Experimental study on the influence of air supply on characteristics of lignite spontaneous combustion

In order to study the influence of gas generated during coal spontaneous combustion on gas explosion, the lignite of 4^# coal seam in Ruian Coal Industry was selected as experimental coal sample.When the air supply was 40 mL/min, 120 mL/min and 200 mL/min respectively, the influence of it on the gas generation during coal spontaneous combustion was studied by tube furnace temperature program and chromatographic analyzer.The molar concentrations of O₂, CO and CO₂ at the outlet of tubular furnace at different temperatures were calculated.The relationship between oxygen consumption rate, gas generation rate, exothermic intensity and coal sample temperature in the low temperature oxidation stage of lignite were calculated.The results show that with the increase of temperature, the oxygen consumption rate, CO generation rate, CO₂ generation rate, exothermic intensity and temperature change exponentially; the oxygen consumption rate and the exothermic intensity increase linearly, at the same oxygen consumption rate, the exothermic intensity is the maximum when the air supply is 120 mL/min, and the exothermic intensity is the minimum when the air supply is 200 mL/min.