| 摘要 |
Zeolite Y and other faujasite type zeolites are made stable to acid by calcination in a steam-containing atmosphere with a slow, controlled heating rate in the temperature range at which chemically bound water in the zeolite is given off, generally from 500 to 650 DEG C. The stabilized product may be extracted with acid to produce a zeolite having a higher silica-alumina ratio. The high silica forms of zeolite ZSM-20 which may be produced by this method are hitherto unknown materials. |
