CRYSTALLIZATION KINETICS OF ZEOLITE-LTL

Zeolites of Linde type L (LTL) have been synthesized at 393-453 K, and reaction parameters were found to be influenced by the source of reactants, the oxide mole composition of the gel, the crystallization temperature and period, and K2O/(K2O + Na2O) ratios. As the latter decreases to 0.67, crystallization becomes faster. At lower ratios, zeolite Y instead of zeolite L is obtained. Crystallization data were analyzed in terms of a first-order kinetics equation. The apparent activation energy for nucleation (En = 27-28 kcal mole-1) and crystal growth (Ec = 17.3 kcal mole-1) were evaluated by applying the Arrhenius equation. The solid products obtained were characterized by XRD, SEM, t.g. d.t.a., i.r., and sorption properties. © 1990 Butterworth-Heinemann.