| 摘要 |
Silica xerogels having a narrow pore diameter distribution in the range of 300-600 A. and surface areas in the range from 200-500 m.2/g. and the process of preparing such xerogels comprising critically controlled steps of precipitation of the silica gel, heat aging the precipitated silica hydrogel slurry, washing the aged product with solutions of salts having displacing effect on sodium, disintegrating the gel, drying the gel by azeotropic distillation with a solvent which is nonmiscible with water, and calcining. Also, a process for preparing such xerogels wherein the non-water miscible solvent is continuously recycled so that a minimum amount of solvent need be used.
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