| 摘要 |
<p>Silicates, for use in prodn. of zeolites for detergents and fillers are obtd. by reaction of amorphous silica contg. diatomaceous material with dilute sodium hydroxide soln. at 50-120 deg.C under atmos. pressure. The reactive silica is used in above the stoichiometric amt. and the silicates extd. by filtration as soon as formed. Fresh NaOH soln. is then added to react with the remaining silica, and this process is repeated until all the silica has been used. Calcium carbonate is used as the source of NaOH.</p> |
