• Electrical & Electronic Materials
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• v.8 no.1
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• pp.95-101
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• 1995

Crystallizable glasses with precipitation of celsian, anorthite, wollastonite and gahnite were prepared for the purpose of insulating dielectric layers in devices such as integrated circuit substrates. The starting glasses were prepared by melting the batches for 1 hour at 1450.deg. C and then Quenching to a distilled water. And crystallization behavior of these glasses were studied by DTA, TMA, XRD analysis and by the measurement of dielectric properties. The overall composition of the glass-ceramic consists in weight percent of 30-35% A1$_{2}$O$_{3}$, 13-26% BaO, 5-21% CaO, 10-24% ZnO, 4.5-9.0% TiO$_{2}$ and 4-8% B$_{2}$O$_{3}$. As a result, in barium-rich glasses only celsian phase was developed in the range of 850-900.deg. C. Also, the thermal expansion coefficient, dielectric constant and quality factor of these glass-ceramics were 68*10$^{-7}$ /.deg. C, about 9 and more than 1000, respectively.

• Journal of Technologic Dentistry
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• v.26 no.1
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• pp.77-88
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• 2004

Glass ceramics for dental crown prosthesis were prepared by crystallization of CaO-MgO-SiO2-P2O5-TiO2 glasses. Their crystallization behaviors have been investigated as a function of heattreatment temperature and holding time in relation to mechanical properties. The results are as follows: Vickers hardness and bending strength of glass ceramics increased due to the precipitation of apatite, whitlockite, $\beta$-wollastonite, magnesium titanate, and diopside crystal phases within glass matrix. The final crystalline phase assemblages and the microstructures of the glass ceramics were found to be dependent on heat-treatment temperature and holding time. Vickers hardnes and bending strength of glass ceramics increased with increasing heat-treatment temperature and holding time.

• Economic and Environmental Geology
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• v.29 no.1
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• pp.11-21
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• 1996

The first Mg-skarn minerals are found from magnetite ore deposits of the Janggun mine, Korea. The skarn minerals are composed of mostly chondrodite, olivine， chlorite, serpentine, phlogophite, talc, apatite, magnesite， dolomite, siderite and trace amount of clinopyroxene, amphibole, garnet, wollastonite associated with magnetite, pyrrhotite and pyrite. The skarn zone is developed in the magnetite deposits at the contact of the Mg-rich Janggun Limestone Formation and the Chunyang granite. The chondrodites are columnar and radial shapes and some of them show twins. The chemical compositions of twinning-type chondrodites have high FeO (4.63 to 5.6 wt%), MnO (0.26 to 0.46 wt%) and low MgO (55.02 to 56.18 wt%) relative to the radial-type chondrodites. Twinning in chondrodite has been formed in close relation to substitution between Mg and Fe + Mn in humite solid solution. Temperature, $-logfo_2$ and $X_{CO2}$ during the skarn stage of magnetite deposits from the Janggun mine range from 395 to $430^{\circ}C$, from 30.5 to 31.2 atm and from 0.06 to 0.09, respectively.

• Journal of the Korean Ceramic Society
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• v.20 no.2
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• pp.153-160
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• 1983

This study was carried out to research the change of mineral phases and the characteristics(apparent specific gra-vity water absorption firing shrinkage modulus of rupture thermal expansion and specific dielectric constant) of the sintered bodies manufactured by kaolin and limestone. Samples were composed of the same theoretical composition as it of anorthite and fired up to 145$0^{\circ}C$ Investigated the change and micro-structure of the mineral phases by XRD and SEM the characterisdtics of the sintered bodies by TMA Automatic Capacitance Bridge and etc. The results were as follow. 1. Reactions of sintering are occurred between 860-95$0^{\circ}C$ and 1200-138$0^{\circ}C$ and state of bloating is occurred at 1410-145$0^{\circ}C$ 2. For the inclusion of feldspar and its fine particles of materials the temperature of producing and collapsing is decreased. 3. Pseudo-wollastonite and gehlenite are formed about 95$0^{\circ}C$ 4. At 114$0^{\circ}C$ anorthite are begin to forming and increase continuously to 138$0^{\circ}C$. Above 141$0^{\circ}C$ content of anorthite are decreased. 5. The variations of bending strength with sintering temperature reflect similar trend of sintered contraction and in-crease continuously from 120$0^{\circ}C$. At 145$0^{\circ}C$ reached about 680kg/cm2. 6. Specific dielectric constant$($\varepsilon$_s)$ of specimen sintered at 141$0^{\circ}C$ is 7.12 and that value is most favorable.

• Economic and Environmental Geology
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• v.14 no.4
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• pp.167-182
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• 1981

Skarn silicates from the Shinyemi lead-zinc ore deposits can be distinguished as following three mineral assemblages: 1) garnet-pyroxene-phlogopite-wollastonite assemblages, 2) garnet-pyroxene assemblages, 3) garnet-epidote assemblages The assemblages are considered to be related with occurrences and kindes of ore minerals, and stage of mineralization in the deposits. Microprobe analyses of some garnets from the deposits show strong chemical zoning which is due to the changing equilibrium condition during growth of garnet crystal. Depositional condition of ore deposits and place of the ore-related igneous rock are discussed in the light of chemical composition of garnet and occurence of skarns in the Shinyemi.

• Journal of the Korean GEO-environmental Society
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• v.17 no.10
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• pp.63-71
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• 2016

Soil filling or replacement are routinely applied for soil restoration of domestic asbestos waste contaminated areas. However, since these soil recovery methods could not fundamentally solve the asbestos contamination, number of research on new alternative technologies have been carried. In this study, comprehensive laboratory test results utilizing wind power apparatus are used to design wind power purification device that can be applied in practice. Preliminary tests were carried out with wollastonite or actual asbestos waste contamination soils to study purification efficiency. Asbestos content measured immediately after in-situ test on asbestos-contaminated soil satisfying for purification standard showing less than 0.25% asbestos content from all tests, hence, analyzed to ensure over 90% of clean soil recovery rate and considered to be excellent applicability of future asbestos-contaminated soil purification.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.231-240
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• 1987

With a purpose to obtain basic informaton for improving poorly drained soil, a pot experiment was conducted about the effect of percolation rate on growth and yield of rice under application of wollastonite and rice straw as soil conditioner. The sandy and clayey soils were selected to compare difference in effectiveness of poor drainage. The results were summarized as follows: 1. Increasing or percolation rate increased rice yield in both sandy and clayey soils, but the effectiveness on yield increase was greater in clayey soil than in sandy. 2. Various materials of soil solution produced from the process of soil reduction were high at the early growing stage, but they were gradually decreased at the later growing stage. 3. With increasing percolation rate, the contents of N, $P_2O_5$ and $K_2O$ in rice plant were decreased, but that of $SiO_2$ was increased. 4. The number of roots at harvest was greater with increased extension as infiltration rate was increased.

• Economic and Environmental Geology
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• v.20 no.3
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• pp.169-177
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• 1987

The Manjang copper magnetite-fluorite orebodies are imbedded within the limestone beds of the Hwajonri Formation. The ore deposits are characterized by magnetite-fluorite bearing skarn orebody in the west orebody and copper sulfide veins of the central and main orebodies. This study includes fluid inclusion geothermometry, salinity analysis, stable isotope analysis, and application of phase rule to mineral associations in skarn ore. Ore minerals are closely associated with the skarn silicates such as garnet, wollastonite and epidote. Magnetite and fluorite are remarkable in the west orebody whereas chalcopyrite is dominate in the central and main orebodies where pyrite and pyrrhotite also appear as sulfide gangues. Homogenization temperature and salinity of fluid inclusions are measured ranging between $240^{\circ}C$ and $350^{\circ}C$, 6.3~12.9 wt. percent in quartz and $220^{\circ}C$ and $350^{\circ}C$, 8.5~9.9wt. percent in fluorite, respectively. This indicates that the filling temperature and salinity are higher in quartz than in fluorite with the tendency of both to be linearly decreased suggesting an attribution of meteoric water to the mineralization. $T-fo_2$ diagram in the Ca-Fe-Si system at 1 kb and $Xco_2$=0.02 shows that the mineral assemblages with decreasing temperature are andradite-hedenbergite-calcite, hedenbergite-andradite-quartz, magnetite-andradite-quartz, and magnetite-quartz-calcite, indicating that magnetite crystallizes mostly late skarn stage at lower temperature. According to the carbon and oxygen isotopic values of the host limestone and calcite in ores, the sourec of carbon might be mixture of host limestone and deep seated carbons. Sulfur isotope data imply that ore fluids be relatively homogeneous in sulfur isotopic composition, mainly derived from igneous source.

• Economic and Environmental Geology
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• v.12 no.3
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• pp.115-126
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• 1979

The Jecheon granite mass has turtle-shape exposure of about $190km^2$ at vicinity of Jecheon-eup, and is elongated in the direction of NEE-SWW. It discordantly intrudes the Bakdalryong metamorphic rocks and the great limestone series(Samtaesan and Hungwolri formation) which belong to the pre-Cambrian and Ordovician, respectively. The mass is composed of five facies of different grain size; texture and charecteristic minerals. The five facies are (1) coarse grained biotite granodiorite, (2) fine grained hornblende biotite granodiorite, (3) coarse grained pink feldspar granodiorite (4) leucogranite, and (5) porphyritic biotite granite. The mutual relationship between each facies is intrusion in (1)-(2) and (2)-(3), but unknown in (3)-(4) and (4)-(5). 22 modal analyses and and 10 chemical analyses on more than a hundred of representative samples taken from the mass are listed as tables. Triangular plot of modal and normative Q-Kf-Pl of this mass show a continuous differentiation products from certain common magma by change of chemical composition and anorthite contents in plagioclase. The metamorphic facies of contact aureole in surrounding rocks adjacent to the granite body are corresponded to hornblende hornfels facies with mineral assemblages of wollastonite-diopside-calcite in calcareous rocks, and of quartz-biotite-muscovite-cordierite in argillaceous rocks. Variation of silica versus oxides of major elements shows that the mass is similar to the trend of Daly's average basalt-andesite-dacite-rhyolite which shows the trend of the fractional crystallization of magma, and is equivalent to the calc-alkali rock series by Peacock. AMF diagram shows that Jecheon granite mass is equivalent to normal diffentiation products such as skaergaard intrusion. The above evidences suggest that the Jecohon granite mass is normal differentiation products formed by fractional crystallization under relatively slow cooling condition.

• Economic and Environmental Geology
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• v.18 no.2
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• pp.139-150
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• 1985

Skarn at the Dielette formed largely in calc-silicate hornfels at the contact with the Flamanville granite. The skarn consists mainly of garnet and pyroxene, and less frequently vesuvianite. Traversing toward calc-silicate hornfels wall rock from a central zone of the skarn, the general sequence of formation of mineral assemblages is: (1) dark brown garnet (2) pale brown garnet-vesuvianite-pyroxene, and (3) pyroxene-prehnite-scapolite-wollastonite envelopes (designated as transition zone) developed between skarn and calc-silicate hornfels. The central zone of the skarn consists mainly of dark brown garnets (garnet I) that contain little or no pyroxene. The pale brown garnet (garnet II) is associated with pyroxene and vesuvianite. The sequence of these garnets results from the zonal growth outward. There is an abrupt discontinuity in composition between garnet I formed in early stage and garnet II in late stage, while each garnet shows relatively uniform composition. At the zone in contact with the granite, the iron contents of garnets decrease toward the marginal zone of the skarn, from an average value of 36 mole % andradite in garnet I to 18 mole % andradite in garnet II. At the zone distant from the granite, the andradite component decreases from 28 mole % in garnet 1 to 19 mole % in garnet II. The variation of the iron contents of pyroxenes is also similar to that of garnets. The sharp discontinuity in composition of garnets and pyroxenes suggests that the skarn of study area was formed by infiltration metasomatic process. The results of the analyses of mineral assemblages of the transition zone by chemical potential diagrams suggest that the transition zone was made by the diffusion of the elements Ca, K and Fe from the skarn to the calc-silicate hornfels contact zone. The estimated temperatures and $Xco_2$ for the formation of the transition zone show $300^{\circ}C$$440^{\circ}C$ and $0.07{\pm}0.05<Xco_2<0.02{\pm}0.01$ at 1 Kb respectively.