摘要 |
<p>Alkali aluminum silicates, particularly a zeolitic molecular sieve powder with an average particle diameter of less than 10 mu and having the portion of particles with a particle size above 45 mu being less than 1 weight % are prepared by hydrothermal crystallization of an alkali aluminate-silicate mixture, separating the crystallization product from the mother liquor and drying with the proviso that the aqueous medium surrounding the crystallization product is adjusted to a pH value between 8.5 and 11 prior to the drying. The product is used as an ion exchanger, e.g., in dehardening water, particularly as a phosphate substitute in washing, rinsing and cleansing agents.</p> |