Kinetic study of the thermal decomposition process of calcite particles in air and CO2 atmosphere

The thermal decomposition process of calcite particles (0.45–3.60 mm average diameter), made up of porous agglomerates of very small CaCO3 microcrystals, was studied in the 975–1216 K temperature range. The experiments were carried out under isothermal conditions in air atmosphere, in CO2 atmosphere, as well as in a gas stream comprising different concentrations of air and CO2. An equation is proposed that relates the calcite conversion degree to both reaction time and operating conditions. The equation satisfactorily fits to the experimental results obtained in the entire tested range of particle sizes and temperatures in all the studied carbon dioxide concentrations