Comparison Analysis on Spontaneous Combustion Limit Parameters of Bituminous Coal with Different Metamorphic Degree

In order to master the spontaneous combustion limit variation law and features of bituminous coal with different metamorphic degree, with the temperatur e rising experiments of the coal spontaneous combustion program, the 02, CO and CO2 variation laws with the coal temperature rising for three bituminous coal with dif ferent metamorphic degree obtained and the oxygen consumption rate and heat releasing intensity of coal was calculated.The spontaneous combustion limit parameter s (fine ground coal thickness, upper air leakage intensity and lower oxygen content) of coal were studied and obtained.The study results showed that in comparison wit h the high metamorphic degree coal samples, under the same conditions, the oxygen consumption rate, heat releasing intensity and upper air leakage intensity of the lo W metamorphic degree coal sample would be high at the low temperature period of the coal spontaneous combustion.The min ground coal thickness and low oxygen Co ntent would be low.The metamorphic degree was close to the coal sample and the limit parameters and the critical point would be closed.The study results would have i mportant theoretical significances to further predict and early warn the coal spontaneous combustion and the coal spontaneous combustion danger area.