Study On Mechanism Of Action Of Radicals And Active Groups In Process Of Coal Oxidation

As the basic energy, coal mine plays an important role in the development of national economy and the improvement of people's living standards. However, the coal spontaneous combustion has led to a direct economic loss of tens of billions of yuan at the same time. Therefore, it is an outstanding issue to complete the mechanism of coal spontaneous combustion and effective control practices.Coal is macromolecular substance with complex structure. During the oxidation,there occurs a series of physical and chemical interactions to coal, of which the process hasn't been described clearly over chemical concepts. It has been indicated that coal spontaneous combustion has relations to coal reactive groups and free radicals, while the specific reactive mechanism and connections between the two factors are to be explored more deeply.It first analyzes the current situation of theories of the chemical molecular structure and the free radical and reactive groups during the coal spontaneous combustion. Then with eight kinds of coal of different metamorphism degrees, namely 1# lignite of Zaha open-pit coal mine in Huolinhe coal electricity group, 2# long flame coal of Yu county dan hou coal mine in Zhangjiakou, 3# non-caking coal of syngenetic proficient in prosperous coal co., LTD in Datong Sanxi, 4# bottle coal of Linnancang coal mine in Kailuan group, 5# 1/3 coking coal of Tangshan coal mine in Kaikuan group, 6# fat coal of Qianjiaying coal mine in Kailuan group, 7# coking coal of Lvjiatuo coal mine in Kailuan group, 8# lean coal of Hebei central energy in Xingtai as research subjects, it analyzes the releasing discipline of gas products during the coal oxidation and changes of free radical concentration and functional groups through programmed temperature-rising oxidation, ESR and infrared spectrum experiments.By analyzing the data resulted from the above experiments, it indicates the released discipline of gas products during the coal oxidation and changes of free radical concentration and determines the temperature point at which the index gases generate and discontinues; it shows changes of free radical concentration of different coal during the oxidation by fitting method; it analyzes the changes of functional groups around the discontinuing temperature points. What's more, with lignite as the example, it analyzes the different stages of coal spontaneous combustion in details, speculates the generating reasons of CO?C₂H₄?C₂H₆?C₃H₈ and lists reaction equation.The mechanism is analyzed macroscopically and microscopically, and it is initiatively concluded that the free radicals-reavtive groups mechanism of different stages in process of coal oxidation.