| 摘要 |
Synthetic molecular sieves are produced by mixing a silica-containing mineral with a sodium or potassium-containing alkaline material, dying and fusing said mixture; forming an aqueous reaction system containing predetermined amounts of said fused mixture, a silica-containing compound, an aluminiumcontaining compound and an alkali metal compound to provide proportions of Na2O, Al2O3, SiO2 and H2O required to produce a predetermined molecular sieve; heating said aqueous solution at a temperature between 20 DEG and 120 DEG C., preferably not greater than 100 DEG C. until crystals of said molecular sieve are formed and recovering said crystals. Especially useful among a large number of named silica containing minerals are basalt, obsidian, perlite, bauxite, andalusite, attapulgite, albite, clinoptilolite, kyanite, mordenlite, diatomite and tripoli. The preferred alkali fusion temperature is 330 DEG -370 DEG C. for at least 8 hours, preferably 16-40 hours. The molar ratio of SiO2 to Al2O3 contained in the preferred minerals is 1:1 to 13:1, especially 0,25:1 to 1,5:1. The alkaline fusion material particularized is sodium hydroxide. The mole oxide ratios prior to crystallization are those specified for zeolites X and A as disclosed and claimed in Specifications 777,232 and 777,233.
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