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利用红外光谱法分析煤氧化和阻化的微观结构变化特征,对研究煤低温氧化和阻化机理有重要意义。采用TENSOR37傅里叶变换红外光谱仪,通过对阳泉无烟煤氧化和阻化的红外光谱图的分析,研究阳泉无烟煤在添加化学阻化剂前后煤分子结构的变化特征。结果表明:红外光谱图中位于高波数的羟基(—OH)吸收峰较弱,吸光度只有0.086～0.122,在加入吸水盐类阻化剂(MgCI_2)后,吸光度约为原煤样的1.5倍,谱峰明显加强;在阻化前的低温氧化过程中,酚、醇、醚、酯的C—O吸光度由0.309降到0.207,甲基(—CH_3)、亚甲基(—CH_2—)的吸光度分别由0.027、0.019、0.042和0.056降到0.012、0.010、0.031和0.047,吸收峰强度逐渐减弱,芳烃C—H吸光度分别由0 031和0.040升高到0.077和0.087;在阻化后的低温氧化过程中,C—O含量基本不变,甲基、亚甲基的吸光度分别由0.017、0.011、0.034和0.040降到0.012、0.009、0.031和0.038,吸收峰减弱的速度明显降低,芳烃C—H的变化并不大。研究表明:在高变质阳泉煤中,含氧官能团和脂肪侧链的含量很低,在低温氧化过程中,很容易被氧化;吸水盐类阻化剂MgCl_2可以通过与煤分子间发生取代和络合等作用,增加煤分子的稳定性,提高煤分子氧化的活化能,降低煤的氧化速率。
Analyzing the microstructure change characteristics of coal oxidation and resistance by using infrared spectroscopy is of great significance for studying the mechanism of low temperature oxidation and resistance of coal. The TENSOR37 Fourier transform infrared spectrometer was used to analyze the change of molecular structure of coal in Yangquan anthracite before and after the addition of chemical inhibitor by analyzing the infrared spectra of oxidation and resistance of anthracite in Yangquan. The results showed that the absorption peak of hydroxyl group (-OH) located at high wave number was weak, the absorbance was only 0.086 ~ 0.122, and the absorbance was about 1.5 times higher than that of original coal sample after the addition of water absorbing salt inhibitor (MgCl2) (P <0.05). The C-O absorbance of phenols, alcohols, ethers and esters decreased from 0.309 to 0.207, and the absorbances of methyl groups (-CH_3) and methylene groups From 0.027,0.019,0.042 and 0.056 down to 0.012,0.010,0.031 and 0.047, the absorption peak intensity gradually weakened, the aromatic C-H absorbance increased from 0 031 and 0.040 to 0.077 and 0.087 respectively. After the low temperature oxidation process , The content of C-O remained unchanged, the absorbance of methyl and methylene decreased from 0.017, 0.011, 0.034 and 0.040 to 0.012, 0.009, 0.031 and 0.038, respectively. Change is not large. The results show that the contents of oxygen-containing functional groups and aliphatic side chains are very low in high metamorphic Yangquan coal, and are easily oxidized in the process of low-temperature oxidation. The salt-tolerant MgCl 2 can be replaced by the intermolecular substitution The same effect, increase the stability of coal molecules, improve the activation energy of coal molecular oxidation, reduce the oxidation rate of coal.