An Experimental Study on Oxidation Rate of Coal:The Influence of Oxygen Concentration

In order to investigate the oxidation characteristics of residual coal of goaf under different oxygen concentration environment, the discarded coal is collected from the actual workplace to analyze the particle size distribution, then five coal samples are prepared by the same granularity ratio. The heating and oxidizing experiments of the coal samples are conducted, on the inlet oxygen concentration at 1.9%, 6.0%, 10.3%, 15.1% and 20.0% respectively, to detect the outlet oxygen concentration in the heating process. Supported by the experimental data, the formulas of the standard oxygen consumption rate are deduced respectively to obtain the change law of the oxidation rate of each coal sample. The results show that the standard oxygen consumption rates are basically equal under different inlet oxygen concentration at the same temperature, which verifies the correctness of the coal-oxygen compound theory. What's more, the curve of the standard oxygen consumption rate with the temperature rising can be divided as the slow oxidation phase, the accelerated oxidation phase and the violent oxidation phase in sequence. The results of the research have a theoretical and practical significance for preventing the spontaneous fire of coal in goaf.