Experiment Study On Critical Temperature Of Coal Spontaneous Combustion And The Influencing Factors

The production volume and consumption of coal are all the biggest in the world, and it occupies more than 70% of the total amount of primary energy production and consumption. However, the spontaneous combustion of coal happens frequently, then brought severe problem to mine safety production and led to big lost of resources and environment pollution. The process of coal spontaneous combustion can be separated by critical temperature as slow oxidation phase at low temperature and rapid oxidation phase at high temperature. The study on critical temperature of coal spontaneous combustion and the influencing factors is of great significance to the research of the process of coal spontaneous combustion, as well as early prediction and forecast of coal spontaneous combustionFive kinds of coals of different metamorphic grade were picked as experimental samples.Firstly, based on the mechanism of coal spontaneous combustion, we elaborated the reaction process and spontaneous combustion essence of oxidation of coal. The spontaneous combustion of coal is mainly due to the oxidation of coal. After the oxidation, heat is released and then lead to the temperature raise of coal in some heat storage environment. The critical temperature is the turning temperature point during the spontaneous combustion of coal;Secondly, programmed heating experiment was launched and the reactants like CO, CO2 and CH4 were analyzed by gaschromatograph to find the changes laws of them, as well to calculate the characteristic parameters like oxygen consumption rate.Thirdly, based on datum of programmed heating experiments, methods of index gases, oxygen consumption rate and crossing-point temperature were adopted to measure the critical temperature of coal spontaneous combustion. What’s more, it is aimed at studying the feasibility of the application of crossing-point temperature method in critical temperature measurement.Finally, experiment condition of oxygen concentration was changed to repeat the experiment to analyze how coal metamorphic grade and oxygen concentration influence the critical temperature.The research results will provide some references to the study of the oxidation process of coal spontaneous combustion at low temperature and the technology of coal spontaneous combustion predication and forecast.