Journal of Science,University of Tehran(not publish)

Journal of Science,University of Tehran(not publish)

Phase Transition of Natural Clinoptilolite to Analcime at Presence of Alkaline Solution

Abstract
Clinoptiloite transforms to analcime under hydrothermal condition in presence of alkaline fluids. The effect of Na+ and K+ concentrations, temperature and run duration are being considered as the variable parameters in the present study. Alkaline solutions were used in concentration of 1.25 up to 7.5mol/lit under temperatures of 100 and 150 ?C. Results of this study show that analcime is synthesized at 150?C and high concentration of Na+. With increasing Na+ content of the fluids and reaction time, the amount of analcime increases drastically. Powder X-ray diffraction study has revealed an orthorhombic symmetry with the unit-cell parameter of a: 13.731 ?, b: 13.726 ?, c: 13.769 ?.
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