• Journal of the Mineralogical Society of Korea
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• v.26 no.3
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• pp.197-207
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• 2013

Soil samples collected at the Kangwon and Donghae mines were investigated for the characterization of heavy metals using physicochemical and mineralogical properties. Arsenic (As) concentrations of soil samples sieved above 18 mesh and under 325 mesh at the Kangwon mine are 250.5 to 445.7 ppm, respectively. For soil samples sieved above 18 mesh at the Donghae mine, the concentrations of As, Pb, and Zn are 70.4, 1,055, and 781.9, while 117.7 ppm for As, 2,295 ppm for Pb, and 1,346 ppm for Zn are shown for the samples sieved under 325 mesh. XRD and SEM data indicated that the samples from the Kangwon mine included quartz, mica, albite, chlorite, magnetite, and amphibole while those from the Donghae mine contained quartz, mica, kaolinite, chlorite, amphibole, and rutile. SEM-EDS showed that magnetite found in the samples at the Kangwon mine was positively correlated with arsenic concentrations whereas ilmenite in the samples from the Donghae mine contained only small amount of As. Our results suggest that physicochemical and mineralogical characterization plays an important role in optimizing recovery treatments of soils contaminated in mine development areas.

• The Journal of the Petrological Society of Korea
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• v.20 no.2
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• pp.115-135
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• 2011

Fe-Ti ore bodies and mafic granulite occur in the Sancheong anorthosites, south Korea. In order to determine their petrogenetic relationship and to classify the Fe-Ti ore bodies, we have synthetically analyzed characteristics in the field, such as distribution and occurrence, and petrologic features through detailed outcrop sketches. The ore bodies are divided into the regular vein dike- and irregular veinlet swarm types, according to their characteristics of contact with the anorthosites and internal structures. The former shows the tabularly intrusive contact and the pervasively ductile-sheared interior, while the latter, the irregularly tortuous contact and the almost intact interior. Most of the ore bodies are cross-cutting the foliation of the anorthosites and possess abundant anorthositic xenoliths, indicating their intrusion after the formation of foliation in the anorthosites. The mafic granulite, also bearing abundant anorthositic xenoliths, shows interior foliations nearly parallel to intrusion contact, and has abundant ilmenites approximately the same as those of the Fe-Ti ore bodies in chemical composition. And its intrusion into adjacent anorthosites is observed and the intrusion is finally changed into an irregular veinlet swarm type ore body. It is, thus, interpreted that the granulite in the study area was the host material of Fe-Ti ore bodies.

• Journal of the Mineralogical Society of Korea
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• v.9 no.1
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• pp.43-53
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• 1996

The detailed crystal chemistry of ilmenite from the Hadong massif was studied by the EPMA, M ssbauer spectroscopy, and Rietveld structural refinement using X-ray powder diffraction data. The ilmenite-bearing anorthosite shows complicated mineral assemblage which consists of plagioclase, clinopyroxene, hornblende, biotite, chlorite, apatite, allanite, and zircon. Anorthite is andesine in composition (Ab 28-57), and clinopyroxene drops in ferro-hypersthene (Fs 62-70). Ilmenite is trigonal symmetry with R space group, whose structure shows the alternation of Fe2+ (M1 site) octahedral layer and Ti (M2 site) layer along c axis. M ssbauer spectroscopy indicates that there are three doubles which assigned to couple of Fe2+($\delta$=0.812, 0.890mm/sec) and one Fe3+($\delta$=0.303mm/sec) in octahedral sites. Their Fe3+/$\Sigma$Fe is 0.065 and chemical formula is established as Fe2+0.94Fe3+0.07Ti0.97O3 using both EPMA and M ssbauer analysis. Rietveld structural refinement reveals that site occupancies of Fe in M1 and Ti in M2 are 91.2% and 89.4%, respectively. This implies that Ti and Fe2+ are alternatively occupy M1 and M2 sites. In addition, smaller M2 site is more preferable to Fe3+ occupancy over M1.

• The Journal of the Petrological Society of Korea
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• v.14 no.1
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• pp.45-60
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• 2005

This study was intended to elucidate the petrography and geochemical characteristics of the Someori Basalt in the Udo monogenetic volcano, eastern Jeju Island. The Someori basalts consist of plagioclase, olivine, orthopyroxene, clinopyroxene and ilmenite. The Someori basalts are plotted into subalkali rock series on the TAS diagram, and belong to tholeiitic basalts in the diagram of alkali index against to Al₂O₃ contents. The basalts belong to tholeiitic rock series, having normative quartz (less than 3.9%) + hypersthene + diopside.

• Resources Recycling
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• v.31 no.2
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• pp.63-69
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• 2022

In this study, mechanical grinding using a planetary ball mill was performed under various conditions to evaluate its effect on the crystal structure of vanadium titanium magnetite (VTM) ore from the Kwain Mine in South Korea. The crystal structure of the activated product was also evaluated. Magnetite and ilmenite were identified as the main types of VTM ore used in the Kwain Mine, and the main types of gangue minerals were iron-based silicate minerals. According to the mechanical activation results, the crystallinity and crystal size decreased as the size of the grinding media (balls) decreased, and the amorphization of the sample/ball filling was significant as the amount of the sample was reduced. In addition, as the grinding speed and time increased, the crystal structure significantly changed, proving that these two parameters had a greater effect on the crystal structure than the ball size and sample/ball filling ratio.

• Resources Recycling
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• v.31 no.2
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• pp.12-19
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• 2022

The study was conducted to develop a vanadium recovery process using reduction pre-treatment in the Vanadium TitanoMagnetite (VTM) The sample for the research was provided by the Gwan-in Mine in Pocheon, Gyeonggi-do. The vanadium content of the sample is 0.54 V₂O₅% and vanadium is concentrated mainly in magnetite and ilmenite. Magnetic separation of the sample can increase vanadium content up to 1.10 V₂O₅%. To increase the vanadium content further, reduction pre-treatment was performed, which is a process of concentrating vanadium present in the iron by reducing iron in magnetite using carbon(C). Based on this reduction pre-treatment, the magnetic separation process was developed, which achieved a vanadium grade of 1.31V₂O₅% and 79.68% recovery. In addition, XRD analysis of the vanadium concentrate before and after reduction and the final vanadium concentrate was performed to confirm the behavior of vanadium by reduction pre-treatment.

• Economic and Environmental Geology
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• v.20 no.1
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• pp.35-60
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• 1987

The geochemical characteristics including minerals, major and trace elements chemistries of the Proterozoic, Jurassic and Cretaceous granites in Korea are systematically summarized and intended to decipher the origin and crystallization process in connection with the tectonic evolution. The granites in Korea are classified into three different ages of the granites with their own distinctive geochemical patterns: 1) Proterozoic granitoids; 2) Jurassic granites(cratonic and mobile belt); 3) Cretaceous-Tertiary granites. The Proterozoic granite gneisses (I-type and ilmenite-series) formed by metamorphism of the geochemically evolved granite protolith. The Proterozoic granites (S-type and ilmenite-series) produced by remobilization of sialic crust. The Jurassic granites (S-type and ilmenite-series) were mainly formed by partial melting of crustal materials, possibly metasedimentary rocks. The Cretaceous granites (I-type and magnetite-series) formed by fractional crystallization of parental magmas from the igneous protolith in the lower crust or upper mantle. The low temperature ($315{\sim}430^{\circ}C$) and small temperature variations (${\pm}20{\sim}30^{\circ}C$) in the cessation of exsolution of perthites for the Proterozoic and Jurassic granites might have been caused by slow cooling of the granites under regional metamorphic regime. The high ($520^{\circ}C$) and large temperature variations (${\pm}110^{\circ}C$) of perthites for the Cretaceous granites postulate that the rapid cooling of the granitic magma. In terms of the oxygen fugacity during the feldspar crystallization in the granite magmas, the Jurassic mobile belt granites were crystallized in the lowest oxygen fugacity condition among the Korean granites, whereas the Cretaceous granites in the Gyeongsang basin at the high oxygen fugacity condition. The Jurassic mobile belt granites are located at the Ogcheon Fold Belt, resulting by closing-collision situation such as compressional tectonic setting, and emplaced into a Kata-Mesozonal ductile crust. The Jurassic cratonic granites might be more evolved either during intrusion through thick crust or owing to lower degree of partial melting in comparison with the mobile belt granites. The Cretaceous granites are possibly comparable with a continental margin of Andinotype. Subduction of the Kula-Pacific ridge provided sufficient heat and water to trigger remelting at various subcrustal and lower crustal igneous protoliths.

• The Journal of the Petrological Society of Korea
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• v.4 no.2
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• pp.91-103
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• 1995

The study area is located at the middle part of Daebo granitic batholith in the Gyeonggi massif. The geology of the area is mostly composed of Precambrian gneiss complex, coarse- grained middle Jurassic and fine-grained early Cretaceous biotite granites, and Cretaceous small stocks and dykes. The gneiss complex consists mainly of banded gneiss, granitc gneiss, some schist and quartzite. The coarse-grained granite can be divided into greyish granite(Gg1 in the margin and slightly pinkish granite(Gp) in the center. The former is hornblende biotite granite characterized by basic clot and xenolith. The latter is generally garnet biotite granite containing only poor basic clot. The fine-grained granite intruded the coarse-grained granite. The K/Ar biotite ages from the granites belong to middle Jurassic and early Cretaceous. The K/Ar biotite ages and geochemical compositions indicate that Gg and Gp were differenciated from a single magmatic body. The granites are calc-alkali and metaluminous-peraluminous. They are S-type(i1menite series) and partly I-type granitedmagnetite series) formed by melting of relatively fixed source composition. Their tectonic settings belong to the compressional suits and VAG of continental margin.

• Economic and Environmental Geology
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• v.44 no.5
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• pp.359-372
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• 2011

TA26 seamount, which is located at south part of Tonga arc, occurs widely hydrothermal plume and is area that sampled hostrock, hydrothermal ore and hydrothermal alteration rock for this study. Hostrocks are basalt and basaltic andesite. Altered rocks by hydrothermal solution consists of plagioclase, pyroxene, pyrite, ilmenite, amorphous silica, barite, smectite, iron sulfates, Fe-Si sulfates and Fe silicates. Gains and losses of major, trace and rare earth elements during wallrock alteration suggest that $K_2O$(+0.04~+0.45 g), $SiO_2$(-6.52~+10.56 g), $H_2O$(-0.03~+6.04 g), $SO_4$(-0.46~+17.54 g), S(-0.46~+13.45 g), total S(-0.51~+16.93 g), Ba(-7.60~+185078.62 g), Sr(-36.18~+3033.08 g), Ag(+54.83 g), Au(+1467.49 g), As(-5.80~+1030.80 g), Cd(+249.78 g), Cu(-100.57~+1357.85 g), Pb(+4.91~+532.65 g), Sb(-0.32~+66.59 g), V(-113.58~+102.94 g) and Zn(-49.56~+14989.92 g) elements are enriched from hydrothermal solution. Therefore, gained(enriched) elements(($K_2O$, $H_2O$, $SO_4$, S, total S, Ba, Sr, Ag, Au, As, Cd, Cu, Pb, Sb, V, Zn) represent a potentially tools for exploration of sea-floor hydrothermal deposits from the Tonga arc.

• The Journal of the Petrological Society of Korea
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• v.7 no.1
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• pp.37-52
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• 1998

The granites in the Jeomchon area can be divided into hornblende biotite granite (Hbgr), deformed biotite granite (Dbgr), deformed pinkish biotite granite(Dpbgr), biotite granite (Btgr), and granite porphyry(Gp). These granites show metaluminous, 1-type and calc-alkaine characteristics from their whole-rock chemistry. Hbgr and Dbgr belong to ilmenite-series granitoids, but Gp to magnetite-series. Dpbgr and Btgr show the intermediate nature between ilmenite- and magnetite-series. Tectonic discriminations indicate that Hbgr and Dbgr were formed in active continental margin environment, whereas Dpbgr, Btgr, and Gp in post-orogenic and/or anorogenic rift-related environment. From the Harker diagrams major oxide contents of Hbgr and Dbgr show a continuous variation with $SiO_2$, indicating that they are genetically correlated with each other. On the other hand, any correlation of major oxides variation cannot be recognized among Dpbgr, Btgr and Gp. It seems like that Hbgr and Dbgr were derived from a same parent granitic magma, judging from their occurrence of outcrop, mineral composition as well as whole-rock chemistry. Variation trends of major oxide contents between Hbgr and Baegnok granodiorite are very similar and continuous. If the two granites were derived from a cogenetic magma, there exists a possibility that the granitic bodies had been separated by Btgr and Gp of Cretaceous age. Three stages of the granitic intrusions are understood in the Jeomchon area. After the intrusion of Hbgr and Dbgr during middle to late Paleozoic time, Dpbgr emplaced into the area next, and finally Btgr and Gp intruded during Cretaceous time. Tectonic movement accompanying shear and/or thrust deformation seems likely to have occurred bewteen the intrusions of Dpbgr and Btgr.