Study on macromolecular structure of different types of contact metamorphic coals
Contact metamorphism occurs when magma intrudes into the coal seam, resulting in changes to the microfraction, grade, chemical composition, physico-chemical structure and process properties of the coal. Different types of contact metamorphic products are formed under different tectonic-thermal condi...
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| Format: | Article |
| Language: | zho |
| Published: |
Editorial Department of Coal Science and Technology
2023-06-01
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| Series: | Meitan kexue jishu |
| Subjects: | |
| Online Access: | http://www.mtkxjs.com.cn/article/doi/10.13199/j.cnki.cst.2021-1466 |
| _version_ | 1797448836806868992 |
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| author | Zhenyu SHU Xiang XU Yingchun WEI Anmin WANG Lu WANG Zhifei LIU Gaojian CHEN Daiyong CAO |
| author_facet | Zhenyu SHU Xiang XU Yingchun WEI Anmin WANG Lu WANG Zhifei LIU Gaojian CHEN Daiyong CAO |
| author_sort | Zhenyu SHU |
| collection | DOAJ |
| description | Contact metamorphism occurs when magma intrudes into the coal seam, resulting in changes to the microfraction, grade, chemical composition, physico-chemical structure and process properties of the coal. Different types of contact metamorphic products are formed under different tectonic-thermal conditions. In order to reveal the variability of different types of contact metamorphic coals and their controlling factors from the macromolecular structure scale, a comparative study of natural coke series samples from the Tashan mine in Datong, Shanxi Province and coal-based graphite series samples from the Lutang mine in Hunan Province was carried out using industrial analysis, elemental analysis, reflectance determination, X-ray diffraction (XRD) and Raman spectroscopy (Raman) test methods, and combined with geological background analysis. The results show that the small shallow-formed rocks have a short thermal action time, poor thermal confinement conditions, belong to high temperature and low pressure condition, narrow contact metamorphic zone, and develop natural coke - thermal transformation coal sequence; the series is in the carbonation stage, and the coal macromolecular structure is dominated by chemical changes, with aromatization and ring condensation dominating. It shows carbon enrichment, dehydrogenation, deoxygenation, reduction of defects in the active sites such as side chains and functional groups, growth of aromatic structural units leading to an increase in defects within the aromatic level, and the aromatic lamellae are not ordered. The acidic and moderately acidic deep-formed rock bodies such as strains and bases intruded in a regional extrusive tectonic setting are well heated, thermally confined and under high temperature and pressure conditions, and the contact metamorphic width can exceed 1km, developing graphite-semi-graphite-anthracite metamorphic sequences; the chemical composition of the coal-based graphite series is highly mature and less variable, and the macromolecular structure is dominated by physical changes, mainly occurring as collagenesis and rank physicochemical interactions. The non-oriented aromatic lamellae are spliced and stacked and rotated and oriented by forces, with a continuous reduction of defects and a transition to a three-dimensional ordered crystal structure. |
| first_indexed | 2024-03-09T14:16:09Z |
| format | Article |
| id | doaj.art-de7b679693be4c1f8af63a6e863fa6f5 |
| institution | Directory Open Access Journal |
| issn | 0253-2336 |
| language | zho |
| last_indexed | 2024-03-09T14:16:09Z |
| publishDate | 2023-06-01 |
| publisher | Editorial Department of Coal Science and Technology |
| record_format | Article |
| series | Meitan kexue jishu |
| spelling | doaj.art-de7b679693be4c1f8af63a6e863fa6f52023-11-29T01:40:25ZzhoEditorial Department of Coal Science and TechnologyMeitan kexue jishu0253-23362023-06-0151614715710.13199/j.cnki.cst.2021-14662021-1466Study on macromolecular structure of different types of contact metamorphic coalsZhenyu SHU0Xiang XU1Yingchun WEI2Anmin WANG3Lu WANG4Zhifei LIU5Gaojian CHEN6Daiyong CAO7School of Geoscience and Surveying Engineering, China University of Mining and Technology−Beijing, Beijing 100083, ChinaSchool of Geoscience and Surveying Engineering, China University of Mining and Technology−Beijing, Beijing 100083, ChinaSchool of Geoscience and Surveying Engineering, China University of Mining and Technology−Beijing, Beijing 100083, ChinaSchool of Geoscience and Surveying Engineering, China University of Mining and Technology−Beijing, Beijing 100083, ChinaDepartment of Geology and Surveying and Mapping Engineering, Shanxi University of Energy, Jinzhong 030600, ChinaCoal Science and Technology Research Institute, Beijing 100013, ChinaSchool of Geoscience and Surveying Engineering, China University of Mining and Technology−Beijing, Beijing 100083, ChinaSchool of Geoscience and Surveying Engineering, China University of Mining and Technology−Beijing, Beijing 100083, ChinaContact metamorphism occurs when magma intrudes into the coal seam, resulting in changes to the microfraction, grade, chemical composition, physico-chemical structure and process properties of the coal. Different types of contact metamorphic products are formed under different tectonic-thermal conditions. In order to reveal the variability of different types of contact metamorphic coals and their controlling factors from the macromolecular structure scale, a comparative study of natural coke series samples from the Tashan mine in Datong, Shanxi Province and coal-based graphite series samples from the Lutang mine in Hunan Province was carried out using industrial analysis, elemental analysis, reflectance determination, X-ray diffraction (XRD) and Raman spectroscopy (Raman) test methods, and combined with geological background analysis. The results show that the small shallow-formed rocks have a short thermal action time, poor thermal confinement conditions, belong to high temperature and low pressure condition, narrow contact metamorphic zone, and develop natural coke - thermal transformation coal sequence; the series is in the carbonation stage, and the coal macromolecular structure is dominated by chemical changes, with aromatization and ring condensation dominating. It shows carbon enrichment, dehydrogenation, deoxygenation, reduction of defects in the active sites such as side chains and functional groups, growth of aromatic structural units leading to an increase in defects within the aromatic level, and the aromatic lamellae are not ordered. The acidic and moderately acidic deep-formed rock bodies such as strains and bases intruded in a regional extrusive tectonic setting are well heated, thermally confined and under high temperature and pressure conditions, and the contact metamorphic width can exceed 1km, developing graphite-semi-graphite-anthracite metamorphic sequences; the chemical composition of the coal-based graphite series is highly mature and less variable, and the macromolecular structure is dominated by physical changes, mainly occurring as collagenesis and rank physicochemical interactions. The non-oriented aromatic lamellae are spliced and stacked and rotated and oriented by forces, with a continuous reduction of defects and a transition to a three-dimensional ordered crystal structure.http://www.mtkxjs.com.cn/article/doi/10.13199/j.cnki.cst.2021-1466magma contact deteriorationnatural cokecoal-based graphitemacromolecular structurehigh temperature and low pressurehigh temperature and high pressure |
| spellingShingle | Zhenyu SHU Xiang XU Yingchun WEI Anmin WANG Lu WANG Zhifei LIU Gaojian CHEN Daiyong CAO Study on macromolecular structure of different types of contact metamorphic coals Meitan kexue jishu magma contact deterioration natural coke coal-based graphite macromolecular structure high temperature and low pressure high temperature and high pressure |
| title | Study on macromolecular structure of different types of contact metamorphic coals |
| title_full | Study on macromolecular structure of different types of contact metamorphic coals |
| title_fullStr | Study on macromolecular structure of different types of contact metamorphic coals |
| title_full_unstemmed | Study on macromolecular structure of different types of contact metamorphic coals |
| title_short | Study on macromolecular structure of different types of contact metamorphic coals |
| title_sort | study on macromolecular structure of different types of contact metamorphic coals |
| topic | magma contact deterioration natural coke coal-based graphite macromolecular structure high temperature and low pressure high temperature and high pressure |
| url | http://www.mtkxjs.com.cn/article/doi/10.13199/j.cnki.cst.2021-1466 |
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