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Volume 41 (2001 - 200･･･
- Issue 4 Pages 163-
- Issue 3 Pages 113-
- Issue 2 Pages 43-
- Issue 1 Pages 1-
Volume 41, Issue 1
Displaying 1-5 of 5 articles from this issue
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Makoto ASADU, Takatsugu MASHIKO, Takabumi SAKAMOTO2001 Volume 41 Issue 1 Pages 1-8
Published: July 31, 2001
Released on J-STAGE: September 20, 2011
JOURNAL FREE ACCESSIn order to develop the method of synthesizing novel layered materials having the effective usage in industry, kanemite, one of the hydrous sodium polysilicate, was converted to some clay minerals.
Kanemite was treated hydrothermally with aluminum and magnesium salts solution for various Al or Mg (in reaction system)/Si (in kanemite) molecular ratios ranging from 0.1 to 2.0 at 200 and 250°C for 1 to 10 days under saturated vapor pressures. The products were examined by means of X-ray diffractometry, thermal analysis, and transmission electron microscopy.
By treatment with basic Magnesium carbonate kanemite changed to trioctahedral smectite and serpentine with increasing Mg/Si ratio. On the other hand, only kaolinite, having 1: 1 structure, was formed by reaction with AlCl3 solution and 2: 1 type mineral of trioctahedral smectite and talc are formed by MgCl2 solution. These results are different from previous studies that the 1: 1 type and 2: 1 type clay minerals had been formed in the high and low ratios of Al or Mg/Si in he reaction system, respectively. There is some possibility, however, that the pH of the solution and/or the structure of the starting material affected the process of hydrothermal reaction.View full abstractDownload PDF (4465K) -
Masahito FUJII, Hitoshi MURAYAMA, Tatsuya KODAMA, Yoshie KITAYAMA2001 Volume 41 Issue 1 Pages 9-15
Published: July 31, 2001
Released on J-STAGE: September 20, 2011
JOURNAL FREE ACCESSDistributions of impurities in natural sepiolite samples produced in Japan, China, U. S. A. and Turkey were studied by Xray diffraction (XRD), thermogravimetry (TG), differential thermal analysis (DTA), differential thermogravimetry (DTG), thermal mass spectrometry (TMS) and chemical analyses. Calsite, magnesite and dolomite were contained in the sepiolite minerals. These carbonates contained in the samples could be easily eliminated by treating with 0.6mol/L aqueous solution of HCI. Weight losses in each sample obtained by TG measurement were consistent with the calculated values from the results of elemental analyses. After the samples were treated with HCl, the weight losses with the decomposition of carbonates did not observed in TG curves of the samples and only the dehydration from the samples contributed to the weight losses in TG-DTA-TMS curves. Especially, in the Japanese and Chinese samples, characteristic dehydration steps in the pure sepiolite were observed. The results of elemental analyses showed that both the Si4+ site in the SiO4 sheet and Mg2+ in the MgO6 sheet of sepiolite samples were partially substituted by metal ions such as aluminum, iron, manganese and titanium ions.View full abstractDownload PDF (1073K) -
Ryuji KITAGAWA, Hirotsugu NISIDO, Jin-Yeon HWANG, Mayumi JIGE2001 Volume 41 Issue 1 Pages 16-19
Published: July 31, 2001
Released on J-STAGE: September 20, 2011
JOURNAL FREE ACCESSNumerous clay veins formed along fractures such as fault, joints, cracks and small fissures are found in granitic rocks in Korea. Granitic rocks of three geological stages (Jurassic, Cretaceous and Paleogene) occur as the Daebo, Bulguksa and Hoam granites, respectively. Specimens from clay veins composed mainly of illite and their host granitoids were dated using the K-Ar method. The respective ages were: Jurassic: granites 143.7Ma and 160Ma, clay veins 104Ma and 107Ma; Cretaceous: granite 133.2Ma, clay veins 93.6Ma, 84.2Ma and 84.3Ma; Paleogene: granite 39.7Ma and 35.4Ma, clay veins 27.1Ma and 23.9Ma. The ages of the clay veins in Korea are clearly much younger than those of their host granitoids.View full abstractDownload PDF (528K) -
Mayumi JIGE, Ryuji KITAGAWA, Victor Zaykov, Valery Udachin, Irina Siny ...2001 Volume 41 Issue 1 Pages 20-25
Published: July 31, 2001
Released on J-STAGE: September 20, 2011
JOURNAL FREE ACCESSThe Au-decoration technique of electron microscopy was applied to the crystal surfaces of pyrophyllite collected from the Urals, Russia. The modes of occurrence of pyrophyllite ores in the Urals are briefly divided into four types, such as the alteration zone of iron sulfide ore deposit, veins with the gold deposit, sediment with coal layers, and weathering crust. Pyrophyllite occurs mainly in the hydrothermal alteration zones of the iron sulfide deposits. In this study, pyrophyllite specimens were collected from the three iron sulfide deposits, i.e., Gay, Kur-Yurt-Tau and Chistogor deposits.
The specimens investigated exclusively exhibited growth patterns of parallel steps with varying step separations. In generally circular and polygonal spiral growth patterns are observed on the crystal surfaces of illite, kaolinite and chlorite formed under the hydrothermal alteration. It is considered from the difference of these morphological characteristics on the crystal surfaces that pyrophyllite particles were formed under the higher temperature and/or supersaturation comparing with other hydrothermal clay minerals.View full abstractDownload PDF (7787K) -
Tsutomu SATO2001 Volume 41 Issue 1 Pages 26-33
Published: July 31, 2001
Released on J-STAGE: September 20, 2011
JOURNAL FREE ACCESSDownload PDF (5200K)
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