Joint Research On Macro Gas Generationg Rules And Micro Changes Of Functional Groups During Isothermal Temperature Oxidation

Most of the coal seam in our country have the nature of spontaneous combustion, spontaneous combustion fire caused by coal oxidation not on ly wastes the mineral resources, and pollutes environment, being a serious threat to the safety production of mine. This paper adopts the method of experiments with theoretical analysis, makes a research on coal macro ch aracterization and micro characteristics in the process of constant temperat ure oxidation in view of the phase of low temperature oxidation of the di fferent types coals, and reveals the coal oxidation mechanism further, whi ch has the vital significance on guiding the forecast and prevention of sp ontaneous combustion of coal oxidation.Firstly, conduct experiments on different kinds of coal samples in diff erent size, different quality during the process of constant temperature oxi dation in use of the thermostatic device system with gas chromatograph. It is concluded that gaseous product characteristics and change tendency under different conditions of coal low temperature oxidation phase is obtai ned by analyzing certain parameters such as oxygen consumption rate, CO generation rate during different oxidation time and how process of coal1ow temperature oxidation changes with the oxygen concentration under the condition of different size, different quality, different types according to t he changes of oxygen concentration in coal sample reaction tank. The qua ntitative calibration is made to grasp the relationship between constant te mperature oxidation time and coal sample oxygen consumption rate, and CO generation rate, analysing of the basic mechanism of coal low temper ature oxidation reaction, and grasping the macroscopic change rule of coal oxidation process as a result.At the same time, Fourier infrared spectrum experiment is conducted to make a study on infrared spectral characteristics of coal samples under the condition of different metamorphic grade, different size, and different constant temperature oxidation time. Variation tendency under different co nditions are analyzed from the points of view of microscopic molecular in the change of functional groups such as hydroxyl, carbonyl and aromatic hydrocarbon, and it is the difference of the reactive group content in the coal molecular that creates the different chemical structure of coal molec ule, which determines the difficulty of the oxidized spontaneous combustio n in intrinsic attribute.The reaction of coal and oxygen compound is a whole system, in w hich the external macro phenomenon and coal molecular functional change s within the characteristics and reaction rules of coal oxidation. Through microscopic analysis of macro characterization parameters, its correspondin g relation was studied between macro properties change rule and microsco pic characteristic changes of different coal sample, which is concluded tha t specific macro characterization parameters is explained by micro change in the process of the coal oxidation. Two interpretations is made at the sa me time from the perspective of macro and micro to verify the the chang e of parameters and phenomenon in the process of coal oxidation reaction to further grasp the development law of coal under the condition of low t emperature oxidation process which provides a theoretical basis and techni cal support for the innovation of comprehensive evaluation index in coal spontaneous combustion and the strengthening of prevention and control w ork in coal spontaneous combustion.