Influence of initial oxidation and secondary oxidation on spontaneous combustion of lignite

Abstract

In order to prevent the re-ignition of residual coal, this study presents a study of initial oxidation and secondary oxidation on the spontaneous combustion characteristics of coal. Three physical experiment methods:pore volume analysis, Fourier transform infrared spectroscopy and cross point temperature method, were used to study the spontaneous combustion of lignite. The results show that the pore volume of coal increases with the increase of oxidation temperature. With the increase of temperature, different functional groups in the coal sample show different trends. Compared with initial oxidation, the tendency of the functional group changes again during the secondary oxidation. In the case of constant initial temperature of secondary oxidation, the crossing point temperature of coal samples show a decreasing trend at first and rising later. And in the case of constant initial temperature of initial oxidation, the crossing point temperature of coal samples show a trend of rising.