ABSTRACT
To ascertain fire prevention and extinguishing mechanism of inert gas in coal mine goaf, TG-DTG-DSC experiments of coal-oxygen reaction at 30–850℃ under N2 and CO2 conditions were carried out, and the thermal characteristics and kinetic factors were analyzed. The process of coal-oxygen reaction was divided into five stages by the four characteristic temperatures of T1 (temperature at which water evaporates completely), T2 (temperature at which coal begins to decompose intensely), T3 (ignition temperature) and T4 (burnout temperature). With the decrease of O2 concentration, T2, T3, and T4 increased, the total mass loss and heat release decreased, and the decomposition degree increased. The injection of N2 and CO2 reduced the apparent activation energy and pre-exponential factor of T1–T2, T2–T3 and T3–T4 stages, and there was dynamic compensation effect between activation energy and pre-exponential factor. Under the same O2 concentration conditions, the effect of CO2 was more significant than that of N2. Reducing oxygen concentration by injecting N2 and CO2 could rapidly reduce the degree of coal-oxygen reaction rate. This study is of great significance for the prediction of coal spontaneous combustion and the using of N2 and CO2 coal fire prevention and extinguishing technology.
Ethics
This article does not present research with ethical considerations.
Authors’ Contributions
Fei Wang conceived of the study, designed the study, coordinated the study and helped draft the manuscript; Hongwei Liu carried out the experiment, participated in data analysis, participated in the design of the study and drafted the manuscript. All authors gave final approval for publication.
Competing Interests
The authors declare no conflict of interest.