Thermal decomposition of partially Mg²⁺‐exchanged forms of zeolite A investigated by DTA‐and X‐ray high temperature methods

Abstract

Abstract Only the application of high temperature X‐ray diffraction and DTA‐methods results in an uncontradicted explanation of processes occuring at thermal decomposition of NaA‐and Mg 2+ ‐exchanged zeolite in the temperature region of 700 to 1100°C. Decomposition of NaA‐zeolite takes place depending on time and temperature in the following sequence: NaA‐zeolite – amorphous phase – carnegieite – nepheline. Zeolites with degrees of exchange of magnesium ions above 50% on the other hand decompose at increasing temperature sucessively to the following phases: NaMgA‐zeolite – amorphous phase – spinel, mullite and amorphous SiO 2 .