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Theoretical Research Advances And Applications Of The Dynamic Metamorphism Of Coals, Liu Hewu, Jiang Bo, Song Yu, Du Zhigang, Zhang Kun, Hou Chenliang, Yang Wenjie, Huang Nini Jun 2026

Theoretical Research Advances And Applications Of The Dynamic Metamorphism Of Coals, Liu Hewu, Jiang Bo, Song Yu, Du Zhigang, Zhang Kun, Hou Chenliang, Yang Wenjie, Huang Nini

Coal Geology & Exploration

Background The dynamic metamorphism of coals, a significant type of coal metamorphism, represents a fundamental research topic of coal geology. The research achievements have been widely applied in fields such as coal resource evaluation, the prevention and control of coal mine gas, and the exploration and exploitation of coalbed methane (CBM), holding great significance for gaining a deep understanding of the microscopic mechanisms underlying coal deformation and metamorphism, coal and gas outbursts, and CBM occurrence. Method Based on a literature survey and analysis, this study presents a systematic review of the development history of research on the dynamic metamorphism of …


Geophysical Responses And Their Statistical Relationships With Lithium And Kaolinite Contents For Lithium-Rich Coals In The Yangquan Mining Area, Chen Tongjun, Xu Haicheng, Li Wan May 2026

Geophysical Responses And Their Statistical Relationships With Lithium And Kaolinite Contents For Lithium-Rich Coals In The Yangquan Mining Area, Chen Tongjun, Xu Haicheng, Li Wan

Coal Geology & Exploration

Objective China, representing the world's largest consumer of lithium resources, suffers from a limited endowment of conventional lithium resources, rendering it inevitable for China to seek to develop and utilize abundant coal-hosted lithium resources. Through a comparative analysis of coal samples from the lithium-rich No. 8 and the ordinary No. 15 coal seams in the Taiyuan Formation, Yangquan mining area, Shanxi Province, this study explored the statistical relationships between the lithium and kaolinite contents and geophysical responses. Accordingly, the feasibility of the indirect detection of coal-hosted lithium resources using geophysical methods was assessed. Methods First, by testing the lithium content …


Mechanisms Behind The Impacts Of Co2 Concentration On Microbial Methanogenesis In Coal Seams, Wang Junyu, Liu Bingjun, Jiang Xiangqing, Chen Ruifeng, Xue Sheng, Zhou Wanlong, Yang Yundu Apr 2026

Mechanisms Behind The Impacts Of Co2 Concentration On Microbial Methanogenesis In Coal Seams, Wang Junyu, Liu Bingjun, Jiang Xiangqing, Chen Ruifeng, Xue Sheng, Zhou Wanlong, Yang Yundu

Coal Geology & Exploration

Background Coal seams exhibit the extensive distribution of a variety of indigenous functional microorganisms. Among these, some archaea enable methane metabolism using CO2 as a substrate, providing the potential for the biological CO2 storage and utilization in coal seams. However, conventional studies focus primarily on the degradation characteristics of coal matrix, leading to a lack of a systematic understanding of the mechanisms governing the adjustment of the methanation process in CO2-bearing environments. Methods This study investigated the bituminous coals with a high volatile content in the Huainan mining area. Using laboratory-scale experiments on methanogenesis through anaerobic …


Mechanisms Behind Permeability Enhancement Of Coal Reservoirs Induced By Electro-Chemical Composite Energy Pulse Fracturing, Meng Bingbing, Cao Yunxing, Duan Hongfei, Zhang Xinsheng, Zhao Lijuan, Shi Bin, Yu Guofeng Feb 2026

Mechanisms Behind Permeability Enhancement Of Coal Reservoirs Induced By Electro-Chemical Composite Energy Pulse Fracturing, Meng Bingbing, Cao Yunxing, Duan Hongfei, Zhang Xinsheng, Zhao Lijuan, Shi Bin, Yu Guofeng

Coal Geology & Exploration

Background Electro-chemical composite energy pulse fracturing (ECCE-PF) technology (i.e., the electrical explosion of metal wires igniting energetic materials) can effectively change the pore structure of coal reservoirs and enhance coal seam permeability. Elucidating the mechanisms behind the influence of this technology on both the scales of modified coal pores/fractures and methane desorption pattern can provide a theoretical basis for the wide application of this technology to coal seam permeability enhancement. Methods This study investigated coal samples from the Zhangcun Coal Mine in the Lu’an coal mining area, Shanxi Province. Using a self-developed ECCE-PF experimental platform, an experimental study was conducted …


Evaluation Of The Proclivity For Recovering Rare Earth Elements Via Heap Leaching Of Coal And Coal Byproducts, Dylan Connell Jan 2026

Evaluation Of The Proclivity For Recovering Rare Earth Elements Via Heap Leaching Of Coal And Coal Byproducts, Dylan Connell

Theses and Dissertations--Mining Engineering

Rare earth elements (REEs) - 17 elements classified as light (LREE) or heavy (HREE) - underpin modern technology. This thesis presents the development, design, and testing of a heap leach pad (HLP) to extract REEs from Western KY No.13 seam coal refuse. Testing included resource estimation, column and heap leaching, and an economic feasibility study. Drillhole analyses identified average REE concentrations in two refuse piles of 286 ppm and 290 ppm. The resource base totaled approximately 7,085 metric tons of REOs. The HLP, constructed with 2,000 metric tons of coal refuse material, was tested continuously over 308 days. Fresh lixiviant …


Implications Of Helium Accumulation Models In Helium-Rich Basins In China For The Enrichment And Exploration Of Helium In Coal Measures, Li Yunbo, Wang Chengtao, Song Dangyu, Shi Xiaowei, Wang Rongqi Jun 2025

Implications Of Helium Accumulation Models In Helium-Rich Basins In China For The Enrichment And Exploration Of Helium In Coal Measures, Li Yunbo, Wang Chengtao, Song Dangyu, Shi Xiaowei, Wang Rongqi

Coal Geology & Exploration

Background Helium is a strategic resource in serious short supply in China, and intensifying its exploration is crucial to national resource security. China enjoys abundant coal measure gas and significant potential for associated helium accumulation. However, relevant research remains in its infancy. Methods Based on a summary and analysis of helium generation, migration, and accumulation theories in natural gas reservoirs, this study systematically investigated the enrichment patterns of helium in coal measures and proposed exploration targets. Results and Conclusions The insights reveal that the helium resources in China exhibit a distribution pattern of zoning in both north-south and east-west directions. …


Magnetic And Optical Properties Of Airborne Dust Particles Nearby Coal-Fired Power Plants In Upper Silesia, Poland: A Mineralogical, Petrographical And Chemical Approach, Chrysoula Chrysakopoulou, Konstantinos Perleros, Małgorzata Wojtaszek-Kalaitzidi, Lambrini Papadopoulou, Nikolaos Kantiranis, Stavros Kalaitzidis Mar 2025

Magnetic And Optical Properties Of Airborne Dust Particles Nearby Coal-Fired Power Plants In Upper Silesia, Poland: A Mineralogical, Petrographical And Chemical Approach, Chrysoula Chrysakopoulou, Konstantinos Perleros, Małgorzata Wojtaszek-Kalaitzidi, Lambrini Papadopoulou, Nikolaos Kantiranis, Stavros Kalaitzidis

Journal of Sustainable Mining

Coal mining and exploitation pose certain challenges in terms of environmental management. The objective of this research is the study of airborne dust from Knurow region, Southern Poland, aiming to identify the level and the features of anthropogenic particles, mostly in the form of fly ash. Two samples collected from a domestic gutter system were analysed regarding their mineralogical, chemical and petrographical features, emphasizing the magnetic fraction and the carbonized organic particles. The airborne dust contains 22 wt.% of fossil and fresh organic matter, whereas the major mineralogical phase is magnetite. The magnetic fraction (up to 3 wt.%) appears in …


Coal Mining-Induced Composite Damage To Geological Bodies And Geological Guarantee Against Damage Reduction, Wang Shuangming, Sun Qiang, Hu Xin, Geng Jishi, Hou Enke, Wang Shengquan, Zhou Shutao, Shi Qingmin, Yuan Shihao, Chen Kai, Song Shijie Jan 2025

Coal Mining-Induced Composite Damage To Geological Bodies And Geological Guarantee Against Damage Reduction, Wang Shuangming, Sun Qiang, Hu Xin, Geng Jishi, Hou Enke, Wang Shengquan, Zhou Shutao, Shi Qingmin, Yuan Shihao, Chen Kai, Song Shijie

Coal Geology & Exploration

Objective and Background Coals have long served as a predominant energy source in China. With an increase in mining scale and intensity in recent years, the correlations between rocks, soils, hydrosphere, and ecological environment in coal mining areas have been strengthened. Given this, there is an urgent need to, from the perspective of Earth system science, understand the coupling relationships and chain characteristics among factors including the movement and deformations of surrounding rocks, rock bursts, coal and gas outbursts, water inrushes, ground subsidence, water and soil erosion, and damage to ecological environments, aiming to achieve safe, green coal mining. Methods …


Impacts Of Coal Fracture Roughness And Aperture On The Seepage Of Injected Water: An Experimental Study, Wang Gang, Chen Xuechang, Chen Hao, Long Qingming, Liu Yixin Jan 2025

Impacts Of Coal Fracture Roughness And Aperture On The Seepage Of Injected Water: An Experimental Study, Wang Gang, Chen Xuechang, Chen Hao, Long Qingming, Liu Yixin

Coal Geology & Exploration

Objective Water injection into coal seams is recognized as a critical technical measure for dust removal and the prevention and control of coal and gas outbursts and rock bursts in coal mines. The effectiveness of this measure is significantly influenced by the morphological characteristics of fractures, such as their roughness and aperture. Methods This study prepared coal samples containing fractures with different roughness and apertures using sandpaper and polyimide tape, calculated the fracture roughness parameters accurately using a confocal laser scanning microscope (CLSM), and tested the seepage rate of fractured coal samples. Results and Conclusions The results indicate that the …


Leveraging Intrinsic Properties For Classification Of Coal Seams Towards Spontaneous Combustion Proclivity And Predicting Susceptibility Using Machine Learning: Smart And Sustainable Mining Approach, Siddhartha Agarwal, Pradeep K. Gautam, Yuhao Zou, Rishabh Dwivedi, D.C. Panigrahi, C. Dagli, Atul Singh Jan 2025

Leveraging Intrinsic Properties For Classification Of Coal Seams Towards Spontaneous Combustion Proclivity And Predicting Susceptibility Using Machine Learning: Smart And Sustainable Mining Approach, Siddhartha Agarwal, Pradeep K. Gautam, Yuhao Zou, Rishabh Dwivedi, D.C. Panigrahi, C. Dagli, Atul Singh

Journal of Sustainable Mining

Mine fires and other hazards caused by spontaneous coal combustion are a pervasive and longstanding issue in Jharia coalfields, India. This study proposes a novel approach to classify coal seams based on their propensity to spontaneous combustion using the intrinsic properties of 30 coal samples from different seams. This method eliminates the need for expensive and time-consuming experimental determinations of susceptibility indices (SI) such as crossing point temperature (CPT), critical air blast (CAB), and differential thermal analysis (DTA). All clustering models, viz. hierarchical, k-means, and multidimensional scaling, aptly classify coal seams into three categories: highly risky, medium risky, and low …


R&D And Application Of An Experimental System For Coal Permeability Enhancement Through Resonance Under The Excitation Of Low-Frequency Vibration, Wen Zhihui, Guo Shuqian, Wei Jianping, Zhang Tiegang, Wang Jianwei, Zhang Libo, Ren Yongjie Sep 2024

R&D And Application Of An Experimental System For Coal Permeability Enhancement Through Resonance Under The Excitation Of Low-Frequency Vibration, Wen Zhihui, Guo Shuqian, Wei Jianping, Zhang Tiegang, Wang Jianwei, Zhang Libo, Ren Yongjie

Coal Geology & Exploration

Objective As an emerging green, efficient method for enhancing coal permeability, coal resonance under the excitation of vibration waves works by stimulating the development of pores and fractures in coals using the stress waves generated by low-frequency vibration. To investigate the impacts of excitation frequency, stress field, and resonance effect on permeability enhancement, as well as exploring the mechanisms behind coal permeability enhancement using the method, this study independently designed and developed an experimental system. Methods The system, consisting of a mainframe control unit, a coal-sample clamping unit, a vibrational excitation unit, and a coal vibration parameter monitoring unit, allows …


Spatio-Temporal Changes In The Gravity And Post-Mining Seismic Activity In Abandoned Deep Coal Mine Kazimierz-Juliusz During Flooding, Andrzej Kotyrba, Łukasz Kortas, Sławomir Siwek Aug 2024

Spatio-Temporal Changes In The Gravity And Post-Mining Seismic Activity In Abandoned Deep Coal Mine Kazimierz-Juliusz During Flooding, Andrzej Kotyrba, Łukasz Kortas, Sławomir Siwek

Journal of Sustainable Mining

The flooding of an underground hard coal mine, resulting in the filling of post-mining voids (workings and goafs) and the repeated saturation of pore and interstitial spaces of the adjacent rock with water, change the mass and its distribution in the near-surface part of the earth’s crust. This process is slow and lasts many years. As a result, the local gravity field undergoes dynamic changes. It depends on the surface morphology and the density of geological strata, which is related to their water content. Changes in the local gravity field can be monitored by periodic gravity surveys performed in the …


Characteristics And Formation Mechanisms Of Microstructures In Coal Treated With Co2 Phase Transition Fracturing, Cao Yunxing, Zhang Xinsheng, Zhang Junsheng, Guo Shuaifang, Meng Bingbing Apr 2023

Characteristics And Formation Mechanisms Of Microstructures In Coal Treated With Co2 Phase Transition Fracturing, Cao Yunxing, Zhang Xinsheng, Zhang Junsheng, Guo Shuaifang, Meng Bingbing

Coal Geology & Exploration

CO2 phase transition fracturing (CPTF) is a newly developed technique for coal mine gas control and is characterized by high efficiency, high coal seam permeability, a high gas drainage rate, and outburst elimination. The core of CPTF is reinforced fracturing and the pressure-relief and permeability-enhancement effects of coal seams under high-pressure dynamic loading. Nevertheless, there is a lack of studies on the morphological characteristics and formation mechanisms of newly formed fractures. Current observation and description of the underground fractures on a centimeter-meter scale primarily aim to reveal the fracturing and permeability-enhancement mechanisms of low-permeability coal seams. However, the study …


Occurrence Modes And Stepwise Chemical Extraction Experiment Of Lithium In No.20 Coal Seam In Pu’An Mining Area, Guizhou Province, Cheng Chen, Song Yang, Zang Jingkun, Cheng Wei Oct 2022

Occurrence Modes And Stepwise Chemical Extraction Experiment Of Lithium In No.20 Coal Seam In Pu’An Mining Area, Guizhou Province, Cheng Chen, Song Yang, Zang Jingkun, Cheng Wei

Coal Geology & Exploration

Lithium (Li) is an important energy metal, and the global demand for Li has grown rapidly in recent years. The discovery of coal-associated Li deposits in China proves that coal mines may serve as a potential alternative of Li resources. No.20 coal seam in Pu’an mining area in Guizhou province of China was selected as the study object. The basic properties, mineral composition, elemental composition, and occurrence modes of Li of the raw coal and six density-graded samples (obtained through a float-sink test) were determined by using coal proximate analysis, optical microscope, X-Ray fluorescence spectroscopy (XRF), inductively coupled plasma mass …


Estimation Of Coal Density Using A 3d Imaging System: Rhovol, F. Nakhaei, Q. P. Campbell, M. Le Roux, S. Botlhoko Aug 2022

Estimation Of Coal Density Using A 3d Imaging System: Rhovol, F. Nakhaei, Q. P. Campbell, M. Le Roux, S. Botlhoko

Mining Engineering Faculty Research & Creative Works

The results of coal sink and float tests are plotted as washability curves. Analysis of these curves indicates the most effective method by which the coal can be cleaned. Sink and float experiments are sampling-dependent, destructive, and use toxic chemicals. The present research introduces an alternative method based on a 3D imaging system called RhoVol, in which the density of individual particles is determined from mass and volume measurements. A quantitative error analysis was conducted on coal sample density measurements obtained by RhoVol, and the main factors influencing the errors identified and investigated. The results show that the drawback of …


An Acid Baking Approach To Enhance Heavy Rare Earth Recovery From Bituminous Coal-Based Sources, Ahmad Nawab, Xinbo Yang, Rick Q. Honaker Jun 2022

An Acid Baking Approach To Enhance Heavy Rare Earth Recovery From Bituminous Coal-Based Sources, Ahmad Nawab, Xinbo Yang, Rick Q. Honaker

Mining Engineering Faculty Publications

The recovery of rare earth elements (REEs) from secondary resources, particularly coal-based materials, has recently received attention due to supply and demand imbalance. Research reported to date indicates that a high REE recovery can be realized when treating bituminous coal sources using strong acid solutions of approximately100 g/L or higher. This study introduces an approach to enhance the total rare earth recovery (TREE), especially for heavy rare earth elements (HREEs), from these coal sources at significantly lower acid concentrations. Based on the presence of REE minerals like monazite and xenotime, a detailed investigation was undertaken to quantify three pre-leach treatment …


Spatial Distribution Of Harmful Trace Elements In Chinese Coals, Cao Qingyi, Ren Wenying, Liang Chaoming, Zhang Yufei, Yang Liu May 2022

Spatial Distribution Of Harmful Trace Elements In Chinese Coals, Cao Qingyi, Ren Wenying, Liang Chaoming, Zhang Yufei, Yang Liu

Coal Geology & Exploration

The potential impact of harmful trace elements in coal on the ecological environment and human health is one of the hot topics in the fields of geochemistry and energy environment. Geochemical mapping plays an important role in the deep understanding of geochemical processes and their changing laws. However, previous studies have not provided the national geochemical maps of harmful trace elements in Chinese coals. In this study, the content data of 1 167 Be, 1 315 Co, 1 406 Cu, 1 191 Mo, 1 247 Th, and 1 390 Zn in Chinese coal samples are analyzed, and their average contents …


Gravity Field Changes During Deep Exploitation Of The Coal Longwall And Their Relation To Stress Distribution And Seismic Activity, Łukasz Kortas Nov 2021

Gravity Field Changes During Deep Exploitation Of The Coal Longwall And Their Relation To Stress Distribution And Seismic Activity, Łukasz Kortas

Journal of Sustainable Mining

Mining operations cause volumetric deformations within the rock mass and changes in its density, to which the gravimetric method is sensitive. These changes are particularly well seen in periodic measurements of the local gravity field. The paper analyses the relationship between the movement of a longwall in a coal seam and the change in the distribution of the gravity field in time and space observed on the ground surface. Relative gravimetric measurements were carried out in six series between 2018 and 2020; before the start of coal extraction, with the progress of the longwall and after the cessation of mining. …


Slippage Effect And The Seepage Mechanism Considering The Compaction And Embedding Action Of Proppant, Cheng Qiaoyun, Li Bobo, Li Jianhua, Gao Zheng, Wang Bin Oct 2021

Slippage Effect And The Seepage Mechanism Considering The Compaction And Embedding Action Of Proppant, Cheng Qiaoyun, Li Bobo, Li Jianhua, Gao Zheng, Wang Bin

Coal Geology & Exploration

Hydraulic fracturing technology is an effective method to improve the efficiency of coalbed methane drainage, but the universal embedding of proppant under stress will change the width of the fractures, which will affect the gas slippage effect and the permeability mechanism. In order to explore the gas slippage effect and coal seepage law under the background of hydraulic fracturing, the Hertzian contact theory is used to quantify the embedding depth of proppant, and the gas slippage coefficient calculation equation and permeability model of the combined effect of proppant and effective stress are constructed. The results show that under different gas …


Evaluation Of Various Separation Techniques For The Removal Of Actinides From A Rare Earth-Containing Solution Generated From Coarse Coal Refuse, Deniz Talan Jan 2021

Evaluation Of Various Separation Techniques For The Removal Of Actinides From A Rare Earth-Containing Solution Generated From Coarse Coal Refuse, Deniz Talan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Rare earth elements have emerged as a vital commodity due to their significance in the production of high-tech devices as well as their utilization in defense and military systems. They are deemed critical due to potential scarcity, supply constraints, and the lack of minable concentrations. Therefore, alternative sources are needed to meet the demand and continue manufacturing rare earth-required products. Coal and coal by-products, in that regard, have presented a significant opportunity and proven to contain a considerable amount of rare earths. However, toxic elements such as thorium and uranium are frequently seen in the same mineralization as rare earths. …


Optimization Of Operating Conditions And Design Parameters On Coal Ultra-Fine Grinding Through Kinetic Stirred Mill Tests And Numerical Modeling, Francisco Patino Jan 2021

Optimization Of Operating Conditions And Design Parameters On Coal Ultra-Fine Grinding Through Kinetic Stirred Mill Tests And Numerical Modeling, Francisco Patino

Graduate Theses, Dissertations, and Problem Reports (ETD)

This study investigated the ultra-fine coal grinding performance of four low- to moderate-cost grinding media: ceramic balls, granular sand, alumina beads, and silica beads. The kinetic grinding tests were conducted using a stirred mill, while different operating conditions, including the media size, solids concentration, and the addition of viscosity modifiers, were examined. Characterization studies in terms of particle size, shape, and surface morphology were further performed to support the experimental findings. Moreover, using population balance modeling, grinding simulation was performed in Matlab to forecast the particle size distribution based on the specific energy input and experimental size-related data. The results …


Rare Earth-Bearing Particles In Fly Ash Carbons: Examples From The Combustion Of Eastern Kentucky Coals, James C. Hower, John G. Groppo Jr. Sep 2020

Rare Earth-Bearing Particles In Fly Ash Carbons: Examples From The Combustion Of Eastern Kentucky Coals, James C. Hower, John G. Groppo Jr.

Center for Applied Energy Research Faculty and Staff Publications

Graphitic carbons from the combustion of bituminous coals and, perhaps, other coal ranks, tend to capture iron and a number of hazardous elements, including As, Hg, and Se. Rare earth elements in fly ashes occur in minerals, such as monazite, xenotime, and davidite. They also occur in sub-nm particles, probably in a mineral form, within the Al–Si glass on the investigated fly ashes. Just as graphitic carbons can capture Fe and hazardous elements, the carbons surrounding the fly ash glass and magnetic particles captures or encapsulates a broad suite of rare earth elements.


Leaching Kinetics Of Rare Earth Elements From Fire Clay Seam Coal, Xinbo Yang, Rick Q. Honaker May 2020

Leaching Kinetics Of Rare Earth Elements From Fire Clay Seam Coal, Xinbo Yang, Rick Q. Honaker

Mining Engineering Faculty Publications

Recovery of rare earth elements (REEs) from coal samples collected from the Fire Clay coal seam using diluted mineral acid solutions was investigated. The initial processing step was coal recovery using conventional froth flotation which concentrated the REEs in tailing material resulting in an upgrade to values around 700 ppm on a dry whole mass basis. Leaching experiments were performed on the flotation tailings material using a 1.2 M sulfuric acid solution adjusted to a temperature of 75 °C to study the extractability of REEs from coal material. The effect of particle size, leaching time, leaching temperature, and solid concentration …


Characterization Of Rare Earth Elements In The Illinois Basin Coals, Alireza Valian Jan 2020

Characterization Of Rare Earth Elements In The Illinois Basin Coals, Alireza Valian

Theses and Dissertations--Mining Engineering

The purpose of this study is to characterize the distribution and occurrence of rare earth elements (REEs) in the coal and coal-related material from the Illinois Basin. For characterizing the distribution of REEs, 17 core samples were investigated from various parts in the basin. Also, several individual samples from coal preparation plants and isolated geological occurrences were included in the study. In result, the average REE concentrations were calculated on a bed-to-bed basis, although the distribution of REEs in the coal beds was found laterally and vertically heterogeneous. A number of trends were found that describe the variations. Most importantly, …


Separation Of Radionuclides From A Rare Earth-Containing Solution By Zeolite Adsorption, Deniz Talan, Qingqing Huang Jan 2020

Separation Of Radionuclides From A Rare Earth-Containing Solution By Zeolite Adsorption, Deniz Talan, Qingqing Huang

Faculty & Staff Scholarship

The increasing industrial demand for rare earths requires new or alternative sources to be found. Within this context, there have been studies validating the technical feasibility of coal and coal byproducts as alternative sources for rare earth elements. Nonetheless, radioactive materials, such as thorium and uranium, are frequently seen in the rare earths’ mineralization, and causes environmental and health concerns. Consequently, there exists an urgent need to remove these radionuclides in order to produce high purity rare earths to diversify the supply chain, as well as maintain an environmentally-favorable extraction process for the surroundings. In this study, an experimental design …


An Improved Method For Characterizing Coal Metamorphism By Xrd, Wang Chao, Zhao Younan, Wang Zhenwei, Lu Zhaolin Dec 2019

An Improved Method For Characterizing Coal Metamorphism By Xrd, Wang Chao, Zhao Younan, Wang Zhenwei, Lu Zhaolin

Coal Geology & Exploration

At present, the X-ray measurement method of coal metamorphism has the problem that the γ band is not well divided, the δ peak information is not used, and the background of the bottom is unreasonable. The X-ray diffraction pattern of coal with different metamorphosed degrees is compared and studied. It is proposed to correct the metamorphic coefficient formula by using the information of the slope of the 002 peak, the extended half-height width and the δ peak without deducting the so-called background information. The calculation of the XRD patterns of coal samples with different degrees of metamorphism is verified. The …


Micro Ct-Based Meticulous Characterization Of Porosity Evolution Of Coal In The Process Of Biodegradation, Dong Zhiwei, Guo Hongyu, Xia Daping, Liu Xile, Bai Yang, Zhao Guojun Oct 2019

Micro Ct-Based Meticulous Characterization Of Porosity Evolution Of Coal In The Process Of Biodegradation, Dong Zhiwei, Guo Hongyu, Xia Daping, Liu Xile, Bai Yang, Zhao Guojun

Coal Geology & Exploration

To explore the bio-permeability enhancing effect via methanogen treatment on different rank coals after anaerobic fermentation, micro-CT was used to analyze the change characteristics of pore structure of coal before and after biodegradation. At the same time, the adsorption characteristics of methanogens on the coal surface after anaerobic biodegradation were observed by scanning electron microscopy to analyze the reasons for the effect difference of biological transformation of different rank coals. The results show that the porosity and total throat length of the coal samples biodegraded increase and the connectivity of the pores is enhanced, it is indicated that coal samples …


Occurrence Of Antimony In Magmatic Intrusive Coal Seam: A Case Study From The Wolonghu Coal Mine, Huaibei Coalfield, China, Ou Jinping, Zheng Liugen, Wei Xiangping, Liu Sikui, Li Liyuan, Liu Meng, Huang Xiaoyu Aug 2019

Occurrence Of Antimony In Magmatic Intrusive Coal Seam: A Case Study From The Wolonghu Coal Mine, Huaibei Coalfield, China, Ou Jinping, Zheng Liugen, Wei Xiangping, Liu Sikui, Li Liyuan, Liu Meng, Huang Xiaoyu

Coal Geology & Exploration

In order to investigate the influence of magmatic alteration on the occurrence characteristics of antimony in coal seam, 12 samples of magmatic magma and coal were collected from Wolonghu coal mine in Huaibei coalfield, Anhui Province, and the content of Sb was determined by atomic fluorescence spectrometry(AFS). The coal quality parameters are analyzed. The results are as follows:the coal in Wolonghu magmatic intrusion area has the characteristics of ultra-low volatile matter, medium ash content and ultra-low sulfur content. And the main forms of sulfur in coal are organic sulfur and pyrite sulfur. Under the influence of magmatic hydrothermal solution, ash …


Technology And Method Of Cbm Concurrent Exploration During Coal Resources Exploration, Lin Yabing, Qin Yong, Duan Zhonghui, Ma Dongmin Feb 2019

Technology And Method Of Cbm Concurrent Exploration During Coal Resources Exploration, Lin Yabing, Qin Yong, Duan Zhonghui, Ma Dongmin

Coal Geology & Exploration

The coal seam serves as a geological carrier for CBM, and exploration of CBM and coal resources is a man-datory requirement for the management of national mineral resources. Based on the practice of project exploration in recent years, it analyzed the evaluation criteria of CBM resources in the process of coal resources exploration. On this basis, the exploration ideas, exploration methods, tasks, report preparations have proposed a method system for CBM in the ex-ploration of coal resources. According to the particularity of CBM exploration work methods, CBM seismic, well logging, drilling, well log, gas drainage, and engineering quality acceptance methods …


Analysis On The Development Characteristics And Influencing Factors Of Gas Pores In Coal, Zhang Hui, Wu Jing, Yuan Liying, Song Xiaozhong, Lin Bowei Jan 2019

Analysis On The Development Characteristics And Influencing Factors Of Gas Pores In Coal, Zhang Hui, Wu Jing, Yuan Liying, Song Xiaozhong, Lin Bowei

Coal Geology & Exploration

Based on the study of coalfield geology and coal petrology, using field emission scanning electron microscopy(FESEM) as the main observation method, nanoscale pore research on coals was carried out for different regions, different geological ages and different metamorphic degrees. The results show that gas pores in coal are the pores left by coalbed methane(gas) generation, accumulation and escape during coal metamorphism, are secondary porosity. The pore diameter is mainly at nanometer size and round shape, with uneven density and distribution. The gas pore is intensive, often forms gas pore group, gas pore zone and gas pore nest. The gas pore …