Coal gangue,which accumulates in the open air,is modified by immersion in rain,and exhibits different tendencies to spontan-eous combustion in different areas of precipitation.To study the role and influence of moisture on the oxidation and spontaneous combus-tion of coal gangue,we used high-sulfur coal gangue prone to spontaneous combustion in the Qipanjing area of Inner Mongolia.First,the coal gangue is soaked with different moisture content(moisture content:0,15%,30%,50%,100%).After soaking for 45 days,the coal gangue is naturally air dried.The dried gangue samples were put into the self-made programmed temperature experiment furnace to con-duct experiments on the pre-treated coal gangue samples(the temperature rise rate was set at 3℃/min,and the temperature rise range was set at 30-390℃).The gas the temperature points of the coal gangue in each stage was collected by air collecting bag(each rise of 15℃ was a stage).Finally,the collected gas was passed into the GC-4000A gas chromatograph.By comparing the O2 consumption、the volume fraction of CO,CH4,C2H4,C2H6 and other index gases produced by coal gangue treated with different moisture content,the results show that:The low temperature oxidation of coal gangue is the best when the moisture content is 15%,the initial formation temperature of CO,CH4,C2H4,C2H6 and other indicator gases is the lowest,and the concentration of various indicator gases is the highest when the temperat-ure is 390℃.When the moisture content exceeds 50%,under the action of moisture dissolution,a large number of combustible substances in the coal gangue are carried and dispersed by moisture,resulting in a significant decrease in the concentration of various indicator gases generated when the moisture content of the coal gangue rises to 390℃,even lower than that of the control experimental group without moisture immersion and redrying treatment.When the coal gangue is immersed in water,the initial temperature points of the various in-dex gases are reduced by about 15℃.
water immersion dryingcoal gangueoxidationspontaneous combustionprogram heats upindicator gas