International Journal of Coal Science & Technology最新文献

Study on signal characteristics of burst tendency coal under different loading rates 不同装载率下爆倾向煤的信号特征研究

IF 8.3 1区工程技术

International Journal of Coal Science & Technology Pub Date : 2024-08-22 DOI: 10.1007/s40789-024-00724-7

Chao Zhou, Xueqiu He, Dazhao Song, Zhenlei Li, Huakang Yang, Yang Liu, Lei Guo

{"title":"Study on signal characteristics of burst tendency coal under different loading rates","authors":"Chao Zhou, Xueqiu He, Dazhao Song, Zhenlei Li, Huakang Yang, Yang Liu, Lei Guo","doi":"10.1007/s40789-024-00724-7","DOIUrl":"https://doi.org/10.1007/s40789-024-00724-7","url":null,"abstract":"In order to study the mechanics, acoustic emission (AE) and electromagnetic emission (EME) response law of bursting liability coal at different loading rates, uniaxial compression tests were carried out on coal mass from Konggu Coal Mine. The corresponding relations among mechanical properties, AE and EME signals in the process of coal failure under loading were analyzed, and the energy evolution law of coal failure with bursting liability under loading rate was discussed. The results show that within a certain range of loading rate, the higher the loading rate, the higher the compressive strength and peak load of bursting liability coal, and the shorter the time for coal to reach the peak load. Under different loading rates, the mechanics, AE and EME signals of coal samples can be well corresponded. When the loading rate is low, the number of blocks destroyed of coal sample is large and the block size is relatively small, and the blocks are mainly scattered around the test platform. When the loading rate is high, the number of damaged blocks is relatively small and the block size is relatively large, and the blocks are far away from the test bench. When loading at a low rate, the internal cracks in coal can be fully developed and connected, and the energy release rate is relatively uniform in the process of loading and failure of coal sample. In the case of high loading rate, the energy release rate of coal sample in the loading process is much smaller than that in the moment of failure. Combining the above test results with the actual situation of the working face, it can be concluded that the total energy stored in the coal of fast mining increases and the threshold of impact decreases compared with that of slow mining. Therefore, under the disturbance of external dynamic load, rapid mining is more likely to induce rock burst.","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Image-based quantitative probing of 3D heterogeneous pore structure in CBM reservoir and permeability estimation with pore network modeling 基于图像的煤层气储层三维异质孔隙结构定量探测以及孔隙网络模型的渗透率估算

IF 8.3 1区工程技术

International Journal of Coal Science & Technology Pub Date : 2024-08-20 DOI: 10.1007/s40789-024-00722-9

Peng Liu, Yulong Zhao, Zhengduo Zhao, Huiming Yang, Baisheng Nie, Hengyi He, Quangui Li, Guangjie Bao

{"title":"Image-based quantitative probing of 3D heterogeneous pore structure in CBM reservoir and permeability estimation with pore network modeling","authors":"Peng Liu, Yulong Zhao, Zhengduo Zhao, Huiming Yang, Baisheng Nie, Hengyi He, Quangui Li, Guangjie Bao","doi":"10.1007/s40789-024-00722-9","DOIUrl":"https://doi.org/10.1007/s40789-024-00722-9","url":null,"abstract":"Coalbed methane (CBM) recovery is attracting global attention due to its huge reserve and low carbon burning benefits for the environment. Fully understanding the complex structure of coal and its transport properties is crucial for CBM development. This study describes the implementation of mercury intrusion and μ-CT techniques for quantitative analysis of 3D pore structure in two anthracite coals. It shows that the porosity is 7.04%–8.47% and 10.88%–12.11%, and the pore connectivity is 0.5422–0.6852 and 0.7948–0.9186 for coal samples 1 and 2, respectively. The fractal dimension and pore geometric tortuosity were calculated based on the data obtained from 3D pore structure. The results show that the pore structure of sample 2 is more complex and developed, with lower tortuosity, indicating the higher fluid deliverability of pore system in sample 2. The tortuosity in three-direction is significantly different, indicating that the pore structure of the studied coals has significant anisotropy. The equivalent pore network model (PNM) was extracted, and the anisotropic permeability was estimated by PNM gas flow simulation. The results show that the anisotropy of permeability is consistent with the slice surface porosity distribution in 3D pore structure. The permeability in the horizontal direction is much greater than that in the vertical direction, indicating that the dominant transportation channel is along the horizontal direction of the studied coals. The research results achieve the visualization of the 3D complex structure of coal and fully capture and quantify pore size, connectivity, curvature, permeability, and its anisotropic characteristics at micron-scale resolution. This provides a prerequisite for the study of mass transfer behaviors and associated transport mechanisms in real pore structures.","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Spectral signatures of solvent-extracted macromolecules in Indian coals of different rank: Insights from fluorescence excitation-emission matrix 不同等级印度煤炭中溶剂萃取大分子的光谱特征：荧光激发-发射矩阵的启示

IF 8.3 1区工程技术

International Journal of Coal Science & Technology Pub Date : 2024-08-12 DOI: 10.1007/s40789-024-00721-w

Archchi Sarkar, Uttam Kumar Bhui, Krittibas Das, Sudip Bhattacharyya, Jitendra Kumar, Darshan Halari

{"title":"Spectral signatures of solvent-extracted macromolecules in Indian coals of different rank: Insights from fluorescence excitation-emission matrix","authors":"Archchi Sarkar, Uttam Kumar Bhui, Krittibas Das, Sudip Bhattacharyya, Jitendra Kumar, Darshan Halari","doi":"10.1007/s40789-024-00721-w","DOIUrl":"https://doi.org/10.1007/s40789-024-00721-w","url":null,"abstract":"Solvent-extracted fractions of six Indian coal samples of different ranks were investigated using multiple geochemical, petrological and spectroscopic proxies and an attempt was made to indicate possible fingerprint regions for different polycyclic aromatic hydrocarbons (PAH) with the help of excitation-emission matrix (EEM). In this study, for the very first time, the influence of rank and maturation of organic matter in the characterisation of coal solvent-extracts from Indian coals were perceived from the viewpoint of fluorescence EEM. Vitrinite reflectance (VRo) values were used to determine the general ranks of the original coal samples viz. lignite, subbituminous, bituminous and anthracite. Different fluorescence peak regions corresponding to different fused aromatic ring (FAR) systems were delineated using the EEM and their indicative depositional environments could be inferred. Our observations indicate that solvent-extracted fractions of low rank coals comprise of a larger number of shorter carbon chains compared to the other samples. For the low rank coal samples, the solvent-extracts show a strong humic influence and the presence of smaller PAH rings while for the medium rank coals, the extracted fractions tend to show a more bimodal distribution of PAHs, possibly comprising of different sized PAHs. Higher fluorescence sensitivity and quick response of smaller PAHs impart a singular centralised region in the EEM for the low rank coal samples while interference in the fluorescence of differently sized PAHs indicate a multimodal distribution of the fluorophores in the medium rank coals. The high rank coal used in this study shows a bimodal distribution with very low intensity of the peaks, indicating the low abundance of extractable macromolecules, possibly as a result of deformation.","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Rate transient analysis for multilateral horizontal well in natural gas hydrate: superposition principle and reciprocity 天然气水合物中多边水平井的速率瞬态分析：叠加原理和互易性

IF 8.3 1区工程技术

International Journal of Coal Science & Technology Pub Date : 2024-08-11 DOI: 10.1007/s40789-024-00720-x

Tianbi Ma, Hongyang Chu, Jiawei Li, Jingxuan Zhang, Yubao Gao, Weiyao Zhu, W. John Lee

{"title":"Rate transient analysis for multilateral horizontal well in natural gas hydrate: superposition principle and reciprocity","authors":"Tianbi Ma, Hongyang Chu, Jiawei Li, Jingxuan Zhang, Yubao Gao, Weiyao Zhu, W. John Lee","doi":"10.1007/s40789-024-00720-x","DOIUrl":"https://doi.org/10.1007/s40789-024-00720-x","url":null,"abstract":"Due to high energy density, clean combustion products and abundant resources, natural gas hydrates (NGHs) have been regarded as an important clean energy source with the potential for large-scale development and utilization. However, pilot tests in NGHs show that their production rates are far below commercial needs. Multilateral well technology may lead to a solution to this problem because it can dramatically expand the drainage area of production wells. This paper presents the practical rate transient analysis for multilateral horizontal wells in NGHs. In developing solution to the diffusivity equation of multilateral horizontal wells in NGHs, the superposition principle and reciprocity are applied. We wrote the governing equation in cylindrical coordinates to describe the NGH flow process. We used the moving boundaries and dissociation coefficients to model the solid-to-gas transition process in hydrates. To obtain solutions for flow in hydrate reservoirs, we used Laplace transforms and the Stehfest numerical inversion method. Superposition principle and Gaussian elimination are applied to obtain the desired solution for multilateral horizontal wells. We validated our proposed model with a commercial numerical simulator. By performing sensitivity analyses, effects on production behavior of the number of branches, dissociation coefficient, radius of the region with dissociated hydrate, and dispersion ratio are determined. A synthetic case study is conducted to show the typical production behaviors.","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141934733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of ground subsidence response to an unconventional longwall panel layout 非常规长壁面板布局的地面沉降响应研究

IF 8.3 1区工程技术

International Journal of Coal Science & Technology Pub Date : 2024-08-06 DOI: 10.1007/s40789-024-00719-4

Pengfei Wang, Zhuang Zhu, Linfeng Guo, Huixian Wang, Yue Qu, Yaoxiong Zhang, Linwei Wang, Hua Wang

{"title":"Investigation of ground subsidence response to an unconventional longwall panel layout","authors":"Pengfei Wang, Zhuang Zhu, Linfeng Guo, Huixian Wang, Yue Qu, Yaoxiong Zhang, Linwei Wang, Hua Wang","doi":"10.1007/s40789-024-00719-4","DOIUrl":"https://doi.org/10.1007/s40789-024-00719-4","url":null,"abstract":"Ground subsidence caused by extraction of longwall panels has always been a great concern all over the world. Conventional longwall mining system (CLMS) gives rise to wavy subsidence causing great damage to surface structures. A coal mine in Shanxi, China, utilizes a split-level longwall layout (SLL) for a sub-horizontal No. 8 coal seam to improve the cavability of mudstone interlayer and top coal. This layout, however, also produced unexpectedly favorable surface subsidence. Subsidence of No. 6 and No. 8 longwall panels was monitored while mining was conducted. Field instrumentation and numerical simulation were carried out. It is demonstrated that an asymmetric subsidence profile with stepped subsidence and cracks occurred on the tailgate side but relatively mild and smooth deformation on the other. Due to elimination of conventional parallelepiped gate pillar, No. 6 and No. 8 gobs were connected. Extraction of two SLL panels acted as one supercritical panel. The maximum possible subsidence was reached which lowers the likelihood of potential future secondary subsidence as underground gob fractures and voids have closed. Therefore, SLL is more favorable for post-mining land reuse as gobs are more consolidated underground.","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141934732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Catalytic coal gasification: mechanism, kinetics, and reactor model 催化煤气化：机理、动力学和反应器模型

IF 8.3 1区工程技术

International Journal of Coal Science & Technology Pub Date : 2024-07-30 DOI: 10.1007/s40789-024-00712-x

Weiwei Li, Chen Wang, Zhongliang Yu, Yuncai Song

引用次数: 0

Study of synergistic behavior during bituminous coal-cow manure co-gasification: The role of intrinsic AAEM and organic matter 烟煤-牛粪联合气化过程中的协同行为研究：固有 AAEM 和有机物的作用

IF 8.3 1区工程技术

International Journal of Coal Science & Technology Pub Date : 2024-07-28 DOI: 10.1007/s40789-024-00694-w

Hongqiao Lu, Meng Ma, Juntao Wei, Yonghui Bai, Peng Lv, Jiaofei Wang, Xudong Song, Guanghua Lu, Guangsuo Yu

{"title":"Study of synergistic behavior during bituminous coal-cow manure co-gasification: The role of intrinsic AAEM and organic matter","authors":"Hongqiao Lu, Meng Ma, Juntao Wei, Yonghui Bai, Peng Lv, Jiaofei Wang, Xudong Song, Guanghua Lu, Guangsuo Yu","doi":"10.1007/s40789-024-00694-w","DOIUrl":"https://doi.org/10.1007/s40789-024-00694-w","url":null,"abstract":"Co-thermal chemical conversion of coal and biomass is one of the important ways to realize efficient and clean utilization of coal. In this study, a typical Ningdong coal-Yangchangwan bituminous coal and cow manure were used to study the synergistic effect of intrinsic alkali, alkaline earth metals (AAEM) and organic matter on the co-gasification of coal and biomass by thermogravimetry analyzer (TG). The results showed that AAEM had obvious synergistic promotion effect on the gasification of a bituminous coal-cow manure mixture in the isothermal gasification (1000 ℃), whereas the organic matter will show the opposite effect on the process. To further investigate the effect of organic matter on the gasification process, the influence of organic matter on non-isothermal (25-1000 ℃) gasification reaction was investigated with heating rate of 10 ℃ /min, the kinetic parameters of the gasification reaction were obtained by Coats-Redfern method. The increase of biomass mass fraction in the sample facilitates the migration of alkali metals from the material to the solid phase. The possible mechanism of the synergistic effect of intrinsic AAEM/organic matter on the co-gasification process was proposed.","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Extractability and mineralogical evaluation of rare earth elements from Waterberg Coalfield run-of-mine and discard coal 瓦特贝格煤田采煤和弃煤中稀土元素的可提取性和矿物学评价

IF 8.3 1区工程技术

International Journal of Coal Science & Technology Pub Date : 2024-07-24 DOI: 10.1007/s40789-024-00702-z

Agnes Modiga, Orevaoghene Eterigho-Ikelegbe, Samson Bada

{"title":"Extractability and mineralogical evaluation of rare earth elements from Waterberg Coalfield run-of-mine and discard coal","authors":"Agnes Modiga, Orevaoghene Eterigho-Ikelegbe, Samson Bada","doi":"10.1007/s40789-024-00702-z","DOIUrl":"https://doi.org/10.1007/s40789-024-00702-z","url":null,"abstract":"This study explores the extraction of rare earth elements (REEs) from high-ash run-of-mine and discard coal sourced from the Waterberg Coalfield. Three distinct methods were employed: (1) ultrasonic-assisted caustic digestion; (2) direct acid leaching; and (3) ultrasonic-assisted caustic-acid leaching. Inductively coupled plasma mass spectrometry was utilized to quantify REEs in both the coals and resultant leachates. Leaching the coals with 40% NaOH at 80 °C, along with 40 kHz sonication, yielded a total rare earth element (TREE) recovery of less than 2%. Notable enrichment of REEs was observed in the run-of-mine and discard coal by 17% and 19%, respectively. Upon employing 7.5% HCl, a recovery of less than 11.0% for TREE was achieved in both coal samples. However, leaching the caustic digested coal samples with 7.5% HCl significantly enhanced the TREE recovery to 88.8% and 80.0% for run-of-mine and discard coal, respectively. X-ray diffraction analysis identified kaolinite and quartz as the predominant minerals. Scanning electron microscopy-energy dispersive microanalysis revealed monazite and xenotime as the REE-bearing minerals within the coal samples. These minerals were found either liberated, attached to, or encapsulated by the clay-quartz matrices. Further mineralogical assessments highlighted the increased REE concentrations in coals post-caustic digestion and subsequent recovery during acid leaching. This increase was attributed to the partial dissolution of kaolinite encapsulating the RE-phosphates and the digestion of REE-bearing minerals. Notably, undissolved REE-bearing elements in the caustic-acid-leached coal indicated the necessity of harsh leaching conditions to augment REE recovery from these coal samples.","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical simulation on the dynamic mechanical response and fracture mechanism of rocks containing a single hole 含单孔岩石的动态力学响应和断裂机制的数值模拟

IF 8.3 1区工程技术

International Journal of Coal Science & Technology Pub Date : 2024-07-19 DOI: 10.1007/s40789-024-00718-5

Zhenyu Han, Kai Liu, Jinyin Ma, Diyuan Li

引用次数: 0

Mechanical responses and fracturing behaviors of coal under complex normal and shear stresses, Part I: Experimental results 复杂法向应力和剪切应力下煤的机械响应和断裂行为，第一部分：实验结果

IF 8.3 1区工程技术

International Journal of Coal Science & Technology Pub Date : 2024-07-17 DOI: 10.1007/s40789-024-00705-w

Z. Y. Song, W. G. Dang, Z. C. Bai, Y. Zhao, P. T. Wang, Z. Yang

{"title":"Mechanical responses and fracturing behaviors of coal under complex normal and shear stresses, Part I: Experimental results","authors":"Z. Y. Song, W. G. Dang, Z. C. Bai, Y. Zhao, P. T. Wang, Z. Yang","doi":"10.1007/s40789-024-00705-w","DOIUrl":"https://doi.org/10.1007/s40789-024-00705-w","url":null,"abstract":"This work presents experimental tests based on coal collected from a coal mine based underground water reservoir (CMUWR). The mechanical responses of dry and water-soaked coal samples under the complex normal and shear stresses under multi-amplitude and variable frequency is investigated. The experimental results reveal the effects of stress path, water soaking and frequency on deformation, energy dissipation, secant modulus and shear failure surface roughness. The experimental results show that when normal and shear stresses are applied simultaneously, there is a significant competitive relationship between them. On the dominant side, the strain rate will be significantly increased. The sample under a loading frequency of 0.2 Hz exhibits a longer fatigue life. During the cyclic shear test, the shear strain of the water-soaked sample is higher than that of the dry samples. The average roughness coefficient of failure surface exhibits an increasing pattern with increase in shear strength, the elevated roughness of a shear surface is advantageous in constraining shear displacements of specimens, thereby lowering the energy dissipation. This study can provide theoretical and practical implications for a long-term safety evaluation of CMUWR.","PeriodicalId":53469,"journal":{"name":"International Journal of Coal Science & Technology","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141744125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0