Study on oxidation characteristics of unloaded coal under differentair leakage condition

In order to master the oxidation characteristics of the unloaded coal under different air leakage conditions and to prevent and the control coal spontaneous combustion disaster, a study on a programmed temperature rise test was applied to make an unloading of the easy spontaneous combustion coal samples after a same initial stress made. With a means to steadily increase the air volume, a comparison was conducted on the oxygen consumption rate, CO gas concentration, CO production rate varied with the coal temperature and the air leakage volume. The results showed that under the condition of different air leakage, the unloaded coal would be more easily oxidized than the original coal sample. Due to the oxidation capacity of each coal sample, the air leakage volume from high to low would be 150、180、120、90、60、210、240 mL/min individually. And the CO concentration and production rate would be in an index relationship to the coal temperature. When the coal temperature is constant, the CO concentration and production rate would be firstly increased and then reduced with the air leakage volume increased. When the air leakage volume reached to 150 mL/min, the CO gas concentration and variation rate would be the maximum and the oxidation capacity of the coal sample would be the best. Based on the test results, in addition to the air leakage volume was controlled at the equivalent flow in the underground mine, to avoid a high temperature point occurred could effectively prevent and control the coal spontaneous combustion in the underground mine.