Abstract:
In order to study the effect of oxygen volume fraction on the spontaneous combustion of coal oxidation at low temperature, the non-adhering coal from a mine in Inner Mongolia was taken as the research object. The low-temperature oxidation experiments of coal were carried out under the conditions of oxygen volume fraction of 5%, 15% and 21% by temperature-programmed experiment device and the production rules of CO, CO2 and C2H4 gas were obtained. The oxygen consumption rate, gas production rate, heat release intensity and apparent activation energy of coal under different oxygen volume fractions were calculated, and the relationship between oxygen volume fraction and activation energy at three temperature stages was analyzed. The results show that the volume fraction of CO, CO2 and C2H4 increases with the increase of oxygen volume fraction, and increases exponentially with the increase of temperature. The change trend of oxygen consumption rate, gas production rate and heat release intensity is the same, and they all increase with the increase of oxygen volume fraction. The apparent activation energy decreases with the increase of oxygen volume fraction in the first and third stages of oxidation reaction. The apparent activation energy increases with the increase of oxygen volume fraction in the second stage, but the activation energy reaches the maximum when the oxygen volume fraction is 5%. It shows that reducing the volume fraction of oxygen can inhibit coal spontaneous combustion at low temperature.