Molecular structure characteristics and model construction of anthracite in Jarud

To construct the macromolecular structure model of anthracite in Jarud of Inner Mongolia, the macromolecule structure of anthracite in this area was investigated using the methods of proximate analysis, ultimate analysis, carbon nuclear magnetic resonance(¹³C-NMR), high resolution transmission electron microscope(HRTEM), and X-ray photoelectric spectrometry(XPS). The results showed that aromatic carbon was the main component of macromolecule structure. Aliphatic carbon existed mainly in the form of short aliphatic chains and naphthenic hydrocarbons. The oxygen-containing functional groups in macromolecule structure of anthracite existed in the form of phenolic hydroxyl group and ether oxygen group. The nitrogen atoms were mainly in the form of pyrrole and pyridine, and the sulfur atoms were mainly in the form of mercaptan and thiophenol. By combining the structure parameter of coal macromolecule obtained by ¹³C-NMR and the size and content of aromatic ring inferred from HRTEM, the averaged macromolecular structure model of anthracite was constructed. Then the constructed model was optimized, and the energy of model was analyzed. The results showed that the aromatic carbon layers of macromolecular structure tended to arrange parallelly. The van der Waals force of non-bonding potential energy is the main factor to stabilize coal structure. The model foundation was built for using molecular dynamics simulations to investigate the jointing and stacking process of aromatic carbon layers and the corresponding reaction path of anthracite graphitization in Jarud at molecular scale.