酸洗脱灰后平顶山煤镜质组分的结构变化

Morphological Changes of Vitrinite Components in Pingdingshan Coal After Acid Elution

利用傅立叶红外光谱(FTIR)技术对平顶山矿区的原生结构煤、糜棱煤和三级酸(HCl-HF-HCl)脱灰处理后的煤镜质组分差异进行了分析,运用origin9.1软件对不同类型煤的红外光谱曲线进行了分段分峰拟合,并计算了红外光谱结构参数。结果表明,经过三级酸脱灰后,灰分脱除率达96%;脱灰后原生结构煤对称的CH2相对含量减少,不对称的CH2增加,糜棱煤呈现相反的趋势,说明脱灰处理对煤的脂肪结构有一定的影响;原生结构煤的结构参数I1(脂肪结构)值、I2(芳香结构)值和A(生烃潜能)值均比较大,说明其含有大量的脂肪烃并具有良好的生烃潜能;芳香烃CC含量较高且脱灰前后变化不明显,说明煤有机键的主要部分为CC,且结构相对稳定;糜棱煤的五取代芳环含量和I1值低于原生结构煤,说明原生结构煤在构造应力作用下发生脂肪侧链脱落,缩合程度增加,导致糜棱煤具有超前演化的特征。

The Fourier transform infrared spectroscopy(FTIR)technique was used to analyze the molecular structure difference among original structural coal,tectonic coal and tertiary acid treated coal(HCl-HF-HCl)in Pingdingshan mining.The curve-fitting analysis was employed to characterize the infrared spectra of different types of coal by using origin 9.1 software,and the FTIR structure parameters were also calculated.The results were obtained as follows:after the ash removal of the third-grade acid,the ash removal rate reaches 96%.After deashing,the relative content of CH2 is reduced,but the asymmetric CH2 is increased in the original structural coal,the tectonic coal exhibits the opposite trend.The tertiary acid treatment has an impact on the aliphatic structure of coal.The structural parameters of the original structural coals I1(aliphatic structure)and I2(aromatic structure)and A(hydrocarbon generation potential)values are relatively large,indicating that it contains a large amount of aliphatic hydrocarbons and has good hydrocarbon generation potential.Tectonic content and I1(aliphatic structure)of the penta-substituted aromatic ring are lower than that in the original structural coal,indicating that the original structural coal is detached from the aliphatic side chain under the tectonic stress,and the degree of branching and condensation increases leading to the inereased advanced evolution in tectonic coal.