The Study On The Mechanism Of Coal Spontaneous Combustion In Goaf With Gob-side Entry Retaining Under Gas Drainage

In the mine of high gas and easy spontaneous combustion, gas drainage and spontaneous combustion in goaf affect a restrain each other. At present, the technology of gob-side entry retaining could solve its gas concentration in the upper corner of goaf, but, the roof strata of goaf and gob-side entry retaining maybe instability crushing with the working face advanced, air leakage will increase in goaf and the spontaneous combustion risk of residual coal will increase too. So it’s a important job that look its internal law and guarantee the gas in the working face not to exceed the limit and make the incontinence coal not spontaneous combustion.In this paper, based on Y pattern ventilation of 24208 work-face and present gas pumping mining technology in Sha-qu mine, according to the practical situation of oxidation spontaneous combustion, we study on oxidation temperature increasing, oxygen consumption and gas occurrence law of coal by testing kinetic parameters of coal at low temperature oxidation conditions and get oxidation characteristic parameters of the coal; we determine the upper strata fracture development of gob-side entry retaining and know the different pumping method how to change the air leakage of goaf by qualitative analysis; we get the distribution of wind seepage and oxygen concentration in goaf by numerical simulation and master the law of flow disturbance in goaf. Based on experimental, measured and numerical simulation, we study on the law and mechanism of spontaneous combustion in goaf with gob-side entry retaining under gas drainage.by temperature programmed reaction, the oxygen consumption velocity become more and more large with the particle size of coal becoming more and more smaller.Especially, when the temperature was more than 120 degree centigrade, this trend was more significantly. The coal of 24208 goaf belong to the second kind spontaneous combustion was determined through programmed heating experiment; we analysis the air leakage channel of roof fracture in goaf with gob-side entry retaining and the source and sink relationship of air leakage in goaf is determined; we determined the coal spontaneous combustion risk regional in goaf at different tendency range by measured and analysis the numerical simulation was anastomosis with the measured data. At last, we got the law and mechanism of spontaneous combustion in goaf with gob-side entry retaining under gas drainage.This paper based on the necessary condition of coal spontaneous combustion, analyzed the attribute of spontaneous combustion coal with different particle size.We study on the mechanism of ventilation donor oxygen and heat storing according to the the ventilation of Y type conditions under gas drainage. It has specific guiding significance for prevention and controlling on spontaneous combustion of coal in the working face with similar condition.