Experimental Study On The Pyrolysis Oxidation Of Coal And Oil Shale Under Common Mining Conditions

With the continuous development of science and technology,the level of social energy consumption continues to grow,and the existing mining coal resources cannot meet the further needs of society.At the same time,coal and crude oil storage continues to decline,and efforts have been made to search for potential coal and alternatives to crude oil.Oil shale(OS)is a rich fossil fuel similar to coal distributed around the world.It is also different from general energy and can be used as an alternative energy source for fossil fuels such as coal and petroleum.The kerogen inside the oil shale,whose main elements are C,H,O elements,can directly react with oxygen.There is a natural fire hazard in the goaf of coal and oil shale mining face.Slowly oxidizing and heating in the goaf to release flammable gas,natural fire and other problems seriously restrict the safe and efficient production of the mine.Aiming at the natural fire prevention and control of the coal mining and oil shale in the 1105 working face of Liangjia Coal Mine,the goaf is a mixture of coal and oil shale,which leads to the unclear division of the "three belts" in the goaf and the fire extinguishing in the later stage.The measures are not targeted;at the same time,the detection of the flag gas of spontaneous combustion in the goaf will change,affecting the effective judgment of the work in the face of spontaneous combustion.Coal and oil shale will interact with each other in the process of continuous heating in the goaf.In this paper,two experiments,temperature programmed and thermogravimetric analysis,are used to compare coal and oil from the perspective of mixing ratio and supply rate.Quantitative and qualitative analysis of the shale working face.First of all,under certain conditions,people have a relatively comprehensive grasp of the pyrolysis and oxidation mechanism of a single substance such as coal,but there are few studies on the catastrophic mechanism of coal and oil shale co-heating.Thermal decomposition is a particularly complicated The process is thought to be the existence of hundreds of complex components and their parallel and/or continuous reactions.Therefore,this paper uses the isothermal conversion method to evaluate the reliability and objectivity of apparent activation energy through international thermal analysis.The Starink and Kissinger-Akahira-Sunose(KAS)methods are used to evaluate the apparent activation energy of coal and oil shale during the conversion process.The method has good adaptability and effectiveness.Secondly,coal and oil shale were sampled at the 1105 working face of Liangjia Mine,and pyrolysis analysis was carried out on different proportions of samples using temperature programmed and thermogravimetric analysis.The temperature programming experiment is based on the different ratio of coal to oil shale and the ventilation rate.The sample is heated from 30-200? at a heating rate of 0.2?/min,and then the gas and temperature are changed to determine the natural ignition of the goaf.Signature gas;coal and oil shale common mining face early warning of natural fire three warning levels,can also be respectively with the highest temperature in the goaf to reach 40-80?,80-140? and 140? or more The situation corresponds.It is an early indicator gas index system that uses CO and C2H4 as the main marker gases and C2H4/C2H6 ratio as the auxiliary marker gas.Thermogravimetric analysis of the TG and DTG data of 30-800? samples of coal and oil shale at different ratios,showing the residual quality of coal and oil shale at different ratios and temperatures.And the value of the mass change ratio.The co-heating of coal and oil shale is a complex multi-stage reaction process.Positive interaction occurs during co-firing,and the co-combustion characteristics and specific reactivity are improved.Because of the rapid combustion of organic matter in coal,the particle temperature increases and reaches Co-pyrolysis with oil shale.The results of the two sets of experiments make the fire prevention and extinguishment of coal and oil shale common mining goaf more targeted and theoretical.