抄録
This paper presents a review on the syntheses of interstratified clay minerals, especially on interstratified mineral of mica/smectite. Concerning the syntheses of interstratified mineral of mica/smectite, three different methods from the stand point of view of starting materials have been reported. They are 1) formation of mixed-layer mineral from mica; 2) formation of mixed-layer mineral from smectite, and 3) formation of mixed-layer mineral from artificial gels or minerals other than mica and smectite. When mica is used as a starting material, the extraction of K ions from interlayers is necessary, and various techniques are employed to extract the interlayer K ions such as penetration of cations into vacant sites in octahedral layers; the oxidation of Fe2+ in octahedral layers, and the extraction of K ions from mica or artificially distorted mica by treatment with chemicals. When smectite is used as a starting material, interstratified mineral of mica/smectite is synthesized in the presence of Kions and/or other cations under hydrothermal conditions. When artificial gels or other minerals are used as a starting material, interstratified mineral of mica/smectite is synthesized under the same conditions. Interstratified mineral of chlorite/smectite has been synthesized from smectite under hydrothermal conditions, and from chlorite by oxidation of Fe2+ in octahedral layers. Synthesis of interstratified mineral of kaolinite/smectite from Al (OH) 3- montmorillonite complex under hydrothermal conditionhas been reported.
