Study on the Change Mechanism of Coal Oxidation Characteristics under Temperature and Stress

Abstract

In order to study the effect of stress and temperature on the spontaneous combustion behavior of deep coal, important conclusions are drawn through relevant experiments and analysis. It is found that stress can inhibit the ability of coal surface to adsorb oxygen, because it causes the pore structure of coal sample to compress, and the available area for oxygen adsorption is limited. Under the same temperature condition, the CO, CO₂ emission and heat discharge increase with the increase of stress. When the stress is the same, the temperature increase also makes the CO, CO₂ emission and heat discharge show the same change trend. The relationship between stress, temperature and heat release is polynomial, and the maximum heat release intensity appears at 120°C and 6 MPa stress. Further analysis shows that the weights of coal ash, moisture, fixed carbon, volatile matter, external stress, temperature and coal heat release are 0.1291, 0.1183, 0.3550, 0.1537, 0.2437, and 0.4419, respectively. The main factor affecting coal sample heat release is its own fixed carbon content. The influence of temperature on heat release from coal sample is greater than that of stress. These research results provide an important reference for further understanding of the oxidation characteristics of deep mining coal and related influencing factors.