Abstract
Beidellite was synthesized from sodium aluminosilicate glass at a hydrothermal pressure of 100 MPa and at temperatures of 250, 300, 350, 400 and 450°C. The initial water/solid ratio of the starting materials was varied in the range 0.155 to 2.17. The run products were analyzed by the powder X-ray diffraction (XRD) method. Correlations among the water/solid ratio, temperature of synthesis, yield of beidellite and its crystallinity indicated: (1) Amount of water intercalated in the structure was limited to three layers even in water-excess condition of synthesis at high pressure and temperature. (2) Beidellite, crystallized from glass by hydration, was in the form of a two-dimensional flake. The dimensions and thickness of a flake were independent of the temperature of synthesis and the water/solid ratio, and were not increased by further hydration.
