• Economic and Environmental Geology
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• v.27 no.5
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• pp.423-440
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• 1994

The Samhwa iron ore deposit, which is of typical magnetite skarn type, is located in the Samhwadong area of Donghae city, Kangwon-do, Korea. Skarn minerals are mainly composed of garnet, clinopyroxene, vesuvianite, wollastonite and small amounts of epidote and quartz. The garnets are isotropic $(Ad_{92.82{\sim}98.37})$ or anisotropic andradite $(Ad_{45.30{\sim}75.85})$ and grossular $(Gr_{86.26{\sim}24.47})$, the clinopyroxenes are ferrosalite and salite, Homogenization temperature of gas rich two phase inclusions in garnet are $368{\sim}593^{\circ}C$, and salnities of polyphase inclusions in garnet have 33.9~68.4 equ. NaCl wt. %. Garnet grain often shows composional variation from its core to rim. In other words, Fe and Al contents in garnet vary inversely, which suggest that the variation depends upon $f_{o2}$ during skarn formation.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.173-174
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• 2006

X-ray analysis on iron ores and reduced iron powders revealed that the main acid-insoluble substances were hexagonal and tetragonal quartz, another substances were sillimanite, alumina-silicate, an unnamed zeolite, all contained Si and Al. Their particle size was in the range of $3{\sim}7\;{\mu}m$. Statistics analysis showed that the AIC for high-grade magnetite powder was $(0.130{\pm}0.010)%$) during the latest five months. The predicting value for reduced iron powder should be 0.179%. However, the testing value for reduced iron powder was $(0.192{\pm}0.014)%$. The limited difference of 0.013% might imply rare pollution coming from the reduction and milling processes. The most important step for control AIC should be the separation process of iron ore powders.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.3
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• pp.264-270
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• 2000

Quantitative analysis of iron ore sinter consisting of hematite, magnetite, calcium ferrite and slag was investigated by X-ray internal standard method. After selecting NaF and $SiO_2$as internal standard materials, the calibration curves were determined and were applied to quantitative analysis of the internal standard method. Calcium ferrite was identified as a solid solution of CaO.$2Fe_2$$O_3$with 7 wt% and 3 wt% solubility of $AI_2$$O_3$and $SiO_2$, respectively. The maximum deviation of quantitative analysis of synthetic iron ore was about $\pm$5 wt%. The contents of each mineral calculated in industrial sinter were 27~40 wt% of hematite, 20~30 wt% of magnetite, 22~33 wt% of calcium ferrite and 10~20 wt% of slag.

• Safety and Health at Work
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• v.6 no.4
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• pp.268-278
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• 2015

Background: This study aimed to assess the whole-body vibration (WBV) exposure among large blast hole drill machine operators with regard to the International Organization for Standardization (ISO) recommended threshold values and its association with machine- and rock-related factors and workers' individual characteristics. Methods: The study population included 28 drill machine operators who had worked in four opencast iron ore mines in eastern India. The study protocol comprised the following: measurements of WBV exposure [frequency weighted root mean square (RMS) acceleration ($m/s^2$)], machine-related data (manufacturer of machine, age of machine, seat height, thickness, and rest height) collected from mine management offices, measurements of rock hardness, uniaxial compressive strength and density, and workers' characteristics via face-to-face interviews. Results: More than 90% of the operators were exposed to a higher level WBV than the ISO upper limit and only 3.6% between the lower and upper limits, mainly in the vertical axis. Bivariate correlations revealed that potential predictors of total WBV exposure were: machine manufacturer (r = 0.453, p = 0.015), age of drill (r = 0.533, p = 0.003), and hardness of rock (r = 0.561, p = 0.002). The stepwise multiple regression model revealed that the potential predictors are age of operator (regression coefficient ${\beta}=-0.052$, standard error SE = 0.023), manufacturer (${\beta}=1.093$, SE = 0.227), rock hardness (${\beta}=0.045$, SE = 0.018), uniaxial compressive strength (${\beta}=0.027$, SE = 0.009), and density (${\beta}=-1.135$, SE = 0.235). Conclusion: Prevention should include using appropriate machines to handle rock hardness, rock uniaxial compressive strength and density, and seat improvement using ergonomic approaches such as including a suspension system.

• Nuclear Engineering and Technology
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• v.55 no.7
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• pp.2380-2387
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• 2023

Hyperspectral data and its ability to explore the minerals and their associated rocks have a remarkable application in mineral exploration and lithological characterization. The present study aims to explore the radiation shielding aspects of the iron ore in Kerala with the aid of the Hyperion hyperspectral dataset. The reflectance-spectra obtained from the laboratory conditions as well as from the image show various absorptions. The results from the spectra are validated with geochemical data and GPS points. The Monte Carlo simulation employed to evaluate the radiation shielding ability. Raising the oxygen ions caused a noteworthy decrease in the µ values of the studied rocks which is accompanied by an increase in Δ_0.5 and Δ_eq values. The Δ_0.5 and Δ_eq values increased by factors of approximately 77 % with raising the oxygen ions between 44.32 and 47.57 wt.%. The µ values varies with the oxygen concentrations, where the µ values decreased from 2.531 to 0.925 cm^-1 (at 0.059 MeV), from 0.381to 0.215 cm^-1 (at 0.662 MeV), and from 0.279 to 0.158 cm^-1 (at 1.25 MeV) with raising the oxygen ions from 44.32 to 47.43 wt.%.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1619-1625
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• 2021

This paper demonstrates the possible nondestructive analysis of iron artifacts' metallurgical characteristics using neutron imaging. Ancient kingdoms of the Korean Peninsula used a direct smelting process for ore smelting and iron bloom production; however, the use of iron blooms was difficult because of their low strength and purity. For reinforcement, iron ingots were produced through refining and forge welding, which then underwent various processes to create different iron goods. To demonstrate the potential analysis using neutron imaging, while ensuring artifacts' safety, a sand iron ingot (SI-I) produced using ancient traditional iron making techniques and a sand iron knife (SI-K) made of SI-I were selected. SI-I was cut into 9 cm², whereas the entirety of SI-K was preserved for analysis. SI-I was found to have an average grain size of 3 ㎛, with observed α-Fe (ferrite) and pearlite with a body-centered cubic (BCC) lattice structure. SI-K had a grain size of 1-3 ㎛, α-Ferrite on its backside, and martensite with a body-centered tetragonal (BCT) structure on its blade. Results show that the sample's metallurgical characteristics can be identified through neutron imaging only, without losing any part of the valuable artifacts, indicating applicability to cultural artifacts requiring complete preservation.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.712-722
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• 2007

This study screened three natural ores (iron, mangenase, and zinc), two types of slags, and two elemental metals (elemental iron and zinc) to evaluate transformation characteristics of CAH mixtures [e.g. Carbontetrachloride (CT), 1,1,1-Trichloroethane (1,1,1-TCA), and Perchloroethene (PCE)]. To select an effective metal medium to treat the CAH mixtures, we measured transformation capacities (CAH mass ultimately transformed/mass of metal added) and the degree of dechlorination. We also considered economical efficiency of the metal media by comparing the value, CAH mass ultimately transformed divided by the price of metal medium added. A simplified mathematical model adapting CAH transformation capacity, first-order transformation kinetics, and available mass of metal transforming CAH was developed and used for estimating CAH transformation rate coefficient and longevity of the metal medium. CAH transformation capacity for elemental iron and elemental zinc were 4258~7129 and $4215{\sim}6330{\mu}g\;CAH\;transformed/g$ metal added, respectively, which are a factor of 80~200 higher than slags and natural ores. They also showed a factor of 1.1 to 2.2 greater degree of dechlorination than the others. Among natural ores and slags, Zinc ore showed the highest transformation capacity, $47{\sim}53{\mu}g\;CAH\;transformed/g$ metal added. Although zinc ore have smaller transformation capacity than elemental metals, economical efficiency of zinc ore is a factor of 10~20 greater than elemental metals tested. Consequently, zinc ore would be more economical medium than the others tested in this study. We estimated the pseudo first-order transformation rate of zinc ore was in the order of CT > 1,1,1-TCA > PCE.

• Journal of the Mineralogical Society of Korea
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• v.11 no.2
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• pp.85-96
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• 1998

The sericite ore is formed by the hydrothermal alteration of rhyodacitic welded tuff. The alteration zone of the host rock can be classified into four types based on the mineral assemblages ; sericite, quartz-sericite, silicified and propylite zone. The sericite ore mainly occurs as vein types and fault clay along the fault plane in the quartz-sericite zone. Mineral components of the sericite ore are mainly sericite with minor diaspore, corundum and pyrite. The sericitic porcelaineous ore is mainly composed of quartz and sericite. Accessory minerals are muscovite, diaspore, sphene, corundum, pyrite, iron-oxides and etc. The chemical compositions of K2O, Al2O3, and ignition loss in the sericite ore increase largely than that of the host rock, while the compositions of SiO2, Na2O and Fe2O3 decrease. XRD patterns of the heat-treated sericite ores show the formation of mullite at $1,200^{\circ}C$. and the diaspore-bearing sericite ore forms mullite and corundum at $1,200^{\circ}C$. The differential thermal analysis of the sericite ores show small endothermic peak at 645~668$^{\circ}C$. and the diaspore-bearing sericite ore shows a strong endothermic peak at $517^{\circ}C$. It indicates that the decomposition of diaspore appear at lower temperature than that of sericite. The thermal expansivity of the sericite ores show the similar pattern. The sericite ores show the thermal expansivity of 3.3~4.7% at 900$^{\circ}C$ and 0.39~0.75% at 1,20$0^{\circ}C$, respectively. DTA-TG curves of the sericite ores show closely relations with the thermal expansivity.

• 한국문화재보존과학회:학술대회논문집
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• 2004.10a
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• pp.33-42
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• 2004

The forged iron axe found in the No. 2 wood-framed tomb (the middle 3rd century) of Hwangseongdong, Gyeongju is rectangular on the plane level. It shows an obtuse angle in the edge part, while the joint part has the both sides folded up and shows the traces of wood. Under the reflected light, the Iron axe shines in metal luster, which is bright light gray or light creamy colors. The result of x-ray diffraction analysis shows that the axe consists of magnetite and geothite, which can explain why the composition and structure of the original ore has been kept intact. The microtexture of the axe has the irregular network of ferrite and pearlite, and tile cementite of tiny amount in the ferrite background. The overall treatment of the texture seems to be thermal with a high ratio of carbon. There are fine-grained magnetite, wolframite, quartz, calcite, mica, hornblende and pyroxene inside the axe. Those must be the impurities that they failed to remove in the refining process. The normal ferrite is composed of pure iron whose $Fe_2O_3$ proportion is from 99.16 to $99.84\;wt.\%$. Other than them, the ferrite parts usually contain $Al_2O_3\;and\;SiO_2$. The irregular network of pearlite also contains Impurities including $Al_2O_3\;and\;SiO_2$ and shows highly diverse patterns of carbon content. It's because the axe was carburized after the material was made to resemble pure iron. The decarbonization work didn't go well along the process marks. It's estimated that the original ore was bloom produced in low-temperature reduction and formed around in $727^{\circ}C$, which is eutetic temperature.

• 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.