| 摘要 |
<p>Process for the semi-continuous preparation of a zeolite A type silicoaluminate of constant and homogeneous quality, which process comprises continuously mixing, with vigorous agitation, a solution of sodium aluminate and a solution of sodium silicate in a container in which the average retention time is from 30 seconds to 20 minutes and the temperature is from 70 to 105 DEG C to form a gel which is subsequently matured over a period of 4 to 7 hours at a temperature of from 80 to 95 DEG C, and wherein during maturing precipitated particles of zeolite are kept in suspension without any shearing force being exerted thereon, or with just enough shearing force to ensure that the particles are kept in suspension. Zeolite A having 95% of crystals with diameter 1-8 pi average diameter 2-4 pi and sequestering power of 120 mgCa/g is claimed.</p> |
