Abstract
Coal spontaneous combustion (CSC) is one of the main disasters that threaten the safe production in coal mines. Moisture, which is the main factor affecting coal oxidation, has a considerable impact on CSC. In this paper, the variation characteristics of TG-DTG and DSC-DDSC curves of two kinds of lignite during low-temperature oxidation were investigated. The following results were obtained: Oxidation-induced heat production (OHP) starts to play a leading role in the temperature range of 50–75 °C; pyrolysis-induced heat absorption (PHA) grows faster than OHP in the temperature range of 70–130 °C; and OHP is dominant in the temperature range of 130–260 °C. Furthermore, for coal samples from Shengli (SL) Coal Mine and Yuanbaoshan (YB) Coal Mine, the initial heat release temperature and the end temperature both conform to the Lorentz function T=T0+2A(B4(M−Mc)2+B2). Thermodynamic parameters reach the maximum under the moisture content of 12%–17% where the CSC is the most likely to occur. In the oxygen adsorption and weight gain stage, the activation energy decreases and gradually stabilizes with the increase in moisture content. In the accelerated oxidation stage, moisture in coal plays a chemical catalytic role in the processes of oxygen chemical adsorption and intermediate complex formation and decomposition. However, excessive moisture cannot accelerate the coal-oxygen composite reaction.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.