Abstract: Wastewater containing ammonium salt will be generated in the sodium dropping process of Y zeolite.Thus more raw material consumption and environment pressure will be caused.However，the product quality can be ensured in the exchange process of ammonium salt.Combining with the actual production，a comparison experiment using aluminum salt to partially replace ammonium salt was carried out.Results showed the exchange efficiency of aluminum salt was higher than that of ammonium salt and the exchange resultant of aluminum salt was still the Y zeolite；comparing with ammonium salt，the crystallinity degree of Y zeolite was lower after the exchange with aluminum salt.Finally，the causes of crystallinity degree became lower after the exchange were analyzed and discussed.

Key words: molecular sieve, exchange, aluminum salt