Research On Spontaneous Combustion Prediction And Prevention Of Gob Area In Fully Mechanized Caving Face Of Hongqinghe Coal Mine

Self-ignition of residual coal in goaf is one of the Imain safety issues in mine production,especially for mines with long working faces,which have a large range of oxidation zones,and it is more difficult to control spontaneous combustion of coal in goaf.This paper takes the 102 working surface of Hongqinghe Coal Mine as the object of study,and uses the research methods,field measurement and numerical simulation to analyze and study the coal spontaneous combustion prevention technology in the goaf of Hongqing Coal Mine.Firstly,using the temperature Programmed experimental platform,the gas concentraions of coal samples with different particle sizes and the oxidation of coal samples under different oxysen concentration conditions were measured,and the consumption of coal samples under different oxygen concentration conditions was calculated based on the measured test data.The oxygen velocity and the coal spontaneous combustion index gas of the 102 working face of Hongqinghe Coal Mine were determined.The oxygen concentration distribution on both sides of the goaf of the 102 working face is measured by the beam tube monitoring system,and the distribution of the residual coal in the goaf is calculated according to the field data and the empirical formula,and the air leakage intensity of the goaf is calculated in combination with the oxygen consumption rate calculated above.According to the coal spontaneous combustion limit parameters of the mine,the dangerous area of spontaneous combustion of coal in goaf is divided,and the limit daily propulsion speed of the working face is calculated.The numerical simulation software was used to simulate the variation of wind flow field and oxygen concentration distribution in the goaf before and after nitrogen injection,and the different nitrogen injection positions in the goaf were selected respectively.The oxygen concentration distribution in the goaf was compared and analyzed by different nitrogen injection schemes.The influence of the nitrogen injection position is determined by this method.At the same time,the influence of nitrogen injection on the oxygen concentration in the goaf is quantitatively analyzed to determine the optimal nitrogen injection amount.Finally,the influence of the nitrogen injection amount on the oxygen concentration of the working surface is analyzed.Finally,based on the above research,combined with the actual situation of Hongqinghe Coal Mine,specific fire prevention measures were proposed,including daily production measures to prevent spontaneous combustion of coal,early prediction and indicators indicators of coal spontaneous combustion in goaf,and prevention and treatment.The technology of spontaneous combustion of empty coal,designed the actual nitrogen injection amount and nitrogen injection pipeline for on-site nitrogen injection,and provided guidance for the fire fighting work in the middle coal mining process.