Experimental study on mechanical damage characteristics of water-bearing tar-rich coal under microwave radiation
Abstract As a recognized special resource, tar-rich coal can extract the country's scarce oil and gas resources and generate semi-coke that can replace anthracite and coking coal. The tar-rich coal in northern Shaanxi is prominent, but due to the dense structure and high strength of tar-rich co...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Springer
2024-01-01
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| Series: | Geomechanics and Geophysics for Geo-Energy and Geo-Resources |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/s40948-023-00726-w |
| _version_ | 1797362776977440768 |
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| author | Pan Yang Pengfei Shan Huicong Xu Jiageng Chen Zhiyong Li Haoqiang Sun |
| author_facet | Pan Yang Pengfei Shan Huicong Xu Jiageng Chen Zhiyong Li Haoqiang Sun |
| author_sort | Pan Yang |
| collection | DOAJ |
| description | Abstract As a recognized special resource, tar-rich coal can extract the country's scarce oil and gas resources and generate semi-coke that can replace anthracite and coking coal. The tar-rich coal in northern Shaanxi is prominent, but due to the dense structure and high strength of tar-rich coal, it is easy to cause frequent dynamic disasters in coal mining. Therefore, the realization of pressure relief and disaster reduction has become the primary problem in mining tar-rich coal. There are many shortcomings in conventional pressure relief methods, so a new method of microwave-weakening coal is proposed. Through different water saturation treatments of tar-rich coal samples, the longitudinal wave velocity degradation trend and surface crack expansion law of water-bearing coal after microwave irradiation were analyzed, and the strength softening characterization and energy evolution relationship under the combined action of microwave and water were studied. Fractal dimension and its internal correlation based on the equivalent side length-mass of coal sample fragments. The experimental results show that: (1) Under the same microwave radiation condition, with the increase of water saturation, the deterioration trend of physical and mechanical parameters such as longitudinal wave velocity and peak strength is obvious. (2) After microwave radiation, the uniaxial compression results show that the coal sample is damaged by load, there is still a high residual strength, the ratio of elastic energy to dissipation energy decreases, and the possibility of rockburst of the coal sample decreases. The strength softening degree of coal specimen under the degradation of microwave and water is the highest, followed by microwave and water. (3) The fractal dimension is inversely proportional to the moisture content and microwave radiation intensity, and the fractal dimension has a significant positive correlation with the peak intensity and longitudinal wave velocity. The mechanical damage law of water-bearing tar-rich coal under microwave action is revealed, which aims to solve the problem of weakening and reducing the impact of hard coal on-site to a certain extent, ensure the safety of working face, and improve the mining efficiency of tar-rich coal. It provides basic theoretical support for microwave-assisted hydraulic fracturing technology and effective weakening measures for hard roof treatment. |
| first_indexed | 2024-03-08T16:12:19Z |
| format | Article |
| id | doaj.art-6b4179547e044ad79d6bf97a644dd491 |
| institution | Directory Open Access Journal |
| issn | 2363-8419 2363-8427 |
| language | English |
| last_indexed | 2024-03-08T16:12:19Z |
| publishDate | 2024-01-01 |
| publisher | Springer |
| record_format | Article |
| series | Geomechanics and Geophysics for Geo-Energy and Geo-Resources |
| spelling | doaj.art-6b4179547e044ad79d6bf97a644dd4912024-01-07T12:53:40ZengSpringerGeomechanics and Geophysics for Geo-Energy and Geo-Resources2363-84192363-84272024-01-0110112110.1007/s40948-023-00726-wExperimental study on mechanical damage characteristics of water-bearing tar-rich coal under microwave radiationPan Yang0Pengfei Shan1Huicong Xu2Jiageng Chen3Zhiyong Li4Haoqiang Sun5College of Energy Science and Engineering, Xi’an University of Science and TechnologyCollege of Energy Science and Engineering, Xi’an University of Science and TechnologyDepartment of Civil and Environmental Engineering, University of StrathclydeXiaojihan Coal Mine, Shaanxi Huadian Yuheng Coal and Electricity Co., Ltd.Xiaojihan Coal Mine, Shaanxi Huadian Yuheng Coal and Electricity Co., Ltd.College of Energy Science and Engineering, Xi’an University of Science and TechnologyAbstract As a recognized special resource, tar-rich coal can extract the country's scarce oil and gas resources and generate semi-coke that can replace anthracite and coking coal. The tar-rich coal in northern Shaanxi is prominent, but due to the dense structure and high strength of tar-rich coal, it is easy to cause frequent dynamic disasters in coal mining. Therefore, the realization of pressure relief and disaster reduction has become the primary problem in mining tar-rich coal. There are many shortcomings in conventional pressure relief methods, so a new method of microwave-weakening coal is proposed. Through different water saturation treatments of tar-rich coal samples, the longitudinal wave velocity degradation trend and surface crack expansion law of water-bearing coal after microwave irradiation were analyzed, and the strength softening characterization and energy evolution relationship under the combined action of microwave and water were studied. Fractal dimension and its internal correlation based on the equivalent side length-mass of coal sample fragments. The experimental results show that: (1) Under the same microwave radiation condition, with the increase of water saturation, the deterioration trend of physical and mechanical parameters such as longitudinal wave velocity and peak strength is obvious. (2) After microwave radiation, the uniaxial compression results show that the coal sample is damaged by load, there is still a high residual strength, the ratio of elastic energy to dissipation energy decreases, and the possibility of rockburst of the coal sample decreases. The strength softening degree of coal specimen under the degradation of microwave and water is the highest, followed by microwave and water. (3) The fractal dimension is inversely proportional to the moisture content and microwave radiation intensity, and the fractal dimension has a significant positive correlation with the peak intensity and longitudinal wave velocity. The mechanical damage law of water-bearing tar-rich coal under microwave action is revealed, which aims to solve the problem of weakening and reducing the impact of hard coal on-site to a certain extent, ensure the safety of working face, and improve the mining efficiency of tar-rich coal. It provides basic theoretical support for microwave-assisted hydraulic fracturing technology and effective weakening measures for hard roof treatment.https://doi.org/10.1007/s40948-023-00726-wMicrowave radiationMoisture contentTar-rich coalEnergy evolutionCrack expansionFractal dimension |
| spellingShingle | Pan Yang Pengfei Shan Huicong Xu Jiageng Chen Zhiyong Li Haoqiang Sun Experimental study on mechanical damage characteristics of water-bearing tar-rich coal under microwave radiation Geomechanics and Geophysics for Geo-Energy and Geo-Resources Microwave radiation Moisture content Tar-rich coal Energy evolution Crack expansion Fractal dimension |
| title | Experimental study on mechanical damage characteristics of water-bearing tar-rich coal under microwave radiation |
| title_full | Experimental study on mechanical damage characteristics of water-bearing tar-rich coal under microwave radiation |
| title_fullStr | Experimental study on mechanical damage characteristics of water-bearing tar-rich coal under microwave radiation |
| title_full_unstemmed | Experimental study on mechanical damage characteristics of water-bearing tar-rich coal under microwave radiation |
| title_short | Experimental study on mechanical damage characteristics of water-bearing tar-rich coal under microwave radiation |
| title_sort | experimental study on mechanical damage characteristics of water bearing tar rich coal under microwave radiation |
| topic | Microwave radiation Moisture content Tar-rich coal Energy evolution Crack expansion Fractal dimension |
| url | https://doi.org/10.1007/s40948-023-00726-w |
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