Effect of coal moisture on the parameters of its thermal decomposition in the study of liability to spontaneous combustion
A. I. DOKUCHAEVA, O. N. MALINNIKOVA
Institute of Complex Exploitation of Mineral Resources of the Russian Academy of Sciences, Moscow, Russia
Keywords: spontaneous combustion of coal, oxidation, chemical activity, maximum weight gain, coal moisture, fractional composition, thermal decomposition of coal, thermogravimetric analysis
Abstract
The dependence of the indicators of thermal decomposition of coal from the Kuzbass and Pechora basins on coal moisture was studied when determining the liability of coal to spontaneous combustion by thermogravimetric analysis. The rates of mass change were calculated, and characteristic temperature points were determined (the onset of mass increase, and the maximum rate of mass change) by heating the coal samples within temperature ranges 120-300 and 300-900 °C. It has been determined that the rate of mass gain within the range of 120-300 °C is 10 times higher for the coals of the Pechora coal basin, prone to spontaneous combustion, while within the range of 300-900 °C it is independent of the tendency of coals to spontaneous combustion. It is shown that with an increase in the moisture content in coal, the rate of thermal decomposition of coal increases with an increase in moisture content within the temperature range of 25-200 °C. Moisture content of coal was not detected to affect the parameters (the temperature points of oxidation onset and mass gain) characterising coal oxidation reaction in the studies by thermogravimetric analysis.
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