Influence of the concentrations of aluminium and silicon in the liquid phase on the growth kinetics of zeolite A and X microcrystals

Bosnar, Sanja; Bronić, Josip; Krznarić, Ivan; Subotić, Boris (2008) Influence of the concentrations of aluminium and silicon in the liquid phase on the growth kinetics of zeolite A and X microcrystals. Croatica Chemica Acta, 78 (1). pp. 1-8. ISSN 0011-1643

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Abstract

Kinetics of the crystal growth of zeolites A and X was measured during their crystallization, at 80 degrees C, from an amorphous aluminosilicate precursor dispersed in a 1.4 M NaOH solution containing different amounts of dissolved NaAlO2 or Na2SiO3. The crystallization pathway and fractions of zeolites A and X in the crystalline end product strongly depend on the composition of the liquid phase of the crystallizing system. Analyses of the changes of the concentrations of aluminum, c(Al), and of silicon, c(Si), in the liquid phase as well as of the dimension, L-m, of the largest crystals of zeolites A and X during crystallization, have shown that the growth rate of zeolite A crystals is size-independent, and that the growth is governed by the reaction of monomeric and/or low-molecular aluminate, silicate and aluminosilicate anions from the liquid phase on the surfaces of growing zeolite crystals. Influence of the composition of the liquid phase of the crystallizing system on the course of crystallization process and on the growth rates of zeolite A and zeolite X crystals are discussed in terms of the possible distribution of aluminate, silicate and/or aluminosilicate anions in the liquid phase.

Item Type:	Article
Uncontrolled Keywords:	zeolite A; zeolite X; aluminate silicate; crystallization; crystal growth; aluminosilicate gel precursors; hydrothermal treatment; crystal-growth; crystallization; nay; precipitation; dissolution; alkalinity; system
Subjects:	NATURAL SCIENCES > Chemistry
Divisions:	Division of Materials Chemistry
Projects:	Project title Project leader Project code Project type Istraživanje procesa kristalizacije i primjene zeolita Boris Subotić 0098060 MZOS
Depositing User:	Boris Subotić
Date Deposited:	06 Nov 2013 13:26
URI:	http://fulir.irb.hr/id/eprint/902

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