Experimental Study On Effect Of Moisture Content On Coal Spontaneous Combustion Characteristics

Coal,as a kind of porous solid combustible mineral with complicated internal Pore and fissure structure,will be fractured due to mining,and the structure of coal will be changed due to the entry of underground water.The risk of coal spontaneous combustion increases with the increase of air leakage in Goaf after water drainage treatment.In this paper,the macro-exothermic characteristics and the law of heat release of coal in the process of oxidation of water-bearing coal in Zhujixi Coal Mine and Yuandian No.2 coal mine are studied,combining with laboratory experiments and theoretical analysis,some experimental references are provided for the prevention and control of coal spontaneous combustion.1)Based on the programmed heating experiment,the outlet concentration and production rate of oxidation gas and the variation law of exothermic characteristics of coal samples with water cut in two mines were determined.The experimental results show that the gas outlet concentration,production rate,oxygen consumption rate and exothermic intensity increase exponentially in the temperature range from 30 °C to200 °C,the exothermic intensity and oxygen consumption rate of coal samples with different water content are obviously different from other coal samples,in which the water content of Zhujixi coal mine is 9.81% and the water content of Yuandian No.2 coal mine is 8.48%,the activation energy and critical point are the lowest,most oxidizable.2)The related parameters were obtained by thermal analysis experiment of coal samples with different water content.The heat release and activation energy of coal samples with different water content were calculated by thermal dynamic equation.The results show that the oxidation process of coal samples with different water content in two mines is similar,and there are five reaction stages,each stage has obvious change with the increase of water content The exothermic energy and activation energy of coal samples with different water content also have obvious difference with the change of water content,with the increase of water content,the exothermic energy and activation energy of coal samples with different water content first increase and then decrease;The coal samples with water content of 9.81% and 8.48% are obviously different from other coal samples,and the reaction is the easiest to carry out.3)The cone calorimeter was used to test the heat release characteristics of combustion of different water-bearing coal samples in two mines,based on the parameters of ignition time,heat release rate,total heat release rate,flue gas generation rate,total smoke release rate and CO generation rate of coal samples with different water content,the combustion efficiency of coal samples was analyzed,the ignition time of coal samples with different water content in two mines decreases at first and then increases with the increase of water content,the heat release rate and its peak value,the total heat release,the flue gas generation rate and its peak value and the total smoke release of coal samples with different water content,with the increase of water content,the total heat release and the total flue gas generation of coal samples are smaller than that of raw coal,and the combustion efficiency of coal samples with different water content is evaluated according to FPI and FGI values,the proper moisture content of coal sample can not only shorten the ignition time of coal sample,increase the heat rele.Figure [37] Table [10] Reference [88]...