The Thermal Decomposition Kinetics Analysis of Magnsite

摘要

Decomposition kinetics of magnesite was investigated by using thermogravimetric (TG) analysis.The thermal decomposition study of magnesite particle size of 40μm,55μm and74μm at the heating rate of 5K/min, 1 0K/min, 15K/min and 20K/min, respectively.The activation energy and pre-exponential factor (A)of different particle sizes were calculated from the peak temperature of derivative thermogravimetry (DTG) date and the decomposition weight loss curves,also combined Ozawa-Doyle method Determine the optimal decomposition mechanism based on the principle of maximum correlation coefficient by using multivariate no-linear titting to 5 most possibility kinetic mechanism functions.The research results indicate that the activation energy of thermal decomposition of magnesite increases with the increasing of particle size;the most probable reaction mechanism of the thermal decomposition process was a three-dimensional boundary reaction (R3).The kinetic equation was as follows: G(a)=1-(l-a)1/3.