Dynamic Characterization during Gas Initial Desorption of Coal Particles and Its Influence on the Initiation of Coal and Gas Outbursts

The law of gas initial desorption from coals is greatly important for understanding the occurrence mechanism and predicting coal outburst (hereinafter referred to as ‘outburst’). However, dynamic characterization remains be investigated. In this study, by monitoring pressure temperature tectonically deformed (TD) primary-undeformed (PU) coal, we established evolution laws key parameters during desorption. results indicate that drop rate, mass flow velocity increase with increasing pressure, stronger effect, generating a high gradient on surface. Under same formed TD surface greater than PU resulting in easily initiating an coal. Moreover, increased increases change rates (falling rate rising rate) mass. minimum final stable temperatures are generally lower compared releasing process expansion energy can divided into two stages exhibiting peaks which increases. peak values both about 2–3 times those addition, total released far also prove damage more likely producing pulverized prone initiate outburst.