1989 Fiscal Year Final Research Report Summary
Cation Exchange and Therna Transformation of Smectites
| Project/Area Number |
62540620
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
鉱物学(含岩石・鉱床学)
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| Research Institution | Osaka University |
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Principal Investigator |
UNO Yasuaki Osaka University, College of General Education, Assistant, 教養学部, 助手 (90029702)
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| Project Period (FY) |
1987 – 1989
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| Keywords | Smectite / Montmorillonite / Cation exchange / Layer charge / Quartz solid solution / High temperature products / Cheto-type / Wyoming-type |
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| Research Abstract |
Cation exchange properties and thermal transformation were investigated for various smectites in bentonite and acid clay deposits. The results are as follows.
1. Smectites have various chemical compositions from one deposit to others. This variation is considered to be related not only to chemical composition of original clay beds, but also to leaching process by supergene wethering.
2. The upper horizon of Ca-type bentonite deposits is strongly altered to acid clays, compared with Na-type bentonite.
3. The variations of optical property of smectites during temperature variation were determined using microphotometer. Refractive indices of smectite increase remarkably with Al-Fe exchange in octahedral sheet of samples. So microphotometric analysis enable to estimate the layer charge of smectite.
4. Cheto-type smectite having large amount of octahedral charge develops high-quartz like phase during high temperature reaction above 800ﾟC whereas Wyoming-type smectite having small amount of octahedral charge does not develop such phase. After excess Mg addition treatment, Wyoming-type smectite also develops high-quartz type phase.
5. Chemical analysis of high-quartz type phases was made using analytical electron microscope. The composition of this phase was found not to be pure SiO_2, but instead showed a structural formula close to MgAl_2Si_5O_<14>.
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Research Products
(10 results)
