Experimental study on the influence law of different stresses on coal autoxidation

In order to study the influence of stress on the coal autoxidation, a set of test device was designed for the influence law of stress on coal autoxidation. Through this test device, different stresses were applied to coal samples to simulate the characteristics of pressure deformation, temperature and gas concentration of fragmentized coal in goaf in the pressure environment, and the change laws of relevant parameters of fragmentized coal under different stresses were quantitatively analyzed. The research results indicate that the compressive deformation and temperature rise range of fragmentized coal in the stage of rising stress are more obvious than that in the stage of constant stress and the temperature rise rate of coal is positively correlated with the displacement change rate, which further verifies that the stress can promote the coal autoxidation; under different stresses, the spontaneous combustion tendency of fragmentized coal is further intensified, and the molecules in coal are easier to oxidize, which leads to the production of CO and CH4 ; according to the volume fraction of CO measured by the test, it is inferred that there are two ways to produce carbon dioxide, including coal oxygen compound reaction and activated decarburization of coal by mechanical crushing.