engleski

Thermal and mechanochemical transformations of potassium exchanged zeolite A

Thermal transformations of potassium-exchanged zeolite A and the x-ray amorphous material obtained by ball milling of the potassium-exchanged zeolite A were investigated by different methods such as: differential thermogravimetry (DTG), differential scanning calorimetry (DSC), X-ray diffractometry, FTIR spectroscopy and scanning-electron microscopy. Controlled heating of crystalline, potassium-exchanged zeolite A causes a phase transformation in the sequence: [0.22Na2O, 0.78K2O] Al2O3 2 SiO2 3.48 H2O amorphous kalsilite + kaliophiliote, while the heating of mechanochemically amorphized potassium-exchanged zeolite A results in its transformation into a mixture of kalsilite and kaliphilite, or even to pure kalsilite at higher transformation temperatures. The differences in the pathways of transformation processes are discussed in the term of structural properties of the starting materials.

Zeolites; Modeling; Crystallization; Population balance

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