Earth Sciences Commons^™

Impacts Of Co2/Ch4/N2 Adsorption/Desorption On The Macromolecular Structure Of Anthracite: Insights From In Situ Raman Spectroscopy, Wang Tian, Pan Jienan, Li Meng, Wang Kai, Tang Zhuyun, Cheng Nannan, Hou Quanlin

Coal Geology & Exploration

Objective and Methods The adsorption/desorption of coalbed methane (CBM) not only induces the macroscopic deformations of coals but also significantly alters their macromolecular structures, with different gases exhibiting greatly varying mechanisms and influence degrees. Utilizing an independently developed in situ laser Raman spectroscopy system, this study revealed the differential structural responses and mechanisms of anthracite under CO₂, CH₄, and N₂ injection. Results and Conclusion Experimental results indicate that gas injection led to notable blue shifts in the D₄, D, D₃, and G peaks characterizing the microcrystalline structures of coals. In contrast, …

Advances In Research On Geological Evaluation Of Compressed Air Energy Storage In Underground Gas Storage Facilities, Jiang Wen, Huang Leqing, Zhang Songhang, Ma Huiying

Coal Geology & Exploration

Background Against the backdrop of achieving peak carbon dioxide emissions and carbon neutrality globally, renewable energy has developed rapidly and is gradually changing the world's energy mix. However, the intermittent and fluctuating nature of photovoltaic and wind power energy is prone to cause grid frequency fluctuations and reduced power supply reliability. Compressed air energy storage (CAES) technology has emerged as the key to the stable operation of the green power grid thanks to its large capacity and low cost.Methods Based on a systematic review of domestic and international literature in recent years, this study organizes the current theoretical and …

Log-Based Identification Of Sedimentary Facies In Coal Measures In The Southern Wuxiang Block, Shanxi Province, China, Jin Yi, Tian Yunqing, Song Huibo, Hu Bin, Yu Zhenfeng

Coal Geology & Exploration

Objective The Carboniferous and Permian coal-bearing strata in the southern Wuxiang block, Qinshui Basin, Shanxi Province, China contain abundant coalbed methane (CBM) resources. To develop intelligent discrimination technology for CBM exploration in this block, it is necessary to establish lithology discrimination criteria based on log data, reveal the response relationships between logging and sedimentary facies, and determine sedimentary patterns. Methods Using a comprehensive analysis of lithologies, sedimentary facies, and logging facies, this study systematically investigated the distributions of logging and sedimentary facies in the Shanxi and Taiyuan formations—the primary coal-bearing strata in the southern Wuxiang block. By comprehensively analyzing the …

Spatial Distribution Of Coalbed Methane Migration Pathways And Selection Of Optimal Target Areas For Coalbed Methane Extraction For Abandoned Mines, Liu Qinjie, Yang Youxing, Wu Benniu, Duan Minke, Deng Zhuoyue, Guo Chenye, Sun Qiang

Coal Geology & Exploration

Objective and Methods The spatial distribution and long-term evolution of effective migration pathways determine the migration pathways of residual coalbed methane (CBM) in abandoned mines. Furthermore, they provide an important basis for selecting the optimal target areas for CBM extraction drilling in abandoned mines and maximizing extraction efficiency. This study investigated the first mining area at the first horizontal elevation of the Songzao Coal Mine in Chongqing. Using a comprehensive approach that integrated theoretical analysis, numerical simulations, and physical simulation experiments using similar materials, this study systematically examined the distribution patterns of effective CBM migration pathways in abandoned mines under …

Geochemical Characteristics And Genesis Of Element Enrichment Of Niobium-Rich-Rare Earth Metal Layer In Longtan Formation Of Zhina Coalfield, Ding Yunlong, Wang Fangfa, Li Bi, Tang Lifang, Yang Yi, Li Shangyuan, Wang Xiaofang, Zou Yinhong, Wang Yang

Coal Geology & Exploration

Background With the increasing demand for strategic metals and the gradual depletion of traditional metal deposit resources, coal and coal-bearing rock series are considered to be potential sources of rare metals, and coal series associated has become one of the main directions of current mineral exploration. A set of coal measure strata rich in niobium (Nb) and rare earth elements (REE) has been found in Zhina coalfield, western Guizhou and the contents of Nb and REE are as high as 334.89 μg/g and 1014.51 μg/g, respectively. This discovery is of great significance to the theoretical study of coal measure metal …

Macroscopic Failure Characteristics And Seepage Pattern Of Damaged Goaf-Side Coal Pillars Under Confined Water Accumulation, Liu Weitao, Chen Dongqi, Liu Yuben, Du Yanhui, Zhao Jiyuan

Coal Geology & Exploration

Background The method of supporting roadways using small coal pillars has been widely applied in China. As a result, the stability of goaf-side coal pillars affects mining safety. Resulting from multiple disturbance effects, coal pillars tend to contain various types of damage fractures. The confined water environment in goaves with water accumulation might cause the instability failure of damaged goaf-side coal pillars. Methods To investigate the impacts of the damage fracture structure on coal stability, this study introduced the concept of relatively stable initial damage fractures. Based on the theory of damage mechanics, this study constructed hydro-mechanical-damage (HMD) coupling models …

3d Advanced Geological Prediction Based On Reflected Seismic Waves And Its Application Effects, Cai Sheng

Coal Geology & Exploration

Objective For the advance geological prediction of tunnels based on reflected seismic waves, the traditional 2D observation method tends to cause spatial positioning deviations of anomalies. To overcome this limitation, this study developed a 3D seismic wave-based advance geological prediction method according to the actual geometries of tunnels. Methods Using the technical path consisting of theoretical analysis, numerical simulation, and engineering verification, this study solved key technical challenges including 3D wavefield reconstruction, spatial modeling, and migration imaging in the 3D detection system. Based on the principle of geometric seismology, this study demonstrated the enhancement effects of 3D observation on the …

A Time Series Forecasting Model Integrating Spatial Features For Inter-Borehole Resistivity And Its Application, Wang Jianghong, Liu Shuo, Wang Gang, Xue Wuqiang, Li Bofan

Coal Geology & Exploration

Background Mine resistivity prediction serves as a core technique for water hazards monitoring in coal mines. However, due to sparse monitoring points and insufficient spatial resolution, conventional prediction approaches fail to capture dynamic resistivity variations under complex geological conditions.Objective and Methods To address this challenge, this study developed a deep learning-based time series forecasting model integrating spatial features for inter-borehole resistivity. Using a prediction framework constructed based on long short-term memory (LSTM) and critical spatial monitoring points selected through Pearson correlation analysis, this model (also referred to as the LSTM model) enabled high-precision prediction of resistivity in unknown areas. …

Hybrid Differentiator-Based Method For Estimating The Drilling Speed Of A Vehicle-Mounted Drilling Rig During Surface Drilling For Mine Rescue, Wang Yunfei, Zhao Jiyun, Hu Yongjie, Zhang Zongyang, Pan Xiaochen

Coal Geology & Exploration

Background Vehicle-mounted drilling rigs (VMDRs), key devices in surface drilling for mine rescue, directly connect the ground and underground disaster-hit areas through vertical drilling, thereby creating rescue channels for trapped people. In this case, the drilling speed of VMDRs serves as an important indicator for evaluating surface drilling operations. However, directly determining the drilling speed is challenging due to the limitations of position sensors. Methods This study developed an estimation method based on a new hybrid differentiator (NHD), allowing the drilling speed to be calculated using measurable displacement signals. First, a continuous switching function was devised, and its convergence characteristics …

Parameter Characteristics And Rock-Breaking Mechanisms Of Horizontal Drilling Of Underground Collapsed Bodies In Coal Mines, Yao Ningping, Dou Xuqian, Han Zhaoyang, Zhang Guohua, Sun Yuchen, Li Hao, Wang Li

Coal Geology & Exploration

Objective With continuously increasing coal mining depth, the risks of hazards such as roof collapse and personnel entrapment caused by high in situ stress and mining-induced pressure have significantly intensified. Drilling emerges as a key means of rapidly establishing rescue passageways. However, the drilling process tends to face multiple challenges, including complex geological structures, unstable collapsed bodies, and low drilling efficiency. Methods This study aims to reveal the rock-breaking mechanisms during the drilling of collapsed bodies, optimize drilling parameters to ensure reliable borehole formation, and achieve efficient drilling of collapsed bodies. To this end, this study developed a large-scale experimental …

Dissolution Mechanism Of Nonionic Polyether Surfactants In Supercritical Co2, Ning Xu, Yanling Wang, Baojun Bai, Shizhang Cui, Zan Gao, Yu Zhang, Di Li, Wenjing Shi, Wenhui Ding, Peixu Ma

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Polyoxyethylene ether is an efficient CO₂-philic compound with significant potential applications in CO₂ flooding, which requires CO₂-philic surfactants with high solubility in supercritical CO₂ (scCO₂). This study elucidates the molecular and atomic-level dissolution mechanism of the fatty alcohol polyoxyethylene ether (AEO) in scCO₂ by combining phase-behavior experiments and molecular dynamics simulations. The solubility of AEO in scCO₂ is measured using a semiconductor laser. AEO containing three polyoxyethylene (EO) groups exhibited the highest solubility in scCO₂.The solubility of AEO in scCO₂ decreased with an increase in the number …

Development And Evaluation Of Supported Ionic Liquid Membrane And Porphyrin Frameworks For Carbon Capture Separation, Sarang Ismail

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The global urgency to mitigate anthropogenic CO₂ emissions has intensified the pursuit of energy-efficient separation technologies. Supported Ionic Liquid Membranes (SILMs) have emerged as promising candidates for CO₂ capture due to their tunable solubility-selectivity and low energy requirements. However, challenges such as mechanical instability, limited scalability, and trade-offs in transport performance have impeded their widespread adoption.

This thesis explores a systematic approach to designing and optimizing SILMs for enhanced CO₂ separation by tailoring polymer–ionic liquid interactions, processing conditions, and material architectures. A comprehensive set of studies were conducted using poly(vinylidene fluoride) (PVDF) with varying molecular weights, different grades of PEBAX®, …

Mantle Flow And Crustal Deformation Revealed By Seismic Anisotropy In The Subduction Zone Beneath Myanmar, Enbo Fan, Mingming Jiang, Yinshuang Ai, Stephen S. Gao, Kelly H. Liu, Yumei He, Yiming Bai, Guangbing Hou, Yuan Ling, Chit Thet Mon, Myo Thant, Kyaing Sein

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The oblique convergence of the Indian and Eurasian plates drives significant deformation in the crust and mantle beneath Myanmar. However, the crustal deformation in the Indo-Burman Ranges (IBR) and mantle flow beneath Myanmar and adjacent areas remain unclear due to limited studies. We utilized data from the newly deployed second phase of the China-Myanmar Geophysical Survey of the Myanmar Orogen array to perform shear wave splitting analysis of PKS, SKKS, and SKS (XKS) phases. Our results, together with previous findings, provide new insights into mantle flow and crustal deformation across central Myanmar. In the IBR, we observed a transition from …

Key Technologies And Approaches For Water Resource Conservation And Utilization In Arid To Semi-Arid Open-Pit Coal Mining Areas In The Northern Sand Prevention Belt Of China, Fang Jie, Xu Zhimin, Cheng Wei, Lu Zihan, Zhao Yongqiang, Zhu Yuhao, Chen Tianci

Coal Geology & Exploration

Background The northern sand prevention belt (NSPB) of China is primarily distributed in arid and semi-arid regions such as Xinjiang, Inner Mongolia, Ningxia, and Gansu. This belt exhibits scarce rainfall and intense evaporation, which lead to a shortage of water resources and vulnerable ecosystems. In recent years, the large-scale development of open-pit coal mines has caused increasingly violent mining disturbance in this belt, as well as increasingly prominent issues such as a decline in regional groundwater levels and ecological contradictions. To address technical challenges in balancing coal exploitation and water resource conservation in this belt, there is an urgent need …

Mechanisms Behind Grouting Pressure Jumping In Low-Permeability Limestones And Techniques For Grouting Pressure Control, Fan Zhenli, Cao Lutong, Cui Yong, Zhang Zhiwei, Zhang Fengda

Coal Geology & Exploration

Background The exploitation of the Carboniferous-Permian coalfields in China is gradually transitioning toward coal seams in lower formations. In this context, issues including the confined water hazards in the floor and karst water preservation become increasingly pronounced. During the advanced surface treatment of karst water hazards in coal seam floors, the unclear patterns of matching between grout selection and grouting pressure control lead to empirical parameter selection, thereby yielding poor performance of grouting reinforcement. Methods This study aims to deal with the phenomena of rapid pressure rise with a limited grout volume in the low-permeability argillaceous limestones within the top …

Suitability Evaluation For Deep Geological Storage Of Mine Water In The Ordos Basin, Gulbostan Tursun, Sui Wanghua, Aibibai Mamat, Yang Weifeng, Chen Ge, Gao Liang

Coal Geology & Exploration

Objective Given the issues of large mine water drainage in coal mines in China, as well as the corresponding high treatment cost and low utilization rate, thoroughly investigating efficient, environmentally friendly, economically feasible mine water treatment technologies is the key to the green transformation and the implementation of the sustainable development strategy in the coal industry. Deep geological storage of mine water represents an emerging technology for mine water treatment, enjoying the advantages of low cost and zero emissions. A key step in the application of this technology is to select suitable target reservoirs. Although relevant studies have proposed some …

Permeability Evolutionary Patterns Of Fractured Rock Masses In Fault Zones Under Seepage-Stress Coupling, Zhao Dekang, Han Bing, Zeng Yifan, Feng Guorui, Xi Yonghong, Chang Bofeng, Li Zhenghao, Wang Pengwei, Wang Lisan

Coal Geology & Exploration

Background In coal mines, fault structures serve as critical pathways for water inrushes from coal seam floors, posing serious threats to the production safety of mines. Delving into the permeability evolutionary patterns of fractured rock masses in fault zones under seepage-stress coupling holds great significance for the prevention and control of water inrushes along faults from coal seam floors.Methods Against the engineering background of the Gaohe Coal Mine under the Shanxi Lu’an Mining (Group) Co., Ltd. in Shanxi Province, this study analyzed the microscopic physical properties and the pore and fracture structures of a fractured rock mass in a …

Theory And Engineering Practice Of Coal-Water Coordinated Mining Based On Constraints Of Formation Bearing Capacity, Pang Zhenzhong, Zeng Yifan, Han Keyao, Wu Qiang, Liu Shouqiang, Hua Zhaolai, Zhao Gangyi, Zhang Shuai, Yang Huxiong, Wang Xuejun, Li Feifan

Coal Geology & Exploration

Background The high-intensity mining of coal resources in the Yushen mining area has caused negative environmental effects and water disasters on coal seam roofs, seriously restricting the sustainable development of the area.Methods and Results Based on a summary of previous research results on the mitigation of the impacts of coal mining on groundwater resources and surface ecosystem, this study analyzed the contradiction between coal mining and the protection of the fragile ecosystem in the Yushen mining area in Shaanxi Province through theoretical analysis, field investigation, and data statistics. Then, it systematically illustrated the concept of the formation bearing capacity …

Impacts Of Boundary Conditions And Parameter Heterogeneity On The Simulation And Prediction Of Water Inflow In Coal Mines, Ji Qiang, Wu Zhenjiang, Yao Yingying

Coal Geology & Exploration

Background Accurate prediction of water inflow in coal mines is essential for ensuring safe mining operations. Three-dimensional (3D) groundwater numerical models can be used to characterize hydrogeological conditions in mining areas and simulate the dynamic processes of water inflow, providing a theoretical basis for scientifically predicting mining-induced water inflow. However, there is a lack of a clear understanding of the impacts of the boundary conditions with surface water-groundwater interactions and the heterogeneity of aquifer permeability coefficients (K) on the simulation and prediction of water inflow during coal mining. Methods This study developed a 3D transient groundwater numerical model …

An Experimental Study On The Seepage Characteristics Of Sandstones With Different Numbers Of Fractures Before And After Grouting, Chen Juntao, Zhou Haoyu, Yu Junjian, Li Guo, Fan Mingjin, Li Lu, Wang Yunhao

Coal Geology & Exploration

Background Grouting in surrounding rocks serves as a conventional approach to controlling disasters in coal mine roadways. The developmental degree of fractures significantly influences the reinforcement and sealing effects of grouting. Methods To determine the changes in the impermeability of fractured surrounding rocks before and after grouting, this study investigated sandstones—the most common sedimentary rocks in coal mines. Using laboratory experiments and numerical simulations, this study explored the permeability variations of sandstone specimens with varying fracture numbers under different confining pressures and assessed the impact of grouting on their seepage performance. Through triaxial compression-seepage experiments using a Rock Top multi-field …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Trace Element Migration In Groundwater In Sandstone Aquifers In The Jurassic Coalfields: A Case Study Of The Guojiahe Coal Mine, Shi Longqing, Qu Xingyue, Cheng Hao

Coal Geology & Exploration

Background The Ordos Basin, a vital energy hub in China, contains considerable coal reserves. However, the environmental issues arising from coal mining warrant attention, especially given the fragile ecosystems of the Jurassic coalfields. Methods This study investigated the Guojiahe Coal Mine in Shaanxi Province. Based on measured concentrations of 31 trace elements dissolved in sandstone aquifers across varying geological ages, this study conducted a comparative analysis of the evolutionary characteristics of these trace elements between unmined reducing and post-mining oxidizing conditions using numerical simulations. Accordingly, it revealed the impacts of coal seam mining on trace element migration in groundwater in …

Seismic Anisotropy Of Sandstone Aquifers In Coal Seam Roofs, Yu Hang, Chen Tongjun

Coal Geology & Exploration

Objective The identification and assessment of sandstone aquifers in coal seam roofs play a vital role in the safe mining of mines. Investigating the rock physics and amplitude variation with incidence and azimuth (AVAz) responses of these sandstone aquifers is critical to the prevention and control of water hazards in mines. Methods By integrating rock physical models Voigt-Reuss-Hill (VRH), differential equivalent medium (DEM), Hudson, and Wood, as well as Gassmann’s anisotropic fluid substitution theory, this study proposed a rock physics modeling method for fractured sandstones of the horizontal transversely isotropic (HTI) media type (hereafter referred to as HTI sandstones). Using …

Research On Monitoring And Early Warning Systems For Mine Water: Progress And Prospects, Yin Shangxian, Ding Yingying, Lian Huiqing, Dong Donglin, Du Tong, Yin Huichao, Zhao Peng, Zhang Yi’An, Wang Xiong

Coal Geology & Exploration

Background Water disasters in mines are occasional accidents occurring due to the influence or triggered by mining-induced intense changes in geological bodies. The complexity, heterogeneity, and dynamics of geological bodies, coupled with the random and instantaneous nature of mining influence, lead to the uncertainty, instability, occasionality, and transience of water disasters in mines. Given that mine water monitoring and early warning serve as a prerequisite for advanced disaster prevention and control, their research and system construction hold great theoretical significance and practical value. Progress and Prospects Fighting against water disasters in mines is conducted throughout the development and utilization of …

Experiments On The Diffusion Patterns Of Coal Gangue-Based Grout In Goaves Under Varying Rock Particle Sizes And Grout Mass Fractions, Zeng Yifan, Yuan Zilong, Li Hao, Wu Qiang, Zhao Gangyi, Zhou Anqi, Gao Xiang, Zhang Shuai, Bai Yanfei, Liang Jin, Yang Huxiong, Sheng Xinli, Yang Donghui, Zhao Yixia

Coal Geology & Exploration

Objective Investigating grout diffusion patterns and predicting the grouting range hold great significance for coal gangue grouting and filling engineering in goaves. Specifically, they are significant for designing grouting hole and row spacing, guiding grouting construction, determining the grouting filling degree, and further ensuring grouting effects. Methods Using crushed rocks as the medium to be grouted and coal gangue-based grout as the grouting materials, this study conducted grouting experiments under different particle sizes of crushed rocks and varying mass fractions of grout. Accordingly, it investigated the flow patterns of gangue-based grout in goaves. Results and Discussion Under a mass fraction …

Differential Roof Water Hazards And Comprehensive Utilization Of Mine Water In The Dongsheng Coalfield, Huang Haiyu, Ding Xiang, Liu Xi, Fan Jiangwei, Ji Zhuochen, Li Zhaoyang

Coal Geology & Exploration

Objective The Dongsheng coalfield exhibits various types of mine water hazards, complex water filling mechanisms, and high water inflow with high total dissolved solids (TDS) content in mining areas. These characteristics pose challenges to the comprehensive utilization of mine water, severely restricting the safe, green, and efficient coal mining in the coalfield. Methods This study aims to reveal the roof water filling characteristics of the Dongsheng coalfield and enhance the comprehensive utilization of mine water. Using methods including statistical analysis of drilling data, analytic hierarchy process, and hydrochemical tests, this study analyzed the strata, spatial distribution of aquifers, and the …

An Experimental Study On Seepage Characteristics And Grouting-Induced Permeability Reduction Of Burnt Rocks, Qian Ziwei, Tan Chunzhi, Sun Qiang, Wang Hai, Zhang Gailing

Coal Geology & Exploration

Background Burnt rocks represent special geobodies formed by the spontaneous combustion of coal seams. Their pore and fracture systems provide preferential spaces for groundwater occurrence and migration while also posing severe water hazard threats to the safe mining of adjacent coal seams. Methods To address this engineering challenge, this study systematically analyzed the void structures within burnt rocks using three-dimensional reconstruction technology. Through laboratory seepage and grouting experiments, this study revealed the seepage patterns and grouting-induced permeability mechanisms of typical burnt rock specimens. Results and Conclusions The burnt rock specimens contained highly developed pores and fractures, with the void structures …

Developmental Pattern Of Water Flowing Fractured Zones In The Soil-Bedrock-Type Overburden And Water-Controlled Mining Strategy Under A Super-Large Mining Height, Zhang Yujun, Hua Zhaolai, Song Yejie, Hu Haoyu, Li Jiawei

Coal Geology & Exploration

Background The heights of water flowing fractured zones represent a key concern in the prevention and control of water disasters occurring in mining face roofs and water resource protection of coal mines. Varying lithologies and structures of the overburden are identified as primary factors governing the height and characteristic differences of water flowing fractured zones. Methods Against the engineering background of a mining face with 10 m super-large mining height in the Caojiatan Coal Mine of Shaanxi Province, this study investigated the differences in the mining-induced responses of the soil-bedrock-type overburden using numerical simulations of stress-seepage coupling and measured heights …

Multi-Objective Allocation Optimization Model For Water Resources From A Coal Mine In The Inner Mongolia-Shaanxi Contiguous Area, Miao Hechao, Dong Shuning, Wang Hao, Yang Yuanyuan, Qiao Wei, Wang Xiaodong, Wang Dongqi, Fu Hongyang, Liu Yuting

Coal Geology & Exploration

Objective In China, as coal resource exploitation shifts gradually from eastern to western regions, coal bases in the western region play an increasingly notable foundational role in the basic energy supply in the national economy. However, due to its fragile ecosystems, the safe, efficient, and green coal exploitation of this region has long been challenged by the contradiction between the prevention and control of water hazards and the conservation of water resources. Therefore, advancing intelligent mine water control technology is identified as a crucial method to address the conflicts between coal mining and mine water in the western region. Additionally, …

Regularity And Mechanisms Of Water-Sand Inrushes Within Mining-Activated Faults, Zhang Shichuan, Huang Pu, Li Yangyang, Wang Chenggong, Wu Zhenhua

Coal Geology & Exploration

Background During underground coal mining, water-sand mixtures within faults may rush into mine floors. The water-sand inrushes are especially prominent under the conditions of high water-yield properties and loose filling structures in fault zones, severely threatening the safe mining of coal mines. Previous studies focus primarily on the impact of a single factor on inrushes. Hence, it is significant to systematical investigate the regularity of water-sand inrushes within faults under the combined effects of multiple factors. Methods Based on the fluid and granular mechanic theories, this study derived the instability criterion and flow formulas of water-sand mixtures. Using orthogonal experiments …