• 광물과산업
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• 제13권1호
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• pp.64-72
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• 2000

한동안 일본의 급성장 수출경제는 멈출 수 없는 것처럼 보였었다. 그러나 이제 지난 10년간 경제가 후퇴하면서 그 희생을 치르고 있다. 제조업 전 분야가 하락세를 면치 못하고 있거나, 기껏해야 현상 유지함으로서 결국 광물 소비량에 영향을 미치고 있다. 대규모 석회석 백운석 자원, 상당한 벤토나이트 및 납석 자원, 그리고 소다회, 융합광물(fused minerals) 등의 합성 원료를 제외하면, 일본에는 규모 있는 광물자원이 거의 없다. 광물자원의 부족과 최근의 엔고 현상 때문에 일본은 중국과 같은 나라의 주요 광물 수출 시장이 되고 있다.

• 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.

• 한국세라믹학회지
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• 제25권3호
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• pp.261-267
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• 1988

완도납석과 carbon black 의 혼합물을 135$0^{\circ}C$에서 질소분위기를 사용하여 탄소환원질화법으로 $\beta$-Sialon 분물에 $\beta$-SiC를 제2상으로 넣어서 $Y_2O_3$와 $ZrO_2$를 각 소결조제로 사용하여 175$0^{\circ}C$에서 2시간 동안 상압소결하였다. 10wt %의 $Y_2O_3$를 소결조제로 사용하였을 때에 파괴인성은 3.8MN/m^{3/2}$, 3점꺽임 강도는 470MN/$m^2$ 그리고 경도는 13.7MN/$m^2$로서 좋은 값을 나타내었다. 이와 같은 파괴인성과 꺽임강도의 증가는 균열편향과 균열나눠짐에 의한 것으로 생각된다.

• 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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• 제19권spc호
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• pp.43-52
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• 1986

Kaolin-pyrophyllite are locally abundant in the three hydrothermal areas at Yangsan-Tongnae area, Hadong-Sancheong area and Haenam area, deposits are originally composed of acidic volcanic rocks and anorthositic rocks in Hadong-Sancheong area. The clay deposits are formed in the near shallow depths environment through acid hydrothermal alteration. Hadong-Sancheong halloysite deposits are formed by alteration of anorthosite. These differences are mainly on the various country rocks, geological structure and properties of hydrothermal solutions. Country rock is mostly underlain by rhyolitic tuffaceous and anorthositic rocks and a large number of clay deposits were formed during volcanic activity through upper Cretaceous-lower Tertiary. Intrusive rocks is broadly distributed in this area and clay deposits are variable in shapelayer and funnel typed. Zonal pattern of mineral assemblage is as follows, Yangsan-Tongnae deposits-kaolinite, pyrophyllite, dumortierite, andalusite and sericite, Hadong-Sancheong-mostly halloysite, and Haenam-dickite, pyrophyllite, alunite and diaspore. The difference in the zonal pattern of altered rock is considered to depend on differences in the initial acidity of related hydrothermal solution, initial acidity was controlled by the oxygen fugacity.

• 자원환경지질
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• 제23권1호
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• pp.11-23
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• 1990

Pyrophyllite, kaolinite, and alunite deposits distributing in Southwestern parts of Cheonnam are classified into three types of minerals assemblages by the results of X-ray diffraction analysis etc. The first mineral assemblages contains pyrophyllite, kaolinite, dickite, quartz, diaspore and/or corundum, the second one contains alunite inseads of corundum, and the third one contains alunite without pyrophyllite and diaspore. It is can be considered that the depoSits which consist mainly of pyrophyllite are formed higher temperature than the other deposits. Judging form the chemical analyses the chemical compositions of hydrothermal solutions acting to the deposits seem to be relatively simple. But the hydrothermal solutions which generated Dogcheon, Jugjcon, Ogmaesan, and Seongsan mine contain rather somewhat higher $K_2O$. The values of the Trace Elements and REE analysis of the host rocks of deposits suggest that the host rocks are these deposits are the last products of magmatic differentiation.

• 한국세라믹학회지
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• 제28권7호
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• pp.531-540
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• 1991

In this study, high quality machinable ceramics was prepared from the K2O-MgO-Al2O3-SiO2-B2O3-F glass system using domestic pyrophyllite. The mixture of pyrophyllite and additives was melted at 1450$^{\circ}C$ for 1 hour and formed in a graphite mold. The base glass was heat-treated at 600$^{\circ}C$ to 1200$^{\circ}C$ with interval of 50$^{\circ}C$ for 3 hours identified by XRD. Crystalline phase were confirmed by XRD and their microstructure was observed by SEM. The glass ceramics which was prepared by heat treatment of base glass at 1150$^{\circ}C$ for short time has good physical, mechanical, thermal, chemical properties and machinability.

• 한국세라믹학회지
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• 제22권5호
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• pp.35-42
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• 1985

$eta$-Sialon powders were prepared by reduction-nitridation from mixture of Wando pyrophyllite and graphite as a reducing agent at 135$0^{\circ}C$ in 80% $N_2$-20% $H_2$ atmosphere. As the reaction products $Si_2ON_2$, $\beta$-$Si_3N_4$ a--$Si_3N_4$ and $\beta$-SiC were observed. Additive agents of MgO, CaO, $Y_2O_3$ were used for promoting the reduction and nitridiation aeaction. The present study was conducted to investigate the effects of silica-carbon ratio ($SiO_2$/C=weight ratio), raction time gas flow rate pellet size and powder packing on synthesis of $\beta$-Sialon from Wando pyropyllite.

• 한국세라믹학회지
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• 제23권4호
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• pp.17-22
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• 1986

$\beta$-Sialon powders were prepared by the reduction-nitridation reaction from the mixture of Wando-pyrophyllite and graphite at 135$0^{\circ}C$ in $N_2-H_2$ atmosphere. The $\beta$-Sialon powders were sintered at 175$0^{\circ}C$ by the pressureless sintering for 90min and the hot-pressing for 60 min respectively. All the sintered bodies showed their relative densities higher than 94% The values of M.O.R fracture toughness(KIC) and hardness showed 32.9kpsi 2.9MN/$m^{1.5}$ , 12.1GN/$m^2$ for the pressure-less sitnered bodies and 48.6kpsi, 4.6 MN/4m^{1.5}$ 15.3GN/$m^2$ for the hot-pressed bodies respectively.

• 한국세라믹학회지
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• 제27권8호
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• pp.1011-1019
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• 1990

Pyrophyllite, which has low impurities, was used in the synthesis of mullite to decrease the glass phase, which can be formed from impurities such as alkali and alkali earth elemetns present in raw materials. But, as pyrophyllite has less alumina content than other aluminosilicate materials such as kaolin, more alumina sources were needed in the synthesis of mullite. In other to investigate the effect of particle size of alumina sources on the mullitization of pyrophyllite, aluminum hydrate gel and activated alumina were used. When activated alumina, which has large particle size, was added to pyrophyllite, mullitization was not fully accomplished regardless of temprature. In the case of aluminum hydrate gel, which has small particle size, the maximum yield of mullite was about 90.3% at 1700$^{\circ}C$, and grain size of mullite was larter than the case of activated alumina was added.