Study of structural transformations in potassium-exchanged zeolite A induced by thermal and mechanochemical treatments

• Published in: Journal of materials science Vol. 32; no. 1; pp. 73 - 78
• Main Authors: KOSANOVIC, C, SUBOTIC, B, SMIT, I, CIZMEK, A, STUBICAR, M, TONEJC, A
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 1997; Springer Nature B.V
• Subjects: Aluminum oxide; Amorphous materials; Ball milling; Chemistry; Differential scanning calorimetry; Differential thermogravimetric analysis; Exact sciences and technology; Fourier transforms; General and physical chemistry; Heat exchange; Infrared heating; Ion-exchange; Materials science; Phase transitions; Potassium; Surface physical chemistry; Thermal transformations; Zeolites; Zeolites: preparations and properties; Differential scanning calorimetry; Amorphous material; Heat treatment; Ball mill; Differential thermal analysis; Zeolite; Experimental study; X ray diffraction; Potassium Ions; Molecular sieve; Phase transformation; Alkali metal Ions; Ion exchange; Modified material
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1023/A:1018514929882

Thermal transformations of potassium-exchanged zeolite A and the X-ray amorphous material obtained by ball milling the potassium-exchanged zeolite A were investigated by different methods, such as differential thermogravimetric analysis (DTA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Controlled heating of crystalline, potassium-exchanged zeolite A causes a phase transformation in the sequence: [0.22 Na2O, 0.78 K2O]·Al2O3·2SiO2·3.48 H2O⇒amorphous⇒kalsilite+kaliophilite, while the heating of mechanochemically amorphous potassium-exchanged zeolite A results in its transformation into a mixture of kalsilite and kaliophilite. The differences in the pathways of the transformation processes are discussed in terms of the structural properties of the starting materials.