准南煤田乌东矿区主采煤层热动力学特性研究

Kinetics of the major coal seam in Wudong coal mine of Southern Junggar coalfield

采集新疆准南煤田乌东矿区主采煤层煤样,采用电镜扫描、X-射线衍射、原位红外光谱分析及热重分析等手段,对不同粒级的煤样及将0.15~0.18mm粒级的煤样在50~500℃范围内,以间隔50℃分别加热后进行实验测试。结果表明:煤样中孔隙与裂隙数量随煤样加热温度的升高而增多;不同粒径煤样的煤化度相差不大;经历不同加热温度的煤样,其煤化度随温度升高呈现波动变化(煤化度在450℃时最大,350℃时最小);煤样煤化程度越高,其芳香微晶结构越发育,煤越易自燃。随粒径减小,煤样的OH-官能团减少,CH-官能团增加;随经历的加热温度升高,煤样的OH-官能团、-CH2-CH3官能团减少,CH-官能团增加;不同含氧官能团随煤样经历的加热温度升高呈先增加后减少的趋势。实验煤样的特征温度随煤样粒径减小总体呈降低趋势;随煤样经历的加热温度升高,特征温度T1、T2无明显变化,T3、T4增大,T5则减小;实验煤样反应活化能随粒径减小总体呈现减小趋势;随经历的加热温度升高,实验煤样反应活化能则呈波动变化。

In the present study,we collect coal samples in Wudong coal mine which are situated in the middle part of Southern Junggar coalfield.The coal samples(0.15-0.18 mm)are divided into ten parts which treated by heating for about twenty minutes in different temperature(from 50℃to 500℃ with interval of50℃)in muffle oven.SEM,XRD,IR and TG are employed to investigate the kinetics.The results show that the surface increases with the decrease of the particle size.The middle-size pores and cracks increases with the increase of the temperature experienced.The coalification of different sizes coal samples stays unchanged.And the coalification of coal samples which experienced different temperatures show a fluctuation of change(peak at 450℃and bottom at 350℃).The higher of the coalification of coal,the more developed of microcrystalline structure of it which indicates the more prone of coal spontaneous combustion.The results from infrared spectra analysis show that the OH-functional group decreases with the decrease of particle size,meanwhile the CH- functional group increases.With the increase of the experienced temperatures,OH-functional group,-CH2-CH3 functional group decreases,CH- functional group increases.Different oxygen functional groups have a fluctuated change with the increase of experienced temperatures.With the increase of the temperatures,the characteristic temperature T1 and T2 stay stable without noticeable changes.The T3 and T4 increase during this process except the T5.The activation energy of experimental coal samples decreases.With the increase of experienced temperature,coal samples’activation energy shows a trend of fluctuation.