摘要
研究孔隙结构和煤的成分对电阻率的影响,可为电法勘探在煤矿井下实际工程中的应用提供一定的理论基础。为此,本文选取了6组煤样,进行低温液氮(LT-LN2A)、FE-SEM扫描电镜和电阻率测量实验,结合煤岩导电机理研究煤岩微观孔隙结构和煤的成分对电阻率的影响。结果表明:煤岩孔隙结构对电阻率的影响为多变量因素制约,即呈多元函数关系。煤样的挥发分大小与孔隙率、比表面积分别呈U型变化规律,中等变质煤的孔隙率和比表面积最低,煤质程度对孔隙率的影响大于比表面积。煤样的电阻率随其挥发分的增加而增大,随变质程度的升高而减小,其与孔隙率也呈U型变化关系;微小孔对电阻率的影响大于大中孔,且微、小孔占比高的煤,电阻率较低;大、中孔占比高的煤,由于裂纹和裂隙的出现,电阻率较高;再者,煤样矿物元素种类及含量与其离子导电作用呈正相关,而与电阻率大小呈负相关。
Investigations on the effects of microscopic pore structure and coal composition on the re- sistivity could provide theoretical basis for the application of electrical prospecting in coal mine. There- fore, in this study, six groups of coal samples were selected and tested by means of low temperature liq- uid nitrogen adsorption （LT-LN2A）, field emission scanning electron microscope （FE-SEM） and resis- tivity-measurement equipment. Then according to the conductive mechanism of coal, effects of micro- scopic pore structure and coal composition on the resistivity were studied. Results show that the effects of pore structure on coal resistivity are multivariate function relation with multiple factors. The porosity and specific surface area （SSA） of coal sample both show U-mode change with the volatile. Porosity and S SA of medium metamorphism coal are the lowest. And effect of metamorphism degree on porosity is greater than the SSA. Coal resistivity increases with the increase in the volatile while decreases withthe increase in metamorphism degree. Meanwhile, a U-mode change also exists between the resistivity and porosity. The effect of micro-pores on resistivity is greater than that of macro-pores and mesopores. And more micro-pores could lead to lower resistivity. In contrast, the higher resistivity appears in coal with more macro-pores and mesopores due to the occurrence of cracks and fractures. In addition, the type and contents of mineral elements in coal keeps and a negative relationship with the resistivity. a positive correlation to the ion conductive function
出处
《采矿与安全工程学报》
EI
CSCD
北大核心
2018年第1期221-228,共8页
Journal of Mining & Safety Engineering
基金
国家重点研发计划项目(2016YFC0600708)
国家自然科学基金项目(51304212)
北京市自然科学基金项目(8152014)
中央高校基本科研业务费专项资金项目(2009QZ09)
关键词
煤
微观孔隙结构
电阻率
挥发分
矿物元素
coal
microscopic pore structure
resistivity
volatile
mineral elements
