In order to reveal the multi-stage evolution mechanism of coal oxidation process, a constant temperature oxidation test was carried out by controlling the volume fraction of environmental oxygen to monitor the dynamic evolution of CO release, oxygen consumption rate and thermodynamic parameters. Based on the identification method of characteristic temperature points, a four-stage oxidation kinetic model was established to analyze the evolution characteristics of activation energy in different reaction stages. The results show that when the oxygen volume fraction increases from 10% to 20%, the CO formation rate increases by 3.2 times, and the linear correlation coefficient R2 between the oxidation heat release intensity and the oxygen consumption rate reaches 0.973. According to the mutation characteristics of thermodynamic parameters, the three critical temperature thresholds in the low temperature oxidation range of coal samples were determined to be 79.1 ℃ ( initial activation ), 124.7 ℃ ( structural deterioration ) and 190.1 ℃ ( severe reaction ), respectively. The kinetic analysis showed that the activation energy of each oxidation stage increased first and then decreased, and the peak value of activation energy in the third stage was 49.8 kJ/mol.
