• 한국세라믹학회지
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• 제14권2호
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• pp.88-94
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• 1977

Zircon sand of two different particle distribution with 2 percent of ground pyrophyllite were adoted to prepare the dense specimens of the stopper nozzle for the tundish. The molding pressure of $600kg/cm^2$ brought about the superior properties to those obtained t the pressure of $300kg/cm^2$, and as the firing temperatures were increased from $1, 350^{\circ}C$ to $1, 600^{\circ}C$, the better characteristics resulted. The addition of 2 percent $MgCr_2O_4$ to zircon pyrophyllite batch was more effective in corrosion-resistance to the blast furnace-slag.

• 한국세라믹학회지
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• 제32권2호
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• pp.171-182
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• 1995

Five eucryptite and ten spodumene compositional powders were syntehsized from three sillimanite group, two kaolin group, and five pyrophyllite group silicate minerals. Those powders were isotatically pressed and fired at 1200~135$0^{\circ}C$ for 2 hrs, and then the sintered bodies were characterized. Silicate minerals with molar ratio of Al2O3 to SiO2 correspond to those of eucryptite and spodumene are kaolin and pyrophyllite group silicate minerals, respectively. Sintering characteristics of eucryptite from kaolin group and spodumene from pyrophyllite group mineral were superior to those from other silicate minerals. Eucryptite sintered bodies with 95~97% relative densities and densified microstructures can be obtained using Hadong pink kaolin as starting materials by sintering over broad temperature zone(1250~135$0^{\circ}C$). The eucryptite sintered bodies which were fired at 130$0^{\circ}C$ for 2hrs, from Hadong pink kaolin had within 3.0wt% microstructural compositional variations compaired with stoichiometric compound, and had good negative thermal expansiion property with -3.55$\times$10-6/$^{\circ}C$ thermal expansion coefficient. Spodumene sintered bodies which were prepared from pyrophyllite group silicate minerals, had dense microstructures and high densities by densification through liquid phase sintering with enlarged temperature range. The specimens which were fired at 130$0^{\circ}C$ for 2 hrs from Gusipyrophillite, had dense microstructure with crystallines mainly, and low thermal expansion property with 0.62$\times$10-6/$^{\circ}C$ thermal expansion coefficient. The porous texture and residual glass phase in LAS system ceramics which were prepared from silicate minerals, tend to increase the thermal expansion properties of sintered bodies to positive direction.

• 한국광물학회지
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• 제5권2호
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• pp.93-101
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• 1992

경남 밀양 일대의 화산암에는 열수변질대가 상당히 넓게 발달하고 있으며, 여러 개의 점토광상이 분포한다. 납석광상은 주로 안산암질 응회암에서 배태된다. 납석광석의 주구성광물은 엽납석과 딕카이트이며, 그외에 일라이트, 토수다이트, 듀모티에라이트, 석영 등의 규산염광물들이 소량 수반되며, 디이아스포아, 황철석, 웨이브라이트 등이 산출된다. 본 지역의 엽잡석은 단지 2M 다형만 산출된다. 엽납석은 약 750${\circ}C$에서 OH가 빠져나감에 따라서 $d_{001}$ 간격이 증간한다. 할로이사이트는 튜브형태로 나타난다. 웨이브라이트는 열수변질작용 말기의 낮은 온도에서 틈을 따라 침천된 것이다. 본 지역의 5개의 변질대로 구분되는데, 주광체로부터 멀어질수록 엽납석-딕카이트대, 실리카대, 일라이트대, 할로이사이트대, 녹니석-알바이트대로 대상분포를 보인다. 점토광물은 모암으로부터 Si와 알카리이온의 용탈에 의해서 형성되었다. 광물조합과 엽납석 다형 및 기존의 열역학적 자료를 밀양광산의 형성온도는 270∼350${\circ}C$ 내외인 것으로 추정된다.

• 한국광물학회지
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• 제14권2호
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• pp.119-127
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• 2001

주구성 양이온이 Si와 Al인 딕카이트와 엽납석에 대하여 적외선분광분석(FTIR)을 실시하였다. 원적외선(Far-IR)영역과 중간적외선(Mid-IR)영역을 이용하였으며, 특히 $200 cm^{-1}$ / 이하의 Far-IR영역에서 처음으로 딕카이트의 흡수선들을 제시하였다. 딕카이트의 경우 일부 시료에서 소량의 카올리나이트나 나크라이트 층이 소량으로 협재되어 있다. 카올리나이트의 결정도를 나타내는 Hinckley지수는 딕카이트의 결정도와는 관련성이 적게 나타났다. 엽납석의 경우, 수산기와 관련된 신축진동흡수띠($3673~3676 cm^{-1}$ )는 약간 이상적인 구조에서 벗어나 있는데, 아마도 미량의 철에 의한 영향이나, 삼사형과 단사형이 섞여 있기 때문인 것으로 보인다.

• 자원환경지질
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• 제33권5호
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• pp.405-415
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• 2000

This study was carried out to understand the formation of acid mine drainage (AMD) by pyrophyllite (so-called Napseok)-rainwater interaction (weathering), dispersion patterns of heavy metals, and patterns of mixing with non-polluted water in the Tongnae pyrophyllite mine. Based on the mass balance and reaction path modeling, using both the geochemistry of water and occurrence of the secondary minerals (weathering products), the geochemical evolution of AMD was simulated by computer code of SOLVEQ and CHILLER. It shows that the pH of stream water is from 6.2 to 7.3 upstream of the Tongnae mine. Close to the mine, the pH decreases to 2. Despite being diluted with non-polluted tributaries, the acidity of mine drainage water maintains as far as downstream. The results of modeling of water-rock interaction show that the activity of hydrogen ion increases (pH decreases), the goncentration of ${HCO_3}^-$ decreases associated with increasing $H^+$ activity, as the reaction is processing. The concentration of ${SO_4}^{2-}$first increases minutely, but later increases rapidly as pH drops below 4.3. The concentrations of cations and heavy metals are controlled by the dissolution of reactants and re-dissolution of derived species (weathering products) according to the pH. The continuous adding of reactive minerals, namely the progressively larger degrees of water-rock interaction, causes the formation of secondary minerals in the following sequence; goethite, then Mn-oxides, then boehmite, then kaolinite, then Ca-nontronite, then Mgnontronite, and finally chalcedony. The results of reaction path modeling agree well with the field data, and offer useful information on the geochemical evolution of AMD. The results of reaction path modeling on the formation of AMD offer useful information for the estimation and the appraisal of pollution caused by water-rock interaction as geological environments. And also, the ones can be used as data for the choice of appropriate remediation technique for AMD.

• 자원환경지질
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• 제25권1호
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• pp.41-50
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• 1992

Mineral assemblages, mineral chemistries and stable isotope compositions of altered rocks of the Ogmae, Seongsan, Haenam and Gusi mines near the Haenam volcanic field in the southwestern part of the Korea peninsula were studied. Characteristic hydrothermal alteration zones in these deposits occurring in the Cretaceous volcanics and volcanogenic sediments, acidic tuff, and rhyolite, were outlined. Genetic environment with particular reference to the spatial and temporal relationships for these deposits were considered. The alteration zones defined by a mineral assemblage in the Ogmae and Seongsan deposits can be classified as alunite, pyrophyllite, kaolinite or dickite, quartz, illite or illite/smectite. Alunite was not developed in the Gusi and Haenam deposits. Boundaries between the adjacent zones are always gradational except for vein-type alunite. Alteration zones are superimposed upon each other in some localities. These deposits formed $71.8{\pm}2.8{\sim}76.6{\pm}2.9$ Ma ago, which is the almost same age of later volcanic rocks $79.4{\pm}1.7{\sim}82.8{\pm}1.2$ Ma, the Haenam Group, corresponding to Campanian. It indicates that hydrothermal alteration of these deposits appeared to be related to felsic volcanism in the area. Consideration of the stability between kaolinite, alunite, pyrite and pyrophyllite, and the geothermometry based on the mineral chemistry of illite and chlorite suggests that the maximum formation temperature for alunite and pyrophyllite can be estimated at about $250^{\circ}C$ and $240{\sim}290^{\circ}C$, respectively. It also suggests that these deposits were formed by acidic sulfate solution with high aqueous silica and potassium activity in a shallow depth environment. Compositional variation of alunite also suggests that the physico-chemical conditions fluctulated considerably during alteration processes, indicating shallow depth environment. The Haenam deposit was formed at a relatively greater depth than the others. The sulfur isotope composition of alunite and pyrite indicates that sulfur probably had a magmatic source, and the oxygen isotope composition for kaolinite indicates that the magmatic hydrothermal solution was diluted by circulating meteoric water.

• 자원환경지질
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• 제43권5호
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• pp.467-475
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• 2010

Landsat과 ASTER 위성영상을 이용한 암상구분은 반건조-건조 지역을 대상으로 활발한 연구가 이루진 바 있으며, 미국 네바다 금속광화대 지역을 중심으로 광물자원탐사를 위한 초기 단계에서 유용한 방법으로서의 가능성에 관한 검증이 이루어졌다. 연구대상 지역인 중앙, 삼성, 경주, 내남 납석광산이 위치하고 있는 경상분지 남동부의 지질은 주로 백악기 하양층군에 속하는 진동층을 기저로 하여 유천층군에 해당하는 중성질 화산암류, 정각산층, 건천리층, 산성 화산암류와 후기에 이들 층을 관입하는 불국사 화강암류들로 구성되어 있다. 위성영상으로부터 납석광상을 추출하기 위한 비연산 모델을 제시하기 위해서, 중앙납석광산으로부터 채취된 응회암질 모암과 열수변질작용에 의해 형성된 납석을 대상으로 이들의 분광반사률을 측정하였다. 이들 분광반사률을 Landsat 영상과 ASTER 영상의 밴드별 분광반사율 곡선을 이용하여 재배열한 결과, Landsat 영상에 대해서는 밴드 5번에서 강한 반사 특성을 보이고, 밴드 7번에서 강한 흡수 특성을 보였다. ASTER 영상에서는 밴드 5와 8번에서 강한 흡수 특성을 밴드 4와 7번에서 반사특성이 나타났다. 이를 바탕으로 Landsat 위성영상의 DN (Digital Number) 값을 이용한 $Py_{Landsat}$ 모델을 적용한 결과, 열수변질대 지역은 1.94 이상으로 상대적으로 높은 값을 보이는데 반해서 이외의 지역은 1.19~1.49 사이의 낮은 값을 갖는 것으로 나타났다. 또한 $Py_{ASTER}$ 모델의 적용결과 납석광산과 다른 대상물간의 치는 콘크리트와 0.472, 나대지와 0.399로, $OHI_b$과, PAK모델의 적용결과 0.452, 0.371과 0.365, 0.311로 보다 큰 차이가 나타남을 알 수 있다. 따라서 이번 연구에서 제안한 $Py_{ASTER}$ 모델은 납석광상을 보다 더 명확하게 규명할 수 있는 것으로 나타났다.

• 자원환경지질
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• 제28권2호
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• pp.93-108
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• 1995

The Bobae sericite deposit occurs in rhyodacite of the Cretaceous volcanogenic sedimentary rocks, Upper Yucheon Group, in the western part of Pusan. The alteration zones are divided into the phyllie and prophylitic zone based on the mineral assemblages. The phyllic zone is subdivided into three subzones; Andalusite-Pyrophyllite, Sericite and Albite subzones. Oxides vs. $Al_2O_3$ contents show variations corresponding to mineral assemblage in each alteration zone. On the basis of bulk chemical compositions, it was found that $SiO_2$ increases in the Andalusite-Pyrophyllite subzone and $K_2O$ in the Sericite subzone. The oxygen, hydrogen and sulfur isotope analysis indicates that the fluids were originally derived from the residual magmatic solution. It has been mixed with abundant meteoric water later. The ore-forming temperatures obtained from sericite (illite) geothermometer are about $250{\sim}350^{\circ}C$. Considering the phase stability relation, PoT conditions of the andalusite-pyrophyllite subzone were estimated to be less than 0.5 kb and almost $400^{\circ}C$, respectively. The K-Ar ages of sericites indicate that the clay deposit is genetically related to the Cretaceous-Paleogene Masan Hornblende-Biotite Granite.

• 한국세라믹학회지
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• 제31권7호
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• pp.784-794
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• 1994

Though spodumene have a law theraml expension and good thermal shock resistance, its sintering temperature is too close to its melting point in the application for industral purpose. Solving the problems, impurities within the silicate minerals act as a frit during firing, so its densification is expected through enlargement of sintering temperature range. By the heat treatment of starting materials, mixtures of silicate mineral, lithium carbonate, if necessary SiO2 or Al2O3 were added for stoichiometric correction, in the range of 1000~125$0^{\circ}C$ for 10 hrs, $\beta$-spodumene single phase was synthesized. Mixtures with sillimanite group minerals, $\beta$-spodumene was formed at 120$0^{\circ}C$ or 125$0^{\circ}C$ via intermediate phases of petalite, Li2SiO3 and LiAlO2. For the case of kaolin group minerals, synthesis were completed at 110$0^{\circ}C$ for Hadon pink kaolin, 120$0^{\circ}C$ for New Zealand white kaolin, When pyrophyllite group minerals were used, those were at the range of 1000~125$0^{\circ}C$. Spodumene was completed at lowest temperature, 100$0^{\circ}C$ from the mixture of Wando pyrophyllite among them. Microstructure of synthesized powders showed the inrregular lump shape such as densed crystallines.

• 자원환경지질
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• 제29권4호
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• pp.439-446
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• 1996

Clay minerals are locally abundant in two hydrothermal areas at Tongnae-Yangsan and Miryang, Gyong-sang-namdo, Korea. This study is done to access the clay forming processes, particularly hydrothermal alteration. Pyrophyllite-kaolin in the Zone is accompanied by sericite, diaspore mixed-layer mica/smectite, alunite, dumortierite and silica minerals. Small nodular diaspore and disseminated fine radiac dumortierite are present in the pyrophyllite-kaoline deposits, the northemly trending belt of rhyolite flows and pyroclastic rock near the intruded by granite rock of Bulkusa Series. Hydrothermal action has formed many clay deposits with a zone containing over 80~90% pyrophyllite, kaolinite, muscovite with a little amount of dumortierite, boehmite, andalusite. Most of the clay deposits occur as irregular, lenticular, massive and assosiated dumortierite was found to coexist with clay deposits. Dumortierite data are as follows: lattice constant a=11.783, b=20.209, c=4,7001, axial ratio a:b:c=0.5835 : 1 : 0.2327, XRD $d{\AA}$ 2.549, 5.89, 5.09.