Kinetic and Thermodynamic Study of Calcite Marble Samples from Lesser Himalayas

Abstract

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 \(10\,^{\circ }\mathrm{C}\,{\cdot }\min ^{-1}\) and \(30\,^{\circ }\mathrm{C}\,{\cdot }\min ^{-1}\). 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, \(E_\mathrm{a}\), for the decomposition process increased from \(158.6\,\mathrm{kJ}\,{\cdot }\mathrm{mol}^{-1}\) to \(179.4\,\mathrm{kJ}\,{\cdot }\,\mathrm{mol}^{-1}\) and from \(214.1\,\mathrm{kJ}\,{\cdot }\, \mathrm{mol}^{-1}\) to \(232.8\,\mathrm{kJ}\,{\cdot }\, \mathrm{mol}^{-1}\) for heating rates of \(10\,^{\circ }\mathrm{C}\,{\cdot }\, \min ^{-1}\) and \(30\,^{\circ }\mathrm{C}\,{\cdot }\, \min ^{-1}\), respectively, with decreasing calcite content. The activation energy values obtained in the present study were in good agreement with previous studies.