• 한국수소및신에너지학회논문집
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• 제17권1호
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• pp.109-116
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• 2006

The heat treatment characteristics of natural talc sample was investigated in diverse analytical view point. The mass decrease comes to heat treatment was resulted by the continuous and the discontinuous process and the obtained result show very similar two step profiles with 8.9 % mass decrease. The dehydroxylation of -OH groups contained talc crystal was analyzed by spectroscopic method and the crystallographic variations was also observed after heat treatment. According to XPS result, the magnesium hydroxide($Mg(OH)_2$) of untreated talc powder changed to magnesium oxides(MgO) after heat treatment.

• 한국광물학회지
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• 제12권1호
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• pp.1-10
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• 1999

Talc (Mg3Si4O10(OH)2), one of the sheet silicate minerals, which is the hydrothermal alteration product of serpentinite at Cheongarm mine was prepared for the high pressure compressibility studies. Energy dispersive X-ray diffraction experiment was carried out using the Synchrotron Radiation with the Mao-Bell type diamond anvil cell at room temperature. Polycrystalline talc was mixed with MgO powder for pressure sensor as well as pressure medium in the sample chamber. High pressure runs were performed at pressures up to 35.2 GPa. Talc shows no phase transition within the present high pressure region. Bulk modulus of this talc was determined by the Birch-Murnaghan equation of state to be 78 GPa assuming its first pressure derivative Ko' of 4.

• Journal of the Korean Wood Science and Technology
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• 제14권4호
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• pp.8-13
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• 1986

To investigate effect of sericite on pilot Fourdrinier paper making for loading, with respectively 15% additive sericite on talc, we made newprint with TMP, and then tested sericite on talc, we made newprint with TMP, and then tested sericite and talc abrasion, physical and strength properites of the paper. Consequently, as a loading materials, sericite had outstanding properties different from talc from the result of this paper; 1. Sericite was a good loading materials because the quantity of abrasion was small. 2. Sericite had a good physical properties of Foudrinier paper because brightness. ash content and water absorption were high. 3. Newsprint paper strengthes of additive talc were nigher than those of additive sericite.

• 한국세라믹학회지
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• 제14권1호
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• pp.12-18
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• 1977

In our former paper, tremolitic talc, -wollastonite-clay system was studied. In this study blast furnace slag was used(B.F.S.) instead of wollastonite for developing a fast-firing wall tile body. The wall tile bodies consisting of tremolitic talc and B.F.S. asmajor constituents have been fired in the temperature range 1000-120$0^{\circ}C$. Some of these bodies have showed good properties for wall tile manufacture. According to the increased content of B.F.S the fired bodies have showed the decreased thermal expansion which was resulted from the fact that the amounts of diopside and anorthite were gradually increased and those of quartz relatively decreased. Being reasonable in low price and thermo-stable properties tremolitic talc and B.F.S. will be good materials for the fast-firing tile body.

• 펄프종이기술
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• 제30권2호
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• pp.40-46
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• 1998

This study was aimed to investigate any improvement of dewatering and energy saving on the papermaking process when the various types of fillers were used, i.e., clay, talc and grounded calcium carbonate (GCC). Cationic polyelectrolyte and alum coagulants neutralized the surface charge of the filler particles and the filler particles were coagulated. The rates of dewatering and drying were investigated. The results indicated that clay tended to intense anion, while talc and GCC tended to anion trend nearly to neutrality. Clay and talc added with EPI-DMA, P-DADMAC and alum respectively as optimum levels showed a significant efficiency on the dewatering and the turbidity dissipation. However, the turbidity and dewatering rate of GCC decreased, when GCC was added with EPI-DMA and P-DADMAC respectively Drying rate of clay was increased when coagulant added. However drying rates of talc and GCC were not affected by coagulant, while the apprarent drying time of talc and GCC in the absence of any coagulant was shorter than the clay in the presence of a coagulant. The result confirmed that talc or GCC was more efficient than clay on the dewatering and drying, which is consistent with a general knowledge in the collodal science.

• 자원환경지질
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• 제24권4호
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• pp.363-378
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• 1991

Field and microscopic evidence, XRD,EPMA and chemical data suggest that parent rock of talc ore deposits of Yesan district was originated from ultramafic igneous rock. Parent rock can be divided into serpentinized dunite, serpentinized peridotite, metagabbro, amphibolite and hornblende schist. The ore deposits are highly sheared, and show many evidences of hydrothermal alteration and metamorphism at the greenschist and albite-epidote amphibolite facies. The process of steatitization is variable depending upon the composition, and the degree of alteration and metamorphism of the parent rocks. Steatitization can be divided into two processes with or without serpentinization. The parent rocks with serpentinization are serpentinized dunite, serpentinized peridotite and metagabbro, showing the following alteration process; olivine ${\rightarrow}$ serpentine${\rightarrow}$ talc. The rocks without serpentinization are amphibolite and hornblende schist showing the following sequence; hornblende${\rightarrow}$ chlorite${\rightarrow}$ talc. Formation of talc deposits is summarized as following six stages; I) Intrusion of ultramafic rocks, 2) autometamorphism, 3) metamorphism at greenschist and albite-epidote-amphibolite facies, 4) brittle deformation, 5) hydrothermal alteration, 6) purification of low-grade talc by late dyke intrusion.

• 펄프종이기술
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• 제41권3호
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• pp.8-12
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• 2009

According to a previous study, talc as a coating pigment can improve the viscosity and the water retention of coating color, the compressibility of coating layer, and hence gravure printability. Talc is also well known for its larger particle size than other pigments, which implies that less binder may be need due to its smaller specific surface area. This study investigated the possibility of reducing binder content for matte grade paper. Coating color was prepared with the Cotalc-2000, which showed the best properties in the previous study. The binder content was varied and the effect of binder content on the physical properties of coated paper and the gravure printability was investigated. It was shown that binder content could be reduced when talc was used as a coating pigment. The reduction in binder content did not influence gloss, roughness and the print density of coated paper but showed improvement in paper porosity, compressibility and missing dot.

• 공업화학
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• 제9권7호
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• pp.961-967
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• 1998

종이제조에 있어서 종이의 광학적 성질 및 인쇄적성을 개선하기 위하여 여러 종류의 충전제가 사용되고 있다. 본 연구는 신문용지 제조에 있어서 여러 종류의 충전제, 즉 경질탄산칼슘(PCC), 중질탄산칼슘(GCC), 그리고 혼합된 충전제(PCC+미세활석(MVP) 또는 활석(talc), GCC+MVP 또는 talc))를 종이에 충전시켰을 때 종이의 여러 물성에 미치는 영향을 검토하였다. 얻어진 결과를 요약하면 다음과 같다. 1) 충전제를 지료전건중량당 5% 처리시 동일 처리조건하에서의 충전제 보류율은 PCC 처리시 GCC 처리시보다 16.8% 정도 높게 나타났으며, PCC 및 GCC를 처리했을 때 모두, 배합한 충전제의 입자경이 커질수록($PCC{\leq}GCC<MVP<talc$) 보류율이 증가하는 경향을 나타내었다. 2) PCC 처리시 무처리보다(92.2%) 대비 2.3% 이상의 비교적 높은 불투명도 개선효과를 나타내었으며, 배합한 충전제의 평균 입자경이 클수록 불투명도가 감소하는 경향을 나타내었다. 3) PCC 단독 처리시 GCC 단독 처리시보다 소폭의 인열강도 하락을 나타내었으며 20% 배합처리한 충전제의 평균 입자경이 커질수록 인열강도가 증가하는 경향을 나타내었다. 4) PCC 단독처리시 비교적 높은 인장강도를 나타내었으며, 다른 충전제와 혼합처리시 인장강도의 하락폭은 GCC 처리쪽이 적은 것으로 나타났다. 5) PCC를 처리하였을 경우, 배합한 충전제의 입자경이 커질수록 ($PCC{\leq}GCC<MVP<talc$) 파열강도는 직선적으로 감소하였다. 6) 충전제를 처리하였을때 무처리보다 비교적 우수한 인쇄적성 효과를 나타내었다.

• 암석학회지
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• 제2권2호
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• pp.95-103
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• 1993

충주부근 활석 광상주변에는 옥천대의 변성퇴적암류에 속하는 계명산층, 문주리층, 대향산 규암층, 향산리 돌로마이트층과 염기성암 기원 변성암류 등이 분포한다. 활석 광상은 향산리 돌로마이트층내에 대향상 규암층 인접부에서 산출된다. 향산리돌로마이트층의 변성광물군은 \circled1방해석-투각섬석-활석-석영, \circled2방해석-활석-석영, \circled3투각섬석-방해석-백운석 \circled4방해석-백운석-금운모-녹니석 등이다. 활석의 $X_{Mg}$(=Mg/(Fe+Mg))는 0.98이며 이상적인 활석의 화학성분에 가깝다. 활석의 형성은 규질 돌로마이트가 중압형 광역변성작용을 받아 형성된 것으로 인지되며, 접촉변성작용 또는 열수 작용의 흔적은 찾아볼 수 없다. 향산리 돌로마이트층엥 인접해 있는 이질암 또는 염기성 변성암의 공생광물군이 \circled1각섬석-흑운모-백운모-녹염석-석영 \circled2흑운모-녹니석-석영 \circled3각섬석-양기석-녹염석-사장석-석영인 것으로 보아 녹염석-앰피볼라이트상 내지 녹색편암상에 해당함을 보여 준다. 활석 생성은 다음의 화학반응과 깊은 관련성이 있다; (I) 3백운석+4석영+$H_2O$=활석+3방해석+3$CO_2$; (II) 3투각섬석+2$H_2O$+6$CO_2$=5활석+6방해석+4 석영, 활석, 투각섬석, 석영과 공생하는 방해석에 대한 지질온도계에서 약 $434^{\circ}C$의 최저 평형 온도를 구할 수 있으며, $X_{$CO_2$}$는 연구지역의 변성압력을 3 kbar로 가정할 때 약 0.1로 산정된다.

• 한국광물학회지
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• 제32권3호
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• pp.201-211
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• 2019

단층 비지는 단층의 미끌림에 의해 입도와 결정도가 낮아지는 특성을 가지는 것으로 알려져 있다. 활석을 비롯한 층상규산염 광물은 단층 비지에 존재하며 단층 약화에서 중요한 역할을 할 수 있는데, 특히 광물 표면에 흡착된 물분자의 존재 여부에 따라 마찰계수가 달라진다. 본 연구에서는 고에너지 볼 밀을 이용해 입도와 결정도를 체계적으로 변화시킨, 분쇄 전후 활석의 함수율과 탈수반응 거동의 변화를 통해 활석이 단층 약화에 미치는 영향에 대해 알아보고자 하였다. 적외선 분광분석 및 열분석 결과, 분쇄 전 활석은 소수성을 띠며 물분자가 거의 존재하지 않는다. 이후 최대 720분까지 진행된 분쇄를 통해 입도가 약 100~300 nm 내외까지 감소하고 비정질화가 진행된 활석에서는 물분자에 의한 함수량이 분쇄 전에 비하여 약 8 wt.% 증가하였다. 또한 분쇄된 시료를 가열할 경우, 분쇄 전에 비하여 기화되는 수증기의 양이 증가한다. 입도 및 결정도 감소에 따라 탈수산기 반응 온도도 분쇄 전 약 $900^{\circ}C$에서 720분 분쇄 후 약 $800^{\circ}C$로 감소하였다. 이와 같이 분쇄된 활석의 입도 및 결정도 감소에 의해 소수성이 친수성으로 바뀌며 층상 규산염 광물의 마찰계수를 낮출 것으로 생각된다. 지진 사이클을 통해 반복되는 단층의 미끌림은 지속적으로 단층 비지에 존재하는 활석의 마찰 계수를 낮출 것으로 생각되며, 오래된 단층이 점점 약화되는 원인에 대한 실마리를 제공할 수 있을 것으로 기대된다.