Process for preparation of ferrierite type zeolites

摘要

A ferrierite type zeolite having a high purity and a high SiO2/Al2O3 molar ratio is prepared by reacting simultaneously and continuously an aqueous sodium and/or potassium silicate solution with an aluminum-containing solution to obtain a homogeneous phase compound of a granular amorphous aluminosilicate containing Al in an amount of 3 to 14 wt. % as calculated as anhydrous Al2O3 and Na and/or K in an amount of 1 to 17 wt. % as calculated as anhydrous Na2O and/or K2O; and then, crystallizing the homogeneous phase compound in the form of a slurry in water or in an aqueous sodium hydroxide and/or potassium hydroxide solution. The molar ratio of K+ to the total of (K++N+) in the slurry is 0.1 to 0.9.