| 摘要 |
<p>Zeolite Y1, having a composition 0.9/sB0.2 Na2O : Al2O3 : WSiO2 : XH2 where W is from 5 to 6, and X is a value up to 9, is prepared from an aqueous sodium aluminosilicate mixture, the major source of silica in said mixture being at least one amorphous solid silica having an average particle size of less than 1 micron. The solid silicas may be fume silicas or chemically precipitated silica sols. Minor proportions of silica gels or silicic acid may be present. The mixture, which has a composition falling within one of the ranges ..Range 1.Range 2 .Na2O/SiO2.0.28 to 0.30.0.40 to 0.42 .SiO2/Al2O3.8 to 10.10 to 27 .H2O/Na2O.30 to 50.30 to 50 is digested at ambient temperature (55 DEG to 100 DEG F.) for from 16 to 40 hours when the initial composition falls within range 2, or for from 20 to 40 hours when the initial composition falls within range 1, heated to an elevated temperature of from 90 DEG to 105 DEG C., and maintained at the elevated temperature until the zeolite has crystallized. The crystals are separated from the mother liquor and may be activated by heating in air or in vacuo to temperatures as high as 700 DEG C. It is exceptionally stable towards steam at elevated temperatures and may be used as an adsorbent in any suitable form, e.g. pelleted with a bonding agent such as clay. Specifications 777,233 and 972,831 are referred</p> |
