フロゴパイトからの混合層鉱物の合成について

抄録

Phlogopite from Hoshi mine Korea was used as the starting material of the experiment. This specimen was pulverized on an agate morter, and was mixed with powder of aluminium sulfate (Al_2(SO_4)_318H_2O) and magnesium carbonate (MgCO_3) in various proportions (phlogopite 0.15g, magnesium carbonate 0〜0.1g and aluminium sulfate 0〜1 g). The mixed powder was put into a small silver crucible and set over water level in the autoclave of the Morey type, and heated at 300℃ (120 atms water vapor) for 3 hours. After the heat duration, the autoclave was cooled to room temperatures. The heating rate is 2℃ a minute and the cooling time was about 10 hours. After cooling, the reaction product in the crucible was washed with distilled water to remove water-soluble material and the residure was studied by X-ray diffraction method and other mineralogical techniques. As a result of this, various kinds of clay minerals could be confirmed along with alunite in range of relative proportions of aluminium sulfate and magnesium carbonate, and an interstratified mineral could be confirmed. Other clay minerals obtained are montmorillonite, vermiculite and septechlorite. The interstratified mineral obtained is geometrically close to the regular mixed-layer mineral of mica (10A)-montmorillonite (15A), but is partially different from such the mineral, that is the 10A mica layer is expandable by the treatment with ethylene glycol. It can be considered that the interstratified mineral was formed from phlogopite due to a leaching of interlayer cation (K^+) at intervals of one layer.