method for preparation of zeolites of the faujasite type containing sodium and lithium cations and zeolites obtained by this process

摘要

1369665 Synthetic faujasite zeolites AZOTE ET PRODUITS CHIMIQUES SA 7 Sept 1971 [18 Sept 1970 10 March 1971] 41747/71 Heading C1A Synthetic faujasite zeolites having the molar composition of the general formula: where x is 0À05-0À95 are prepared by forming a gel of sodium and/or lithium aluminosilicate from a mixture having the following composition expressed as the molar ratio of the oxides: and then adding reactive amorphous silica of particle size less than 100 Á together with a Li compound and any further Na compound and water to form an amorphous mixture having the following composition expressed as the molar ratios of the oxides: and then crystallizing the mixture at a temperature of 20-105‹ C., filtering, washing and drying the precipitate and then finally activating the product. The gel may be formed by adding a solution of sodium and/or lithium silicate to an aqueous solution of sodium aluminate. The particle size of the silica added may be less than 50 Á. The faujasite may be activated by heating to 200-600‹ C. The lithium content of the amorphous mixture may be adjusted by ion exchange.