抄録
Ammonium montmorillonite was hydrothermally synthesized from the amorphous gels at 240°C for 40-50 days. X-ray diffraction analysis, differential thermal analysis, infrared spectroscopy, chemical analysis and electron microscopy proved that ammonium montmorillonite was synthesized without other crystalline phases and its properties were identical to natural montmorillonite exchanged to ammonium type. However, formation region of this montmorillonite was fairly limitted and formation of non-swelling material like mica was observed in the samples treated at 240°C longer than 50 days and in the sample treated for 50 days at 250°C. Magnesium montmorillonite and another crystalline phase, i.e. zeolite-type compound with chemical formula of (NH4)1.1 (Mg0.1Al0.9) Si2O6·nH2O, which was considered to be ammonium substituted analcime-type compound, was found in the sample treated for 150 days at 240°C.
