The Effect of Crystallization Condition on the Crystallization Rate of Zeolite A

제올라이트 A의 결정화 속도에 대한 결정화 조건의 영향

  • Chung, Kyeong-Hwan (Department of Chemical Technology, College of Engineering, Chonnam National University) ;
  • Seo, Gon (Department of Chemical Technology, College of Engineering, Chonnam National University)
  • 정경환 (전남대학교 공과대학 공업화학과) ;
  • 서곤 (전남대학교 공과대학 공업화학과)
  • Received : 1992.09.08
  • Accepted : 1992.11.09
  • Published : 1993.03.01

Abstract

The effects of temperature and of $Na_2O$ and $SiO_2$ contents on the crystallization of zeolite A were studied, by examining crystallization curves and particle size distributions of final products at various crystallization conditions. Crystallization process could be simulated adopting the assumptions of constant linear growth rate and equilibrium between amorphous solid phase and soluble species. Rate constants were determined by comparing the simulated crystallization curves with experimental data. Rate constant for linear growth increased with temperature and crystallization rate at different mole ratio of $Na_2O/H_2O$ correlated reasonably well with increase of soluble species. The rate constant of crystallization did not increase with increase in mole ratio of $Na_2O/H_2O$, but the rate of nuclei formation and the fraction of soluble species were enhanced. The rate constants for linear growth of zeolite A were determined as $0.07{\sim}0.24{\mu}m{\cdot}min^{-1}$ at these experimental conditions Apparent activation energy was estimated as $49kJ{\cdot}mol^{-1}$.

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