Research Of Composite Inhibitor Affecting Spontaneous Combustion Of Coal

Coal spontaneous combustion is one of the important factors resulting in coal mine fires, which seriously threatens coal mines’ safety production and brings huge economic losses to coal industry. With deeper insight into the mechanism of coal selfignition, a variety of its prevention and control technologies develop much further as well. Thanks to its good effect, the inhibitor has been widely used in the prevention and control of coal spontaneous combustion, and this technology has become one of the major methods in fire control. However, based on a wide range of researches on the application of different kinds of inhibitors, the single inhibitor may not be the best choice to restrain coal seam self-ignition fire because either physical or chemical inhibitors have their weaknesses. Therefore, on the basis of previous researches of inhibitors, this research aims at studying composite inhibitors which composite the physical inhibitor superabsorbent polymer(SP) and the chemical inhibitor ascorbic acid(A)Firstly, this study prepared composite inhibitors in different mixing proportion of these two inhibitors. Industrial analysis and moisture test were followed to help master the physical properties of coal. And then, this study took advantages of programmed heating experiment system and Simultaneous thermal analysis respectively to carry on heat oxidation experiments and TG-DSC experiments separately by adding composite inhibitors of different mixing proportion.Macroscopically this study mastered the cross point temperatures, oxygen consumption amounts, CO emission amounts and value of characteristic temperatures etc. of the oxidation tests with and without inhibitors. And these results are valid parameters to judge characteristics of coal spontaneous combustion. Besides, the experiments also found that the best mixing proportion for the composite inhibitor was 1:5, and the best concentration of the inhibitor is 10 wt %. Secondly, by using Fourier transform infrared spectrometer to explore the change characteristics of the reactive groups in coal before and after inhibiting microscopically, it is concluded that composite inhibitors can reduce the content of active functional groups of coal surface and inerting its oxidation activity, which suppressing the coal spontaneous combustion.Finally, results of the activation energise calculated by the FWO(Flynn-Wall-Ozawa)method demonstrated that the composite inhibitors were effective to mitigate the coal oxidation.