| 摘要 |
PURPOSE:To enhance moisture adsorbing capacity and to suppress the side reaction at the time of dehydration treatment, by treating A-type zeolite in a carbonic acid-containing aqueous medium before or after granulation and controlling the pH of the resulting suspension to below 10. CONSTITUTION:Carbon dioxide is blown in an aqueous slurry of A-type zeolite particles and, if necessary, said slurry is recirculated until the pH thereof is adjusted to below 10. The zeolite after treatment is washed with water to remove alkali carbonate and filtered. A clayey binder or/and a water soluble polymer binder are mixed with the filtered zeolite and the resulting mixture is subjected to a known granulation means to obtain dehydration grade zeolite. As a separate method, untreated A-type zeolite formed into granular zeolite may be treated in a carbonic acid-containing aqueous medium in the same way to be dried at 150-350 deg.C.
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