• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.237-237
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• 2012

토파즈는 Al2SiO4 ((F,OH)2) 화학성분을 이루고 있는 광물로써 주로 Fe, Cr, V 등과 같은 불순물을 포함하고 있다. 토파즈는 colorless, blue, pink, yellow 등 다양한 컬러로 산출된다. 결정 내 Si4+ 가 있어야 할 자리에 Al3+ 가 치환되면 Al3+ 를 둘러싸고 있는 4개의 산소 중 하나의 최외각 전자가 전자가를 맞추기 위해 주변에 있던 수소와 결합하여 hole center를 형성한다. 이때 토파즈는 옅은 황색의 컬러를 발색하게 된다. 그 외 청색과 핑크색 등의 컬러는 Al3+ 자리에 치환된 Fe, Cr 등과 같은 불순물에 의해 발색을 일으킨다. 또한 토파즈는 인위적으로 감마선, 전자 빔, 양성자 빔, 중성자 빔을 통해서도 hole center를 형성시켜 컬러를 발색시킬 수 있다고 잘 알려져 있다. 본 연구에서는 총 8개의 무색 토파즈를 이용하여 다양한 조건(energy 및 dose)의 전자 빔 조사를 통해 각 조건 별 컬러변화 및 분광학적 특성변화를 관찰하였다. 모든 시료는 WD-XRF를 통해 정성분석을 하였고, 전자스핀공명(ESR)기기를 통해 전자 빔 조사 전과 후 전자의 스핀 특성 변화를 관찰하였다. 자외선-가시광선 분광분석결과 모든 시료는 전자빔 조사 후 황색과 관련이 있는 450 nm 부근의 파장 영역에서 흡수 peak가 증가하는 것을 확인할 수 있었다. 또한 전자 빔 조사 후 전자스핀공명 분석 결과에서도 Fe3+ 와 관련이 있는 g=3.5~4 영역은 감소하는 반면에 hole center와 관련이 있는 g=2.012 영역이 증가하는 향상을 보였다. 본 연구결과를 통해 우리는 전자 빔 조사 조건에 따라 토파즈의 결정 내부에 미치는 영향 및 컬러 변화와의 상관관계에 대해 확인할 수 있었다.

• Journal of environmental and Sanitary engineering
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• v.14 no.2
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• pp.40-45
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• 1999

This study deals with an investigation on low cost adsorbents locally available n dyeing wastewater treatment of color removal. Peat, bentonite, slag and fly ash were utilized for this study. Considering that low cost adsorbents contained in $SiO_2$, $Fe_2O_3$ and $Al_2O_3$ compositions, and coagulants were mainly used aluminate and ferrate in color removal. Color of dyeing wastewater was high removed in peat, berntonite and slag except for fly ash with passed time. It could be known that color removal of peat and slag were increased to pH 4, but was hardly changed with advancing to alkaline. Color intended to be high removed with increasing of agitation speed but to be almost slow after 150rpm. As a result on the experiment of Freundlich adsorption isotherms, adsorption intensity(l/n) appeared to be peat>fly ash>slag>bentonite and adsorption capacity(k) came out peat>bentonite>slag>fly ash. Therefore, if low cost adsorbents substituted for existing adsorbents, peat, bentonite and slag could look forward to an expected economical effect.

• Economic and Environmental Geology
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• v.27 no.6
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• pp.523-535
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• 1994

The strata-bound type iron ore bodies in the Chungju mine are interbedded with metamorphic rocks which are intruded by Mesozoic granitic rocks. The iron ore deposit occurs as layer or lens shape which are concordant with the metamorphic rocks. The iron ore is classified into banded and massive types based on the mode of texture and occurrence. Grain size and iron-oxides tend to become coarser toward massive ore than banded ore. Banded ores commonly contain internal layers defined by alternating magnetite- rich, hematite-rich, magnetite-hematite, and quartz-rich mesobands. The banded iron ore consists of hematite, magnetite, quartz, feldspar, and minor amounts of biotite, muscovite, chlorite, carbonates, epidote, allanite, and zircon. Massive ores which are characterized by high magnetite content occur in contact of granitic rocks. The massive iron ores consist mostly of magnetite and quartz, with minor amounts of hematite, pyrite, microcline, biotite, muscovite, chlorite, carbonates, epidote, allanite and zircon. Magnetite from banded and massive ores is almost pure $Fe_3O_4$ in composition, including 0.14 to 0.27 wt.% MnO and 0.10 to 0.15 wt.% MnO, respectively. Hematite of the ore contains 0.87 to 1.27 wt.% $TiO_2$ in banded ore and 3.44 to 6.96 wt.% $TiO_2$ in massive ore, respectively. Biotite shows a little compositional variation depending on ore types. Biotite of the banded ore has lower FeO, $TiO_2$ and $Al_2O_3$, and higher MgO and $SiO_2$ than the massive ore. The modes of occurrence and petrography of ore implies that massive ores might have been formed either under more reducing environments or higher temperature condition than banded ore. Banded ores might represent early episode of iron enrichment due to regional metamorphism. Massive ores might be related to the contact metamorphism resulting from late granitic intrusion.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.457-464
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• 2022

In this study, XRF, Loss on ignition, SEM, and PSA analysis were performed on four types of fly ash in Vietnam and compared with fly ash in Korea. As a result, PC boiler fly ash in Vietnam has a similar chemical composition to that of PC boiler fly ash in Korea, where the content of SiO₂, Al₂O₃, and Fe₂O₃ accounts for about 70%. In addition, the result showed that blast furnace slags in Vietnam and Korea have similar quality criteria and performance. A binder material mixing test using four types of fly ash supplied from Vietnam was conducted, and the compressive strength ranged from 7.60 to 13.25 MPa after 28 days of curing. Vinh Tan fly ash showing the highest compressive strength was selected as the soil injection material for the chemical grouting method. For the formulation of the chemical grouting method, sodium silicate No.3 and silica-sol were used as liquid-A. As a result of measuring the gel time and the compressive strength of the homogel, they showed good performance satisfying the quality criteria applied in Korean construction fields. Therefore, Vinh Tan fly ash can be used as a soil injection material for the chemical grouting method.

• Journal of the Korean Professional Engineers Association
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• v.34 no.1
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• pp.59-65
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• 2001

Imported China Jades are mostly talc and serpentine groups, and that's occured troubles for our health and life of living organism. Serpentine is a group of common rock-forming minerals having the formula:(Mg$.$Fe)$^3$Si$_2$O$\_$5/(OH)$_4$. Sometime, simulated by nephrite or jade and translucent varieties we used for ornamental and decorative purposes. But it's forbid by heating materials for sauna and heating mats etc. that reason are it's occured asbestos dusts(chrysotile dusts) easily by the beating operations.

• Journal of the Korean Professional Engineers Association
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• v.34 no.1
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• pp.66-73
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• 2001

Imported China Jades are mostly talc and serpentine groups, and that's occured troubles for our health and life of living organism. Serpentine is a group of common rock-forming minerals having the formula : (Mg$.$Fe)$_3$Si$_2$O$\_$5/(OH)$_4$. Sometime, simulated by nephrite or jade and translucent varieties are used for ornamental and decorative purposes. But it's forbid by beating materials for sauna and heating mats etc. that reason are it's occured asbestos dusts (chrysotile dusts) easily by the heating operations.

• Journal of the Mineralogical Society of Korea
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• v.25 no.3
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• pp.143-153
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• 2012

Mica-type minerals (illites) in the shales of the Jigunsan formation at Seokgaejae in Samchuk-City, Gangwon-do are studied using electron probe micro analysis (EPMA). The average chemical formula of the mica-type mineral obtained from the quantitative analysis is $(K_{1.17}Na_{0.04}Ca_{0.01})(Al_{2.80}Mg_{1.17}Fe_{0.78})(Si_{6.34}Al_{1.66})O_{20}(OH)_4$, which shows a chemical formula within the range of illite. These illites so called can be considered as mixed-phases among muscovite, pyrophyllite and chlorite due to the low contents of interlayer cations and high Mg, Fe. The formula of illite is separated into those three minerals and the method for the separation is newly formulated and proposed in this study. From the formula of illite, the content of muscovite is estimated from K (Na and Ca included), the content of chlorite by Mg+Fe, and the rest remains as pyrophyllite. The chemical formula of muscovite can be calculated by subtracting the compositions of pyrophyllite and chlorite from the analyzed composition of illite using an ideal formula for pyrophyllite and analyzed average formula for chlorite. The calculated formula of muscovite is supposed to be stoichiometric in principle. The result of the separation of analyzed illite is 61% muscovite, 27.3% chlorite and 11.7% pyrophyllite and the calculated formula of muscovite after separation is $(K,Na,Ca)_{2.00}Al_{3.69}(Si_{6.75}Al_{1.25})O_{20}(OH)_4$. The calculated formula of muscovite slightly low in Al content can be considered to be reasonable in general when the low content of Al in the rock and the uncertainties of chlorite compositions used in the calculation are counted. This supports that the method of separation proposed in this study is also applicable.

• The Journal of the Petrological Society of Korea
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• v.4 no.1
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• pp.49-58
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• 1995

Staurolite-biotite-andalusite-garnet (SBAG) assemblage and its sub-assemblages (SBA and SBG) commonly occur in the Dueumri Formation near the Chunyang granite, belonging to andalusite and sillimanite zones. The occurrence of the SBAG mineral assemblage is unusual because it is univariant in the $K_2O-FeO-MgO-Al_2O_3-SiO_2-H_2O$ (KFMASH) model system. We used projection and singular value decomposition (SVD) methods to investigate the equilibrium relationship between SBAG and its sub-assemblage. The SVD modelling of single specimen containing the SBAG assemblage suggests no reaction relationship with respect to mass-balance. Thus, the SBAG assemblages are stabilized by non-KFMASH component. On the other hand, the AFM-Mn projection suggests a reaction relationship between SBAG and its sub-assemblage because they intersect each other in this composition space. The SVD modelling, however, suggests no reaction relationship between these assemblages. Thus, the SBAG assemblages are likely to be stabilized by the variation in bulk-rock composition and/or 1.1~2,. The stable occurrence of staurolite in the sillimanite zone is compatible with pressure estimates from the garnet-plagioclase-biotite-muscovite geobarometer.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.7
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• pp.1051-1057
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• 2003

This study is about controlled impurities, which make metal alloys, especially AC4CH alloy that is made by restraining 0.2％ Fe and Aluminum to make a matrix material. A metal matrix composite is produced using the squeeze casting method. The first step in the squeeze casting method is to add some organic binder including aluminum borate whisker into the matrix. After the fabrication of a metal matrix composite, each is individually appended to an inanimate binder such as SiO$_2$, Al$_2$O$_3$, and TiO$_2$. Through experiments the mechanical property changes were investigated between the metal matrix composite and AC4CH alloy. This study proves the superiority of the mechanical property of a metal matrix composites over AC4CH according to the previous tests and results that were mentioned above. One excellent property of matrix material composites is the infiltrated TiO$_2$ reinforcement. This material is a good substitute for the existing materials that are used in the development of industries today.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.198-203
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• 2001

This study is about controlled impurities, which make metal alloys, especially AC4CH alloy that is made by restraining 0.2% Fe and Aluminum to make a matrix material. A metal matrix composite is produced using the squeeze casting method. The first step in the squeeze casting method is to add some organic binder including aluminum borate whisker into the matrix. After the fabrication of a metal matrix composite, each is individually appended to an inanimate binder such as $SiO_2,\;Al_2O_3$, and $TiO_2$. Through experiments the mechanical property changes were investigated between the metal matrix composite and AC4CH alloy. This study proves the superiority of the mechanical property of a metal matrix composites over AC4CH according to the previous tests and results that were mentioned above. One excellent property of matrix material composites is the infiltrated $TiO_2$ reinforcement. This material is a good substitute for the existing materials that are used in the development of industries today.