Study On High Temperature Resistive Characteristic Of Coal Spontaneous Combustion Inhibitor

Coal spontaneous combustion is one of the major disasters in the coal industry.It not only poses a huge threat to the safe production of coal mines,but also causes a large amount of waste of coal resources and serious environmental pollution.In order to prevent the occurrence of coal mine fires,a large number of fire prevention technologies have emerged,and the prevention and control of coal spontaneous combustion technology has become one of the important fire prevention methods.At present,most researches on coal auto-ignition inhibitors focus on low-temperature resistive action,while under high temperature conditions,the research on the inhibitory effect and resistive properties of inhibitors is still insufficient.In view of this,this paper studies the low temperature and on high temperature resistive characteristic of common inhibitors,and selects a new high temperature and oxidation resistant inhibitor from the perspective of free radical reaction mechanism,and then studies from the oxidation products,thermal properties and functional groups of coal.The resistance effect was analyzed and the inhibition mechanism was analyzed.In this paper,the temperature-temperature oxidation experiment system is used to study the low temperature and high temperature resistive properties of common halide salt inhibitors and gel-type inhibitors.It is found that the commonly used inhibitors have better resistive action in the low temperature stage,and are easy to fail under high temperature conditions,and the resistive effect is obviously reduced.Further based on the free radical reaction mechanism,a new high temperature and oxidation resistant inhibitor was optimized based on the oxygen consumption,oxygen consumption rate,CO production,and inhibition rate.From Tetrakis[β-（3,5-di-tert-butyl-4-hydroxyphenyl）propionic acid]pentaerythritol ester（antioxidant 1010）and dilauryl thiodipropionate（antioxidant DLTP）in a ratio of 1:3.The new high temperature resistant resisting agent has a resistivity of up to 78%in the high temperature stage（150°C-180°C）,while the magnesium chloride resistivity is only about 15%under the same conditions.The variation of thermal properties of coal before and after the addition of new high temperature resistant inhibitor was studied by synchronous thermal analysis.The results show that the new high temperature resistant inhibitor is significantly higher than the characteristic temperature point of the magnesium oxidation process（such as the dry cracking temperature point and the ignition temperature point）,which significantly reduces the heat production of coal in different oxidation stages and increases the coal.The activation energy of each stage of oxidation,thereby better inhibiting the oxidation of coal.The resistance mechanism was analyzed by Fourier transform infrared spectroscopy.The variation of functional groups in coal before and after the addition of new high temperature resistant inhibitor was studied.The results show that the new high temperature resistant inhibitor can significantly reduce the oxidation reaction consumption of key reactive functional groups such as-CH₃,-CH₂-,-OH,and correspondingly reduce the increase of C=O and-COOH,thus inhibiting Coal oxygen reaction.According to the analysis of the inhibition mechanism,the new high temperature resistant inhibitor mainly breaks the chain reaction of active free radicals through inerting group activity;at the same time,it has good thermal stability and is not easy to decompose,so it shows good under high temperature conditions.The effect of suppressing spontaneous combustion of coal.The research results of this paper provide new research ideas and theoretical basis for the exploration and research of new coal mine inhibitors,which are of great significance for mine fire prevention.