• Resources Recycling
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• v.8 no.5
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• pp.44-50
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• 1999

The sbdy iwestlgaled ihc propa-ties of Lhe dust\ulcorner rrom fe~~oallomya ~~ufacturTeh. e chemical composition, cornpasitlon material, p d c l e sire md shapes of the bulk dust, sired dust and magnetically separated durl were mvesligaled. As the re\ulcornerulL, we suppose that the dust from &gh Carbon Fenama~~gunesMc anuiact~vingP rocess is not sufiicient as solulce material of Mn because of ale low Mn canlenl (13.5%) and complicaled composition mate~ial. The dust from Bug F!lter or AOD Proccss is mi~inlym ade up of 0.2-2 pm Mn30, (Hausmam~iu)p iutlde in spherical shape and thc Mn content is 63.190.The dust from Cooler of AOD Process is inninly made up of coarse Ca(O1-Or)zM. n,FeyO,, SiO, and fine Mn30d.

• Resources Recycling
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• v.28 no.5
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• pp.30-41
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• 2019

Global production of zinc is about 13 million tons and zinc is the fourth-most widely used primary metal in the world following iron, aluminum and copper. When zinc is recycled to produce secondary zinc, it can save about 75 % of the total energy that is needed to produce the primary zinc from ore, and in therms of $CO_2$ emissions reduced by about 40 %. However, since zinc is mainly used for galvanizing of steel, the recycling rate of zinc is about 25 %, which is lower than other metals. The raw materials for recycling of zinc include dusts generated in the production of steel and brass, sludge in the production process of non-ferrous metals, dross in the melting of zinc ingots or hot dip galvanizing, waste batteries, and metallic scrap. Among them, steelmaking dust and waste batteries are most actively recycled up to now. Most of the recycling process uses pyrometallurgical methods. Recently, however, much attention has been given to a combined process of pyrometallurgical and hydrometallurgical processes.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.32 no.4
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• pp.143-150
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• 2022

Geopolymers were made by mixing IGCC slag and aluminum smelted waste and their properties were compared with those of IGCC slag based geopolymers. When two raw materials were mixed, the highest compressive strength was obtained at 1.78 of Si/Al ratio. Because the change in compressive strength and density was not so sensitive by the change in Si/Al ratio; that is, the permissible range of Si/Al ratio mixing ratio is broad, it was speculated this broad permissible range would be advantageous for commercialization. The Compressive strength of geopolymers including red mud was higher than that of IGCC based ones and the safety was confirmed by TCLP test. Therefore, it was concluded that the making geopolymers by mixing red mud not only enhances the properties of geopolymers but also gives a recyclability as safe construction materials.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.5
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• pp.189-196
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• 2007

The purpose of this study was to analyze steel corrosion resistance of concrete containing copper slag. The specimens were made with normal portland cement and pozzolan materials with various replacement ratio and with W/B ratio ranging from 35% to 55%. Compressive strength, coefficient of chloride diffusion, corrosion area ratio and weight reduction ratio were determinated for the test. The results show that the concrete with pozzolan materials is superior resistant to chloride ions compared to the concrete without pozzolan materials. It was observed that blast furnace slag replacement ratio of 20% gives the best results with respect to chloride ion penetration and corrosion tests and observed that copper slag replacement ratio of 10% gives the seperior resistance compared to normal concrete.

• Resources Recycling
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• v.26 no.3
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• pp.69-78
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• 2017

Magnesium has been used as parts of vehicles, case materials of notebook PC and mobile phone, and its demand has been increasing recently. Its extraction technologies were classified according to the two major reduction methods: the fused salt electrolysis and the thermal reduction method. A research on the extraction of magnesium from magnesite which has been being carried out at KIGAM was briefly introduced here. Magnesium was prepared using a fused salt electrolysis method through preparation of anhydrous magnesium chloride with lab scale experiments.

• Resources Recycling
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• v.19 no.6
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• pp.27-35
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• 2010

Rare earth alloys and compounds are the raw materials for the manufacture of advanced materials. Although domestic monazite ores have been found, there are some difficulties in recovering rare earth from these ores. Rare earth ores are found in few countries and these countries put an embargo on the export of rare earth ores for the protection of their industry. We gathered some information on the hydrometallurgical and pyrometallurgical processes to recover rare earths from bastnasite, monazite, and xenotime which consist of 95% of the total rare earth ores. Since rare earth with the purity more than 6N is needed for use in advanced materials, some separation methods such as fractional crystallization, precipitation, ion exchange, and solvent extraction were introduced.

• Resources Recycling
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• v.27 no.6
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• pp.3-10
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• 2018

Tungsten is a metal with high melting point and used as a raw material for the production of super alloys. Tungsten exists as $WO{_4}^{2-}$ in alkaline solution. As solution pH decreases, polymerization reaction of $WO{_4}^{2-}$ occurs to result in the precipitation of tungstic acid. The hydrometallurgical process for the recovery of tungsten from ores or secondary resources can be classified as acid and alkaline leaching. In selecting a process for the recovery of pure tungsten from secondary resources, the nature and concentration of impurities in the secondary resources and the manufactured tungsten materials should be considered.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.4
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• pp.213-218
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• 2009

Electrowinning process recovers uranium with actinide elements from spent fuels and is a key step in the Pyroprocessing because of proliferation resistance. An analysis of heat transfer of the Electrowinning cell was conducted to develop basic tool for designing engineering-scale Electrowinner. For the calculation of the heat transfer, ANSYS CFX commercial code was adapted. As a result of the calculation, the vertical Heating Zone length had great effect upon temperature of LiCl-KCl eutectic salt. To maintain constant temperature in the salt, the Heating Zone length should be three times longer than the height of the salt. However, the argon and salt temperatures were barely affected by the Cooling Zone length. The temperature under the Cell cover was mainly influenced by the number of the cooling plates. When the cooling plates were installed more than the number of 5, temperature under the cover was maintained below $250^{\circ}C$. These temperature properties had similar tendency toward the temperature of the Cell which was measured from experiments, Simulated heat transfer information from this study could be used to design engineering-scale Electrowinner.

• Resources Recycling
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• v.25 no.1
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• pp.40-47
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• 2016

Nickel laterite ore is classified into two principal ore types: saprolite (silicate ore) and limonite (oxide ore). Saprolite-type ore characterized by high magnesia and silica contents is treated by pyrometallurgy process. On the other hand, limonite-type ore is subjected to hydrometallurgy process to produce nickel products. Hydrometallurgy process requires that a raw material to meet the demands that Si+Mg contents lower than 10% and Fe content over than 40%. It is therefore required that separation of saprilite-type ore to use nickel laterite ore as a raw material for hydrometallurgy process. In this study, separation of sparolite-type ore and limonite-type ore from nickel laterite ore from New Caledonia has been tried by dry classification. The results show that -5 mm size fraction and +5 mm size fraction of the nickel laterite ore contains mainly limonite-type ore and saprolite-type ore, respectively. To understand the moisture content of the raw ore on the dry classification, nickel laterite ore with different moisture contents of 23.0% and 9.1% were subjected to the dry classification. The results show that drying of the ore makes the separation more efficient as the amount of the fine product, that can be subjected to hydrometallurgy process without further separation or drying operations, was increased.

• Journal of Conservation Science
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• v.34 no.6
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• pp.581-593
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• 2018

Studies on ancient iron production technologies still have challenges to overcome, although there have been many results that have enabled us to understand these old technologies. The purpose of this study is to propose a suitable temperature condition for smelting experiments. The target for reconstruction is a smelting-smithing process in the ancient Jungwon area, and the experiment was designed on the basis of published research, such as archaeological evidence. Experiment A was performed at a low temperature to produce low-carbon iron, while Experiment B was conducted at a relatively high temperature to synthesize high-carbon iron. In addition, the low-carbon iron proved to be suitable for the smithing process. Moreover, aspects such as the microstructure and chemical composition of the slag and the surface condition of the furnace wall showed that the low-temperature smelting process was closer to the ancient method. It is important to mention the premise that the reconstruction of ancient technology can be achieved when the results of an experiment replicate the conditions of a real site. The results show that direct smelting, which produces low-carbon iron bloom under a low-temperature condition, should be the subject of smelting experiments concerning the iron production technologies of the ancient Jungwon area.