Study on Inhibition of Spontaneous Combustion of Coal by Liquid CO2

To study the inerting and cooling characteristics of liquid CO2 in coal mine, the coal samples before and after liquid CO2 inerting treatment were analyzed and studied. The results of temperature-programmed oxidation experiment show that the coal sample can inhibit the oxidation of coal to a certain extent after liquid CO2 inerting. The TG-DSC experiment results show that T1 and T2 of treated coal are higher than those of raw coal, which indicates that the desorption and heat absorption of CO2 has a more obvious effect on the early stage of coal oxidation at low temperature. The characteristic temperature T3 and T4 of L-CO2 coal are lower than that of raw coal, indicating that the oxidation rate of raw coal is faster. The T4 of L-CO2 coal is higher than that of raw coal. The results showed that L-CO2 inhibited spontaneous combustion of coal. After the coal sample was treated with liquid CO2, the apparent activation energy of the coal increased slightly. The heat release of raw coal is 10.78% higher than that of treated coal samples. From the point of view of heat change, it shows that raw coal is more prone to spontaneous combustion. Liquid CO2 has a good cooling and inerting effect on fire prevention.