Thermogravimetric Dynamics Experimental Study On Coal Spontaneous Combustion Characteristics Of Gushan Coal Mine In Pingzhuang

Underground mine fires are mainly caused by coal spontaneous combustion, Consequently, scientifically determining coal spontaneous combustion tendency as well as coal spontaneous combustion period will have very important significance on reducing and eliminating the harm caused by coal spontaneous combustion. In this paper, application of thermo gravimetric(TG) analysis and macro-dynamics method, spontaneous combustion characteristics of five kinds of typical coal samples from Pingzhuang Gushan coal mine were systematically studied, and coal spontaneous combustion period was concluded, which have an important guiding significance on early prediction of coal spontaneous combustion of Pingzhuang Gushan coal mine. Firstly, the paper aimed at China's current inadequacy of determining method of coal spontaneous combustion stage, using TG analysis method, which obtained the characteristic temperatures of TG curves about five typical coal samples, and analyzed the process of coal spontaneous combustion. Secondly, application of different dynamics mechanism model function, experimental data and correlation analysis were respectively processed, thus which derived activation energy, pre-exponential factor and spontaneous combustion period, and focusing on combining oxygen intake capability and release heat of oxygen adsorption weight incremental stage with activation energy before ignition point stage to study coal spontaneous combustion tendency. At last, in connection with coal sectional activation energy and pre-exponential factor, correspondingly oxidation reaction rate was respectively derived for each segment, using piecewise-weighted calculation method, coal spontaneous combustion period was derived. In addition, these experimental result curves of different heating rates showed that TG curves moved to high temperature with increasing heating rate; using TG dynamics method to obtain coal sample activation energy at different heating rates, it was found that coal activation energy gradually increased with increasing heating rate, spontaneous combustion tendency decreased, that is, heating rate is an important factor of affecting coal spontaneous combustion tendency characterization.