The invention discloses a preparing method of an H-ZSM-34
molecular sieve. The preparing method of the H-ZSM-34
molecular sieve comprises the steps of preparing a mixture A from n(Al2O), n(Na2O), n(K2O), n (SiO2) and n (H2O) according to the proportion of 1:5.1:9.13:10.54:129.98, adding an aluminum source into an
aqueous solution, continuing to add an alkaline source and a
silicon source, and after stirring,
ageing to obtain a clarified
crystal seed solution; adding
sodium hydroxide and water-soluble
silica gel into an
aqueous solution with a certain volume, after stirring, adding aluminum
sulfate crystals and a
crystal seed solution with a certain volume in sequence, stirring at the
room temperature, putting the mixture into a kettle, conducting
crystallization, taking the solution out ofthe kettle, conducting suction
filtration and washing, and conducting
drying and
roasting to obtain Na-ZSM-34; adding a certain amount of Na-ZSM-34 into a 1mol / L
ammonium nitrate solution according to the
solid-to-
liquid ratio of 1:20 to be stirred, and conducting suction
filtration, washing and
drying; repeating
ammonia exchanging four times, afterwards, obtaining NH4-ZSM-34, and
roasting NH4-ZSM-34 through air to obtain the H-ZSM-34
molecular sieve. The conversion rate of
chloromethane in the reaction of using the H-ZSM-34 molecular
sieve to prepare propylene through
chloromethane is 87.0%,the selectivity sum of
ethylene and propylene is 41.4%, the sum of the yields of
ethylene and propylene is 36%, and the H-ZSM-34 molecular
sieve does not get inactivated within 24 h. The preparing method has the advantages of being simple in technology, easy to operate and high in production efficiency.