Study on Spontaneous Combustion Characteristics of Coal Secondary Oxidation based on TG-FTIR

In order to explore the spontaneous combustion characteristics of coal secondary oxidation,a comparative study was carried out on raw coal samples and pre-oxidized coal samples by means of TG-FTIR.The results show that the overall reaction process of raw coal and pre-oxidized coal is similar;with the pre-oxidation degree of coal deepens,the characteristic temperature before the coal sample burning point first decreases and then increases,while the characteristic temperature change is not obvious after the burning point;with the pre-oxidation degree of coal deepens,the amount of gas released before coal sample ignition point first increases and then decreases,while the amount after combustion point basically remains unchanged;activation energy of pre-oxidation coal sample is lower than that of the raw coal sample,the activation energy of coal sample first decreases and then increases with the degree of pre-oxidation deepens,the activation energy reaches the minimum at the pre-oxidation temperature of 160 ℃.Therefore,the oxidation property of pre-oxidized coal sample is better than that of raw coal sample,and spontaneous combustion is more likely to occur.