Experimental study on CO generation law of coal left in goaf in shallow-buried comprehensive and mechanized coal mining face

In order to explore the law of CO generation in the oxidation process of coal leftover in shallow-buried comprehensive and mechanized mining areas, This article takes the shallow coal seam Gaojialiang Mine as the research object, and compares it with the deep coal seam Yangquan mine. Using the oil bath temperature-raising oxidation system, a temperature-increasing oxidation test was carried out on the coal samples of the fully mechanized coal mining face in different coal seams of Gaojialiang Mine and Yangquan Mine. Research shows: Each coal sample in the shallow-buried Gaojialiang Mine consumes O₂ at a low temperature of 40 ℃ to produce CO volume fraction of 1×10^-4; The oxygen consumption rate, CO production rate and heat release intensity of each coal sample during the oxidation and heating process gradually increase with the increase of temperature; The coal sample of the shallow-buried Gaojialiang Mine produced two critical temperatures of 40 ℃ and 130 ℃, corresponding to the starting point of accelerated oxidation reaction and the starting point of violent oxidation reaction, respectively. However, the Yangquan coal sample in the deep-buried coal seam has only one insignificant critical temperature, and relatively lagging behind, reaching 100 ℃~120 ℃. At the same coal temperature, the CO production and production rate of each coal seam in the shallow-buried Gaojialiang Mine, and the consumption and consumption rate of O₂ in each coal seam are significantly greater than those of the deep-buried coal seam in Yangquan Mine. The coal seams of the shallow-buried Gaojialiang Mine enter the accelerated oxidation stage earlier than Yangquan coal seams, and the required temperature is lower. The shallower the coal seam is buried, the faster the coal's oxygen consumption rate and CO production rate during heating oxidation., The increase in temperature promotes the oxidation exotherm of coal samples at shallow depths more strongly.