碎粉煤孔渗对冰冻的响应  

Response of Porosity and Permeability of Powder Structural Coal on Freeze

作　　者：储小送 屈争辉[1,2] 余坤[1] 余可龙 邵春景 

机构地区：[1]中国矿业大学资源与地球科学学院,江苏徐州221116 [2]中国矿业大学煤层气资源与成藏过程教育部重点实验室,江苏徐州221008

出　　处：《煤矿安全》2016年第4期1-5,共5页Safety in Coal Mines

基　　金：国家自然科学基金资助项目(41302130;41430317);国家级大学生创新训练资助项目(201510290062)

摘　　要：以强脆性变形碎粉煤为例,应用压汞法、低温液氮法和稳态法对原样、冰冻7 d及30 d样品进行测试,结果表明:冰冻对样品孔容、孔径结构存在损伤;冰冻后,撑裂作用使样品中较小的孔向更大孔转移,不同冰冻时间和孔径范围内损伤程度明显差异;冰冻30 d样品时,围限作用限制了损伤的发展;对纳米级孔,孔容随冰冻时间依次降低,冰冻时间越长,撑裂会充分发挥作用,附加围限作用(冰冻30 d样品),撑裂后仍在100 nm以内的孔增加量有限;冰冻后样渗透性得到改善,围限作用使冰冻30 d样品渗流孔增加有限,导致其渗透率相对于原样的增幅小于冰冻7 d样品。This paper,taking strong brittle deformation of powder structural coal as an example,we use the methods of mercury intrusion porosimetry,low temperature liquid nitrogen and steady- state to test the original,frozen samples for 7 days and 30 days. Results show that the method of freezing damages to pore volume,pore structure of samples,and makes smaller pores transfer to the larger pores because of cracked effect. The damage extent was different in various pore sizes and different freezing time. In the sample of frozen 30 days,due to the confined effect of the peripheral square barrel,the development of the damage was restricted; for nanoscale pore,pore volume fell in turn with the frozen time. The longer the freezing time,cracked effect will fully exert its effect,and additional confined effect,the increasing amount of pore that is still within 100 nm after cracking is limited,resulting in the loss of this phase pore. After freezing,the permeability of the sample was improved. Due to the confined effect,compared to the original,the increase of seepage- flow pores of frozen sample for 30 days is less than frozen sample for 7 days.

关 键 词：构造煤 冰冻法 撑裂作用 围限作用 孔渗 

分 类 号：TD712[矿业工程—矿井通风与安全]