Abstract:

The synthesis of 13X zeolite with K-feldspar powder as raw materials is characterized by XRD, SEM, IR, chemical analysis and Raman spectroscopy. The investigation discovers the inducement period, the crystal period of the crystallizing process and the average growth speed of 13X zeolite grains. The experimental results demonstrate that the reactive mixture is firstly transformed into aluminosilicate gels, and then the gels is transformed into 13X zeolite crystal grains while synthesizing 13X zeolite from the aluminosilicate precursor prepared by baking the K-feldspar powder. 13X zeolite has already appeared before the mixture all transforming into the aluminosilicate gels. The growth of 13X zeolite is mainly in the aluminosilicate gels, which is a process of putting the aluminosilicate gels structure in order while the liquid participates in the formation of 13X zeolite. [TO₄] tetrahedrons of the aluminosilicate gels connect each other to form the framework of 13X zeolite. A model for the formation of 13X zeolite is proposed, which involves that silicate ions and aluminate (or ferrite) ions polymerize to double six-membered rings, the secondary building unit, then the double sixmembered rings interconnecting to SOD cages, and then SOD cages further interconnecting to form the framework of 13X zeolite.

Key words: K-feldspar powder, 13X zeolite molecular sieve, hydrothermal synthesis, crystallizing reaction