煤矿安全2024，Vol.55Issue(3)：73-83,11.DOI:10.13347/j.cnki.mkaq.20230797
基于低温液氮浸溶处理的淮南矿区松软中阶煤孔隙特征
Pore characteristics of soft medium rank coal in Huainan Mining Area based on low temperature liquid nitrogen immersion treatment
摘要
Abstract
In order to study the influence of low temperature liquid nitrogen immersion treatment on the pore structure and fractal characteristics of middle grade coal in Huainan Mining Area,coal samples were treated with different liquid nitrogen immersion time,and the pore structure of coal was measured by mercury injection and liquid nitrogen adsorption method.The fractal theory was combined to analyze the development law and scale characteristics of coal pores under different immersion time from multiple angles.The results show that with the increase of liquid nitrogen immersion time,the total pore volume of coal increases from 198.089×10-3 cm3/g to 371.553×10-3 cm3/g,while the total specific surface area decreases from 4.984 m2/g to 4.496 m2/g,and the ef-fect is significant.The adsorption pore decreases,the seepage pore increases,and the pore connectivity of the adsorption pore in-creases to form a larger level of pore,which gradually changes to the seepage pore.There was a negative linear correlation between D1(fractal dimension of seepage pore)and D2(fractal dimension of adsorption pore)and the immersion time of liquid nitrogen,and the influence of liquid nitrogen immersion on D1 was more significant than that of D2.D1 and D2 decreased gradually with the in-crease of liquid nitrogen immersion time,indicating that the structural complexity of internal pores decreased with the increase of li-quid nitrogen immersion time,and the porosity and permeability of coal increased.Dc(comprehensive fractal dimension)decreases with the increase of average pore diameter and total pore volume of coal body,and increases with the increase of total specific sur-face area.With the increase of liquid nitrogen immersion time,the comprehensive fractal dimension of coal body decreases,the ad-sorption capacity of coal body is weakened,and the seepage capacity is enhanced,which is helpful to improve the coal-bed methane extraction effect of low permeability coal seam in Huainan Mining Area.关键词
液氮浸溶/压汞/氮气吸附/孔隙结构/分形维数/液氮致裂Key words
liquid nitrogen immersion/mercury intrusion/nitrogen adsorption/pore structure/fractal dimension/liquid nitrogen cracking分类
矿业与冶金引用本文复制引用
李峰,薛生,涂庆毅,张远远..基于低温液氮浸溶处理的淮南矿区松软中阶煤孔隙特征[J].煤矿安全,2024,55(3):73-83,11.基金项目
安徽省高校科学研究优秀青年资助项目(2022AH030087) （2022AH030087）
安徽省重点研究与开发计划资助项目(2022I07020020) （2022I07020020）
