Electron diffraction and X-ray investigation of hydrothermally vitrified 5 A zeolite containing trapped gases

The mechanism of gas fixation by hydrothermal treatment of zeolite type 5 A in the presence of densified gas has been examined by electron diffraction and X rays. Gas trapping seems to occur in an X-ray amorphous phase which is formed within a broad spectrum of fixation conditions. The amorphous matrix recrystallizes at 8500C regardless of the parameter combination selected for vitrification. The recrystallization product consists essentially of anorthite and nepheline phases. In addition some CaAl2Si2O8 was found. Observations made by X rays and by electron diffraction correlate well with leak rate data. 18 references, 9 figures, 1 table