不同煤层煤氧化自燃性实验分析

Experimental analysis on characteristics of oxidation and spontaneous combustion of coal in different coal seams

为研究不同煤层煤自然发火特征的异同性及规律,以淮南矿区1号、3号、6号、13号煤层为研究对象,通过自然发火实验,对不同煤层煤的自然发火期周期、煤样70℃时放热强度和R70值进行分析。研究结果表明:4个不同煤层煤样自燃性由强到弱依次为:3煤>6煤>1煤>13煤;变质程度相近的4个煤层,3煤自然发火期最短,这与煤体中硫分和水分含量高有关;13煤变质程度较高,且前期放热强度、耗氧速率增长缓慢,其自燃性较弱;4个不同煤层煤的耗氧速率、CO,CO2产生率,以及C2H4/C2H6值随煤温升高具有相似的变化规律;煤中CH4气体大量解吸出现于煤温60℃之前,煤中灰分在80~120℃开始逐渐吸热融化,解析和融化均会抑制煤氧接触并且减小煤氧反应放热总量。

In order to study the similarities and differences and the laws about the characteristics of spontaneous combustion of coal in different coal seams,taking No.1,No.3,No.6 and No.13 coal seams in Huainan mining area as the research objects,the heat release intensity and R70 value of different coal seam coal spontaneous combustion periods and coal samples at 70℃were analyzed.The results showed that by the research on the cycle of spontaneous combustion period and the heat liberation intensity and R70 value when the temperature of coal samples was 70℃according to the experimental analysis,the spontaneous combustion property of coal samples from four different coal seams was in the order of No.3>No.6>No.1>No.13 from strong to weak.For the four coal seams with similar metamorphic degree,the spontaneous combustion period of No.3 was the shortest,which was related to the high sulfur content and high water content in the coal.The metamorphic degree of No.13 was higher,and its early heat liberation intensity and oxygen consumption rate increased slowly,with a weaker spontaneous combustion property.The oxygen consumption rate,the generation rate of CO and CO 2,and the C 2H 4/C 2H 6 value of coal samples from four different coal seams had the similar change laws with the increase of coal temperature.The mass desorption of CH 4 gas in the coal appeared before the temperature of coal samples reached 60℃,then the ash in the coal would absorb heat and melt gradually in 80-120℃,and both the desorption and melting would inhibit the contact between coal and oxygen and reduce the total heat liberation amount of coal and oxygen reaction.