Gases and thermal behavior during high-temperature oxidation of weathered coal

  • Jun Deng
  • Jia-Jia Song
  • Jing-Yu ZhaoEmail author
  • Yan-Ni Zhang
  • Yu-Xuan Zhang
  • Chi-Min ShuEmail author


In order to investigate the spontaneous combustion characteristics of weathered coal, gas generation and thermal behavior of weathered and fresh coal were analyzed. A self-made high-temperature-programmed experimental system was applied to simulate the spontaneous combustion of weathered and fresh coal. The characteristic parameters during oxidation were between 30 and 650 °C. The growth rate obtained through the analysis of an indicator gas was adopted to calculate the characteristic temperatures of high-temperature spontaneous combustion of coal. A C80 Calvet calorimeter was used to capture the thermal behavior during oxidation. At a high temperature and low oxygen concentration, weathered coal continued oxidizing and releasing thermal energy to sustain oxidation. The concentration of gases produced through high-temperature oxidation was lower for weathered coal than for fresh coal. The exothermic onset temperature of weathered coal was 43 °C, which was lower than the exothermic onset temperature of fresh coal. A salient difference was observed in the thermal energy release between weathered coal and fresh coal at different oxidation stages. From the critical temperature to crack temperature, the percentage of thermal energy release of weathered coal was much lower than that of fresh coal.


Spontaneous combustion Characteristic temperature Exothermic onset temperature Thermal energy release Oxidation stage 

List of symbols


Ash content on an air-dried basis (%)


Fixed carbon on an air-dried basis (%)


Moisture on an air-dried basis (%)


First characteristic temperature, critical temperature (°C)


Second characteristic temperature, active temperature (°C)


Third characteristic temperature, pyrolysis temperature (°C)


Fourth characteristic temperature, ignition temperature (°C)


Fifth characteristic temperature, burned-out temperature (°C)


Volatile content on an air-dried basis (%)



This manuscript was edited by Wallace Academic Editing. This Project was supported by National Natural Science Foundation of China (Grant No. 5167-4191), National Natural Science Foundation of China of China (Grant No. 5180-4246), and Natural Science Basic Research Plan in Shaanxi Province of China (Program No. 2017JQ5047).


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Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2019

Authors and Affiliations

  1. 1.School of Safety Science and EngineeringXi’an University of Science and TechnologyXi’anPeople’s Republic of China
  2. 2.Shaanxi Key Laboratory of Prevention and Control of Coal FireXi’an University of Science and TechnologyXi’anPeople’s Republic of China
  3. 3.Department of Safety, Health, and Environmental EngineeringNational Yunlin University of Science and Technology (YunTech)YunlinROC
  4. 4.Center for Process Safety and Industrial Disaster Prevention, School of EngineeringYunTechYunlinROC

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