Thermodynamic studies of zeolites: analcime and dehydrated analcime

Abstract

Calorimetric measurements have been carried out on a pure speciment of analcime whose composition was Na/sub 0.96/Al/sub 0.96/Si/sub 2.04/O/sub 6/.H/sub 2/O and on the corresponding anhydride. The low-temperature heat capacity, standard enthalpy of formation (298.15 K), and high-temperature enthalpy increments have been determined by adiabatic, solution, and drop-calorimetric techniques, respectively. Thermodynamic functions have been calculated for analcime (to 600 K) and for dehydrated analcime (to 1000 K).