巻号一覧
28 巻 (1988)
- 4 号 p. 175-
- 3 号 p. 119-
- 2 号 p. 1-
- 1 号 p. 1-
28 巻, 3 号
選択された号の論文の5件中1～5を表示しています
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黄 辰淵1988 年 28 巻 3 号 p. 119-125
発行日: 1988/09/01
公開日: 2011/09/20
ジャーナル フリーSamples of a mixture of Fe, Mg-chlorite and sericite, a Mg-chlorite, a Fe-chlorite, and a sericite were treated with 0.05N H2SO4 in a closed system at 25, 50, and 80°C for varying periods of time, and the susceptibility of the minerals to the treatment, in terms of dissolution of cations such as Si, Al, Mg, Fe, and K, has been investigated. The dissolution rate of the cations increased with temperature for all samples examined, and the rate was higher in the chlorites than in the sericite at all temperatures. The dissolution of the cations was incongruent, and the chlorites released Al, Mg, and Fe more rapidly than Si. It seemed, for the chlorites, that the cations in the interlayer and octahedral sheets were dissolved at a higher rate than those in the tetrahedral sheets. It was found also that the Fe-rich chlorite was more susceptible to the acid treatment than the Mg-rich one.抄録全体を表示PDF形式でダウンロード (679K) -
河野 元治, 下田 右1988 年 28 巻 3 号 p. 126-133
発行日: 1988/09/01
公開日: 2011/09/20
ジャーナル フリーA non-regularly interstratified mica/smectite was found in an argillized vein of the hydrothermally altered andesite at Tenei district, Fukushima Prefecture. The mineral has a 23.9 Å reflection and the proportions of mica and smectite layers are 83% and 17%, respectively. Chemical analysis of the mineral shows the structural formula of (Na0.21 K0.77 Ca0.28 Mg0.02)(Al3.69 Fe0.22 Mg0.19 Ti0.01)(Si6.24 Al1.76) O20 (OH) 4, and it seems to consist of muscovite-like and montmorillonite-beidellite-like layers.
Chemical analysis of the bulk samples from the argillized vein and the accompanying less wellargillized and non-argillized parts showed that the argillized vein contained K20 and H2O in high amounts relative to the non-argillized part. The high content of the two elements in the argillized vein was considered to be attributed to the presence of interstratified mica/smectite mineral, and that they were supplied possibly from hydrothermal solutions.抄録全体を表示PDF形式でダウンロード (680K) -
坂本 尚史, 安藤 徹, 大塚 良平1988 年 28 巻 3 号 p. 134-142
発行日: 1988/09/01
公開日: 2011/09/20
ジャーナル フリーThe upper Paleozoic series are widely distributed in the western part of Jiangxi Province, China. The sepiolite-bearing clay occurs as thin beds in the cherty limestone of the lower Permian series near Leping City. These sepiolite beds are recognized as the most important deposit in China.
The X-ray diffraction pattern of the purified specimen clearly indicates that this material is an well crystallized α-sepiolite with a small amount of talc. The structural formula calculated on the basis of 32 oxygens in the half-unit cell of dehydrated sepiolite is as follows:
(Si11.59 Al0.41)12(Al1.42 Fe3+0.41 Mg5.36)7.19 O32 · Ca0.02 Na0.03K0.12
This specimen may be specified as aluminian sepiolite characterized by high content of aluminum. Mineralogical data such as TG-DTG-DTA curves, IR spectra, SEM and TEM, etc. are also presented.
In the light of the mode of occurrence, these piolite has been primarily formed as β-sepiolite of marine origin, and then changed to α-sepiolite in subsequent diagenetic process.抄録全体を表示PDF形式でダウンロード (5054K) -
山崎 淳司, 松本 寛人, 大塚 良平1988 年 28 巻 3 号 p. 143-154
発行日: 1988/09/01
公開日: 2011/09/20
ジャーナル フリーThermal stability of fibrous zeolites and their cation exchanged forms has been investigated by means of high temperature X-ray powder diffraction and thermal analysis (TG-DTA). Heating natrolite and tetranatrolite, which carry only Na+ as exchangeable cation, caused them to transform into dehydrated phases at 350-400°C, which were maintainedup to 600-750°C. In contrast, those with both Na+and Ca2+(mesolite, gonnardite, thomsonite) and those with only Ca2+(scolecite) and only Ba2+(edingtonite) as exchangeable cations were decomposed and transformed directly into amorphous phase at 400-450°C, with no intermediate stage of dehydrated phase. Replacement of Na+of natural gonnardite by Ca2+resulted in a remarkable decrease of thermalstability in terms of lowering of decomposition temperature, whereas the reverse was true when the original exchangeable cation (Ca2+) of scolecite was substituted by Na+. Replacement of the original exchangeable cations of natrolite, tetranatrolite, gonnardite and thomsonite by K+lowered themperature of dehydration by 200-250°C, but heightened the temperature of decomposition by 250-550°C (natrolite and tetranatrolite) or even caused the appearance of dehydrated phase which did not form when the natural samples were heated (gonnardite, thomsonite). All the above results indicate that the observed differences of thermal stability is interpreted in terms of difference in the population of exchangeable cations in the zeolite structure: In the Na-and K-forms, the exchangeable cations should occupy all the available exchange sites, making the alumino-silicate framework rigid and resistant to thermal decomposition, whereas in the Ca-and Ba-forms the exchangeable cations fill up only one half of the exchange sites, leaving another half vacant and thus making the alumino-silicate chains susceptible to distortion and hence to thermal decomposition. Particularly high thermal stability of K-forms is ascribed to the residence site of K+ions of large size and low ionic potential (charge over radius) by which the ions fit well the 8-membered oxygen rings of exchange sites, imparting the structural stability.抄録全体を表示PDF形式でダウンロード (1159K) -
岩崎 孝志, 小野寺 嘉郎, 林 拓道, 鳥居 一雄1988 年 28 巻 3 号 p. 155-164
発行日: 1988/09/01
公開日: 2011/09/20
ジャーナル フリーSix dioctahedral smectites were tested as a Li+ adsorbent in L+ diluted solution 10, 30, and 50 mg/l under hydrothermal conditions of 100, 150, and 200°C. Layer charge of these smectites arises mainly by Mg+ for Al3+ substitution in the octahedral sheet and balanced by the interlayer cations, which are dominantly Na+ and Ca2+ ions with various ratios. After thehydrothermal treatment, smectites were examined by X-ray powder diffraction (XRD) and the amount of adsorbed Li+ were detemined by chemical analysis.
The hydrothermal reaction reaches adsorption equilibrium within 24h above 150°C. The amount of Li+ adsorbed on the smectites increased with hydrothermal temperature and reached about 50% of cation exchange capacity at 200°C for 24h (sample HH). Because reduced charge phase was recognized in the XRD patterns of treated smectites and its peak intensity increased with the temperature, it is presumed that the Li+ ions at least partly penetrated into the octahedral sheet of smectite. Ca2+, which are usually contained in geothermal brine with the concentration of almost the same order of Li+ ion, and Mg2+ hindered the Li+ adsorption on smectites exponentially because of the ion selectivity on the silicate surface. Dioctahedral smectites are therefore effective as a Li+ adsorbent if they are applied on the geothermal brine with low Ca2+ and Mg2+ contents.抄録全体を表示PDF形式でダウンロード (876K)
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