褐煤二次氧化特性与临界温度范围实验研究

Experimental Study on Secondary Oxidation Characteristics and Critical Temperature Range of Brown Coal

为了研究在不同温度及时间下处理后的褐煤的二次氧化特性和临界温度范围,在100～175℃的环境下对云南褐煤进行60～120 min氧化预处理,随后测试其自燃特性。同时对处理后的煤样进行热重、红外光谱以及扫描电子显微镜分析。结果表明:预氧化煤样的自燃特性增强,H2O2氧化升温至90℃最短仅需15 min,且煤样含氧官能团增加,表面结构松散化。二次氧化的煤样的自燃特性的变化受到预先氧化的温度和时间2种因素的共同影响,均呈现先增强后减弱的趋势,处理120 min后煤样在200～400℃间的表观活化能为66.530～68.985 kJ/mol。

In order to study the secondary oxidation characteristics and the critical temperature range of brown coal treated at different temperature and time. The Yunnan brown coal was pretreated by 60 min to 120 min oxidation at 100 ℃ to 175 ℃, and then its spontaneous combustion characteristics are tested. At the same time, the treated coal samples were analyzed by Thermogravimetry（TG）, Fourier transform infrared spectroscopy（FTIR） and scanning electron microscopy. The result shows that：the spontaneous combustion characteristics of the pre-oxidized coal sample are enhanced, and the oxidation of H2 O2 heats up to90 ℃ with a minimum of 15 min. The oxygen functional groups in coal samples increase and the surface structure is loose. The variation of the spontaneous combustion characteristics of the secondary oxidation coal sample is affected by the two factors of the pre-oxidation temperature and time, showing a tendency to increase first and then decrease. After treatment with 120 min, the apparent activation energy of coal sample at 200 ℃ to 400 ℃ is 66.530 kJ/mol to 68.985 kJ/mol.