• Journal of the Korean Ceramic Society
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• v.52 no.5
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• pp.389-394
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• 2015

Direct reduced iron was made using an electric furnace. The reduction ratio of direct reduced iron varied depending on the grade of iron ore. Coal played an important role as a reducing agent in making the direct reduced iron. The coal must contain a suitable amount of volatile components having high calorie values and low impurity content. In this study, oxidized pellets were directly reduced using anthracite as a reductant in an electric furnace. Direct reduction behaviors of hematite and magnetite pellets were confirmed in a coal-based experiment. Reduction behaviors were demonstrated by analyzing the chemical compositions, measuring the reducibility, and observing the phase changes and microstructure. The superior reducibility of hematite pellets can be ascribed to their high effective diffusivity, which is due to their high porosity. The quickly after reducing for 40min and achieves a high value at the end of the reduction.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.1
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• pp.138-143
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• 2003

Ultrasonic flowmeters have more advantages than the conventional method using pressure-difference. In these reasons, many advanced nations are already selling the commercial model. In RIST, we have been developed ultrasonic gas flow meter for the localization since a project was been contracted with POSCO in 1997. This paper describes a new ultrasonic gas flowmeter. This ultrasonic gas flowmeter is developed for accurate measurement of gases in a harsh environmental conditions. It is especially suited for measuring LDG. COG, BFG gases produced in iron & steel making process. In this study, we had developed the commercial model about the first tested model and applied a completed system to the POSCO gas line. Its performance has been proven by extensive field tests for several months in POSCO, iron & steel making company.

• Journal of Conservation Science
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• v.2 no.2 s.2
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• pp.25-30
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• 1993

Materials (refractory, stone) of iron making furnace excavated from Kalcheon were investigated by the scanning electron microscopy(SEM) with an energy dispersive X-ray analysis (EDAX), X-ray fluorescence(XRF), and X-ray diffraction(XRD). Chemical composition of the refractory materials were $SiO_2(68.74\%),\;Al_2O_3(18.40\%),\;CaO(0.42\%),\;MgO(1.04\%)\;and\;K_2O(2.26\%)$ in weight ratio, which were the typical components presented in common clay. The results of chemical analysis for the stone and the glaze coated, alkali ion(K, Na, Ca) components of the glaze contained high concentration than that the stone. It was suggested that this change had a close relationship with the kinds of fuels used.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.245-253
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• 2004

There has been recent demand for extending the life of age-degraded structures and equipment by such techniques as diagnosis, maintenance, safety assessment, and estimating residual life on iron-making plants and hydraulic, thermal, and nuclear power plants. These techniques take into account comprehensive scenarios that may cause malfunction and structural damage and allow an assessment of risk based on the likely scenarios. In particular the safety assessment and residual life estimation of age-degraded ships and equipment facilities require consideration of various factors such as mechanical and thermal stresses, corrosion, hardness, load variation due to changes of operating condition, crack generation and strength reduction of material by fatigue. In this study, a detail thermal stress analysis, one of useful techniques of safety assessment and maintenance, is performed on a blast furnace by using general FEM code (MSC/NASTRAN).

• Journal of the Korea Furniture Society
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• v.11 no.1
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• pp.1-11
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• 2000

While furniture making in general has been traditionally regarded as labor-intensive industry, the making of metal furniture has immense potential in terms of its growth and as a value added industry. Granted that the technology and designing of metal furniture in Korea are still behind the standards enjoyed by the developed nations of the world, still its future here is promising when we consider the comparatively short history of its industry, Korea depends on imports from abroad for almost all the natural resources she needs for industry. Metal (especially iron) industry is, however, one field where she has some advantage over other nations. Korea is a major producer of iron and her technology in this field is competitive in the international market. When viewed from the points of environment and ecology metal furniture has good points, as metals are recyclable when they are discarded and collected properly according to their reusability. This adds to the merits its industry has here as this country, with her limited natural resources, has yet to solve the pressing problem of disposing ever-increasing waste matter from homes and factories.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.76-81
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• 2001

Ultrasonic flowmeters have more advantages than the conventional method using pressure-difference. In these reasons, many advanced nations are already selling the commercial model. In RIST, we have been developed ultrasonic gas flow meter for the localization since a project was been contracted with POSCO in 1997. This paper describes a new ultrasonic gas flowmeter. This ultrasonic gas flowmeter is developed for accurate measurement of gases in a harsh environmental conditions. It is especially suited for measuring LDG, COG, BFG gases produced in iron & steel making process. In this study, we had developed the commercial model about the first tested model and applied a completed system to the POSCO gas line. Its performance has already well been proven by extensive field tests for several months in POSCO, iron & steel making company.

• 한국가스학회:학술대회논문집
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• 1998.09a
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• pp.9-12
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• 1998

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.3
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• pp.246-253
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• 2002

This paper describes the development and the field application of the ultrasonic gas flowmeter for accurate measurement of the volumetric flow rate of gases in a harsh environmental conditions in iron & steel making company. This ultrasonic flowmeter is especially suited for measuring LDG, COG, BFG gases produced in iron & steel making process. This is a transit time type ultrasonic flowmeter. We have developed the transmitting & receiving algorithm of ultrasonic wave and the ultrasonic signal processing algorithm to develope a transit time type ultrasonic flowmeter. We have evaluated the performance of ultrasonic flowmeter by the calibration system with Venturi type standard flowmeter. We has confirmed its reliability by extensive field tests for a year in POSCO, iron & steel making company. Now we have developed the commercial model of ultrasonic flowmeter and applied to the POSCO gas line.

• Korean Journal of Heritage: History & Science
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• v.53 no.2
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• pp.4-23
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• 2020

The purpose of this study was to explore the diversity of Korea's iron casting technology and to examine various casting methods. The study involved a literature review, analysis of artifacts, local investigation of production tools and technology, and scientific analysis of casting and cast materials. Bellows technology, or Bulmi technology, is a form of iron casting technology that uses bellows to melt cast iron before the molten iron is poured into a clay cast. This technology, handed down only in Jeju Island, relies on use of a clay cast instead of the sand cast that is more common in mainland Korea. Casting methods for cast iron pots can be broadly divided into two: sand mold casting and porcelain casting. The former uses a sand cast made from mixing seokbire (clay mixed with soft stones), sand and clay, while the latter uses a clay cast, formed by mixing clay with rice straw and reed. The five steps in the sand mold casting method for iron pot are cast making, filling, melting iron into molten iron, pouring the molten iron into the cast mold, and refining the final product. The six steps in the porcelain clay casting method are cast making, cast firing, spreading jilmeok, melting iron into molten iron, pouring the molten iron, and refining the final product. The two casting methods differ in terms of materials, cast firing, and spreading of jilmeok. This study provided insight into Korea's unique iron casting technology by examining the scientific principles behind the materials and tools used in each stage of iron pot casting: collecting and kneading mud, producing a cast, biscuit firing, hwajeokmosal (building sand on the heated cast) and spreading jilmeok, drying and biyaljil (spreading jilmeok evenly on the cast), hapjang (combining two half-sized casts to make one complete cast), producing a smelting furnace, roasting twice, smelting, pouring molten iron into a cast, and refining the final product. Scientific analysis of the final product and materials involved in porcelain clay casting showed that the main components were mud and sand (SiO₂, Al₂O₃, and Fe₂O₃). The release agent was found to be graphite, containing SiO₂, Al₂O₃, Fe₂O₃, and K₂O. The completed cast iron pot had the structure of white cast iron, comprised of cementite (Fe₃C) and pearlite (a layered structure of ferrite and cementite).

• Economic and Environmental Geology
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• v.56 no.4
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• pp.475-499
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• 2023

To infer the provenance of raw iron materials utilized in iron production at the archaeological sites in Gyeongsang province, petrographic and geochemical analyses were conducted for smelting samples and major iron ores sourced from ore deposits. The smelting samples excavated from various iron archaeological sites were classified into different types according to their refining processes, such as iron bloom, iron bloom slag, pig iron, pig iron slag, forging iron flake, smithery iron, iron flake, and arrowhead. These samples exhibited discernable differences in their mineralogical components and texture. The enrichments of major elements such as aluminum and calcium in silicate minerals of the residual slags and the high contents of trace elements such as nickel and copper in some iron-making relics reflect the characteristics of raw iron ores, and thus can be regarded as potential indicators for inferring the provenance of source materials. In particular, the compositional ranges of Pb-Sr isotope ratios for the iron smelting samples were classified into three categories: 1) those exhibiting similar ratios to those of the raw iron ores, 2) those enriched in strontium isotope ratio, and 3) those enriched in both lead and strontium isotope ratios. The observed distinct Pb-Sr isotope characteristics in the iron smelting samples suggest the potential contribution of specific additives being introduced during the high-temperature refining process. These results provide a new perspective on the interpretation of the provenance study of the iron archaeological samples in Gyeongsang province, particularly in terms of the potential contribution of additives on the refining process.