淮南矿区气煤二次氧化煤样物理吸氧特性实验研究

Experimental Study on Physical Oxygen Absorption Characteristics of Gas Coal Secondary Oxidation Coal Samples in Huainan Mining Area

针对二次氧化煤样物理吸氧特性的系统研究,对于预防和治理采空区和老空区的自然发火隐患和灾害具有重要意义。以淮南矿业集团顾桥煤矿13#煤层的气煤煤样为研究对象,通过比表面积和煤的物理吸氧量实验,系统的气煤煤样在不同预氧化温度和不同预处理时间条件下,煤样和新鲜煤样的比表面积和物理吸氧能力的变化规律。研究发现,相较于新鲜煤样,经过预氧化处理后的煤样比表面积并非呈单调上升趋势,而是呈现先增大后降低的趋势,其峰值出现在70℃,相较于新鲜煤样增幅达到了1.97倍;经过预氧化处理,原先新鲜煤样中的微孔和超微孔在预处理过程的影响下变成了孔径为5~20 nm的中孔;物理吸氧量的变化趋势与BET比表面积的变化趋势具有较强的正相关性。研究成果为防治煤矿采空区和老空区自然发火提供必要的理论支撑。

The systematic study of the physical oxygen absorption characteristics of secondary oxidized coal samples is of great significance for preventing and controlling the natural fire hazards and disasters in goafs and old goafs.Takes the gas coal sample from the No.13 coal seam of Guqiao coal mine,Huainan mining group as the research object.Through experiments on specific surface area and physical oxygen absorption of coal,the changes in specific surface area and physical oxygen absorption capacity of the gas coal sample and fresh coal sample under different pre oxidation temperatures and pre treatment times are systematically studied.Research has found that compared to fresh coal samples,the specific surface area of pre oxidized coal samples does not show a monotonic increase trend,but shows a trend of first increasing and then decreasing.Its peak appears at 70℃,with an increase of 1.97 times compared to fresh coal samples;After pre oxidation treatment,the micropores and ultra micropores in the original fresh coal sample were transformed into mesopores with a pore size of 5-20 nm under the influence of the pretreatment process;there is a strong positive correlation between the trend of physical oxygen uptake and the trend of BET specific surface area.The research results provide necessary theoretical support for the prevention and control of spontaneous combustion in coal mine goaf and old goaf.