Microhardness of Coal from Near-Fault Zones in Coal Seams Threatened with Gas-Geodynamic Phenomena, Upper Silesian Coal Basin, Poland
Near-fault coal displays some specific structural and textural features. As the distance to the fault diminishes, one can observe ever stronger, gradual degradation of coal, demonstrated by the emergence of structural distortions exogenic in their origin, visible under a microscope. The process of g...
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MDPI AG
2019-05-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/12/9/1756 |
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| author | Katarzyna Godyń Alena Kožušníková |
| author_facet | Katarzyna Godyń Alena Kožušníková |
| author_sort | Katarzyna Godyń |
| collection | DOAJ |
| description | Near-fault coal displays some specific structural and textural features. As the distance to the fault diminishes, one can observe ever stronger, gradual degradation of coal, demonstrated by the emergence of structural distortions exogenic in their origin, visible under a microscope. The process of gradual degradation of coal—manifested by the appearance of structural distortions exogenic in their origin—takes place. This can be observed under a microscope. The measurements of the microhardness of structurally altered coal carried out using the Vickers hardness test. For the purpose of this research, a microhardness tester by the CSM Instruments was used. The microhardness of particular structural types of coal was measured. The procedure encompassed both structurally unaltered and altered coal. The tested objects were exogenically fractured fragments, cataclastic, and mylonitic structures. Each of the analyzed structural types displayed a different range of the microhardness, with the highest values confirmed for the structurally unaltered coal. In the case of fractured coal, the microhardness values were somewhat lower. Finally, the lowest values were ascertained for cataclastic coal. Mylonitic coal, in turn, displayed microhardness values similar to those found in the unaltered coal. It was also observed that, in the case of the unaltered, fractured, and cataclastic coal, cracks propagated in the manner typical of brittle materials, whereas the mylonitic coal revealed some degree of elasticity. The analyzed microhardness parameters expose the structural−textural features of coal, particularly when it comes to the degree and character of destruction of the rock’s original matrix. The specific structural−textural composition of particular types of near-fault creations influences both their sorption parameters and the compactness of coal in a seam. |
| first_indexed | 2024-04-12T19:43:36Z |
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| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-04-12T19:43:36Z |
| publishDate | 2019-05-01 |
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| record_format | Article |
| series | Energies |
| spelling | doaj.art-cfd23fe0f04540dba3a8e86d0b4e59742022-12-22T03:19:01ZengMDPI AGEnergies1996-10732019-05-01129175610.3390/en12091756en12091756Microhardness of Coal from Near-Fault Zones in Coal Seams Threatened with Gas-Geodynamic Phenomena, Upper Silesian Coal Basin, PolandKatarzyna Godyń0Alena Kožušníková1The Strata Mechanics Research Institute of the Polish Academy of Sciences, Reymonta 27, 30-059 Kraków, PolandInstitute of Geonics of the Czech Academy of Sciences, Studentská 1768, 708 00 Ostrava-Poruba, Czech RepublicNear-fault coal displays some specific structural and textural features. As the distance to the fault diminishes, one can observe ever stronger, gradual degradation of coal, demonstrated by the emergence of structural distortions exogenic in their origin, visible under a microscope. The process of gradual degradation of coal—manifested by the appearance of structural distortions exogenic in their origin—takes place. This can be observed under a microscope. The measurements of the microhardness of structurally altered coal carried out using the Vickers hardness test. For the purpose of this research, a microhardness tester by the CSM Instruments was used. The microhardness of particular structural types of coal was measured. The procedure encompassed both structurally unaltered and altered coal. The tested objects were exogenically fractured fragments, cataclastic, and mylonitic structures. Each of the analyzed structural types displayed a different range of the microhardness, with the highest values confirmed for the structurally unaltered coal. In the case of fractured coal, the microhardness values were somewhat lower. Finally, the lowest values were ascertained for cataclastic coal. Mylonitic coal, in turn, displayed microhardness values similar to those found in the unaltered coal. It was also observed that, in the case of the unaltered, fractured, and cataclastic coal, cracks propagated in the manner typical of brittle materials, whereas the mylonitic coal revealed some degree of elasticity. The analyzed microhardness parameters expose the structural−textural features of coal, particularly when it comes to the degree and character of destruction of the rock’s original matrix. The specific structural−textural composition of particular types of near-fault creations influences both their sorption parameters and the compactness of coal in a seam.https://www.mdpi.com/1996-1073/12/9/1756Vickers microhardnessfaultsstructurally altered coalUpper Silesian Coal Basin |
| spellingShingle | Katarzyna Godyń Alena Kožušníková Microhardness of Coal from Near-Fault Zones in Coal Seams Threatened with Gas-Geodynamic Phenomena, Upper Silesian Coal Basin, Poland Energies Vickers microhardness faults structurally altered coal Upper Silesian Coal Basin |
| title | Microhardness of Coal from Near-Fault Zones in Coal Seams Threatened with Gas-Geodynamic Phenomena, Upper Silesian Coal Basin, Poland |
| title_full | Microhardness of Coal from Near-Fault Zones in Coal Seams Threatened with Gas-Geodynamic Phenomena, Upper Silesian Coal Basin, Poland |
| title_fullStr | Microhardness of Coal from Near-Fault Zones in Coal Seams Threatened with Gas-Geodynamic Phenomena, Upper Silesian Coal Basin, Poland |
| title_full_unstemmed | Microhardness of Coal from Near-Fault Zones in Coal Seams Threatened with Gas-Geodynamic Phenomena, Upper Silesian Coal Basin, Poland |
| title_short | Microhardness of Coal from Near-Fault Zones in Coal Seams Threatened with Gas-Geodynamic Phenomena, Upper Silesian Coal Basin, Poland |
| title_sort | microhardness of coal from near fault zones in coal seams threatened with gas geodynamic phenomena upper silesian coal basin poland |
| topic | Vickers microhardness faults structurally altered coal Upper Silesian Coal Basin |
| url | https://www.mdpi.com/1996-1073/12/9/1756 |
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