The thermal decomposition of vermiculite

Vermiculite shows some promising potentials, both as ion-exchange material and thermal insulation. The thermal decomposition of vermiculite from Sokli, Finland, has been studied by various thermoanalytical methods, including high-temperature X-ray diffraction and high-pressure DTA. The major phases occurring during successive heating are: 15Å → 11.8Å → 10.1Å → 9.74Å → 9.3Å (all d₀₀₂ spacings). Reaction enthalpies and activation energies are given for most of the reactions. For the evaluation of kinetic parameters, high-temperature X-ray diffraction is suggested as a powerful tool, superior to most conventional methods.