Research On Low Molecular Compound In Coal Oxidized Spontaneous Combustion Mechanism

Coal is a sort of mixture which composed of the bulky molecular compound and the low molecular compound. And the compound is composed of chemical bonds and functional groups. The low molecular compound is one of the most important components, and there are 10%²3%, even 40% reported, of the organic matter in coal be low molecular compound. It reacts important role during the spontaneous combustion of coal. The oxidation spontaneous combustion mechanism for the low molecular compound was studied by the quantum chemistry theory on the microscopic level for the first time, and the reaction process of the oxidation spontaneous combustion for the low molecular compound was studied at B3LYP/6-31G level by quantum chemical DFT method, and built the oxidation spontaneous combustion mechanism theory for the low molecular compound, which filled a gap in coal spontaneous combustion researching field. This researching is very important to mine development design, safety work, fire comprehensive control, coal comprehensive utilization. The main contents and achievements in this thesis include several aspects as follow:The vibration frequency and the parameters of molecule structure such as bond length, bond angle and dihedral angle can be gained while optimizing the basal chemical structure cell of coal molecule at B3LYP/6-31G level by quantum chemical DFT method. According to the molecule orbital theory, the oxidation spontaneous combustion reaction of the low molecular compound in coal takes place at the atoms which charge density is thick. And gained the active point at which the oxidation spontaneous combustion reaction of the low molecular compound in coal takes place.Based on the active constituent of the chemical reaction process about coal spontaneous combustion, which generates H₂O, CO, CO₂, CH₄ and C₂H₄, was deduced by chemical reaction mechanism theory. The geometry of reactants,...