.

• 한국초전도ㆍ저온공학회논문지
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• 제19권1호
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• pp.22-25
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• 2017

Steel slag has been considered as an industrial waste. A huge amount of slag is produced as a byproduct and the steel slag usually has been dumped in a landfill site. However the steel slag contains valuable resources such as iron, copper, manganese, and magnesium. Superconducting magnetic separation has been applied on recovery of the valuable resources from the steel slag and this process also has intended to reduce the waste to be dumped. Cryo-cooled Nb-Ti superconducting magnet with 100 mm bore and 600 mm of height was used as the magnetic separator. The separating efficiency was evaluated in the function of magnetic field. A steel slag was ground and analyzed for the composition. Iron containing minerals were successfully concentrated from less iron containing portion. The separation efficiency was highly dependent on the particle size giving higher separating efficiency with finer particle. The magnetic field also effects on the separation ratio. Current study showed that an appropriate grinding of slag and magnetic separation lead to the recovery of metal resources from steel slag waste rather than dumping all of the volume.

• 한국수소및신에너지학회논문집
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• 제22권6호
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• pp.913-924
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• 2011

A steady-state analysis has been conducted to predict the behavior of the slag layer in the entrained-flow slagging coal gasifier. The analysis takes into consideration the composition dependent slag properties such as density, viscosity, heat capacity, thermal conductivity, and temperature of critical viscosity. The amount of added flux to the design coal and the variation of syngas temperature inside the gasifier have been adopted as calculation parameters. The predicted results are the local thickness of the molten and the solid slag layers, and the slag viscosity and the velocity distribution across the molten slag layer along the gasifier wall near the slag tap.

• 한국건축시공학회지
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• 제12권5호
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• pp.478-489
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• 2012

Each year, about four million tons of steel slag, a by-product produced during the manufacture of steel by refining pig iron in the converter furnace, is generated. It is difficult to recycle this steel slag as aggregate for concrete because the reaction with water and free-CaO in steel slag results in a volume expansion that leads to cracking. However, the steel slag used in this study is atomized using an air-jet method, which rapidly changes the melting substance at high temperature into a solid at a room temperature and prevents free-CaO from being generated in steel slag. This rapidly-cooled steel slag has a spherical shape and is even heavier than natural aggregate, making it suitable for the aggregate of radiation shielding concrete. This study deals with the radiation shielding property of concrete that uses the rapidly-cooled steel slag from the oxidizing process in the converter furnace as fine aggregate. It was shown that the radiation shielding performance of concrete mixed with rapidly-cooled steel slag is even more superior than that of ordinary concrete.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2007년도 추계 학술논문 발표대회
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• pp.75-78
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• 2007

The steel slag, a by-product which is produced by refining pig iron during the manufacture of steel, is mainly used as road materials after aging. It is necessary to age steel slag for long time in air because the reaction with water and free-CaO in steel slag could make the expansion of volume. This problem prevents steel slag from being used as aggregate for concrete. However, steel slag used in this study was controled by a air-jet method which rapidly cools substance melted at a high temperature. The rapidly-chilled method would prevent from generation of free-CaO in steel slag. Also, Molten steel slag rapidly-chilled by air in high speed becomes a fine aggregate of nearly spherical shape. This study dealt with the influence of the using rate of rapidly-chilled steel slag and polymer resin on fluidity of polymer concrete, as a results Since RCSS has spherical shape and high density, up to replacement ratio of 100%, increases concrete fluidity under same polymer content and decrease polymer content in order to secure the same fluidity

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.66-67
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• 2013

Replacing a large amount of ground granulated blast furnace slag is limited because early age strength is low due to latent hydraulic property despite excellence of long-term strength. This study aimed to examine produceableness of high-activated ground granulated blast furnace slag using slag by-product from steel process. As experimental variable, the properties of strength development were analyzed by setting fineness and replacement ratio of slag by-product, curing conditions, and W/B. The results of study showed that high-activated ground granulated blast furnace slag using slag by-product as an activator improve the compressive strength of mortar. It is expected to be used as binder for secondary product of concrete considering curing and mixing conditions because high-activated ground granulated blast furnace slag can be hydrated by itself.

• Computers and Concrete
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• 제16권2호
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• pp.261-274
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• 2015

This study established the standard recommended values and expansion fracture threshold values for the content of steel slag in controlled low-strength materials (CLSM) to ensure the appropriate use of steel slag aggregates and the prevention of abnormal expansion. The steel slags used in this study included basic oxygen furnace (BOF) slag and desulfurization slag (DS), which replaced 5-50% of natural river sand by weight in cement mixtures. The steel slag mortars were tested by high-temperature ($100^{\circ}C$) curing for 96 h and autoclave expansion. The results showed that the effects of the steel slag content varied based on the free lime (f-CaO) content. No more than 30% of the natural river sand should be replaced with steel slag to avoid fracture failure. The expansion fracture threshold value was 0.10%, above which there was a risk of potential failure. Based on the scanning electron microscopy (SEM) analysis, the high-temperature catalysis resulted in the immediate extrusion of peripheral hydration products from the calcium hydroxide crystals, leading to a local stress concentration and, eventually, deformation and cracking.

• 한국농공학회논문집
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• 제64권4호
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• pp.65-72
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• 2022

For sustainable development in the construction industry, blast furnace slag has been used as a substitute for cement in concrete. In contrast, ferronickel slag, which is the by-product generated during smelting to ferronickel used in the manufacturing of stainless steel and nickel alloys, has a limitation to use as a binder and an aggregate due to its expansive characteristics. Recently, stabilization technology of ferronickel slag has been improved and studies have been carried out to utilize ferronicke slag as fine aggregate in concrete. Therefore, in this study, basic mechanical properties of concrete used in ferronickel slag aggregate was evaluated. The compressive strength (24, 30, 40 MPa) and replacement rate of ferronickel slag aggregate (0, 10, 25, 50%) were considered as experimental variables. As a result of test, concrete replaced fine aggregate with 25% ferronickel slag aggregate showed superior performance in the compressive strength and flexural strength.

• The Korean Journal of Ceramics
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• 제5권1호
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• pp.35-39
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• 1999

For many years, alkali activated blast furnace slag cement containing no ordinary portland cement has received much attention in the view of energy saving and its many excellent properties. We examined the structural change of slag glass which was activated by alkali metal compounds using IR spectroscopy. The properties of hydrated products and unhydrated slag grains was characterized by XRD and micro-conduction calorimeter. Ion concentration change in the liquid during the hydration of blast furnace slag was also studied to investigated the hydration mechanism.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회 논문집(I)
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• pp.105-110
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• 1998

The propose of this study is to examine the mechanical properties of mortar using ground granulated blast-furnace(GGBF) slag. In this study, the mortar replaced by varying fineness and content of GGBF slag is investigated through the change of compressive strength, chemical resistance and weight loss. As the result, it has been found that GGBF slag increase somewhat higher flow value and compressive strength. In addition, the chemical resistance of motar using GGBF slag shows higher flow that of motar not containing GGBF slag.