Study on spontaneous combustion characteristics of oxidized coal in re-mining coal seam

According to the current situation of spontaneous combustion of coal in the re-mining coal seam, the differences of spontaneous combustion characteristics of oxidized coal in Jinggezhuang Mine with four different re-mining times are analyzed. The characteristic of gas content changes and spontaneous combustion tendency changes of coal samples during spontaneous oxidation process with different re-mining times were compared by using temperature-programmed gas chromatography. The results indicate that the CO concentration produced by the four kinds of coal samples changed differently before and after 170 ℃; the longer the re-mining time is, the later the coal sample produces CH₄, C₂H₄ and C₂H₆ gases; through the comprehensive analysis of temperature and FCC composite index of different coal samples, it is concluded that the spontaneous combustion oxidation capacity of coal samples with short time re-mining is stronger than that with long time re-mining; in the low temperature and high temperature section of the same kind of coal, the tendency of spontaneous combustion is changing with the apparent activation energy.