TITLE:
Synthesis of Faujasite from Egyptian Clays: Characterizations and Removal of Heavy Metals
AUTHORS:
Mohamed A. Moneim, Ezzat A. Ahmed
KEYWORDS:
Faujasite, Kaoline, Smectite, Hydrothermal Reactions, Zeolite, Clay
JOURNAL NAME:
Geomaterials,
Vol.5 No.2,
April
15,
2015
ABSTRACT: Three clay samples with
different mineral compositions (kaolinite, smectite-kaoline, and smectite-rich)
were used for zeolite synthesis using the method of hydrothermal reactions
after fusion with NaOH. The conditions of hydrothermal crystallization
(zeolitization) were found to be at temperature of 100°C, and time span between
72 h and 96 h for kaoline and smectite-rich samples, while 48 h for the smectite-kaolinite
sample. The results indicate that zeolites began to crystallize from clay
samples after 48 h, and crystallization increased with increasing time. The
synthetic materials have been characterized by X-ray diffraction (XRD),
scanning electron microscope (SEM), fourier transform infrared spectroscopy
(FT-IR) and thermogravimetric (DTA/TGA) analysis. The results indicate that low
silica NaX-faujasite type with well-developed octahedral and cubic crystals was
synthesized from the three samples. No big difference in the characterization
between the three synthetic materials was detected, but smectite-kaolinite
sample as raw material was relatively better in crystallization of synthetic
zeolite. Applications of the synthetic materials in the removal of heavy metals
proved that the synthetic faujasite has strong effect for removing of Cr3+,
Co2+, Ni2+ and
Mn2+ from aqueous
solution.