期刊封面

更多>>

Online System Service

更多>>

About the Journal

更多>>
Journal:
Coal Geology & Exploration
Establishment year:
1973
 
Periodicity:
Biomonthly
Supervised by:
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp.
Sponsored by：
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp.
Editor-in-chief:
 DONG Shuning
 
Associate E ditor-in-chief:

 LIU Cheng, James W. LaMoreaux 

 

Executive Editor-in-chief:
JIN Xianglan 

 

ISSN:
1001-1986
CN:
61-1155/P
Web:
www.mdkt.cbpt.cnki.net

Download Center

更多>>

Article list

  • 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;Equipment Business Department (Equipment Research Institute) of Middling Coal Energy Co., Ltd.;National Engineering Research Center of Coal Mine Water Hazard Controlling, China University of Mining and Technology(Beijing);Yellow River Institute of Eco-Environmental Research;Shaanxi Shaanmei Caojiatan Mining Co., Ltd.;Emergency Management Bureau of Ordos;Kailuan (Group

    [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 and its significance for the ecological environment. A formula for calculating the height of water flowing fractured zones that was applicable to ecologically fragile mining areas in western China was determined through fitting using mathematical statistics. Dominant factors controlling the formation structure damage were identified using the theory of simply supported beams and hydrogeological theories. Finally, based on the theory of coal-water coordinated development, this study devised the architecture of highly beneficial, coordinated coal mining technology based on the formation bearing capacity and developed the corresponding mining philosophy. This technology was applied to mining face 122107 in the Caojiatan Coal Mine. After mining along this mining face by gradually increasing the mining height based on blocks and segments, the overburden of the roof showed a stepped broken morphology generally. The water inflow along the mining face fluctuated around 170 m3/h throughout the mining process, not exceeding the drainage capacity of the mining face. [Conclusions] The results indicate that it is necessary to take the formation bearing capacity as a core evaluation index for ecologically fragile mining areas. By controlling the dynamic balance between the mining technique and the formation bearing capacity, the coordination between resource development and ecological protection can be achieved.This mining approach can ensure highly beneficial coal resource mining while also addressing the contradiction between coal mining and the protection of the fragile ecosystem. The results of this study will provide a theoretical and technical reference for other arid and semi-arid mining areas in western China.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 2184K]

  • 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;State Key Laboratory of Water Resource Protection and Utilization in Coal Mining;National Institute of Clean-and-Low-Carbon Energy;School of Resources and Geosciences, China University of Mining and Technology;School of Environment and Spatial Informatics, China University of Mining and Technology;

    [Background] The northern sand prevention belt(NSPB) of China is primarily distributed in arid and semiarid 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 to develop a technology system for water resource conservation in open-pit coal mining areas. [Methods and Results] This study investigated the distribution of open-pit coal mines in the NSPB and revealed the regional hydrogeological characteristics such as rainfall, evaporation, water-bearing media, water inflow, and water quality in three typical regions of the NSPB:eastern Inner Mongolia, western Inner Mongolia, and northern Xinjiang. It developed key technologies for the conservation of multiple water sources, including surface water, groundwater, atmospheric condensate water, and mine water in open-pit coal mining areas. These key technologies include(1) a multi-level mine water storage model that integrates surface reservoirs, reinjection into the Quaternary aquifer, and subsurface reservoirs;(2) the interception and storage of surface water;(3) the efficient capture and utilization of atmospheric condensate water;(4) groundwater source control dominated by curtain grouting, and(5) the artificial reconstruction of ecological aquifers in open-pit mining areas. As a result, a technology for three-dimensional water resource conservation in open-pit mining areas is formed. Additionally,this study explored technologies for the treatment of substantial suspended solids in mine water, low-cost and large-scale mine water treatment, and novel ecological precision irrigation in open-pit mining areas. [Conclusions] By establishing a three-dimensional, low-cost, efficient, large-scale, and replicable model for the conservation, treatment, and utilization of water resources for open-pit coal mines in the NSPB and developing a proactive and systematic technical integration system for the conservation, storage, and utilization of surface and subsurface water resources, this study contributes greatly to address the ecological restoration challenges in mining areas characterized by drought and scarce rainfall in the NSPB. The results of this study hold great significance for ensuring water supply for ecological conservation and restoration in the NSPB and for serving national strategies such as energy security and ecological civilization construction.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 2409K]

  • 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;College of Earth Science and Engineering, Shandong University of Science and Technology;

    [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 sandstone aquifers within the study area. [Results and Conclusions] The results indicate that the trace elements are unevenly distributed in the vertical direction, with significant differences in their concentrations observed between coal-bearing strata and their overlying strata. The behavior of specific elements is associated with the variation in groundwater flow(Q), as indicated by positive and negative correlations between C(the concentration of a trace element) and Q. Based on these findings, this study developed the geochemical models of As, Se,Cr, Fe, and heavy metal elements, elucidating the dissolution behavior of trace elements and its controlling mechanisms under the influence of coal mining. The dissolution of trace elements is found to be primarily governed by adsorption and the dissolution of oxide minerals. About 8.11×10~(-8) Gmol of trace elements that are closely related to the environment are transported into groundwater every month, with the concentrations of several elements exceeding relevant standards. Among these, Fe, Mn, Al, Cu, and Zn originate primarily from coal-bearing strata, while V, Cr, and Co are predominantly derived from the Cretaceous sandstone strata. Therefore, there is an urgent need to strengthen environmental protection and management around the Jurassic coalfields in the Ordos Basin.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 2422K]

  • 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;China Coal Energy Research Institute Co., Ltd.;China Coal Rock Burst & Water Hazard Control Center;

    [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 spatial configuration of aquifers and coal seams to be mined in the Dongsheng coalfield. Accordingly, it explored the characteristics of roof water hazards, the hydrochemical characteristics of mine water, and the ways of the reutilization of mine water. [Results and Conclusions] With an increase in the burial depth of coal seams, the overall water filling intensity of mines in the Dongsheng coalfield gradually increases from northeast to southwest. This is primarily attributed to the aquifers of the Jurassic Zhiluo Formation. Mining areas like Shendong and Wanli suffer various roof water hazards in shallowly buried, thin bedrocks. In contrast, mining areas like Khujirt and Nalinhe in the west are subjected to roof water hazards of single types in thick sandstones. The overall TDS content of mine water gradually increases from northeast to southwest with the burial depth of coal seams. The primary cause of this TDS content variation is that the shallowly buried zones are prone to be recharged by the Quaternary phreatic aquifers, whereas aquifers in the deep parts primarily receive lateral recharge and exhibit slow runoff. The comprehensive utilization of mine water in the Dongsheng coalfield can be divided into four modes: quality-based cascade utilization of water resources mines,coordinated allocation of water resources among mines, coordinated water purification and utilization of coal mines and chemical industry, and mining area-agriculture-ecology combined allocation and utilization of water resources. These mine water utilization modes can effectively reduce the demand of relevant water consumption sectors for water resources from surface and groundwater systems. This will help save at least 3 579.16×104 m3 of water resources annually.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 8353K]

  • Impacts of boundary conditions and parameter heterogeneity on the simulation and prediction of water inflow in coal mines

    JI Qiang;WU Zhenjiang;YAO Yingying;School of Human Settlements and Civil Engineering, Xi'an Jiaotong University;

    [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 for a typical coal mine. Through multi-scenario simulation experiments, this study quantitatively analyzed the impacts of rainfall infiltration recharge, infiltration process in the unsaturated zone, and river boundary configurations on the simulations of water inflow. Employing geostatistical methods, this study established 3D heterogeneous permeability coefficient fields to explore the impact of parameter heterogeneity. [Results and Conclusions] The simulations using the initial model revealed that the average water inflow in the mining area decreased by 25.48% in the case where only the heterogeneity of rainfall infiltration recharge was considered. When the impact of vertical kinematic wave infiltration in the unsaturated zone was incorporated, the average water inflow increased by 18.68% and the water inflow was more prone to undergo periodic fluctuations compared to the initial model. Assuming that rivers were connected to the aquiclude via a tectonic fracture zone, the average water inflow in the mining face rose by 7.51% compared to the initial model, showing an accelerated growth trend. An increase in K heterogeneity corresponded to rapidly increasing water inflow. Meanwhile, the ratio of water inflow in the mining face to the average water inflow in the mining area increased to 85%-88% gradually, resulting in concentrated water inflow in the mining area. However, extreme K heterogeneity led to dispersed water inflow. Compared to the homogeneous generalized parameters, the random, heterogeneous K distribution was associated with more gentle growth trends in water inflow. Among all scenarios, the scenario where river channels lay the phreatic aquifer manifested a minimal impact on water inflow. In contrast, significant water inflow deviations from the initial model were observed under scenarios such as river channels passing through a locally fractured aquiclude, low-heterogeneity parameters, and vertical infiltration from the unsaturated zone. This study provides a critical reference for accurately simulating groundwater dynamics under complex mining conditions.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 1992K]

  • Seismic anisotropy of sandstone aquifers in coal seam roofs

    YU Hang;CHEN Tongjun;School of Resources and Geosciences, China University of Mining and Technology;

    [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 this method, this study explored the impacts of fracture parameters and water saturation on seismic rock physical responses of the sandstones. Accordingly, it constructed a two-layer theoretical forward model, calculated the reflection coefficients of HTI sandstones, and analyzed the relationships of the reflection coefficients with the fracture density and water saturation. [Results and Conclusions] The rock physics modeling results indicate that a higher fracture density corresponded to lower compressional and shear wave(also referred to as P-and S-wave) velocities and stronger anisotropy. As the water saturation increased, the P-wave velocity decreased initially and then increased, whereas the S-wave velocity decreased slightly. Concurrently, with an increase in the water saturation, anisotropy coefficients ε~((v)) and δ~((v)) increased, while anisotropy coefficient γ ~((v))remained unchanged. The AVAz forward modeling results indicate that a higher fracture density was associated with more pronounced azimuthal anisotropy of the sandstones' reflection coefficients and larger differences in P-wave reflection coefficients between saturated and dry sandstones. The saturation state of sandstones was the most distinguishable in the case where the angle of incidence and azimuth were 40° and 0°, respectively.Indicators for sensitivity to the fracture density and water saturation of sandstone aquifers included the fitted slope and intercept of the AVAz curves, as well as the isotropic and anisotropic components of the amplitude versus offset(AVO)gradients. The results of this study provide a theoretical basis for the identification and assessment of sandstone aquifers.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 1973K]

  • 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;College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing);Hebei State Key Laboratory of Mine Disaster Prevention, North China Institute of Science and Technology;Ordos Guoyuan Mining Development Co., Ltd.;

    [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 coals. Starting from scratch, the monitoring and early warning of these disasters have undergone human experience-based identification, physical mechanism-guided information acquisition and identification, and intelligent monitoring and early warning driven by physics and data, with systematic transformation, industrial demonstration, and large-scale applications having been achieved presently. Significant advances have been made in relevant basic research, technological research and development, and system construction, enabling advanced early warning in some typical scenarios. These achievements underscore the belief that the prevention, control, and early warning of water disasters in mines can be achieved. However, the unclear physical mechanisms underlying the disasters lead to incomplete index systems, insufficient information acquisition, and inaccurate assessment and prediction. These issues tend to result in frequent occurrences of missed, false, and inaccurate early warnings. Consequently, the overall goal of advanced and precise early warnings has not been fulfilled for a vast majority of scenarios, facing serious challenges.Based on the review of the advances in research, this study proposed a system architecture for the monitoring and early warning of mine water, followed by theoretical discussions about four key technologies: the index system, information perception(monitoring), evaluation and prediction, and identification and early warning. Accordingly, this study summarized the connotations and interrelationships of these technologies, as well as relevant challenges. Furthermore, it pointed out that the monitoring and early warning should shift from methodologies based on physical mechanisms to the physics-data dual-driving mechanism. This overall development direction includes seven specific directions: constructing a comprehensive index system, optimizing the layout of the perception system, total-factor joint monitoring of multiple disasters, establishing geological-hydrological models + deep learning-based prediction models, setting early warning rules and factor thresholds, real-time and advance warning, and image monitoring and big data processing. These directions will lay the foundation for theoretical research, technological research and development, and system construction in this field.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 1814K]

  • 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;Inner Mongolia Research Institute, China University of Mining and Technology (Beijing);National Engineering Research Center of Coal Mine Water Hazard Controlling, China University of Mining and Technology (Beijing);Key Laboratory of Mine Water Control and Resources Utilization, National Mine Safety Administration;Emergency Management Bureau of O

    [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 of 50%, the diffusion distances of the grout in crushed rocks with particle sizes of 3-5, >5-7, and >7-9 mm were determined at 5.0, 5.5, and 6.2 cm, respectively, with a maximum difference in the diffusion distance of1.2 cm. When the mass fraction of the grout was reduced to 40%, the diffusion distances increased to 10.2, 14.5, and18.0 cm, respectively, with the maximum difference in the diffusion distance expanding to 7.8 cm. When the mass fraction further decreased to 30%, the diffusion distance exhibited a nonlinear growth, reaching 20.5, 28.0, and 34.0 cm, respectively. In this case, the maximum difference in the diffusion distance surged to 13.5 cm. Overall, the diffusion distance increased with both decreasing grout mass fraction and increasing particle size of the crushed rocks, with variations in grout mass fractions producing more significant impacts on the diffusion distance than changes in particle sizes of crushed rocks. The coal gangue-based grout experienced three flow stages in crushed rocks, i.e., rapid grouting, stable grouting, and blockage, which were prolonged with a decrease in the grout mass fraction. The diffusion distance of coal gangue-based grout in crushed rocks increased with a decrease in grout mass fraction. Furthermore, with an increase in the particle size of the crushed rocks, the grout mass fraction produced more significant impacts on the diffusion distance of coal gangue-based grout, as evinced by the nonlinear characteristics of the fitting coefficient(m). Through analyses of the impacts of both the particle size of crushed rocks and the grout mass fraction on the diffusion distance of grout, the basic relationship between the diffusion distance and mass fraction was determined. In combination with the basic relationship between the particle size and mass fraction, a dimensional analysis was further conducted. As a result,a dual-parameter equation for predicting grout diffusion distance that can be applied to coal gangue grouting filling in goaves was established. These findings were applied in the design of surface filling engineering in goaves via coal gangue grouting within a certain coal mine in northern Shaanxi, providing full-chain technical support for large-scale coal gangue grouting filling in goaves. The results of this study offer a valuable reference for the collaborative disposal of solid waste in mines. This will contribute to the achievement of the goals of peak carbon dioxide emissions and carbon neutrality.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 1859K]

  • An experimental study on seepage characteristics and grouting-induced permeability reduction of burnt rocks

    QIAN Ziwei;TAN Chunzhi;SUN Qiang;WANG Hai;ZHANG Gailing;School of Resources and Geosciences, China University of Mining and Technology;College of Geology and Environment, Xi'an University of Science and Technology;CCTEG Xi'an Research Institute (Group) Co., Ltd.;

    [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 showing complex and various spatial distributions. The interconnected large pores and fractures accounted for 56.72% of the total volume of voids, suggesting moderate connectivity in primary pore and fracture networks. Seepage experiments indicate that the burnt rocks exhibited a significant nonlinear relationship between the hydraulic gradient and flow velocity of seepage, with their seepage dynamics behavior consistent with the patterns characterized by the Forchheimer equation. The permeability varied significantly along different seepage directions, with differences in permeability coefficients of about 50%. Clay-cement grout exhibited high injectability within pore-fracture systems in the burnt rocks. The effective diffusion distance of the grout was predominately governed by the geometrical confinement effect of the pore-fracture throats. The proportion of pores and fractures filled by grout gradually decreased with an increase in the distance from the grouting port. The burnt rocks exhibited significant permeability reduction after grouting. The hydraulic gradient and flow velocity maintained a nonlinear relationship after grouting. Within 14 days after grouting, the permeability reduction rate increased with time, eventually stabilizing. These findings provide a theoretical basis and technical reference for water hazard prevention and control during coal seam mining in burnt rock areas.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 2758K]

  • 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;College of Energy and Mining Engineering, Shandong University of Science and Technology;State Key Laboratory of Coal Resource Efficient Mining and Clean Utilization;National Demonstration Center for Experimental Mining Engineering Education, Shandong University of Science and Technology;

    [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 coupling experimental apparatus, this study investigated the stress-strain behavior and permeability variations of sandstone specimens with different numbers(1, 2, and 3) of fractures before and after grouting under confining pressures of 6 MPa, 8 MPa, and 10 MPa.[Results and Conclusions] The ratio of the permeability of the fractured sandstones after grouting to that before grouting is defined as the grouting repair coefficient(Zs). Experiments indicate that a lower grouting repair coefficient is associated with a higher repair degree of the permeability. Under the same confining pressure, the permeability of the sandstone specimens increased to 27.6 to 283.4 times and decreased by 64.32% to 98.47% compared to their original permeability before and after grouting, respectively as the fracture number increased, with the grouting repair coefficient exhibiting a power-law decreasing trend. Under the same fracture number, when the confining pressure increased from6 MPa to 8 MPa and 10 MPa, the permeability of the sandstone specimens decreased by 48.42% to 85.30% before grounting and by 53.89% to 90.14% after grouting. Regarding the failure characteristics before and after grouting, fractures in the sandstone specimens propagated gradually from their ends to adjacent fractures and thus were interconnected with the latter as the fracture number increased, leading to the formation of more complex failure patterns and more secondary cracks. Based on engineering practice, random fractures were generated at a ratio of 1:100 relevant to the original fracture numbers(i.e., 1, 2, and 3) using software COMSOL and Matlab. The analysis of water flow velocity and grouting effects of the mining face roof and the bottom boundary of the sandstone aquifer verified the conclusion that more fractures within a certain range corresponded to a higher repair degree for sandstone permeability after grouting.This conclusion will provide strong technical support and scientific guidance for the safe mining of coal resources and disaster prevention and control.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 1870K]

  • 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;CCTEG Coal Mining Research Institute;Coal Mining and Designing Department, Tiandi Science &Technology Co., Ltd.;State Key Laboratory of Intelligent Coal Mining and Strata Control;Shaanxi Shanmei Caojiatan Mining Co., Ltd.;Mining Research Branch,CCTEG China Coal Research Institute;

    [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 of water flowing fractured zones in the overburden. Furthermore, this study proposed a water-controlled mining strategy in the presence of composite water bodies in the roof and analyzed the performance of mining using this strategy. [Results and Conclusions] The results indicate that the roof of the mining face with 10 m super high mining height represents a typical overburden structure of the soil-bedrock type. The laterites in the overburden enable fracture healing, resulting in repeat water resistance and thus inhibiting mining-induced fractures. Accordingly, the fractured zone/mining height ratio of the mining face is 22.56, and mining-induced fractures largely propagate below the laterites.Although very few fractures extend to laterites, the overall water resistance of the laterites remains. In this case, the bedrock and laterites exhibit the variation pattern of traditional water flowing fractured zones. Based on the analysis of the evolution of mining-induced failures in the overburden and the water filling pattern of the roof aquifer, this study proposed a water-controlled mining strategy consisting of the precise drainage of static reserves, increased discharge and water diversion for dynamic supply, full-space flow field monitoring, and the prevention of local roof cutting and leakage. A comprehensive analysis of multiple factors, including water levels in long-term hydrological observation holes,water inflow along the mining face, and hydrochemistry during the mining process, reveals that the mining-induced fractures only propagated to bedrock fissures and the aquifer in the weathering zone, while the Quaternary aquifer was unaffected by mining. These contribute to the safe and efficient water-controlled mining of the mining face with a super-large mining height. The results of this study can provide a basis for the prevention and control of the overburden failure and water disasters, as well as water resources protection, in mining with super-large mining heights and high mining intensity in China.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 3478K]

  • Regularity and mechanisms of water-sand inrushes within mining-activated faults

    ZHANG Shichuan;HUANG Pu;LI Yangyang;WANG Chenggong;WU Zhenhua;College of Energy and Mining Engineering, Shandong University of Science and Technology;Pengzhuang Coal Mine, Shandong Energy Luxi Mining Co., Ltd.;

    [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 on three factors at four levels, along with a deformations-seepage test system for fractured rocks, this study investigated the impacts of clay mass fraction, sand-grain size, and initial water pressure on the inrush behavior. [Results and Conclusions] Clay significantly inhibited the inrush behavior. Under a clay mass fraction of 40%, the inrush behavior exhibited extremely low flow and load. The initial water pressure served as the primary force driving the inrush behavior. An increase in initial water pressure significantly enhanced the inrush intensity. The sand grain size manifested a nonlinearly regulating effect on the inrush behavior. Small or large sand grain sizes were prone to cause system instability, while moderate grain sizes could balance permeability and system stability. The multivariate statistical analysis reveals that the impacts of various factors on the inrush behavior decreased in the order of clay content, initial water pressure, and sand-grain size. The predicted optimal test conditions to minimize the flow, load, and pore water pressure include a clay mass fraction of 30%, an initial water pressure of 0.3 MPa, and sand grain size ranges of [0.3, 0.5] mm,[1, 2] mm, and [0.5, 1.0) mm, respectively. The results of this study will provide a theoretical basis for the prevention and control of water-sand inrushes caused by mining-induced fault activation.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 2998K]

  • 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;CCTEG Coal Mining Research Institute;Coal Mining and Designing Department, Tiandi Science and Technology Co., Ltd.;Coal Mining and Designing Branch, China Coal Research Institute;

    [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 part of the Ordovician limestones in the Xin'an Coalfield, Western Henan. It investigated three typical grout types applied in surface treatment engineering of the Mengjin Coal Mine in the Xin'an Coalfield: pure cement grout, clay grout, and clay-cement grout through a range of experiments on the grouting pressure at the borehole head,static rheological characteristics, liquid-phase particle size distribution, zeta potential, electrical conductivity, microscopic morphology, and element distribution of the three grout types. Based on the flocculation mechanisms of cement and clay particles, this study analyzed pressure rise differences of three grout types from the physical and chemical perspectives. [Results and Conclusions] Positively-charged cement particles and negatively-charged clay particles were prone to form three-dimensional reticular flocs due to strong electrostatic attraction. Consequently, the clay-cement grout exhibited large particles(sizes: > 600 μm). Furthermore, particles with sizes greater than 100 μm accounted for 78% of the total. These particles easily blocked up fractures. Compared to the cement grout, the clay-cement grout showed decreased electrical conductivity of 1.87 mS/cm. As a result, clay particles were observed to encapsulate cement particles post-mixing. The cement grout, characterized by small particle sizes, lower static yield stress, and low viscosity, can easily pass through narrow fractures, ensuring stable grouting pressure. In contrast, the clay-cement grout featured a static yield stress 4.5 times higher and a static viscosity 4.0 times compared to the cement grout. Therefore, such grout was prone to block fractures, and the pressure rise rate was approximately 10 times greater than that of the cement grout. An alternating grouting technique using clay-cement grout and cement grout was proposed following the principle of stepwise and gradual pressure rise, consisting of low-pressure filling, medium-pressure diffusion, and high-pressure fracture reinforcement(also referred to as the “three-stage” alternating grouting technique). This technique can significantly enhance the treatment efficiency, providing a valuable reference for grouting treatment of low-permeability limestones under similar conditions.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 2411K]

  • 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;CCTEG Xi'an Research Institute (Group) Co., Ltd.;School of Earth Sciences and Surveying Engineering,Taiyuan University of Technology;Qilu Jiaotong College, Shandong University;National Engineering Research Center of Coal Mine Water Hazard Controlling, China University of Mining and Technology (Beijing);Faculty of Mining Engineering, Taiyuan University of Technology;Department of Resources Geo

    [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 fault zone initially. Then, using triaxial seepage tests, this study investigated the permeability evolutionary patterns of the fractured rock mass under cyclic loading and unloading, establishing the quantitative coupling relationship between the permeability coefficient and the confining pressure. Finally, based on the mechanical model analysis, this study constructed a numerical model for water inrushes along fault Fw159 in the Gaohe Coal Mine. Accordingly, the formation and evolution patterns of pathways for water inrushes from coal seam floors were analyzed. [Results and Conclusions] The pores and fractures in the fractured rock mass of the fault zone exhibited complex structures, rough edges, and non-directional development microscopically, and these characteristics governed the permeability of the rock mass. A negative exponential relationship was observed between the permeability coefficient and the confining pressure, with the variations in the seepage pressure playing a significant role in the displacement of the fractured zone in the floor and the formation of hydraulically conductive pathways. During coal mining, stress disturbance preceded the displacement effect, which became gradually pronounced after mining-induced stress peaked. As pore water pressure reached 3 MPa, confined water accumulated at the bottom of fault Fw159, migrating upward along the fractured zone of the fault until instability failure occurred. The results of this study reveal the inherent relationships between the permeability characteristics of fractured rock masses in fault zones and the water inrushes along faults from coal seam floors in coal mines, providing a theoretical basis for the prevention and control of water inrushes from coal seam floors and safe mining in coal mines.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 1940K]

  • 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;College of Water Resources and Hydropower, Xi'an University of Technology;CCTEG Xi'an Research Institute (Group) Co., Ltd.;State Key Laboratory of Coal Mine Disaster Prevention and Control;

    [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, this approach is also an urgent need for the conservation and utilization of water resources in mining areas on the premise of guaranteeing the production safety of coal enterprises. [Methods] The existing technology of mine water allocation faces several issues, including less comprehensive allocation rules based on supply priorities and water quality and insufficient consideration of the special properties of mine water. To overcome these limitations, using surface water, groundwater, mine water, and reclaimed water as water sources, this study developed a multi-objective allocation optimization model considering economic and environmental benefits and equity for water resources in coal mining areas. Based on the newly established water resource allocation rules and in combination with the conditions including water balance, water quality standards, and constraints on water consumption, this study employed the non-dominated sorting genetic algorithm Ⅱ(NSGA-Ⅱ) to determine the monthly allocation schemes for water resources under the base year of current status level in a coal mine within the Inner Mongolia-Shaanxi contiguous area. Moreover, this study assessed the allocation schemes orientated to economic benefits, environmental benefits, and equity, based on the Pareto solution set. This study case validated the effectiveness of the model. [Results and Conclusions] The allocation results proved reasonable, with the average annual utilization rate of mine water determined at about 78.4%. The average monthly utilization rate of mine water was positively correlated with the difference between monthly water supply and demand, with ecological and agricultural water demand acting as significant influential factors. April and August saw the highest(92.2%) and lowest(31.4%) average monthly utilization rates of mine water, respectively. Economy-or environment-orientated schemes are recommended for the two months.For the environment-orientated scheme from January to December, the utilization rate ranges of surface water, groundwater, mine water, and reclaimed water were calculated at 100%, 35.21% to 100.00%, 32.18% to 95.11%, and 82.89% to100.00%, respectively. The satisfaction rates for domestic, industrial, ecological, and agricultural water ranged from95.00% to 98.16%, from 97.27% to 109.14%, from 94.35% to 105.05%, and from 81.95% to 108.85%, respectively. The low utilization rate of mine water corresponded to increased utilization rates of other water sources, indicating an unreasonable water supply structure. The results of this study provide a theoretical basis and practical guidance for the scientific management and comprehensive utilization of mine water in mining areas while also offering a reference for the allocation optimization of similar resources.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 1798K]

  • Groundwater rebound and seepage characteristics and water quality evolution in a sealed mining area in North China type coalfield

    YIN Huiyong;SUN Dehui;DONG Fangying;WANG Fanhua;ZHANG Lifeng;WU Tao;LIU Chao;ZENG Yifan;College of Earth Science and Engineering, Shandong University of Science and Technology;Zaozhuang Mining Group Co., Ltd.;Binhu Coal Mine, Zaozhuang Mining Group Co., Ltd.;College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing);

    [Background] The seepage field and water quality evolution associated with the groundwater rebound induced by the sealing of mining areas significantly affects the prevention and control of mine water hazards, as well as the recycling of water resources. Systematically elucidating the mechanisms underlying the seepage-hydrochemistry synergy of groundwater is recognized as a fundamental scientific issue for promoting the collaborative management and resource development of the water systems in mining areas. [Methods] Based on the engineering background of the sealed No.116 mining area in the Binhu Coal Mine, Zaozhuang, Shandong Province, this study investigated the groundwater rebound and seepage characteristics, along with the associated evolutionary patterns of ion concentrations and mineral phases in groundwater, using hydrochemical tests, numerical simulation, and theoretical calculation. Furthermore, this study characterized groundwater rebound and hydrochemical evolutionary models. [Results and Conclusions] The existing accumulated water was primarily distributed in the western part of the No.116 mining area in the Binhu Coal Mine. Based on the water inflow before the sealing of the mining area, it can be estimated that the accumulated water would fill the whole goaf within 426 days. Specifically, within the initial 90 days after sealing, the water inrush points continuously discharged water, causing the groundwater level in the goaf to rise to-450 to-250 m rapidly. Within90-360 days post-sealing, the groundwater rebound in the goaf slowed down, with the water level on both sides of the goaf reaching-150 m. Consequently, the water level remained relatively stable until at day 455 post-sealing, when the goaf was full of accumulated water. The process was largely consistent with the expected results. By this time, the groundwater flow field roughly reached equilibrium. During the water rebound along fractures and water inrush from Ordovician limestone and the fourteenth limestone aquifers, cation exchange was accelerated, with the Na+ and K+ concentrations increasing rapidly and the Ca~(2+) and Mg~(2+) concentrations decreasing significantly. At this stage, the quantities of mineral phases such as albite, potassium feldspar, and halite increased, while those of quartz, calcite, and dolomite decreased due to dissolution or precipitation. After the goaf sealing, water-rock interactions persisted during the reinjection of the accumulated water, but the cation exchange rate slowed down. The mineral phases showed similar but weakened variation trends compared to the water inrush stage. Finally, a hydrochemical equilibrium system characterized by high Na~+/K~+ and low Ca~(2+)/Mg~(2+) concentrations was formed. The whole process reflects the hydrochemical evolution model of the sealed mining area from dynamic water inrush disturbance to slow self-equilibrium. The results of this study provide a reference for revealing the evolutionary pattern of the water environment in goaves under similar settings and offer a theoretical basis for the development and utilization of groundwater resources in sealed mines.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 3755K]

  • Design and efficiency assessment of a passive treatment system for acid mine drainage

    YAN Ruiwen;ZHU Jun;ZHU Junhao;LIN Gang;ZHANG Wanqiu;JIA Zenghua;WANG Wenming;XI Furui;College of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing);Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences;China Geo-Engineering Corporation;China Institute of Geo-Environmental Monitoring;Key Laboratory of Mine Ecological Effects and Systematic Restoration, Ministry of Natural Resources;

    [Background] Acid mine drainage(AMD) refers to highly acidic, heavy metal-rich effluent generated from mining activities, potentially causing severe environmental contamination. [Methods] Focusing on the Lujiang alum mine in Anhui Province, this study established a systematic framework for the design and assessment of an integrated passive AMD treatment system using the Phreeqc and AMDTreat software. Based on a comprehensive analysis of the onsite hydrogeochemical characteristics(pH: 2.93-3.06, Fe: 5.98-42.52 mg/L, and Al: 18.87-32.14 mg/L) and physical conditions(flow rate: 50-96 m~3/h, available area: about 50 000 m~2), this study proposed a hybrid passive treatment system comprising a vertical flow wetland and a following aerobic artificial wetland. Finally, this study predicted the performance of the system using a Phreeqc-based hydrogeochemical model. [Results and Conclusions] The results indicate that the integrated passive treatment system could effectively increase the effluent pH to approximately 7.6 and yield high removal rates of above 99.0% for Fe and Al and above 97.0% for other heavy metals like Cu. Accordingly, the effluent quality after treatment satisfied the criteria for class III water specified in Chinese standard Environmental Quality Standards for Surface Water(GB 3838-2002). The life-cycle cost analysis performed using AMDTreat indicates that the construction costs and annual operation and maintenance(O&M) costs of the proposed system were approximately 3.68 million yuan and 0.46 million yuan, respectively. Therefore, this system enjoys significant long-term cost advantages over traditional active treatment technologies. The proposed design method that integrates technology selection,efficiency simulation, and economic assessment not only suits the AMD treatment of the Lujiang alum mine but also provides a scientific basis and technical reference for ecological restoration of similar mining areas.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 1642K]

  • Conversion relationships and three-dimensional storage and utilization modes of four water resources in an open-pit mining area

    CHEN Tianci;XU Zhimin;SUN Yajun;FANG Jie;WANG Qiangmin;XIONG Xiaofeng;ZHU Yuhao;LU Zihan;WAN Fei;School of Resources and Geosciences, China University of Mining and Technology;Fundamental Research Laboratory for Mine Water Hazards Prevention and Controlling Technology;State Key Laboratory of Water Resource Protection and Utilization in Coal Mining, National Institute of Clean-and-Low-Carbon Energy;CCTEG Xi'an Research Institute (Group) Co., Ltd.;

    [Background] Open-pit coal mines in China are primarily distributed in arid and semi-arid regions such as Xinjiang and Inner Mongolia. However, the contradiction between coal mining and groundwater resource conservation is increasingly prominent in these regions. Specifically, a substantial amount of mine water inflow produced during coal mining tends to lead to the further loss of groundwater resources within the influence range of a mining area. Concurrently, the failure of efficient mine water storage intensifies the regional water shortage. [Methods] This study investigated a typical open-pit coal mine in eastern Inner Mongolia. Using methods such as field survey and sampling, borehole monitoring, laboratory hydrochemical tests, and numerical simulation, this study primarily determined the quantitative composition, hydrogeochemical characteristics, and mutual conversion relationships of meteoric water, surface water,groundwater, and mine water(collectively referred to as the four water resources). Furthermore, this study established a three-dimensional storage and comprehensive allocation and utilization system for the four water resources in the openpit mining area. [Results and Conclusions] The results indicate that the groundwater and mine water in the mining area were primarily recharged by meteoric water. Under the influence of open-pit coal mining, the regional groundwater loss reached 3 081.2×104 m3/a, leading to the formation of a groundwater depression cone with an average area of 15.26 km2and a radius of approximately 1.88 km. Given the scarce meteoric water and intense evaporation in the area, the total groundwater loss in the mining area could exceed 40×108 m3/a. Accordingly, this study proposed a three-dimensional mine water storage framework, which involved five modes: surface storage, storage on the pit bottom and slopes, the reconstruction of ecological aquifers in the waste dump, water reinjection into the Quaternary loose aquifer, and water reinjection into the deep bedrock aquifer in the coal seam floor. By combining the water quality and quantity characteristics of the four water resources and the water demand of various water consumption sectors, this study proposed five water allocation and utilization pathways: production and ecological water use within the mining area, as well as domestic,industrial, agricultural, and ecological water use in surrounding areas. By constructing an allocation model for the four water resources using an improved genetic algorithm, this study established a three-dimensional storage and comprehensive allocation and utilization system characterized by four water resources, five storage modes, and five utilization pathways for the open-pit mining area. Combining the calculation results of the allocation model of the four water resources, this study developed a groundwater resource conservation philosophy for the mining area, which utilizes groundwater drained from mines as the water source, centers on water reinjection(365×104 m3/a) into the Quaternary aquifer outside the grouting curtain used to cut off water on the east slope, and stores water(20×104 m3) dynamically on the pit bottom and slopes. Simulation results indicate that the maximum rise in the groundwater table of the Quaternary aquifer outside the grouting curtain reached 1.54 m. This finding indicates that the philosophy can effectively reduce groundwater loss caused by open-pit coal mining and facilitate regional groundwater table rise. The results of this study hold significant theoretical implications and considerable engineering application value for the efficient storage, conservation, allocation, and utilization of open-pit mine water.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 2511K]

  • 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;School of Resources and Geosciences, China University of Mining and Technology;Key Laboratory of Xinjiang Coal Resources Green Mining, Ministry of Education, Xinjiang Institute of Engineering;State Key Laboratory of Internet of Things for Smart City, University of Macao;

    [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 criteria for the selection, there is an urgent need to develop methods for quantitative selection and evaluation. [Methods] Using a fuzzy comprehensive evaluation method and the analytic hierarchy process(AHP), this study proposed a suitability evaluation index system for the deep geological storage of mine water in the Ordos Basin and developed an evaluation method.Specifically, the evaluation indices were selected based on geologic stability, storage potential, and hydrogeological conditions. Then, based on the geological characteristics of the first-order tectonic units and deep strata in the basin, the scores and weights of individual evaluation indices of the tectonic units were determined. Finally, the comprehensive suitability score was calculated by combining the weights. [Results and Conclusions] The analysis and calculation of geological conditions reveal that the Ordos Basin has a potential geological storage capacity for liquids of 9.78×1012 m3,suggesting great storage potential. The evaluation method and indices were proposed in combination with the geological characteristics of the Ordos Basin. The evaluation indices included three first-level and 12 second-level indices for the suitability evaluation of tectonic units, as well as four first-level and 19 second-level evaluation indices for the suitability evaluation of deep strata. The evaluation results reveal that the slope tectonic unit in northern Shaanxi is the most suitable area for deep mine water storage. Within this slope, the suitable deep reservoirs include the reservoir-cap rock assemblages of the Ermaying, Heshanggou, and Liujiagou formations, as well as the self-reservoir-self-caprock assemblage of the Majiagou Formation. The results of this study provide a basis for selecting the preferential areas for mine water storage for experiments.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 1744K]

  • Advances in key technologies for the management, restoration, development, and utilization of coal mining subsidence areas

    MENG Zhuanghan;WANG Yutao;TIAN Yanzhe;CCTEG Ecological Environment Technology Co., Ltd.;School of Civil Engineering and Architecture, Xi'an University of Technology;

    [Background] Coal mining subsidence areas, formed by the exploitation of coal resources, have emerged as severe challenges to the construction of ecological civilization and the sustainable development of the social economy in China. Their management, restoration, development, and utilization play a significant role in ecological security, food security, and energy transformation. [Methods] This study aims to address the unresolved and emerging issues in the management of coal mining subsidence areas. Based on the core concepts of management, restoration, development, and utilization, this study developed a dual-level zoning basis system combining theories and reality. Accordingly, coal mining subsidence areas in China were classified into six types of functional areas: cultivated land restoration areas in plains,ecological conservation areas in alpine forest lands and grasslands, wetland construction areas in areas with high phreatic surfaces, renewable energy development areas in deserts, urban construction and utilization areas, and underground space development and utilization areas. For these areas, this study systematically summarized the advances in key technologies, practical achievements, and existing challenges. [Advances] For cultivated land restoration areas in plains, the filling material optimization, scientific soil reconstruction technology, and proactive restoration strategy have been integrated to restore the productivity of destroyed cultivated land. For ecological conservation areas in alpine forest lands and grasslands, the selection and configuration of hardy plants, the construction of matching soil matrix, reasonable artificial vegetation rehabilitation, and differential water resource management have been combined to address the challenge in ecological reconstruction in extreme environments. For wetland construction areas in areas with high phreatic surfaces,novel wetland agriculture, artificial regulation of water resources, and photovoltaic development have been jointly adopted to reconstruct hydrological systems and transform ecological value. For renewable energy development areas in deserts, renewable energy development and construction, ecological effect assessment, and renewable energy consumption have been explored to support the construction of energy bases in deserts, Gobi, and wastelands. For urban construction and utilization areas, a whole-process technology chain consisting of fine-scale exploration, targeted management,deformation-resistant structures, grouting quality detection, multi-approach collaborative monitoring, monitoring and early warning of residual deformations, and collapse risk control has been utilized to ensure the safe construction of aboveground and ground engineering. For underground space development and utilization areas, multi-dimensional development and utilization paths for abandoned mines have been explored based on the function transformation potential and development suitability of abandoned mines. [Prospects] From the perspectives of intelligence level, digital transformation, and the economic development of carbon sinks, this study envisions the management, restoration, development, and utilization trends of coal mining subsidence areas. Moreover, this study proposes subsequent research directions, including the resource utilization of Yellow River sediments and corresponding intelligent mining and restoration coordination, the precise configuration of communities facilitating ecological restoration and frozen soil protection in alpine mining areas, and the economic value assessment of wetland carbon sinks in subsidence areas with high phreatic surfaces. The results of this study will serve as a reference for the sustainable development of mining cities in China.

    2025 07 v.53;No.331 [Abstract][OnlineView][Download 3442K]