高硫煤二次氧化自燃特性参数的实验研究

摘要

In order to solve the problems present in the prediction and prevention of coal spontaneous combustion in a second-mining coal face in the high-sulfur coal mine, contrast analysis was carried out on the characteristic parameters of the high-sulfur coal spontaneous combustion in the process of its initial and secondary oxidation by using the experimental method of programmed temperature-rise. The results showed that the oxygen consumption rate, the generation rate of CO and CO2 and the exothermic intensity of the high-sulfur coal were all increased at the low-temperature stage in the secondary oxidation as compared to that in the initial oxidation, but after the critical temperature, the reaction intensity of the secondary oxidation decreased, and the indicator gases of the secondary oxidation were different from that of the initial oxidation;FeS2 in high-sulfur coal had a certain impact on the oxygen adsorption of coal, the H+ produced in the initial oxidation played a catalytic role on coal-oxygen oxidation, and the reaction product was Fe( OH) 3;the colloid reduced the porosity of coal molecule and prevented the coal-oxygen compound reaction in the secondary oxidation. The experimental results provided data support for the prediction of high-sulfur coal spontaneous combustion in the second-mining coal face and the fire prevention after the closed face was unsealed.%为研究高硫煤矿复采工作面煤自燃预测预防的问题，采用程序升温实验方法对高硫煤的初次和二次氧化自燃特性参数进行了对比分析。结果表明：高硫煤在二次氧化低温阶段耗氧速率、CO产生率、CO2产生率和放热强度较初次氧化均有所上升，临界温度之后，二次氧化反应剧烈程度有所下降，且二次氧化与初次氧化指标气体不同；高硫煤中的FeS2对煤氧吸附有一定的影响，初次氧化产生的H+对煤氧复合起促进作用，反应产物Fe(OH)3胶体降低了煤分子的孔隙率，阻碍了二次氧化的煤氧复合反应。实验结果为高硫煤矿复采自燃预报及封闭工作面启封后的防火工作提供了数据支撑。