热重-FTIR法分析不粘煤氧化特性参数

针对不粘煤粉生产过程的氧化自燃灾害,采用TG分析实验研究煤粉在空气条件下的氧化参数与动力学特征.利用FTIR-850红外光谱仪对煤样做红外光谱图分析,研究不同氧化温度下煤化学结构的官能团变化.结果表明:TG/DTG曲线上存在7个特征温度点,特征温度与升温速率呈正相关.将煤粉氧化过程分为失水失重(T1～T2)、吸氧增重(...

Oxidation Characteristic Parameters of Non-Caking Coal by TG and FTIR

Aimed at the spontaneous combustion disaster of non-caking pulverized coal in its production process,the oxidation parameters and dynamic characteristics of pulverized coal under the air condition were studied by thermogravimetric analysis experiments.The FTIR-850 infrared spectrometer was used to analyze the infrared spectrum of coal samples,and the functional groups of coal chemical structure under different oxidation temperatures were studied.The results showed that there are seven characteristic temperature points on the TG/DTG curve.The characteristic temperature was positively correlated with the heating rate.The oxidation process of pulverized coal was divided into four stages:loss of water and weight(T1—T2),oxygen uptake and weight gain(T2—T4),pyrolysis(T4—T5),and combustion(T5—T7).The positions of the peaks were similar,but with different intensities under different oxidation temperatures,showing that the numbers of functional groups in coal samples with different oxidation temperatures were different.The activation energies of oxidation process were calculated by two equal conversion methods(F-W-O model and V-W model),ranging from 66.2 kJ/mol to 92.9 kJ/mol.The activation energies and pre-exponential factors of four stages of pulverized coal oxidation were calculated by the C-R method,and the mechanism functions were determined.It was concluded that the pulverized coal belonged to twodimensional diffusion reaction,three-dimensional diffusion reaction,random nucleation reaction and threedimensional diffusion reaction in T1—T2,T2—T4,T4—T5 and T5—T7 stages,respectively.