近年来，随着煤矿开采逐步向纵深发展，开采过程伴随着大型化、机械化和智能化，矿井粉尘对企业安全生产和工人职业安全健康所带来的影响日益严重。目前，开采工作面的降尘措施仍主要采取煤层注水或喷雾降尘的方法。因此，针对不同煤阶煤样的润湿特性进行研究，可以为矿井粉尘防治以及表面活性剂的筛选提供帮助。

本文通过工业分析和元素分析、固体核磁碳谱测试、X射线光电子能谱以及傅里叶变换红外光谱测试，对布尔台不粘煤、王家岭焦煤和陈召无烟煤三种煤样的结构特性进行实验研究。根据得出的碳骨架结构、几种主要元素的赋存形态和官能团类型及含量等基本参数对煤分子结构进行构建。然后结合分子动力学的模拟方法，对三种煤样的微观润湿特性进行了研究。主要研究成果如下：

通过工业分析和元素分析，确定了三种煤样中存在的主要元素含量及其原子比；由固体核磁碳谱实验分析了三种煤样煤分子结构中不同碳原子的具体峰位归属及其相对含量百分比，计算得出布尔台不粘煤、王家岭焦煤、陈召无烟煤的桥碳比分别为0.23、0.26和0.28；利用FT-IR测试技术，确定了三种煤样中芳香烃、含氧官能团、脂肪烃和羟基四种主要官能团的种类及含量。基于以上对煤结构特性和参数的分析与计算，通过计算模型与实验模型的不断对比与修正，最终构建出误差在0.95%范围内的布尔台不粘煤、王家岭焦煤和陈召无烟煤的煤分子结构，其分子式分别为C₂₃₅H₁₇₈N₂O₃₅，C₂₀₂H₁₄₈N₂O₁₆和C₂₀₀H₁₀₄N₂O₉。

运用分子动力学的模拟方法，对三种煤样煤分子的微观润湿特性进行研究并进一步阐述其微观润湿机理。在与水的吸附特性方面，布尔台不粘煤和王家岭焦煤的最大正负电势上均大于水分子的最大正负电势，表现为更容易克服水分子内部的吸引力而使其牢牢的吸附在煤分子表面。同时，三种不同煤阶的煤-水体系其相互作用能分别为-858.18 kcal/mol、-761.55 kcal/mol和-586.89 kcal/mol。随着煤阶的升高，相互作用能在数值上逐渐减小，所形成的氢键数量也逐渐减少，煤分子对水分子的吸附能力降低，其润湿性逐渐变差。在水分子的运动特性方面，对应体系中水分子的扩散能力增强，其扩散系数分别为0.414×10^-8 m²/s、0.492×10^-8 m²/s和0.556×10^-8 m²/s，煤-水界面处水分子的径向分布函数也依次升高。通过比较不同含氧官能团中氧原子和氢原子的电荷值，结合其与水分子进行动力学模拟后的相互作用能、范德华作用能和静电作用能，确定了不同含氧官能团对润湿性的贡献度排序为羧基＞羟基＞羰基。煤阶越低的煤样，由于其丰富的含氧官能团和不均匀的表面结构，导致其与水分子之间的相互作用更强，表现出了较好的润湿性。

In recent years, with the gradual development of coal mining in depth, the mining process is accompanied by large-scale, mechanized and intelligent, mine dust has increasingly serious impact on enterprise production safety and workers occupational safety and health. At present, the dust removal measures of mining working face are still mainly taken by coal seam water injection or spray dust removal. Therefore, it is very helpful to study the wetting characteristics of coal samples with different metamorphic degrees for mine dust control and screening of dust suppressor.

In this paper, the organic structure characteristics of Buertai non-stick coal, Wangjialing coking coal and Chenzhao smokeless coal were studied by industrial analysis and elemental analysis, solid nuclear magnetic carbon spectroscopy, X-ray photoelectron spectroscopy and fourier transform infrared spectroscopy. According to the obtained carbon skeleton structure, the occurrence form of several main elements, the type and content of functional groups and other basic parameters, the coal macromolecular structure was constructed. Then combined with the molecular dynamic simulation method, the microscopic wetting characteristics of three coal samples were studied. The main research results are as follows:

The content and atomic ratio of main elements in three coal samples were determined by industrial analysis and elemental analysis. Based on the solid state nuclear magnetic carbon spectroscopy experiment, the specific peak position and relative content percentage of different carbon atoms in the molecular structure of three coal samples were analyzed, and the bridge carbon ratio of Buertai non-stick coal, Wangjialing coking coal and Chenzhao smokeless coal was calculated as 0.23, 0.26 and 0.28, respectively. The types and contents of aromatic hydrocarbons, oxygen-containing functional groups, aliphatic hydrocarbons and hydroxyl groups in three coal samples were determined by FT-IR test. Based on the above analysis and calculation of coal structural characteristics and parameters, through the constant comparison and modification of the calculation model and the experimental model, the coal molecular structure of Buertai non-stick coal, Wangjialing coking coal and Chenzhao smokeless coal with an error range of 0.95% is finally constructed. The molecular formula is C₂₃₅H₁₇₈N₂O₃₅, C₂₀₂H₁₄₈N₂O₁₆ and C₂₀₀H₁₀₄N₂O₉, respectively.

The micro-wetting properties of three coal samples with different rank were studied by molecular dynamics simulation. And further elaborated its micro-wetting mechanism. In terms of adsorption characteristics with water, the maximum positive and negative potentials of Boertai non-stick coal and Wangjialing coking coal are greater than that of water molecules, indicating that it is easier to overcome the internal attraction of water molecules. At the same time, the interaction energies of the three coal-water systems with different metamorphic degrees are -858.18 kcal/mol, -761.55 kcal/mol and -586.89 kcal/mol, respectively. As the metamorphism of coal samples increases, the interaction energy decreases numerically, and the number of hydrogen bonds formed also decreases gradually. In terms of the motion characteristics of water molecules, the diffusion capacity of water molecules in the corresponding system is enhanced, and the diffusion coefficients are 0.414×10^-8 m²/s, 0.492×10^-8 m²/s and 0.556×10^-8 m²/s, respectively. By comparing the charge values of oxygen and hydrogen atoms in different oxygen-containing functional groups, and combining their interaction energy, van der Waals interaction energy and electrostatic interaction energy after dynamic simulation with water molecules, the wettability contribution of different oxygen-containing functional groups was determined as carboxyl group > hydroxyl group > carbonyl group. The coal samples with lower degree of metamorphism have stronger interaction with water molecules due to its rich oxygen-containing functional groups and uneven surface structure, showing better wettability.