• Journal of Conservation Science
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• v.35 no.4
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• pp.373-383
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• 2019

We characterized the smelting process and smelting furnace through scanning electron microscopy-energy dispersive spectroscopy, wavelength dispersive X-ray fluorescence, X-ray diffraction, and raman micro-spectroscopy with 13 relics including slags and furnace walls excavated from square-shaped building sites and pits of the Three Kingdoms site at the Ungyo site section I. Our results revealed that the principal components were FeO and SiO₂; and CuO, PbO, and ZnO were contained in small quantities. Furthermore, fayalite, magnetite, augite, copper, and cuprite were found. High contents of FeO or SiO₂ components seem to have been added to form fayalite to remove gangue in the smelting process. The relatively low content of S detected in the copper prills suggests that roasting was performed well. Cristobalite and mullite, which are minerals that indicate high-temperature found in the furnace wall, show that the smelting temperature was higher than 1,250℃. The findings of this study show a high possibility that the Wanju Ungyo site is smelting remains of copper ores, which are nonferrous metals, rather than iron. Various smelting byproducts excavated in this area in the future will help us better understand the copper smelting process that may have been performed since ancient times.

• Journal of Magnetics
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• v.21 no.2
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• pp.204-208
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• 2016

This paper demonstrates the key parameter detection for smelting of submerged arc furnace (SAF) based on magnetic field radiation. A magnetic field radiation model for the inner structure of SAF is established based on relative theory of electromagnetic field. A simple equipment of 3D magnetic field detection system is developed by theoretical derivation and simulation. The experiments are carried out under the environment of industrial field and AC magnetic field generated by electrode currents and molten currents in the furnace is reflected outside of the furnace. The experimental results show that the key parameters of smelting including the position of electrode tip, the length of electric arc, and the liquid level of molten bath can be achieved. The computed tomography for SAF can be realized by the detection for smelting.

• Journal of Conservation Science
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• v.34 no.4
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• pp.273-281
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• 2018

$Ji{\check{u}}di{\grave{a}}n$ iron production site in China is a relic smelting site, which in the past produced pig iron. In this study, scientific analysis of the smelting furnace and collected slag was conducted to reveal some aspects of the ancient Chinese smelting technique. A 3D model of the smelting furnace showed a narrow lower part and an upper section which increased in diameter upwards. Although the smelting furnace relic does not include the upper part and its complete shape cannot be predicted, the remaining part suggests that the furnace had a larger diameter in the central part compared to the upper and lower parts. Most of the collected slag was completely vitrified. Long prismatic fayalite was observed in the matrix of some samples. The iron particles contained phosphorus, which could not be discharged during smelting work. In addition, as the $CaO/SiO_2$ ratio was 0.42 or lower in the results of the content analysis, no CaO slag former had been added. However, the ratio of $CaO/SiO_2$ to $Al_2O_3/SiO_2$ did not have a constant trend. This needs to be investigated in a further study.

• Journal of Magnetics
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• v.21 no.3
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• pp.322-329
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• 2016

In this paper, we propose an array sensing detection method for smelting of submerged arc furnaces (SAF) based on electromagnetic radiation. AC magnetic field generated by electrode currents and molten currents in the furnace is reflected outside of the furnace. According to the spatial distribution of electromagnetic field a radiation model of SAF is built. We design a 3D magnetic field sensing array system in order to collect the magnetic field information. Through the collected information, the current distribution characteristics of SAF are described and the key parameters of smelting are obtained. Theoretical simulation and field test show that the curves acquired by the sensing array can accurately reflect the information of the relative displacement when the relative displacement between the array and electrode is 10 cm. Compared with the detection method of 3D single point, the proposed array sensing method of magnetic field obtains better results in terms of real-time and accuracy, and has good practical value for industrial measurement.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.375-380
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• 2001

MF is a half shaft blast furnace which has been developed at Mitsui Miike Smelter in the 1960’s to treat vertical retort residue. The MF has also been tested for treatment of various recycling materials and wastes. Now various secondaries and wastes (EAF dust, zinc leaching residue, Cu sludge, etc ) are mainly treated. Powder materials are briquetted with reductant before being fed to the furnace. Products are crude zinc oxide, matte, non-hazardous slag and steam. Zinc and lead are recovered in oxide dust, and copper and silver are recovered in matte. The MF can be widely applied to many kinds of materials which contain such non-ferrous metal-valuables. In addition, the improvement in operation and technology has effectively made the unit capacity much larger. The MF now has many advantages for these treatment processes.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2004.05a
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• pp.53-58
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• 2004

동제련 공정중 고품질의 전기동을 효율적으로 생산하기 위해서는 Anode중에 적정량의 비소(As)가 필요하다. 그러나 Cu가 약30% 함유되어 있는 동정광에 함유된 비소는 Smelting Furnace 용련과정에서 비소 특성상 약 70%가 Offgas로 휘발되어 황산공장으로 유입 처리되고, 나머지 30%만 아노드(Anode)로 유입되므로 별도로 전련공정에서 발생된 Cu-Cement(비소 함유)를 정제로에 Recycle 하고 있으며, 부족시 추가로 비소 Source를 구입하여 정제로에 투입하고 있다. 이를 효과적으로 해결하기 위하여 현재 위탁처리를 하고있는 As가 함유된 폐수처리 2차 중화시 발생된 2차 Cake 60W.T/D중 30W.T/D를 기존 Converter Slag 건조용 Rotary Dryer를 이용하여 Converter Furnace에 Recycle 함으로써 전련 Anode에 필요한 비소를 공급하고, 또한 2차 Cake에 혼입되어 있는 CaO 활용으로 부재료 절감, 유가금속(Cu등) 회수등 및 2차 Cake 위탁처리비용을 절감하며, Cu-Cement는 Smelting Furnace에 투입하여 정제로 투입시 발생되는 문제점들을 동시에 해결코자 한다.

• Korean Journal of Heritage: History & Science
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• v.57 no.2
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• pp.6-25
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• 2024

This study concentrated on a report on the results of smelting experiments conducted eight times by the Jungwon National Research Institute of Cultural Heritage, put together the goals and results of the operation, and examined changes in the content of experiments and in the experimental results. First, changes related to operation, such as the ratio of raw materials to fuel and the presence or absence of additives, were reviewed depending on the operation goal. In addition, the results of metallurgical analysis of raw materials, formations, and byproducts were summarized and reviewed by comparing them with materials excavated from the ruins. The operation method varied up to the eighth smelting experiment in terms of iron ore roasting, additives, and raw material/fuel ratio. After reviewing the results again, pure iron with a low carbon content began to be confirmed through metallurgical analysis. As a result, it was confirmed that the charging ratio of raw materials and fuel plays an important role depending on the purpose of production. In addition, most of the products are gray cast iron, and it was deemed that this is due to changes in the internal structure of the pig iron while it was left in the furnace for a long time. The iron was an ingot that was in a molten state even though the carbon content did not reach 4.3%, where the process reaction takes place, and it was deemed to have been caused by excessive operating temperature. Based on the previously reviewed results and the structure and shape of the experimental furnace used in other ironmaking technology restoration experiments, this study finally attempted to restore the structure of an ancient iron smelting furnace, including the furnace's upper structure. By comprehensively referring to the remaining conditions of the excavated iron smelting furnace and the characteristics of the blow pipe, the form of the ancient iron smelting furnace was subdivided into six categories: furnace wall thickness, furnace height, blower height, blow pipe size, furnace inner wall shape, and top shape, and a restoration plan was proposed. To improve the problems of the restoration plan and the Jungwon National Research Institute of Cultural Heritage's experiments that have been conducted through continuous trial and error, an experiment that reflects changes in operating methods by lowering the furnace height and controlling the blowing volume is necessary.

• Korean Journal of Heritage: History & Science
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• v.48 no.4
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• pp.138-153
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• 2015

A Jincheon Seokjangri B23 furnace was reconstructed and iron smelting experiment was performed to investigate an ancient Baekjae iron production process. The work mainly described in this paper is the $1^{st}$ and $2^{nd}$ experiments among the several experiments carried out at Jungwon National Research Institute of Cultural Heritage. Iron ore(magnetite) and oak charcoal were used as a source and a foot bellow was used for air supply. Common results of the experiments are masses of iron, slag and charcoal formed in the furnace. Most iron lumps were formed nearby the tuyere rather than the area of tapping hole. Metallographic and chemical analysis shows that the iron lumps can be used for either forge or cast depending on their carbon content. Low Fe content and glassy texture of the inner slags suggest that the operation environment was quite reducing. Based on the results of the iron smelting experiments, measurements and analysis, various information was obtained regarding physical-chemical and metallurgical processes of the ancient iron smelting process. It is firmly believed that its undisclosed contents can be revealed more in depth with continual reconstitution experiments.

• Resources Recycling
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• v.12 no.2
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• pp.21-27
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• 2003

Smelting reduction technique in arc furnace was applied for the recovery of valuable metal such as V from LD slag. In the present study, the parameters for increasing the reduction rate and the reduction efficiency were selected by changing the oxide additives, melting temperature and basicity. The optimum condition for LD-slag reduction was achieved by $Al_2$$O_3$ addition. The reduction ratio of V was increased in increasing the basicity.

• Archives of Metallurgy and Materials
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• v.65 no.1
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• pp.349-355
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• 2020

Copper slag differs by chemical composition and structure, depending on the type of processing. Copper slag typically contains about 1 wt.% copper and 40 wt.% iron depending upon the initial ore quality and type of furnace used. The aim is to produce a typical foundry pig iron with the chemical composition of C > 3.40 wt.%, Si 1.40 to 1.80 wt.%, Mn 0.30 to 0.90 wt.%, P < 0.03 wt.% and S < 0.03 wt.% from copper slag. But foundry pig iron manufactured from copper slag contains a high sulphur content. Therefore, this study examines how to conduct desulphurization. Desulphurization roasting and reduction smelting with desulphurization additives used to remove sulphur from the copper slag. The results showed that desulphurization effect of desulphurization roasting is poor but when combined with reduction smelting with CaO addition is possible to manufacture low sulphur pig iron from copper smelting slag.