采用直流电场作为物理场,利用已研制的电场作用下煤的瓦斯吸附试验装置,对电压作用下煤的瓦斯吸附性进行了试验研究,对电压作用前后试验煤样表面结构进行了XPS能谱测试,对煤样表面结构C元素含氧官能团的种类及其相对含量进行了分析,目...采用直流电场作为物理场,利用已研制的电场作用下煤的瓦斯吸附试验装置,对电压作用下煤的瓦斯吸附性进行了试验研究,对电压作用前后试验煤样表面结构进行了XPS能谱测试,对煤样表面结构C元素含氧官能团的种类及其相对含量进行了分析,目的是基于煤表面结构揭示电场作用对煤的瓦斯吸附性影响机理。试验结果表明:电压作用可以弱化煤的瓦斯吸附性,在80 k Hz/1 k V,80 k Hz/3 k V和80 k Hz/5 k V电场作用下,煤表面结构C元素含氧官能团发生改性,C—C/C—H键相对含量从47.22%减少到24.95%,生成C—O键、C=O羰基官能团、COO—羧基或醌官能团,使得这3种含氧官能团相对含量增加,其最大值分别为54.44%,13.89%和7.39%;随着煤表面结构C元素C—C/C—H键相对含量的减少,煤的瓦斯饱和吸附量a呈线性规律减小,吸附常数b呈指数规律减小;与电场作用前相比,作用后煤总孔面积、中值孔径(体积)、中值孔径(面积)和平均孔径等孔隙结构参数均增加。展开更多
In some of the coalfields in India, coal seams are only developed but no extraction of pillars is possible due to the presence of surface or sub-surface structures and also non-availability of stowing materials which ...In some of the coalfields in India, coal seams are only developed but no extraction of pillars is possible due to the presence of surface or sub-surface structures and also non-availability of stowing materials which leads to huge amounts of coal being locked-up underground. Spontaneous heating and fire, accumulation of poisonous gases, severe stability issues leading to unsafe workings and environmental hazards are the major problems associated with the developed coal pillars. So, there is a pressing need for a technology for the mining industry to extract the huge amount of coal locked-up under different constraints. In this study, the locked-up coal is proposed to be extracted by artificially strengthening the rib pillars. The detailed comparative study is carried out to know the increase of extraction percentage of locked-up coal by strengthening the rib pillars with FRP. Extraction methodology is designed and studied through numerical modelling for its stability analysis to evaluate its suitability of application in underground.展开更多
The Wongawilli strip pillar mining technique,which combines the strip pillar mining layout and Wongawilli mining technology,is a new high efficient mining technology for mining under surface structures. The Wongawilli...The Wongawilli strip pillar mining technique,which combines the strip pillar mining layout and Wongawilli mining technology,is a new high efficient mining technology for mining under surface structures. The Wongawilli strip pillar mining technique was studied in this paper using theoretical analysis and numerical simulation. As an example,the geological and mining conditions of a coal mine were used to design the Wongawilli strip pillar plans,including the support parameters of the entries and the mining technology. In order to control the surrounding rocks and manage the roof effectively during coal mining,the stress fields,displacement fields and plastic zones were studied by numerical simulation. The stress fields,displacement fields,and plastic zones generated by Wongawilli strip pillar mining were obtained. And the surface movement and deformation were also determined after mining was completed and its effects on surface structures were analyzed and evaluated. The results demonstrate that it is feasible to mine under surface structures with the Wongawilli strip pillar mining technique. This mining method can protect the surface structures from damages.展开更多
文摘采用直流电场作为物理场,利用已研制的电场作用下煤的瓦斯吸附试验装置,对电压作用下煤的瓦斯吸附性进行了试验研究,对电压作用前后试验煤样表面结构进行了XPS能谱测试,对煤样表面结构C元素含氧官能团的种类及其相对含量进行了分析,目的是基于煤表面结构揭示电场作用对煤的瓦斯吸附性影响机理。试验结果表明:电压作用可以弱化煤的瓦斯吸附性,在80 k Hz/1 k V,80 k Hz/3 k V和80 k Hz/5 k V电场作用下,煤表面结构C元素含氧官能团发生改性,C—C/C—H键相对含量从47.22%减少到24.95%,生成C—O键、C=O羰基官能团、COO—羧基或醌官能团,使得这3种含氧官能团相对含量增加,其最大值分别为54.44%,13.89%和7.39%;随着煤表面结构C元素C—C/C—H键相对含量的减少,煤的瓦斯饱和吸附量a呈线性规律减小,吸附常数b呈指数规律减小;与电场作用前相比,作用后煤总孔面积、中值孔径(体积)、中值孔径(面积)和平均孔径等孔隙结构参数均增加。
基金a part of the 12th Five Year Plan Project(No.ESC 0105),acronymed as‘‘De Coal Art”
文摘In some of the coalfields in India, coal seams are only developed but no extraction of pillars is possible due to the presence of surface or sub-surface structures and also non-availability of stowing materials which leads to huge amounts of coal being locked-up underground. Spontaneous heating and fire, accumulation of poisonous gases, severe stability issues leading to unsafe workings and environmental hazards are the major problems associated with the developed coal pillars. So, there is a pressing need for a technology for the mining industry to extract the huge amount of coal locked-up under different constraints. In this study, the locked-up coal is proposed to be extracted by artificially strengthening the rib pillars. The detailed comparative study is carried out to know the increase of extraction percentage of locked-up coal by strengthening the rib pillars with FRP. Extraction methodology is designed and studied through numerical modelling for its stability analysis to evaluate its suitability of application in underground.
基金sponsored by the National Natural Science Foundation of China (No.51374092)
文摘The Wongawilli strip pillar mining technique,which combines the strip pillar mining layout and Wongawilli mining technology,is a new high efficient mining technology for mining under surface structures. The Wongawilli strip pillar mining technique was studied in this paper using theoretical analysis and numerical simulation. As an example,the geological and mining conditions of a coal mine were used to design the Wongawilli strip pillar plans,including the support parameters of the entries and the mining technology. In order to control the surrounding rocks and manage the roof effectively during coal mining,the stress fields,displacement fields and plastic zones were studied by numerical simulation. The stress fields,displacement fields,and plastic zones generated by Wongawilli strip pillar mining were obtained. And the surface movement and deformation were also determined after mining was completed and its effects on surface structures were analyzed and evaluated. The results demonstrate that it is feasible to mine under surface structures with the Wongawilli strip pillar mining technique. This mining method can protect the surface structures from damages.
