| 摘要 |
<p>Zeolite Y, having composition expressed in oxide-mole-ratios as 0.9/sB0.2 Na2O : Al2O3 - WSiO2 : XH2 wherein W is 3 to 5, X is 0 to 9, and having a specified X-ray powder diffraction pattern, is prepared by crystallization at 20 DEG to 125 DEG C. from an aqueous, sodium aluminosilicate reactant mixture, having a composition within one of the ranges <TABS:1011772/C1/1> the major silica source being at least one amorphous solid silica having an average particle size of less than 1 micron, e.g. fume silicas, flocculated silica sols, or commercial powdered silicas. Minor proportions of silica gels, or silicic acid, may be employed. A source of alumina may be activated alumina, gamma alumina, alumina trihydrate, sodium aluminate; sodium hydroxide may supply the sodium ion. Zeolite Y crystals may be activated by heating in air or vacuum to as high as 700 DEG C., and may be used as an adsorbent in powder form or pelleted in admixture with a bonding agent such as clay.</p> |
