淮南矿区1/3焦煤二次氧化煤样孔隙特性实验研究

Experimental Study on Pore Characteristics of 1/3 Coking Coal Secondary Oxidation Coal in Huainan Mining Area

采空区二次氧化煤样自然发火为煤矿安全生产带来了巨大隐患。以淮南矿业集团顾桥煤矿1/3焦煤为研究对象,利用实验研究的方法,系统研究了不同预氧化温度和预氧化时间对煤孔隙特性的影响,研究发现:新鲜煤样和不同预氧化处理煤样的等温吸附曲线均呈典型的第Ⅱ类等温吸附曲线;预氧化处理对煤中孔隙的影响主要集中在0.45~20 nm,其中,2~4 nm内微孔的数量和总孔容在减少,在4~20 nm内的孔隙的数量和总孔容则显著增大;煤样的比表面积随着预氧化温度的提升呈现出先增大后变小的趋势,并在70℃时达到最大值;预氧化处理后,孔径处于0.45~5.9 nm时,孔隙的数量和总孔容有较大的变化。研究成果可为采空区自然发火防控提供必要的科学理论支撑。

The spontaneous combustion of secondary oxidized coal samples in goaf has brought huge hidden dangers to coal mine safety production.Takes 1/3 coking coal from Guqiao coal mine of Huainan mining group as the research object,and uses experimental research methods to systematically study the effects of different preoxidation temperatures and preoxidation times on the pore characteristics of coal.The study found that the isothermal adsorption curves of fresh coal samples and coal samples with different preoxidation treatments show typical typeⅡisothermal adsorption curves;The effect of preoxidation treatment on pores in coal is mainly concentrated in the range of 0.45-20 nm.Among them,the number and total pore volume of pores in the range of 2-4 nm decrease,while the number and total pore volume of pores in the range of 4-20 nm significantly increase;The specific surface area of coal samples shows a trend of first increasing and then decreasing with the increase of preoxidation temperature,and reaches its maximum value at 70℃;after preoxidation treatment,there is a significant change in the number and total pore volume of pores with pore sizes between 0.45 and 5.9 nm.The researchresultscanprovide necessaryscientifictheory support for the prevention and control of spontaneous combustion in goaf.