Experimental Study on Spontaneous Combustion Characteristics of Different Degrees of Metamorphic Coal

The oxidation heating experiment of coal with different degrees of metamorphism was carried out by means of programmed heating experiment device, the relationship between critical temperature change, CO, CO₂ and CH₄ concentration change in the experimental process were analyzed. The results show that: the critical temperature increases with the increase of metamorphic coal of 64.79 ℃（long flame coal）, 69.86 ℃（non-caking coal） and 71.23 ℃（gas coal）; the concentration of CO, CO₂ and CH₄ decreases with the increase of the metamorphic degree. To a certain extent, the tendency of spontaneous combustion of coal decreases with the increase of coal metamorphism.