Abstract：Decomposition kinetics experiments were carried on limestone powders by thermogravimetry analyzer.The data were analyzed by the method of Kissinger and activation energy extrapolation.The results show that activation energy of limestone particles with average grain size of 34.26 μm tend to unanimity.The value of activation energy is about 209 kJ/mol.The thermal decomposition model of limestone conforms to the shrinking cylinder model with surface reaction rate controlling mechanism.The value of pre-exponential factor lnA is 16.21 s^-1.High activation of limestone is liable to calcine prime quicklime with high activity and low burnt.Calculating activation energy of limestone can be use to select high quality limestone sources.

Keywords：limestone;decomposition kinetics;thermogravimetry analysis;activationenergy