| 摘要 |
Zeolite Y comprising aluminum ions supplied and fixed by ion-exchange is produced by subjecting zeolite NaY to a series of treatment steps comprising e.g. ammonium ion-exchange and calcination. In order to supply and fix the aluminum ions, an aluminum ion-exchange is carried out, followed by further calcination in a saturated or substantially saturated steam (water vapor) atmosphere at 400 DEG -900 DEG C. If the zeolite unit cell size is to be reduced to 24.15-24.35 ANGSTROM , simultaneously as the aluminum ions are fixed, the last-mentioned calcination is carried out in a saturated or essentially saturated (steam) water vapor atmosphere at 500 DEG -900 DEG C. It is further disclosed that the steam used in the calcination step can be supplied either from an external source or solely by vaporization of water present in the zeolite. |
