从分子层面认识煤的分子结构特征对实现煤炭合理利用及高效转化具有重要意义。以淮北矿业集团青东煤矿煤为研究对象，通过工业分析、元素分析、核磁共振碳谱（13 C-NMR）及X射线光电子能谱（XPS）等测试方法，对其分子结构进行研究。结果表明，青东煤的芳香化合物以2、3环结构为主；脂肪结构以甲、乙基侧链及环烷烃形式为主；分子结构中芳香桥碳与周碳比为0.35。氧原子以羰基和酚羟基形式存在，氮原子分别以吡啶和吡咯形式存在，硫原子含量较低，在该模型中不再考虑。依此构建青东煤大分子平均结构模型，其分子式为C142H128 N2O3 ，分子量为1 910.60。煤的大分子结构中芳香结构单元包括2个苯环，2个萘，4个蒽；杂原子以2个羰基和1个酚羟基、1个吡啶和1个吡咯的形式存在。对单个大分子结构模型进行结构优化和退火动力学模拟研究，桥键、脂肪键等化学键发生了明显的扭转，分子内芳香片层之间的π-π相互作用使相邻芳香片层之间趋于近似平行排列；总势能由2 121.14 kJ/mol下降到1 255.85 kJ/mol，其中键伸缩能及范德华能占主导地位。将18个青东煤大分子模型构建成聚集态结构模型。经过分子力学和分子动力学模拟优化后，大分子受周围分子的制约，原本近似平行排列的片状芳香碳结构发生扭曲形变，结构杂乱。研究构建的青东煤大分子结构模型可为选择浮选药剂提供模型基础。

Understanding the structural characteristics of coal molecules at the molecular scale is of significance to realize rational utilization and efficient transformation of coal.The macromolecule structure of coal sample, from Qingdong Coal Mine of Huaibei Mining Group, was studied using the methods of proximate analysis, elemental analysis, carbon nuclear magnetic resonance ( 13 C-NMR) and X-ray photoelectric spectrometry (XPS).The results showed that the aromatic structure in the macromolecular structure of Qingdong coal was mainly composed of naphthalene and anthracene, and the aliphatic carbon existed mainly in the form of —CH3 , —CH2  and cycloalkanes.The ratio  of aromatic bridge carbon to aromatic peripheral carbon was 0.35.The oxygen and nitrogen atom were in the form of carbonyl group and phenolic hydroxyl group, and pyridine and pyrrole, respectively.Sulfur atom was too low to considered in the model.Based on this, the average macromolecular structure model of Qingdong coal was established.Its molecular formula was C142 H128 N2O3 , and its molecular weight was 1 910.60.The aromatic structural units in the macromolecular structure of coal sample included 2 benzene rings, 2 naphthalene and 4 anthracene.The heteroatoms in the molecular structure of coal were in the form of 2 carbonyl groups, 1 phenolic hydroxyl group, 1 pyridine group and 1 pyrrole group.Optimization and annealing molecular dynamics simulations of a single constructed model were performed.The chemical bonds such as bridge bonds and fat bonds were obviously twisted.The intramolecular π -π interactions between aromatic layers enabled their quasi-parallel arrangement.The total energy decreased from 2 121.14 kJ/mol to 1 255.85 kJ/mol, in which bond stretch energy and van der Waals energy played a key role in energy.Eighteen macromolecular models of Qingdong coal were constructed into an aggregation structure.After the optimization of molecular mechanics and molecular dynamics simulations, the macromolecules in the aggregated structure model were constrained by the surrounding molecules, and the originally parallel-arranged flaky aromatic carbon structures were bent and twisted, aromatic carbon layers in the structure were disorderly.In the study, the Qingdong coal macromolecular structure model was constructed to provide a model basis for further flotation reagent selection.