• Journal of the Korean Society for Heat Treatment
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• v.36 no.1
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• pp.22-32
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• 2023

In general, when scrap is dissolved in an electric arc furnace, the amount of electric furnace steel dust (EAFD) generated is about 1.5% of the scrap charge amount, and the electric furnace steel dust collected by the bag filter is charged into the Rotary Kiln or Rotary Hearth Furnace (RHF), and the zinc component is recovered as crude zinc oxide, at which time a clinker of Fe-Base is generated. In this research, first, for the efficient resource conversion of electric furnace steel dust, a reduction and roasting experiment was conducted and the reaction kinetics was examined. As a result of the experiment, it was observed that the reduction and roasting reaction was actively conducted in the range of 1100~1150℃, and melting occurred in the range of 1250℃. In the past, this clinker was widely used as a roadbed material for road construction and an Fe-Source for cement production, but in recent years, it has been mainly reclaimed due to strengthening environmental standards. However, landfill treatment is by no means a desirable treatment method due to environmental pollution caused by leachate, expensive landfill costs, and waste of Fe resources. Therefore, in order to more actively recycle the Fe component in the clinker, first of all the clinker was pulverized into an optimal particle size, and anthracite and binder (starch) were added to the magnetic material obtained by specific gravity and magnetic separation for briquet. As a experimental results, it was possible to efficiently separate clinker as Fe component and other slag component by specific gravity and magnetic force. As a results of loading and dissolving the manufactured briquet clinker in an electric arc furnace, it was observed that the unit of power and production yield were clearly improved and the carbon addition effect in molten metal was also somewhat.

• Journal of Korea Foundry Society
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• v.31 no.6
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• pp.336-341
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• 2011

Recently, aluminium usage in the automobile industry has been increased cause of its lightweight. The aluminium has a melting-solidification process in producing line and another melting process was needed in manufacturing process. Two times of melting process for making ingot and casting not only makes the loss of time and money but contaminates the air with Sox, Nox. For this reason, the holding furnace with laminated adiabatic material was developed. This holding furnace can deliver the molten aluminium directly to the industry needing molten aluminium. Recent holding furnace has above $15^{\circ}C/h$ of cooling rate and that causes solidification of molten aluminium. The ANSYS software was used to analysis the heat transfer. The adiabatic materials were laminated with optimized arrangement and holding furnace shape was changed with optimized modelling by ANSYS analysis for reducing the cooling rate of molten aluminium in holding furnace.

• Journal of the Korea Concrete Institute
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• v.12 no.4
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• pp.49-58
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• 2000

There are many methods to improve the performance of concrete. Especially, granuated blast furnace slag. by-products used in concrete as the replacement material of cement, could contribute to improve the fluidity, resistance of chemical attack and strength of concrete. Also, it could contribute to decrease the rate of generating hydration heat, in addition to cost-down of concrete and prevention of enviromental pollution. Therefore, in order to establish the systemical application of granuated blast furnace slag in normal concrete, the engineering properties of concrete, such as fluidity, strength, setting and hydration properties etc.. was evaluated. In this study, replacement ratio of granuated blast furnace slag was 0, 30, 50, 70(%), and target slump was 8, 12, 15, 18(cm). Results from the experiment, granuated blast furnace slag showed the outstanding effects of improving the engineering properties of concrete. From now on, positive application of granuated blast furnace slag is expected in the point of improving the performance and cost-down of concrete.

• Journal of the Korean Society of Industry Convergence
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• v.8 no.3
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• pp.169-176
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• 2005

The purpose of this study is to develop the high strength crushed sand concrete in conditions of water binder ratios of 25, 30, 35% and blast-furnace slag substitutions of 0, 15, 30, 45%. Additionally, in case of water binder ratio of 30%, the maximum size of coarse aggregate is two kinds of 13, 19 mm. The conclusions of this study are as follows ; 1. The compressive strength appeared lower in early age as compared with that of plain concrete according to increasing of the blast-furnace slag substitution. But, the compressive strength was respectively 5, 6, 10% larger than that of plain concrete in case of 25, 30, 35% water binder ratios, 28 days, 30% blast-furnace slag substitution and 19mm coarse aggregate. 2. According to increasing of the blast-furnace slag substitution, the modulus of elasticity and the tensile strength of concrete increased. 3. The length change by the shrinkage increased when the larger coarse aggregate was used, and decreased according to higher blast-furnace slag substitution.

• Journal of the Korea Concrete Institute
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• v.14 no.4
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• pp.597-607
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• 2002

Electric arc furnace and converter slag are produced by about 6 millions tons in Korea at 2000 year. But compared with blast furnace slag, those are utilized only in unvalued material like landfill and road construction. There are unstable materials, like free CaO, in electric arc furnace and converter slag at steel-manufacturing process. This might cause volume expansion in concrete, if electric arc furnace and converter slag aggregates were used in concrete. This expansion may reach to crack or collapse of concrete. It is therefore settled by standard specification for concrete that electric arc furnace and converter slag aggregates have not to use in concrete. First of all, volume stability and stabilized process should be solved in electric arc furnace and converter slag aggregate to use in concrete. In this study, 6 types of aging are evaluated for effects of stabilization to reduce the expansion of electric arc furnace and converter slag. h converter slag aggregate, these types of aging are not good for volume stability for concrete aggregate, and even if converter slag aggregate is treated with aging, concrete with it has some problems that strength is reduced with curing days. But in electric arc furnace slag aggregate treated with hotwater and steam aging, the expansion of electric arc furnace slag aggregate is reduced about two times than that of converter slag aggregate, and electric arc furnace slag aggregate concrete has good results in strength compared with control concrete using crushed stone.

• Magazine of the Korea Concrete Institute
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• v.6 no.4
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• pp.113-122
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• 1994

To examine the applicabilty of the converter furnace slag from iron-works as concrete aggregate respective concrete furnace slag with contents of 20%. 40%, 60%. 80% were mixed with granulated slag, and the strength and stability tests for these specimens were followed. The slump value of the concrete mixed with converter furnace slag was higher than that of the conventional concrete. Furnace slag and granulated slag was increased as the increase of converter furnace content. The strength of the concrete mixed with converter furnace slag and granulate slag increased as an increase of converter furnace content and age. The expansion rate of the concrete mixed with converter furnace slag and granulated slag increased from 0.007% to 0.19% as the converter furnace content changed from 20% to 80%. From the above results in the strength and expansion rate, the concrete with the converter furnace content of 40% was considered to be recommandable for the stable construction of the concrete. Calculated formulas for tensile strength(${\sigma}_t$) and flexural strength(${\sigma}_f$) from the regression a.nalysis of the correlations among these compressive strength (${\sigma}_c$), tensile strength and flexural strength are as follows. ${\sigma}_t$ = 0.16952${\sigma}_c$ - 4.9313 ${\sigma}_f$ = 0.25727${\sigma}_c$ + 6.0528

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10c
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• pp.54-59
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• 1998

This experimental Study presents the flow properties of mortar Using the Blast-furnace Slag Sand. It gives following result. The substitution rate is inversely proportional to flow. But W/C ratio is directly proportional to flow. Consequently Flow characteristics of the Blast-furnace mortar is simillar to the river sand mortar.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.22-25
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• 1995

This paper shows adaptive control using RHPC(Receding Horizon Predictive Control) with equality constraint which applied to Electric Furnace. The control strategy includes monotonic weighting (improving transient response) and pre-filtering (enhancing robustness), which is effective on real process. We can observe the performance of RHPC and confirm the practical aspect of RHPC with unmodelled dynamics through the experiment of Electric Furnace. Finally, this paper verifies the feasibility of RHPC to real process.

• Journal of the Korean Ceramic Society
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• v.32 no.11
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• pp.1241-1245
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• 1995

Ultrathin oxynitride (SiOxNy) films, 8nm thick, were formed on Si(100) in furnace using O2 and N2O as reactant gas. Compared with conventional furnace grown oxide, oxynitride dielectrics show better characteristics of Qbd and I-V, and less flat-band voltage shift. Excellent diffusion barrier property to dopant (BF2) is also confirmed.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.57-59
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• 2004

Arc-furnace is one of the large loads in the electric power system. When the arc-furnace operates, it may cause a bus voltage fluctuation in the power system, because it consumes a lot of reactive power. In this paper, we simulated this phenomenon by using a PSAF program with on-site measured arc-furnace load for different amount of cutailment load.