Journal of the Clay Science Society of Japan (in Japanese)
Online ISSN : 2186-3563
Print ISSN : 0470-6455
ISSN-L : 0470-6455
Volume 38, Issue 3
Displaying 1-8 of 8 articles from this issue
  • Mitsuo SATO
    1999 Volume 38 Issue 3 Pages 139-144
    Published: March 31, 1999
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
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  • Naotatsu SHIKAZONO
    1999 Volume 38 Issue 3 Pages 145-152
    Published: March 31, 1999
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
    Geochemistry of groundwater originated from rainwater can be interpreted in terms of model calculations based on chemical equilibrium between aqueous species and minerals, dissolution kinetics of silicates and carbonates and groundwater flow. The model calculations predict increases in pH and Si, Ca, Na and K concentrations in groundwater interacting with feldspar. This theoretical prediction is consistent with natural groundwater chemistry in general. Weathering trend in granitic rocks from the surface to deeper part (gibbsite → kaolinite → montmorillonite) can be reasonably explained by the model calculations. The geochemical evolution of groundwater and weathering trend depend on initial composition of rainwater, minerals interacting with groundwater, minerals precipitating from groundwater, kinetic factors, physical properties of rocks (permeability, porosity etc.), and whether the system is open to atmosphere or closed.
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  • a potential substitute for foamed styrol
    Hiromoto NAKAZAWA
    1999 Volume 38 Issue 3 Pages 153-161
    Published: March 31, 1999
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
    To minimize the ecological change due to the human activities, is a current consensus of the world.
    The man-induced flow of materials, i. e. from the Earth's crust to surface by mining, utilizing, and abandoning of metals and petroleum, is the original sin for the Earth's ecology. It is, therefore, require presently for science and technology to find probable method of recycled use of metals and petroleum as well as to find probable substitutes produced by some constituents of the natural environment of the Earth's surface. Clays and clay minerals are the attractive materials from such an ecological point of view, because they have many utilizable properties and return again to the Earth when they are abandoned after use.
    Natural organics produced by biological activities are also attractive for their reproducibility and abandability in the natural cycles of materials.
    Based on such concept and some previous works ourself, we have tried to create a substitute of polystyrene foam, a popular petroleum product widely used as packing and insulating buffer material. The principle was a lyophilization of a thixotropic sols of clays and bio-organic compounds, which make porous composites having similar nature to those of polystyrene foam.
    Finally, we are successful in producing a porous clay/bio-organic composite having suitable properties as a substitute of polystyrene foam and in developing a method of its industrialization. Its compression strength is rather better than that of the latter. A problem is, however, remained for its practical production, i. e. its cost of production is still higher than that of polystyrene foam in the present market.
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  • Yoshie KITAYAMA
    1999 Volume 38 Issue 3 Pages 162-166
    Published: March 31, 1999
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
    Many convenient materials and tools have been supplied by the chemical industry. Accompanying with such phenomena, pollutants and industrial waste has been accumulated in the environment. Clay minerals play important roles in environmental studies. Interactions between metal ions in aqueous solution and clays were discussed. Affinity of various clay minerals for divalent metal ions in aqueous solution was different and the sorption ability of clay minerals for metal ions did not exceed their CEC values. Sorption of non polar organic compounds in aqueous solution with clays was promoted by the intercalation of cation surfactants in the interlayer of the clays. Sepiolite has been used as a useful deodorizer because the smelling materials such as NH3, alkylamine and thiophen are strongly adsorbed in the intracrystalline channels of sepiolite.
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  • Hideo MINATO, Yashuhiro SHIBUE
    1999 Volume 38 Issue 3 Pages 167-180
    Published: March 31, 1999
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
    Hazardous wastes contaminated with heavy metals, arenic and other toxic metals ware previously discharged to non lined landfills around final disposal sites of town waste disposals, in and around industry areas, and mining facilities. These wastes often provoke enviromental pollution to soils, groundwater, surface water, and other local geologic units which causes serious health risks. In order to protect from the enviromental pollutions, some kinds of clay mineral and natural zeolites with calcium compounds can be applied in two ways. One is mixing treatment of these materials to in situ remedy for toxic metals pollution within wastes. Ion-exchange property of zeolites and adsorption of clay minerals are elective in this treatment, which makes geochemically and mineral chemically stable state that reduces leaching of the toxic metals. The other is more physical and mechanical ways, that is a use of a mixture of clay minerals and natural zeolites with calcium compounds for liner materials at solid waste disposal site of which impermeable property as well as adsorption successfully shields migration of toxic metals from waste sites. This mixing technique is also utilized for new treatment processes in polluted sites by toxic metals, especially in soil of polluted by 6+ chromium. In this paper, we report typical results of laboratory experiment and some case studies of the remedation techniques by using clay minerals and natural zeolite with calcium compounds in industrial facility, solid disposal site, and disposal site of ore-processing residue and slag in smelting process, in Japan. These new techniques are introduced in international meetings, also, and they are reported in opportunity of International Symposium, held by 111th Committee on Development on the New Utilization of Minerals, Japan Society for the Promotion of Science (JSPS), October, 1998 in Toyko.
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  • Masakazu ITO, Takashi ISHII, Hitoshi NAKASHIMA, Yukiya HIRATA
    1999 Volume 38 Issue 3 Pages 181-187
    Published: March 31, 1999
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
    Origin and formation condition of bentonite were obtained by new methods at four mines: Tsukinuno, Kawasaki, Dobuyama and Kuroishi. The Tsukinuno bentonite was considered diagenetic and the others were hydrothermal origin. The formation age were obtained by fission-track and K-Ar methods. The eruption age of original rock of these four bentonite deposits were 12-17 Ma. The fission track length and the difference between fission-track and K-Ar age indicate the hydrthemal activity in the Kawasaki, the Dobuyama and the Kuroishi deposits.
    The composition of plagioclase in bentonitized tuff is related to original volcanic rocks. Plagioclase were measured by refractive index. Plagioclase in the Tsukinuno bentonite had a little sodium rich composition than the other bentonites.
    Formation temperature of bentonite were measured by oxygen and hydrogen isotopic study. Formation temperature of four bentonite were several dozen °C Formation temperature of Dobuyama bentonite was lowest, and Kuroishi was highest of four bentonites.
    Thermal history of bentonite were measured by ESR and Thermoluminescence. Kawasaki, Dobuyama and Kuroishi bentonite were suffered some heat evidence until 1-2 million years ago. Tsukinuno bentonite was suffered heat until several hundred thousand years ago.
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  • Haruto MURAISHI
    1999 Volume 38 Issue 3 Pages 188-196
    Published: March 31, 1999
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
    The cation exchanged magadiite and kenyaite were prepared by exchanging the interlayer Na ion of synthesized samples with a series of alkali metal cations, and the effects of the exchangeble cations on the thermal behavior of magadiite and kenyaite were investigated in the temperature range of 200 to 1100°C.
    Dehydration of the constitution water occurred in a stepwise fashion. On the first stage the adjacent silanol groups on the same layer surface condensed to form siloxane bonds and the resulting water was evolved. The dehydration temperature did not affect any cations. On the second stage the dehydration took place with the condensation reaction between the two silanol groups on the surfaces located opposite of each other. A three-dimensional network structure was consequently formed, and their dehydration temperatures increased with the increasing radii of the cations. After the dehydration, Li and Na ions resulted in the formation of quartz, and K, Rb andCs ions resulted in the formation of cristobalite. On the process of heating, these crystal phases were finally transformed into tridymite, and the rate of the polymorphic transition was decreased in the order Li>Na>K>Rb> Cs.
    The principal results are summarized as follows. The interlayer cation species influenced (1) the dehydration temperature of the constitution water: 300-700°C, (2) the thermostability of the layered structure (temperature of destruction of layered structure): 600-850°C, (3) the recrystallization temperature and the types of resulting crystal phase: 600-900°C, (4) the polymorphic transition temperature: 600-1100°C, and (5) the kinetics for polymorphic transition: 800°C. It was postulated that the fluctuations for such thermal behavior were cased by the difference in ionic radius, electric charge density, diffusion coefficients, and breaking of=Si-O-Si=bond of the cations.
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  • Takabumi SAKAMOTO, Atsushi YAMAZAKI, Shoichi KOBAYASHI
    1999 Volume 38 Issue 3 Pages 197-206
    Published: March 31, 1999
    Released on J-STAGE: September 20, 2011
    JOURNAL FREE ACCESS
    Talc has been known as a low reactive mineral under hydrothermal conditions in comparison with the other clays. However, it was expected that grinding treatment increase its reactivity by so-called mechanochemical effect.
    In the present study, naturally occurred talc from China was ground in vibrating mill to X-ray amorphous state. The ground talc was then treated hydrothermally with aluminum salts solution for various Al (in reaction systems)/Si (in ground talc) molecular ratios ranging from 0.1 to 2.0. The products were examined by means of X-ray diffractometry, thermal analysis, and infrared absorption spectroscopy.
    It was found that the ground talc is successively converted to trioctahedral smectite, dioctahedral smectite, and kaolinite with increasing the Al/Si ratios, by treatment with acidic aluminum bearing solution such as AlCl3, Al2(S04)3, and Al (NO3)3. Al24O11(OH)44Cl6 phase and alunite were also formed as the coproducts in the way of AlCl3 and Al2(SO4)3 solution treatment, respectively.
    On the other hand, by the treatment with NaAlO2, the ground talc changed to a trioctahedral smectite and an analcime at low Al/Si ratios, but a serpentine and a hydroxysodalite were formed at high Al/Si ratios. In these cases, the reaction was proceeded in basic condition, and the pH value was increased with increasing of the Al/Si ratios.
    It is concluded that grinding significantly increases the hydrothermal reactivity of talc, and the hydrothermal products of the ground talc are controlled by the Si/Al ratio and pH value in reaction system.
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