The synthesis of NaA-type zeolite from superalkaline reaction mixtures by influence on the formation-and transformation rate of the polymorphous phases according to the Ostwald step rule is discussed. The appearence time of NaA as a single crystallization product is described in dependence on the reaction conditions. The kinetics of the zeolite crystallization and the property alterations of the reaction products in dependence on the time are investigated in the pilot scale.Die Synthese .van NaA-Zeolith aus hochalkalischen Reaktionsgemischen durch gezielte Beeinflussung von Bildungs-und Transformationsgeschwindigkeit der polymorphen Phasen entsprechend der Ostwaldschen Stufenregel wird untersucht und die Existenzzeit einphasiger Kristallisationsprodukte von NaA-Zeolith in Abhangigkeit von den Reaktionsbedingungen dargestellt. Die Kinetik der NaA-Kristallisation und die Eigenschaftsiinderungen der Kristallisationsprodukte in Abhangigkeit von der Reaktionszeit werden im kleintechnischen MaRstab verfolgt.

The synthesis of faujasite-type zeolite from superalkaline reaction mixtures are described. The contribution shows the influence of component K2O added in the system Na2O-Al2O3-SiO2-H2O with H2O/(K2O + Na2O) = 13-15. The reaction course was investigated in the range K2O/(K2O + Na2O) from about 0.07 to 0.5. Under used conditions it is quite possible to isolate faujasite-type zeolite as a single crystalline phase. By means of IR spectroscopy, low SiO2/Al2O3 ratios from 2.0 to 2.1 in the faujasite framework have been indicated. The low SiO2/Al2O3 ratios are interpreted by a higher stability of the Si-O-Al- than the Si-O-Si- bond with increasing hydroxyl ion concentration.