• Journal of the Korean Institute of Gas
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• v.24 no.5
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• pp.10-19
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• 2020

Valve leak accidents in petrochemistry plants and gas utilities cause human and property damage. The main reason why happen gas inhalation, poisoning, fire and explosion accidents is gas valve leakage. To prevent gas leakage, inspectors check the facilities in the field. And they are at risk of gas leak accidents. So we applied IoT-based risk assessment, monitoring and automatic control system. It can detect both internal and external gas leakage, do real-time monitoring of industrial valve in the plant by using hybrid sensor. As the new safety management system for industrial valve is developed, it needs method to evaluate device performance and environmental components for the system. This study is about development of method to verify performance of the explosion-proofed hybrid sensing system include gas detector and optical fiber sensor supporting wire and wireless communication.

• Clean Technology
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• v.23 no.1
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• pp.54-63
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• 2017

Volatile organic compounds (VOCs) are widely used in both industrial and domestic activities. VOCs are one of the most unpleasant, frequently complaint-rousing factors of pollution around the world. It is now necessary to research and develop an alternative technology that could overcome the problems of the existing odor-control and VOC-eliminating techniques. In this study, essential oil and photocatalytic process was applied in the removal of benzene and toluene, typical VOCs in petrochemistry plant. therefore, this study conducted experiments on the selection of appropriate essential oil, photodegradation, hydroxyl radical generation capacity. The removal efficiency and reaction rate were performed to selecte the type and concentration of essential oil. As a result, removal efficiency of Hinoki Cypress oil was approximately 70% and reaction rate of Hinoki Cypress was high. The results of photolysis experiment, photocatalytic oxidation process showed that the decomposition efficiency of VOCs increased considerably with increasing UV lamp power. In addition, the conversion of VOCs was increased up to $0.1gL^{-1}$ photocatalysts. The hydroxyl radicals measure was performed to determine the ability to generate hydroxyl radicals. The analytical result showed that high $TiO_2$ concentration and lamp power was produced many hydroxyl radical. Experiments of the removal efficiency and reaction rate were performed using essential oil and photooxidation. As a result, the removal efficiency showed that the removal efficiency was increased high temperature and reaction time. The activation energy was calculated from the reaction rate equation at various temperature condition. Activation energy was approximately $18kJmol^{-1}$.

• Journal of the Korean earth science society
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• v.25 no.4
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• pp.251-264
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• 2004

The Charnockite in Sancheong region is quarzofeldspathic rock containing orthopyroxene and garnet with a color dark than common granitic rocks. The Chamockite are mostly massive and medium to coarse-grained with K-feldspar phenocryst, but reveal weak foliation. The rock consist mainly of quartz, K-feldspar, plagioclase and orhopyroxene, with biotite, garnet, and anthophyllite. In petrochemistry, the Chamockite has 61-65% $SiO_2$ contents, varying gradually into the margin contacted with orthogneiss, which have compositions of felsic igneous rocks. Major element show almost systematical variation with those of the marginal orthogneisses, except the hornblende gneiss and anorthosite. The Charnockite and orthogneisses show the tholeiitic differentiational trend. Trace and rare earth element abundance patterns in the Charnockite show remarkable negative Sr and Eu anomalies similar to orthogneisses, but different from the hornblende gneiss and anorthosite. Eu contents of the Charnockite are richer than that of orthogneisses. The metamorphic condition of the Charnockite were tested by an orthopyroxene-garnet geotherrnorneter and a plagioclase-garnet geobarometer. Estimated P-T conditions are about $761^{\circ}C$ and 7 kbar at peak metamorphism, but $653^{\circ}C$ and 6.4 kbar at retrograde metamorphism. This suggests that the Charnockite have from an early stage of high-grade metamorphism to represent the granulite facies and then to a late stage medium-grade metamorphism belonging to the amphibolite facies.

• The Journal of the Petrological Society of Korea
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• v.12 no.3
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• pp.135-153
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• 2003

In order to understand its origin and petrogenesis, petrochemical studies of major, trace elements, REE, and stable isotopes of oxygen and carbon from the Hongcheon Fe-REE deposits have been investigated. The Hongcheon Fe-REE deposit intruding into Precambrian metasedimentary rocks consists of magnetite, various carbonates such as ankerite, siderite, magnesite and strontianite, monazite, aegirine-augite, Na-amphibole, and sulfides. Compared with major elements abundances of typical ferro-carbonatites, the Hongcheon Fe-REE deposit is enriched in FeO and depleted in CaO with increasing of $SiO_2$, where $TiO_2$and $A1_2O_3$increased and CaO, FeO, MgO and $P_2O_5$ are slightly decreased, but those are rather scattered and their trends are somewhat ambiguous. V Ni, U and Rb slightly increasing with of $SiO_2$increase and scattering or no trends of other detected elements. Nb, Zr and Zn are depleted then the abundances of typical ferro-carbonatites (Woolley and Kempe, 1989). In rare earth elements a large enrichment of total REE (maximum 14.8 wt%) and LREE relative to chondrites and HREE depleted more then the values of ferro-carbontites therefore La/Lu ratios shows large abundances (max. 16,197). The results of stable isotopes of O and C from minerals of ankerite and strontianite and whole rocks represent studied rocks are from igneous carbonatitic melts. Although petrochemical characteristics of the Hongcheon Fe-REE deposits are somewhat different from normal ferro-carbonatites from the world, this discrepancy suggests another conclusion that petrochemical characteristic of the studied Fe-REE mineralized rocks are similar to those of phoscorites from Kovdor, Russia and Sokli, Finland showing the same petrochemical compositions described above.

• 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.34 no.1
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• pp.55-70
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• 2001

Granitoids in the Younggwang-Kimje area can be divided into two types of granite. One is foliated granite (Cheongup and Kochang foliated granites) developed along the NE-SW direction kwangju fault system and the other is undeformed granite (Kimje and Younggwang granites) developed in the western part of the area. $SiO_2$ content of study area, Younggwang granite is 62.8-74.0%, Kochang foliated granite is 64.5-74.4%, Cheongup foliated granite is 64.5-70.2%, Kimje granite is 63.4-72.0%. The result indicated that these granitoids belong to the intermediate and acidic rock. In Harker's diagram, as $SiO_2$ increases, $Al_2O_3$, $Fe_2O_3$, MgO, CaO, $TiO_2$> $P_2O_{5}$s and MnO decrease, but $K_2O$ increases. In AFM diagram, Younggwang granite, Kochang foliated granite, Cheongup foliated granite and Kimje granite belong to calk-alkaline rock series. And in triangular diagrams of normative Qz-Or-Pl and An-Ab-Or, they are located in granodiorite and granite region. On the co-variation diagrams of trace elements with silica, Ba, Co, Li, Nb, An, Rb elements show increasing patterns. The diagrams of ACF and $Na_2O$ vs. $K_2O$ ratios indicate that granitoids of the study area belong to I-type.

• Journal of the Korean earth science society
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• v.22 no.1
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• pp.1-9
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• 2001

Composition of the major and trace elements, Rb-Sr isochron age Sr-Nd isotope composition were determined for foliated in the Jeonju area, in the middle part of the Ogcheon Fold Bet, Korea. The geochemical characteristics of the Jeonju foliated granite indicate that the granite had been crystallized from a calc-alkaline series, and formed in a volcanic are environment. The isotopic compositions of the Jeonju foliated granite give Rb-Sr whole rock errorchron age of 168.2${\pm}$8 Ma(2${\sigma}$), corresponding to the middle Jurassic period, with the Sr initial ratio of 0.71354${\pm}$0.00031. $^{143}$Nd/$^{144}$Nd ratios, ${\varepsilon}$Nd and ${\varepsilon}$Sr values range from 0.511477 to 0.511744, -15.4${\sim}$-21.2, and +108.8${\sim}$+l42.6, respectively. Model ages were caculated to be 1.82${\sim}$2.89Ga. The isotopic data of Jeonju foliated granite indicate that the source material may have been derived from partial melting of continental crust materials.

• The Journal of the Petrological Society of Korea
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• v.14 no.4 s.42
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• pp.212-225
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• 2005

This study has been designed to elucidate the morphology of Jisagae columnar joints and the petrography and petrochemistry of Daepodong basalt in Jeju Island, distributed along the 3.5 km-long coast from Seongcheonpo to Weolpyeongdong. Colonnade of the Jisagae columnar joint typically occurs within the upper part of a flow and consists of relatively well-formed basalt columns. Most columns are straight with parallel sides and diameters from 100 cm to 205 cm, $130\~139\;cm$ in maximum. Length of the columns extends up to 20 m. Most columns tend to have 6 or 5 sides but sometimes they have as few as $3\~4$ or as many as 7 or 8 sides. The Daepodong basalt consists of plagioclase, olivine, orthopyroxene, clinopyroxene, ilmenite and magnetite. Plagioclase is labradorite, clinopyroxene is augite, orthopyroxene is bronzite and olivine is chrysolite and hyalosiderite. The Daepodong basalt shows porphyritic texture with matrix of mainly intersetal texture. The Daepodong basalt is plotted into alkali rock series on the TAS diagram. The tectonic setting of the Daepodong basalt represents within plate environment.

• Economic and Environmental Geology
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• v.27 no.4
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• pp.375-385
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• 1994

The studied area is composed of Precambrian gneiss complex, middle Jurassic biotite granite, late Cretaceour sediments, volcanics and pink feldspar granite. Characteristic minerals of the biotite granite is plagioclase and hornblende whereas the pink feldspar granite is pink feldspar (perthite) and quartz. Plagioclase compositions of the biotite granite and the pink feldspar granite are oligoclase to calcic andesine ($An_{18-44}$) and sodic albite ($An_{0.5-5.0}$), respectively. In the variation diagrams of the Harker and normative Q-Or-Pl diagram, the biotite granite belongs to the category from granodiorite to granite, the pink feldspar granite from nomal to late granite. The values of D.I. L.I. and alkalinity of the pink feldspar granite are higher than those of the biotite granite. While CaO is enriched in the biotite granite, $K_2O$ is enriched in the pink feldspar granite. The ratio of $K_2O/Na_2O$ which indicates the relative ratio of alkali is 1.06 in the pink feldspar granite, and 0.86 in the biotite granite. In A-M-F and N-C-K diagrams both these granites are plotted in peraluminus granite ($Al_2O_3$>$Na_2O+K_2O+CaO$) region, assigned to calc alkaline series and alkaline series respectively. Put into the form of A-C-F diagram, the biotite granite falls under I-type, and the pink feldspar granite S-type. On the base of whole rock ratios of $Fe^{+3}/Fe^{+2}+Fe^{+3}$ and $^{87}Sr/^{86}Sr$ for the granites in studied area, the biotite granite indicates ilmenite series (0.26) and S-type and/or contaminated I-type ($0.72020{\pm}0.00050$), the pink feldspar granite magnetite series (0.44) and I-type ($0.70826{\pm}0.00020$).

• Economic and Environmental Geology
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• v.27 no.4
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• pp.345-361
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• 1994

Lens shaped titanomagnetite ore bodies in the Soyeonpyeong iron mine are embedded in amphibolites, which were intruded into Precambrian metasediments such as garnet-mica schist, marble, mica schist, and quartz schist. Mineral chemistry, K-Ar dating and hydrogen and oxygen stable isotopic analysis for the amphibolites and titanomagnetite ores were conducted to interpret petrogenesis of amphibolite and ore genesis of titanomagnetite iron ore deposits. Amphibolites of igneous origin have unusually high content of $TiO_2$, ranging from 0.94 to 6.39 wt.% with an average value of 4.05 wt.%. REE patterns of the different lithology of the amphibolite show the similar trend with an enrichment of LREE. Amphiboles of amphibolites are consist mainly of calcic amphiboles such as ferro-hornblende, tschermakite, ferroan pargasite, and ferroan pargasitic hornblende. K-Ar ages of hornblende from amphibolite and gneissic amphibolite were determined as $440.04{\pm}6.39Ma$ and $351.03{\pm}5.21Ma$, respectively. This indicates two metamorphic events of Paleozoic age in the Korean peninsula which are correlated with Altin orogeny in China. The titanomagnetite mineralization seems to have occurred before Cambrian age based on occurrence of orebodies and ages of host amphibolites. The Soyeonpyeong iron ores are composed mainly of titanomagnetite, ilmenite, and secondary minerals such as ilmenite and hercynite exsolved in titanomagnetite. The temperature and the oxygen fugacity estimated by the titanomagnetite-ilmenite geothermometer are $500{\sim}600^{\circ}C$ (ave. $550^{\circ}C$) and about $2{\pm}10^{-23}bar$, respectively. Hornblendes from ores and amphibolites which responsible for magnetite ore mineralization, have a relatively homogeneous isotopic composition ranging from +0.8 to +3.9 ‰ in ${\delta}^{18}O$ and from -87.8 to -113.3 ‰ in ${\delta}D$. The calculated oxygen and hydrogen isotopic compositions of the fluids which were in equilibrium with hornblende at $550^{\circ}C$, range from 2.8 to 5.9‰ in ${\delta}^{18}O_{H2O}$ and from -60.41 to -81.31 ‰ in ${\delta}D_{H2O}$. The ${\delta}^{18}O_{H2O}$ value of magnetite ore fluids are in between +6.4 to + 7.9 ‰. All of these values fall in the range of primary magmatic water. A slight oxygen shift means that $^{18}O$-depleted meteoric water be acted with basic fluids during immiscible processes between silicate and titaniferous oxide melt. Mineral chemistry, isotopic compositions, and occurences of amphibolites and orebodies, suggest that the titanomagnetite melt be separated immisciblely from the titaniferous basic magma.