In order to study the spontaneous combustion characteristics of residual coal in the goaf of Longfeng Coal Mine in Guizhou,the simultaneous thermal analysis(TG-DSC)experimental device was used to test the variation of the characteristic temperature and heat release of anthracite in the mine at different heating rates and oxygen concentrations,then Coats-Redfern integral formula was used to quantitatively analyze the activation energy.The results show that at the same oxygen concentration,the characteristic temperature points of coal samples increase with the increase of heating rate.The charac-teristic temperature point T2 of coal samples with the same heating rate fluctuates with the increase of oxygen concentration.T3 increases first and then decreases,but T,,T4,T5 and T6 decrease gradually.With the increase of heating rate,the peak value of heat release,peak temperature and heat release of coal samples gradually increase.The initial exothermic temperature and peak temperature of coal sam-ples decrease with the increase of oxygen concentration,but the exothermic peak and heat release first increase and then decrease,reaching the maximum at 15％oxygen concentration.The most probable mechanism function of the thermal decomposition/combustion stage of the coal sample conforms to the A-E equation of n=4.The activation energies of the coal sample at 21％oxygen concentration and different heating rates are 141.18,129.84,118.03,102.05 and 84.38 kJ/mol,respectively,which de-crease with the increase of heating rate.The activation energies of the coal sample at 10 K/min heating rate and different oxygen concentrations are 85.24,97.79,114.51,125.18 and 129.84 kJ/mol,re-spectively,which increase with the increase of oxygen concentration.The experimental results provide a thoretical basis for the prevention and control of coal spontaneous combustion in the mine.
关键词
煤自燃/升温速率/氧气浓度/特征温度/放热量/活化能
Key words
coal spontaneous combustion/heating rate/oxygen concentration/characteristic tempera-ture/heat release/activation energy
维普
万方数据