弱酸及添加表面活性剂对煤体孔隙的影响及分形特征研究

Effect of weak acid and surfactant on coal pore and fractal characteristics

以五轮山煤矿8号煤层为研究对象,经水、乙酸和在乙酸中添加不同表面活性剂对煤样进行浸泡实验,采用压汞法对各样品煤孔隙特征进行分析,并采用Menger海绵模型和Sierpinski垫片模型对孔隙分形进行计算分析。结果表明:所有样品的孔隙分布均呈“M”形;原煤及经水、乙酸处理后的煤样进退汞曲线产生较大的滞后环,在乙酸中添加不同表面活性剂后,煤样进退汞曲线滞后环减小;通过Menger海绵模型计算的分形维数,添加油酸钠的煤样品渗流孔隙和吸附孔隙分形维数为2.76和2.92,其他样品的分形维数均大于3;通过Sierpinski垫片模型计算的分形维数,经水处理后的煤样品分形维数增大,其他样品均减小。

Taking No.8 coal seam in Wulunshan Coal Mine as the research object,the coal samples were soaked with water,acetic acid and different surfactantsin acetic acid,then the pore characteristics of each sample coal were analyzed by mercury injection method,and the pore fractal was calculated based on Menger sponge model and Sierpinski gasket model.The results show that the pore distribution of all samples is“M”type;raw coal and mercury curve of coal samples treated with water and acetic acid have a large hysteresis loop,and the hysteresis loops of the mercury curve decrease when different surfactants are added to acetic acid;among the fractal dimensions calculated by Menger sponge model,the seepage and adsorption pore fractal dimensions of coal samples with NBSP are 2.76 and 2.92,and the fractal dimensions of other samples are greater than 3;the fractal dimensions calculated by the Sierpinski gasket model,and the fractal dimensions of coal samples treated with water increases,while the others decrease.