• Journal of the Korea Concrete Institute
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• v.21 no.5
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• pp.581-588
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• 2009

An amount of electric arc furnace slag, by-products generated in iron manufacture, is being increased. Therefore, it is required to recycle the electric arc furnace slag. Currently, it is possible to use the electric arc furnace slag as the aggregates of the concrete through the insurance of volume stability but not in the past because of the expansibility of f-CaO and f-MgO. In this study, simple beam tests via Ichinose method were performed to estimate the bond properties of reinforced concrete (RC) beams using the electric arc furnace slag. The results of the test showed that the showed that specimens using the electric arc furnace oxidizing slag aggregates have similar or more bond capacity relative to the specimen of natural aggregates. Especially, bond capacity of the specimens using the slag aggregates was almost one and a half times higher than a specimen using natural aggregates.

• Resources Recycling
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• v.24 no.6
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• pp.31-37
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• 2015

Ground granulated blast-furnace slag (GGBFS) which is by-product of steel industry has been recycled as a cement admixture though the other steel slags are used as aggregates. In this study, the electric arc furnace slag (EAFS) was used as a cement admixture after the reduction of iron oxide in the slag at the interface of molten slag and water quenching. Consequently, the reformed EAFS (REAFS) had higher grindability than that of granulated blast furnace slag. And in mortar tests, the strength properties of specimens using REAFS were 98% of plain specimens of GGBFS upto 20% replacement ratio of GGBFS with REAFS.

• Resources Recycling
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• v.6 no.1
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• pp.23-28
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• 1997

Iron and slag were prepared by melting mixed industrial wastes in an induction furnace. The wastes were steel can, limestone sludge, waste foundry sand, coal fly ash, and glasses. The effects of their mixing ratio on the charactenstics of the meltcd slag were investigated. The wastes were melted to slag under the constant basicity of 1.2. It was found that the major phases of the slag were P-C,S and C,AS and then ratio was determined by the mixing ratio af waste materials. The recovery of iron was about 93-95%. The feasibility of using the slag as the aggregate was confirmed by thc elution and campression tests.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.404-408
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• 2001

This paper focuses on the pilot-scale investigation of direct recycling of electric arc furnace (EAF) stainless steelmaking dust. The direct recycling of EAF dust is to make pellets with the mixture of the dust and the reducing agent carbon, then introduce the pellets to the EAF. The valuable metals in the dust are reduced and get into the steel as the alloying elements. Experiments simulating direct recycling in an EAF were performed using an induction furnace. But it seems difficult to reduce all metal oxides in the dust so that some metal reducing agents added in the late stage of reduction process. The valuable metals in the dust were reduced partly by carbon and partly by metal reducing agent for the economical concern. The recovery of iron, chromium and nickel from the flue dust and the amount of metal oxides in the slag were measured. The results showed that the direct recycling of EAF stainless steelmaking dust is practicable. It wes also found that direct recycling of flue EAF stainless steelmaking dusts does not affect the chemistry and quality of stainless steel produced in the EAF. It is benefit not only for the environmental protection but also for the recovery of valuable metal resources in this way.

• International Journal of Highway Engineering
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• v.17 no.1
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• pp.25-33
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• 2015

PURPOSES : This paper, presents the results of a laboratory study aimed to verify the suitability of a particular type of Electric Arc Furnace (EAF) steel slag to be recycled in the lithic skeleton of both dense graded and porous asphalt mixtures for flexible pavements. METHODS : Cyclic creep and stiffness modulus tests were performed to evaluate the mechanical performance of three different asphalt mixtures (dense graded, porous asphalt, and stone mastic) prepared with two types of EAF steel slag. For comparison purposes, the same three mixtures were also designed with conventional aggregates (basalt and limestone). RESULTS : All the asphalt mixtures prepared with EAF steel slag satisfied the current requirements of the European standards, which support EAF steel slag as a suitable material for flexible pavement construction. CONCLUSIONS : Based on the experimental work, the use of waste material obtained from steel production (e.g. EAF steel slag) as an alternative in the lithic skeleton of asphalt mixtures can be a satisfactory and reasonable choice that fulfills the "Zero Waste" objective that many iron and steel industries have pursued in the past decades.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.4
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• pp.571-578
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• 2004

The purpose of this study is to estimate of emission factors of the air pollutants for the melting furnaces for the iron and steel industry. The result of this study is able to obtaine the emission factor of particulate matters (PM), sulfur dioxide. nitrogen oxides for melting furnace. The emission factors of each pollutants were as follows : - the emission factor varied between 6.13E-03~6.12E-01 kg/ton for PM -1.59E-01~2.45E+00kg/ton for $SO_2$ - 6.82E-02~6.88E-01 kg/ton for NOx, respectively. Analysis of the differences in the emission factors of ours and U.S. EPA's yielded the following results for the Wilcoxon method : p>0.05. The statistical analysis showed no differences in the our emission factors and U.S. EPA's

• Korean Journal of Materials Research
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• v.16 no.5
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• pp.336-340
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• 2006

Fluorspar has been essential flux in steelmaking process. The main effects of fluorspar addition are lowering of the viscosity and melting temperature of slag. In recent years, due to the increasing price and environmental problem of fluorspar, various types of fluorspar substitute have been investigated. In this study, iron oxide by-products such as sinter dust, basic oxygen furnace (BOF) sludge and mill scale were developed as a substitute in terms of waste recycling. Several plant trials were carried out by addition of briquetted substitutes of $4{\sim}6$ kg/ton to compare with the fluorspar of $0.7{\sim}1$ kg/ton. The substitutes showed a similar behavior of slag formation, phosphorus removal and MgO saturation content.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.240-241
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• 2000

Sapphire fiber has been used to provide an optical path for the total radiation pyrometry. In measuring the temperature, we use the two-color detector, which consists of a high-performance Silicon detector mounted in a "sandwich" configuration over a Germanium detector. Sapphire fiber can withstand high temperature in the molten steel for two and a half hours. The maximum value of the error is the $\pm$2.5$^{\circ}C$ in the range of 152$0^{\circ}C$~1$600^{\circ}C$. This paper presents the simple scheme for measuring the molten steel temperature in the blast furnace of the iron ＆ steel making process.g process.

• Journal of Korea Foundry Society
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• v.23 no.3
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• pp.122-129
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• 2003

The abilities and fading behaviors of 5 different inoculants were evaluated by the thermal analyses of the melts which were held at constant temperature after addition in induction furnace. The silicon content was preserved at the high holding temperature of 1,450${\sim}$1,500$^{\circ}C$, which reduced by oxidation at the low one. The inoculation temperature should be higher to obtain better and reproducible result. The inoculation performance of 1%Ba-Fe-Si was the best on the bases of effect and fading behavior.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.5 s.98
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• pp.98-103
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• 1999

The application field of porous mold is more and more expended. A mixture of alumina and cast iron is used for making porous mold using slip and vacuum casting method in this study. Slip casting is a process that slurry is poured into silicon rubber mold, dried in vacuum oven, debinded and sintered in furnace, In this procedure, slurry is composed of powder, binder, dispersion agent, and water. Vacuum casting is a technique for removing air bubbles existed in the slurry under vacuum condition. Since ceramics has a tendency of over-shrinkage after sintering, cast iron is used to compensate dimensional change. The results shows that sintering temperature has a great effect on characteristics of alumina-cast iron composite sintered parts. Finally ceramic-metal composite sintered mold can be used for aluminum alloy casting of shoe mold using this process.