Shaanxi Coal Group Shenmu Zhangjiamao Mining Co., Ltd.
School of Safety Science and Engineering, Xi’an University of Science and Technology

为了探究煤体经液态CO2溶浸、酸化后，煤体有机基团化学结构的变化特征，在25℃、3MPa实验条件下，对无烟煤进行了液态CO2溶浸及酸化煤样实验；通过傅里叶红外光谱(FTIR)分析了煤体在液态CO2溶浸及酸化过程中官能团变化规律。结果表明：液态CO2溶浸过程主要发生溶胀、溶解、萃取、键解离和取代反应，液态CO2酸化过程除了发生以上反应外还会发生不同类型的加成反应；以上反应共同造成煤样不同类型的官能团、小分子相有机质、大分子相有机质发生溶出、重组过程；此外，煤样经液态CO2溶浸、酸化后芳香性与缩合度均得到了提升。

In order to explore the change characteristics of organic group chemical structure of coal after liquid CO2 leaching and acidification, liquid CO2 leaching and acidification coal sample experiments were carried out on anthracite at 25 ℃ and 3 MPa. The changes of functional groups in the process of CO2 leaching and acidification were analyzed by Fourier infrared spectroscopy (FTIR). The results show that swelling, dissolution, extraction, bond dissociation and substitution are the main reactions in the liquid CO2 leaching process, and different types of addition reactions occur in the liquid CO2 acidification process besides the above reactions. The above reactions result in dissolution and recombination of different types of functional groups, small molecule phase organic matter and large molecule phase organic matter. In addition, the aromaticity and condensation degree of coal samples are improved after liquid CO2 leaching and acidification.

1 实验研究
1.1 实验煤样的制备
1.2 液态CO2溶浸-酸化煤体实验
2 结果讨论
2.1 FTIR定量分析
2.2 芳香结构的定量分析
2.3 含氧官能团的定量分析
2.4 脂肪烃的定量分析
2.5 羟基官能团的定量分析
2.6 FTIR半定量表征参数分析
3 煤体有机质演化规律
4 结语

LIU Tingfang, LEI Jie, LI Jie, et al. Experimental study on evolution of organic groups in coal rock by liquid CO2 leaching and acidification[J]. Safety in Coal Mines, 2023, 54（11）: 69−76.