Kinetic and Thermodynamic Study of Calcite Marble Samples from Lesser Himalayas

A kinetic and thermodynamic study of selected calcite marble samples from Lesser Himalayas has been performed using thermogravimetric and differential thermal analyses at heating rates of 10 degrees C . min(-1) and 30 degrees C min(-1). The minero-petrography of calcite grains, phase analysis, chemical analysis, and minor impurities determination were carried out using thin-section polarized light microscopy, X-ray diffraction, X-ray fluorescence, and electron microprobe analysis, respectively. The calcite content of the investigated marble samples varied from 97.50 mass% to 98.70 mass%. The activation energy, Ea, for the decomposition process increased from 158.6 kJ . mol(-1) to 179.4 kJ . mol(-1) and from 214.1 kJ . mol(-1) to 232.8 kJ . mol(-1) for heating rates of 10 degrees C min(-1) and 30 degrees C min(-1), respectively, with decreasing calcite content. The activation energy values obtained in the present study were in good agreement with previous studies.