Abstract:Over the past decade,China has achieved remarkable progress in the prevention and control of coal bursts.The scientific philosophy of burst prevention has taken root,and a coherent body of policies,regulations and technical solu-tions has erected a solid safety barrier for coal-resource development.However,as coal mining depths continue to in-crease and extraction intensity keeps rising,the number of rock burst mines across the country has reached 177(based on incomplete statistics),showing a year-on-year upward trend.At the same time,coal production capacity has been shifting westward to the core mining bases of"Shanxi-Shaanxi-Inner Mongolia-Xinjiang".The modern mining model character-ized by"concentrated single-mine operations"presents new challenges for rock burst prevention,with no ready-made ex-perience to draw from.Rock burst has become a critical factor restricting the scientific and rational release of production capacity in these regions.Currently,the engineering context of deep mining and ten-million-ton production capacity in coal mines has significantly reduced the margin for error and opportunities for trial-and-error in rock burst prevention.The traditional approach of"experience-based trials and adjustments after implementation"can no longer address the existing challenges.In particular,regional measures covering large-scale mining areas,such as surface fracturing and ultra-long boreholes underground,now demand unprecedented levels of differentiation and precision.Although the industry agrees that effective burst prevention must start at the source,turning this consensus into executable scientific theory,engineer-ing technology and dedicated equipment remains an unresolved issue.Worth noting is that the rapid advance of digital and intelligent technologies in recent years has opened new windows of opportunity;a novel paradigm of digital source pre-vention is emerging.At this hinge moment,a systematic review of China's coal-burst status and problems and an in-depth analysis of the core contradictions will not only furnish the cognitive foundation required for high-quality development of the coal sector,but also provide methodological support for building a precise,digital burst-prevention system.

Abstract:To address the safety needs of coalburst mines in China and fulfill the national"zero coalburst"management objectives of no casualties,no roadway damage,and no equipment damage,this study proposes the hierarchical preven-tion and control objectives and technical paths for"zero coalburst":① The highest objective is"no coalburst occurrence"with the technical path of"no stress overrun".Through theoretical derivation,critical stress formulas were obtained for 3 types of coalbursts,namely coal compression-type coalburst,roof tensile-type coalburst,and fault shear-type coalburst.An analysis was conducted on"no stress overrun",systematically investigating the influence relationships between the actual stress of the 3 types of coalbursts and mining conditions as well as geological conditions,and the relationships between critical stress and the geometric parameters of the coal-rock deformation system and its own physical and mechanical para-meters."No stress overrun"can be achieved by reducing actual stress and increasing critical stress;on this basis,engineer-ing measures for reducing actual stress and increasing critical stress for the 3 types of coalbursts were systematically sor-ted out.② The basic objective is"no coalburst damage"with the technical path of"no residual energy".Through theoret-ical derivation,formulas for energy release and energy absorption of the 3 types of coalbursts have been obtained.An ana-lysis was performed on"no residual energy",systematically studying the maximum released energy and absorbed energy of the 3 types of coalbursts.Impact tests on rock samples and support structures were carried out,and the results showed that the drilling structure of rock samples can absorb impact energy and reduce the overall damage of rock samples.En-ergy-absorbing devices can significantly improve the energy absorption capacity of supports,with the energy absorbed by the energy-absorbing devices accounting for 78.6％of the total energy absorbed by the supports."No residual energy"can be achieved by reducing the energy released by coalbursts and increasing the energy absorbed by the surrounding rock and supports.The engineering measures for reducing the released energy of the 3 types of coalbursts,the engineering meas-ures for increasing the absorbed energy of surrounding rock and supports were systematically sorted out.③ The bottom-line objective is"no coalburst injuries"with the technical path of"adequate space guarantee".The roadway deformation values causing coalburst injuries were analyzed and determined as follows:the section shrinkage rate exceeds 20％,and the support deformation exceeds 20 cm."Adequate space guarantee"can be achieved by energy-absorbing devices.En-ergy-absorbing devices can share up to 70％of the impact deformation of hydraulic supports through yielding deforma-tion,which protects the roadway support structure and controls the support deformation within 20 cm.The engineering measures are as follows:Roadways shall be reinforced with energy-absorbing hydraulic supports,and the appropriate type and model of energy-absorbing hydraulic supports shall be selected based on the maximum released energy of coalburst,the direction of impact load and the roadway conditions.This study confirms that the"zero coalburst"prevention and con-trol objective can be achieved through stress control,energy control,and space control,providing theoretical and technical support for coalburst mines to realize"zero coalburst".

Abstract:Underground Coal Gasification(UCG)is a chemical mining method that converts underground coal into com-bustible gases such as H2,CH4,and CO through controlled combustion.UCG is an important technical means for achiev-ing clean and efficient utilization of deep coal resources.A large number of gasification chambers are formed after the completion of UCG,which serve as high-quality natural spaces for the geological storage of carbon dioxide.However,the current UCG technology faces challenges such as difficult reaction process control,poor gas production quality and stabil-ity,uncertain gasification chamber stability,and inadequate long-term sealing of the cover layer,which hinder its wide-spread application.The work focuses on the development prospects of deep underground coal gasification coupled with carbon dioxide storage(UCG-CCS),systematically reviewing the research progress at home and abroad in three aspects:first,the generation laws and regulation methods of underground gasification products;second,three dimensional evolu-tion characteristics of gasification chambers under multi-field coupling conditions;third,the dynamic evolution mechan-ism of the sealing properties of the surrounding rock under the thermal effect of CO2 sequestration in the gasification chambers.On this basis,three core scientific challenges that urgently need to be addressed at present are summarized:① Unclear mechanism for efficient gas production regulation under the thermal and mass transport conditions of native dense coal;② Unclear mechanism for secondary weak surface formation in the surrounding rock of underground gasifica-tion chambers under multi field coupling conditions;③ Unclear dynamic evolution mechanism of gasification chamber sealing under chemical mechanical coupling.Furthermore,three major research challenges have been summarized:how to achieve long-term stable and efficient gas production in UCG,how to control the stability of gasification cavity structure under high recovery rate conditions,and how to achieve long-term safe CO2 storage in gasification chambers of UCG.Fi-nally,the key research directions for future work are prospected,which provides references for the clean and efficient util-ization of deep coal resources and the safe sequestration of CO2.

Abstract:As the primary energy source in China,coal plays a crucial role in national energy security.More than two-thirds of coal reserves are distributed in arid and water-scarce regions.Low-quality coal accounts for approximately 40％of total resources.With the widespread application of fully mechanized mining,the production of fine coal(＜6 mm)has increased to more than 40％of raw coal.Although dry separation technologies for ≥6 mm coarse coal have achieved stable industrial application in several mining areas,the separation accuracy for＜6 mm fine coal remains limited.In addi-tion,hydraulic fracturing and water spraying for dust suppression during mining substantially increase the moisture con-tent of raw coal(above 15％),leading to pronounced particle agglomeration.These factors highlight the need to develop effective dry separation theories and technologies for moist and low-quality fine coal.The performance constraints of gas-solid fluidized separation and vibration-air synergistic separation technologies that have been utilized in industrial applica-tions are examined.Based on flow responses,interface formation mechanisms,and equipment adaptability under condi-tions of moist low-quality fine coal,several key scientific questions are summarized.These include density-stratification regulation and multiscale flow coupling in gas-solid fluidized separation,controllable construction of stable force fields for vibration-air synergistic separation of low-quality fine coal,and nonequilibrium thermos-hydrodynamic coupling mechan-isms governing moisture removal from wet particles.The numerical simulations and theoretical models from experimental studies are synthesized,concerning fine dense-medium gas-solid fluidized separation,vibration-air synergistic separation,fluidized-bed drying,and transient steam flash drying.For fine dense-medium gas-solid fluidized beds,findings related to bed expansion,pressure fluctuations,bubble dynamics,and electrical capacitance tomography(ECT)are summarized with corresponding flow-regime criteria,density-control correlations,and quantitative instability indicators.For vibration-air-flow synergistic separation,the researches are reviewed on vibration acceleration responses,the evolution of surging struc-tures,three-dimensional particle dynamics,interface formation behavior,and parameter combinations involving high-fre-quency vibration and stepped air distribution.For drying processes,studies on liquid-bridge mechanics,heat and mass transfer under vibration-airflow coupling,nonequilibrium thermodynamic drying models,and the energy distribution and moisture-migration characteristics during saturated-steam pressurization followed by rapid depressurization are synthes-ized.Building on these findings,the processes of drying,dry screening,and dry separation are reorganized to summarize and discuss an integrated"Drying-Dry screening-Dry separation"beneficiation approach for＜6 mm fine coal.In this scheme,moderate drying reduces liquid-bridge adhesion,dry screening forms a narrow size-fraction feed,and gas-solid fluidized or vibration-airflow synergistic separators accomplish dry separation,thereby expanding the applicability of dry beneficiation to a broader range of coal types and particle sizes.Overall,existed studies have established a preliminary foundation in multiscale coupling mechanisms,quantitative characterization of flow stability,and integrated design of dry-ing and separation.The further progress is needed in multiphysics coupling under complex operating conditions,intelli-gent monitoring and adaptive control,and the integration of dry beneficiation with waste-heat recovery and carbon-reduc-tion objectives.That provides references for future research and process optimization related to the efficient dry upgrading of fine coal.

Abstract:In recent years,the number of coal mine closures in our country has gradually increased,and abandoned coal mine goaf areas have become potential sources of groundwater pollution,characterized primarily by high sulfate mine wa-ter.Under certain conditions,native microbial communities within these goaf areas can drive the sulfur cycle,stimulating the potential for natural purification of mine water.To explore the evolutionary control mechanism of mine water quality in closed coal mine goaf areas and the microbial mechanism of sulfate removal,this paper used a typical coal mine in Northwest China as the research object.Through the design of five long-term indoor microcosm experiments under differ-ent conditions(experimental group,coal multi-group,culture medium group,culture medium and microbial group,and sterilization group),and utilizing water chemistry testing,16S rDNA high-throughput sequencing,and other testing meth-ods,the hydrochemical characteristics and microbial mechanisms of sulfate removal in mine water were systematically in-vestigated.The hydrochemical characteristics study showed that the SO42-concentration in the experimental group and the coal multi-group system first increased and then decreased.The SO42-concentration decreased by 96％in the culture medi-um group,by 95％in the culture medium and microbial group,and by 57％in the sterilization group.These hydrochemic-al indicators suggest that,under anaerobic conditions and with available carbon sources,closing the coal mine goaf has the potential for low-cost biological removal of sulfate from mine water.Microbial sequencing results showed that exogenous microorganisms may disrupt the native microbial ecological metabolic network.Bacteria species that degrade micromolec-ular organic matter in coal exist in the goaf system,forming a synergistic system with sulfate-reducing bacteria.The relat-ive abundance of sulfate-reducing bacteria in the three groups(culture medium group,culture medium and microbial group,and sterilization group)was significantly increased,reaching as high as 70.1％and 79％,respectively,indicating that the microbial reduction process is key to controlling sulfate removal.Based on the above research findings,the evolu-tion mechanism of mine water quality in closed coal mine goaf areas was elucidated:Under conditions without exogenous small-molecule carbon sources,indigenous SRB(stomach-derived biofilm organisms)are in a low-activity or dormant state,and the evolution of mine water quality in goaf areas is dominated by hydrochemical processes such as pyrite oxida-tion,mineral dissolution,and clay mineral adsorption.However,with the addition of exogenous carbon sources,microbial activity becomes the main controlling factor.The type and concentration of the carbon source determine the direction of the mutual transformation and coupling between the hydrochemical field and the microbial field in the evolution of mine water quality in closed coal mine goaf areas.If indigenous bacterial communities with the ability to degrade coal organic matter can be domesticated or enriched,low-cost self-purification of mine water can be achieved.

Abstract:The period of the 14th Five-Year Plan is a crucial stage for China's coal industry to fulfill its core mission of ensuring energy security and accelerate its transformation towards intelligence,greenization,and integration,achieving high-quality development.This article systematically summarizes the major progress made in scientific and technological innovation in China's coal industry during the 14th Five-Year Plan period,analyzes the new situation and challenges faced by the current industry development,and in light of national strategic demands and the laws of industrial evolution,pro-poses thoughts on the direction of scientific and technological innovation in the 15th Five-Year Plan period.During the 14th Five-Year Plan period,the scientific and technological innovation system of the coal industry has been continuously improved,and a series of major breakthroughs and landmark achievements have been made in ten key areas including geo-logical exploration,mine construction,green mining,disaster prevention and control,coal mining equipment,intelligent coal mines,clean and efficient utilization,ecological restoration,energy conservation and environmental protection,and occupational health.The industry as a whole has achieved a major transformation from tracking and imitating to being on par and even leading in some fields.Currently,the international energy landscape is undergoing profound changes,and the domestic energy structure is accelerating its adjustment.Facing the new requirements of building an energy power and a modern industrial system in the 15 th Five-Year Plan period,the development goals of scientific and technological innova-tion in the coal industry in the 15th Five-Year Plan period are proposed in three aspects:national security,energy trans-formation,and industry development.These include supporting the construction of a new energy system through the de-velopment of clean and efficient coal utilization,ensuring national energy security through promoting self-reliance and strength in coal science and technology,and leading industry transformation and upgrading through the expansion of AI applications to drive intelligent construction.Based on these three goals and the index requirements pointed out in relev-ant national industrial policies,six directions of thought for scientific and technological innovation in the coal industry in the 15th Five-Year Plan period are proposed:① Deep coal resource extraction,focusing on breakthroughs in basic theor-ies of mining at depth,safety guarantee technologies,and disruptive cutting-edge technologies;② Achieving self-reliance and control of the industrial chain,fully promoting the domestic research and development and industrial application of large-scale open-pit continuous mining and stripping equipment,transportation equipment,self-reliant industrial control systems,and intelligent operation and maintenance platforms;③ Clean and efficient utilization of coal,strengthening technological research and development in green mining,clean utilization,low-carbon conversion,and new coal-based materials;④ Synergistic and integrated development of coal and new energy,upgrading mining areas into multi-energy complementary comprehensive energy bases by revitalizing mining area space resources,promoting clean energy substitu-tion for production energy,and building an integrated source-grid-load-storage system;⑤ Upgrading intelligent coal mine technology,breaking through the technical bottlenecks for stable and regular operation around intelligent tunneling,intelli-gent coal mining,intelligent open-pit mining and stripping,intelligent coal preparation,auxiliary transportation,and other systems,and achieving unmanned and less manned operations;⑥ AI+coal related scenarios,promoting the in-depth ap-plication of AI technology in scenarios such as safe production,coal conversion,coal mining equipment manufacturing,knowledge graph construction,embodied intelligence,and auxiliary programming.Finally,five measures for building a high-level scientific and technological innovation system are proposed to form a continuous innovative force that pro-motes the high-quality development of the coal industry and supports the construction of Chinese-style modernization.

Abstract:Precise monitoring and quantitative inversion of coal-rock fracture geometries and stress-field distributions are regarded as fundamental scientific prerequisites for elucidating the evolution of rockburst processes and associated failure mechanisms,and are considered an essential approach for resolving dynamic disaster evolution in deep engineer-ing.Microcrack source models corresponding to different fracture types are established on the basis of the displacement discontinuity theory.By modifying the Bott assumption,a stress inversion model applicable to tensile-shear fractures is proposed,and a composite failure criterion is constructed through the integration of the Griffith and Mohr-Coulomb criter-ia,enabling effective identification of true fracture planes.With the optimal compatibility between source-mechanism parameters and stress-field parameters taken as the target,a joint iterative inversion method of microcrack sources and stress fields is further developed,followed by laboratory-scale monitoring and inversion experiments on coal-rock fail-ure.The results indicate that the offset angle α effectively discriminates tensile,shear,and compressive fracture types.The iterative solution method for fracture planes and stress based on the tensile-shear composite failure criterion enables ro-bust selection of true fracture planes and improves stress inversion accuracy.Establishment of a joint alternating inversion model of microcrack sources and stress effectively reduces the deviation between theoretical and actual slip directions.During three-point bending tests on coal-rock specimens,α predominantly ranges between 0° and 20°,indicating that microcracks mainly exhibit tensile-shear composite characteristics.The stress inversion model yields a maximum princip-al stress σ1 in tension,whereas σ2 and σ3 are compressive.The average stress shape ratio reaches 0.87,demonstrating the dominance of σ1 and the near equivalence of σ2 and σ3,consistent with the loading state of three-point bending speci-mens.The stress distribution governs crack motion predominantly as tensile separation along the X-ax is and promotes crack development preferentially oriented along the Y-axis.Moreover,stress rotation reduces the Y-axis component of fracture-plane orientation,increases the angle between crack motion and the X-axis,and this alteration intensifies with increasing rotation angle.Optimization of the stress inversion process using the joint inversion method progressively lowers the mean slip deviation angle between theoretical and actual slip directions by 33.91％,79.86％,and 94.12％,re-spectively.Compared with the VAVRYČUK method,the proposed tensile-shear source stress inversion method achieves up to a 6.49％reduction in the noise error rate of the stress shape ratio,while improving the average accuracy of three-directional stress inversion by approximately 15％-40％.These findings provide a rigorous methodological framework for investigating the dynamic failure evolution of coal-rock masses and offer new theoretical support for deciphering the in-cubation mechanisms of rockburst hazards and advancing disaster early-warning strategies in deep engineering.

Abstract:Although tunnel structures are confined by the surrounding strata,and relative movement between the structure and strata is not obvious under seismic loads,resulting in significantly superior seismic performance compared to surface structures,they are not entirely"seismic-free".With the continuous development of the construction of tunnels and under-ground engineering,it is a major challenge for structural earthquake-resistant fortification design.Therefore,it is of great significance to conduct in-depth research on the seismic performance of underground structures and to promote their seis-mic resilience.First of all,the established tunnel seismic damage databases worldwide are reviewed.Based on the typical tunnel seismic cases,the main seismic damage characteristics are summarized,and the damage influencing factors and mechanisms are analyzed,respectively.Then,to effectively recognize the ground motion features of a rock mass,an ex-tensive literature review is performed to explore the rate-dependent effect and the mechanical behavior under cyclic load-ing and unloading of rock and joint,and stress wave propagation principles in jointed rock.Additionally,from the per-spective of seismic analysis of underground engineering structures,research progress and urgent key issues to be solved in the physical similarity experiment,dynamic time-history analysis,simplified seismic analysis method,wave analysis method,and seismic vulnerability analysis.Finally,the current common seismic protection countermeasures of under-ground structures are sorted out to provide a reference for seismic reinforcement of tunnels and underground projects in the future.It can be seen that tunnel lining will emerge with different degrees of damage during a certain level of earth-quakes,such as slight cracks,spalling,leakage,dislocation,and collapse,which are related to ground motion parameters,structural characteristics,and geological conditions.Engineering rock mass exhibits a very strong rate-dependent effect.When it is subject to cyclic loading and unloading,the stress-strain curve will exhibit closed plastic hysteresis loops,and irreversible cumulative damage occurs.It is worthy of attention to develop a dynamic constitutive model that can charac-terize the rate effect and cyclic load properties of geotechnical and concrete materials and embed it into numerical simula-tion.Poor surrounding rock conditions will aggravate the acceleration,dynamic earth pressure,and strain response of the lining structure.Considering that the dynamic response of the lining structure crossing the fault zone is more intense,the study of structural response under coupling strong earthquake,fault dislocation,and high ground stress may be necessary.Since the sudden change of stiffness and the effect of stress concentration,the structural junctions and spatially overlap-ping sections between tunnel groups are often the weak links of tunnel seismic resistance.The simplified seismic analysis method considering the group cavities effect needs to be further explored.Integrating seismic vulnerability and functional recovery capacity of underground structures is a critical approach to enhancing seismic resilience.The combination of multiple protection strategies,the introduction of new materials,and new structural systems is the focus of future seismic protection design.

Abstract:To address the problem that the strength and permeability of coal briquettes used in physical similarity simula-tion tests differ significantly from those of raw coal,this study investigates the pore structure,mechanical and seepage characteristics of coal samples with different ranks after hot-pressing,and reveals the influence mechanism of coal rank on the properties of hot-pressed coal briquettes.Using a self-developed hot-pressed coal briquette forming system,hot-pressed coal briquette specimens of four different coal ranks are prepared.The pore structure characteristics of hot-pressed coal briquettes and raw coal with different coal ranks are comprehensively characterized and compared via high-pressure mercury intrusion and low-pressure nitrogen adsorption tests.Uniaxial compression and triaxial seepage tests are conduc-ted to analyze the influence of coal rank on the mechanical and seepage properties of hot-pressed briquettes.Finally,based on the key parameters obtained,the similarity between hot-pressed coal briquettes and raw coal is quantitatively evaluated using a Euclidean distance-based similarity measurement method.Results indicate that in terms of pore structure,with the increase of coal rank,the most probable pore diameter of hot-pressed coal briquettes first increases and then decreases,and the pore connectivity first enhances and then weakens.In terms of mechanical and seepage properties,uniaxial compress-ive strength and elastic modulus of hot-pressed coal briquettes decrease gradually with increasing coal rank,while initial permeability first increases and then decreases.Similarity analysis indicates that hot-pressed lignite briquettes exhibit the highest similarity to their raw coal,with the most probable pore diameter being 0.8 times that of raw coal,uniaxial com-pressive strength of 13.04 MPa,elastic modulus of 1.012 times that of raw coal,peak principal stress difference of 0.98 times that of raw coal,and initial permeability of 1.3 times that of raw coal.Hot-pressed coal briquettes of other coal ranks still show certain gaps compared with their corresponding raw coal.However,compared with conventional cold-pressed briquettes,all hot-pressed briquettes of different coal ranks show increased strength and reduced permeability,and this modification effect gradually weakens with increasing coal rank,indicating that coal rank is a key factor influencing the performance improvement of hot-pressed coal briquettes.

Abstract:Weakly cemented overlying strata could induce intense ground pressure in working faces,potentially leading to support crushing,which severely threaten safety and impede production.This study focused on the top coal caving mining of a 55 m ultra-thick coal seam in the top slice of Zhundong No.2 Coal Mine.Field measurements,theoretical analysis,laboratory experiments,and numerical simulations were employed to investigate the ground pressure behavior and control strategies under weakly cemented overlying strata.The results indicate that the overlying strata in the first mining area of Zhundong No.2 Coal Mine are characterized by thick bedrock layers with weak overall cementation,where soft or ex-tremely soft rock strata account for 87％.During the advancement of the 1101 top coal caving face,the main roof ma-sonry beam experienced secondary fracture instability under dynamic loads from high-position rock block rotation,dis-rupting the original masonry beam bearing structure.Consequently,the supports transitioned from bearing predetermined loads to jointly resisting deformation with the immediate roof,triggering intense ground pressure.Based on this,a stabil-ity equation for the arched structural rock blocks above the supports was established,revealing stress distribution patterns at different positions.A novel"arch-shaped"layout of the working face and corresponding mining technology were pro-posed to form a dip bearing structure in the roof,thereby controlling strong ground pressure.This structure converted par-tial overburden loads into internal forces between arched blocks.Numerical simulations further demonstrated that the new technology reduced the development of plastic zones in the roof,decreased roof subsidence by 33.1％,and elevated vertic-al stress by 18％,as the arched structure transferred part of the overburden load into internal stresses,effectively lowering the overall load on supports.Field implementation confirmed the efficacy of this technology,the peak load on supports de-creased by 12％,the range of intense pressure manifestation narrowed from supports No.20-No.120 to No.40-No.100,and maximum compressive stress at the arch foot facilitated timely fracturing and caving of triangular coal and roof at both ends of the face.

Abstract:Mechanical gripper is the key to realize coal gangue separation by intelligent gangue separation robot.In the process of intelligent separation of coal and gangue,there are some problems such as large difference of gangue particle size,wet and slippery surface,large impact force of dynamic grabbing and mechanical fatigue of long-term continuous op-eration,which lead to low comprehensive separation rate of coal and gangue.In view of the above problems,this paper designs a new type of compliant mechanical gripper by combining passive compliant mechanism with active compliant control.Firstly,the sorting process of gangue sorting robot is analyzed.Based on the kinematic characteristics and physic-al characteristics of gangue,a mechanical gripper scheme with passive compliant mechanism is proposed.The flexible transmission element is used to replace the traditional rigid structure,the rubber buffer gasket is set on the contact surface of the claw,and the multi-stage buffer system is constructed by integrating the universal ball stud,the torsion spring and the rubber-coated bearing.By optimizing the structural parameters of the mechanical gripper,the stiffness of the mechan-ical gripper system is further improved,its service life is prolonged,and its grasping stability is enhanced.Secondly,based on the multi-source real-time feedback data such as force,displacement and velocity,the admittance-impedance hybrid controller is integrated to realize the adaptive compliance control in the process of gangue grabbing.Finally,the position and particle size parameters of gangue are obtained by building a visual recognition and positioning system,and a mul-tivariate gangue sorting test is designed:50 groups of samples of 3 kinds of materials and 3 kinds of particle size grades are selected to carry out 50 groups of comparative tests to test the grasping performance of the compliant mechanical grip-per and verify the effectiveness of the compliant grasping control algorithm.The test shows that the compliant mechanical gripper designed in this paper can adapt to a larger range of gangue particle size,reduce the dynamic grasping impact force,reduce the mechanical loss,improve the reliability of gangue grasping,and the comprehensive separation rate of gangue is 94％.The experiment proves that the design of the mechanical mechanism of the compliant mechanical gripper is reasonable,the stiffness improvement method of the mechanical gripper based on parameter optimization is feasible,and the compliant grasping control algorithm based on admittance-impedance hybrid control is effective.The research res-ults will provide technical support for improving the comprehensive sorting rate of the gangue sorting robot and prolong-ing the service life of the mechanical gripper.

Abstract:Multi-scale pore-fracture structures are widely occurred in coal reservoirs,and serving as the main spaces for gas storage and transport.Restructuring these multi-scale pore-fracture structures to enhance fluid adsorption and trans-port behaviors is critical to the successful implementation of in-situ modified mining technologies for the safe and effi-cient extraction of deep coal and coalbed methane resources.To address the limitations of conventional stimulation tech-niques and the unclear modification mechanisms,the multi-scale pore-fracture structure of coal mass,from nano-pores and micro-fractures to macro-fractures,and their impact on gas desorption,diffusion,and flow are analyzed.Two core modi-fication principles are proposed,one is enhancing desorption and transport by modifying the fluid occurrence state,and the other is improving the permeability by modifying the pore-fracture structure.Two multi-scale modification approaches are introduced,one is enhancing the desorption through competitive adsorption and thermal effects to reduce CH4 adsorption capacity,and the other is enhancing the permeability through dissolution-induced pore expansion and fracturing-induced fracture creation.Using supercritical CO2(ScCO2)as an example,the experimental results reveal the evolution of multi-scale pore-fracture structures in coal mass under ScCO2 injection,involving adsorption swelling,dissolution,mechanical weakening,and fracture generation.These processes collectively affect the adsorption and transport properties of coal mass.A multi-field coupling framework is established to describe mass transfer across scales,and porosity-permeability evolution.This work provides a theoretical foundation for targeted reservoir modification to enhance permeability,and CO2 geological storage in deep coal seams.

Abstract:The evaluation and exploration of strategic natural helium and hydrogen resources are of significant national importance.Studies on the occurrence,distribution,genetic mechanisms,and enrichment patterns of helium and hydrogen in coal measures are therefore of particular relevance.This paper systematically reviews domestic and international re-search progress,and integrates analyses of geological conditions,high-abundance anomaly distributions,and controlling factors in representative basins.Comparative studies were carried out on typical cases such as the Xujiaweizi Fault De-pression in the Songliao Basin,the Zhanhua Sag in the Bohai Bay Basin,and the Sanjiaobei area on the eastern margin of the Ordos Basin.The results can be summarized as follows:① Coal-measure helium and hydrogen resources are charac-terized by multiple-source supply and widespread distribution.Coal-measure helium is dominated by crustal radiogenic helium with"internal-external"multi-source supply,whereas coal-measure hydrogen is jointly generated by organic mat-ter thermal decomposition,water-rock interaction,deep degassing and microbial processes.In coal-bearing basins such as the Songliao,Ordos,Sichuan and Junggar basins,uranium-rich source rocks,favorable reservoirs and effective seals com-monly occur in combination,providing geological conditions favorable for the formation and enrichment of helium and hydrogen anomalies.② The enrichment processes are controlled by the coupling of source-reservoir-seal assemblages and fault transport systems.Coal seams and mudstones serve both as reservoirs and local sources,while thick mudstone and evaporite layers act as key seals.Deep faults function as conduits for crustal or mantle gases during active tectonic periods and form closed systems during quiescent stages.③ The enrichment patterns are governed by the synergy of"generation-migration-accumulation-preservation"with different basins exhibiting varied combinations of source intensity,fault trans-missibility,caprock integrity,and reservoir quality,reflecting both basin aggregation and tectonic belt constraints.④ The occurrence states of gases are diverse:helium is mainly present in the free state,hosted in pores and fractures and partly dissolved in formation water,while hydrogen occurs in free,adsorbed,and dissolved states.Gas accumulations are com-monly developed in synclinal cores,faulted depressions,and areas with well-developed caprocks.Tectonic stability and caprock continuity are the key factors determining preservation and industrial potential.

Abstract:Mine auxiliary transportation material scheduling is an important part of coal mine safety and efficient produc-tion.The transportation environment in coal mines is complex,accidents occur frequently,and the demand for materials is widely distributed.The transportation of materials mainly relies on manual shift scheduling,which is difficult to dispatch vehicles and has a low degree of information transparency.It has become an important direction for the intelligent con-struction of coal mines.With the research and application of auxiliary transportation robots,material distribution is gradu-ally achieving continuous transportation and is moving towards intelligent dispatching.Aiming at the problem of auxiliary transportation material scheduling in mines,it is mapped to the horizontal transportation of automated terminals,and a centralized dynamic scheduling method for auxiliary transportation robots based on digital twins is proposed.To minim-ize the maximum transportation time of auxiliary transportation robots while ensuring conflict-free path planning,a two-stage scheduling model is proposed,which integrates balanced task allocation and addresses constraints such as robot en-durance,load capacity,and potential malfunctions.A two-layer algorithm is designed by combining the cultural genetic al-gorithm with the Dijkstra algorithm incorporating time window constraints to solve the model.Once the generated dis-patching plan is simulated and validated through a digital twin system,the dispatching system centrally controls the trans-portation robots and fixed equipment to collaboratively execute the transportation tasks.Based on the actual auxiliary transportation operations of a mine in Guizhou Province,a digital twin system for auxiliary transportation was designed and implemented.Following the verification of virtual-physical consistency,simulation analyses and experimental tests were conducted to evaluate the performance of the proposed model and algorithm.The results show that the dynamic scheduling strategy for auxiliary transportation robots can rationally allocate scheduling tasks,detect and resolve robot conflicts,and the task allocation balance rate reaches 94.5％.Analyze the relationship between factors such as the number of orders,the number of vehicles,and the utilization rate of sections and the dispatching of transportation robots,improve the utilization rate of robots,and optimize the allocation of underground resources;Analyze the relationship between factors such as the number of orders,the number of vehicles,and the utilization rate of sections and the dispatching of transportation robots,improve the utilization rate of robots,and optimize the allocation of underground resources;Com-pared with manual scheduling,the dynamic scheduling strategy reduced the maximum order completion time by 34.4％,achieved an anti-disturbance stability of 98.3％,and reached a robot equipment utilization rate of 92.79％.The proposed model and algorithm demonstrated their effectiveness in avoiding operational conflicts among underground robots and in implementing interference-resistant scheduling,thereby enhancing the scheduling efficiency of auxiliary transportation ro-bots.

Abstract:The safe and efficient development of deep special space represented by the closed underground mined space,salt caverns,porous aquifers and deep coal seams is an important way and a major strategic demand to ensure the safety of national deep resources and energy.This paper focuses on the scientific and technological problems behind the bottleneck of deep special space exploration,evaluation and utilization,systematically combs the research status of deep special space exploration,evaluation and utilization,and summarizes the key technical system that needs to be broken through in deep special space exploration,evaluation and utilization.The results show that:High-precision detection and inversion model-ing is the premise to realize the utilization of deep special space,the precise detection and intelligent identification techno-logy of deep spatial structure and disaster is in the stage of transition from single breakthrough to system integration,but the adaptability of complex environment is still the main challenge.Dynamic identification of multi-field and multi-re-source and scientific evaluation of development potential are the core challenges of deep space development and utiliza-tion,machine learning and intelligent algorithms are triggering technological paradigm changes in the evaluation and util-ization of deep underground space.The resource,energy and functional reuse of mine underground space have become the key path to promote the transformation of resource-based cities and implement the"double carbon"strategy,the lack of evaluation model,adaptation system and technical system,and the lack of reuse cases are the biggest obstacles to standard formulation.CO2 geological storage in deep coal seam,salt cavern hydrogen storage,sediment expansion and compressed air energy storage,aquifer gas storage,abandoned roadway physical energy storage are the main utilization methods of deep special space at this stage;however,due to the lack of systematic and authoritative national standards/industry standards,the construction of demonstration projects is in its infancy.Breaking through the five technical systems of"pre-cise detection and storage space fine characterization""multi-resource and multi-physical field dynamic intelligent identi-fication and evaluation","full-scene intelligent monitoring and safety guarantee for mine underground space reuse","full-life cycle safety monitoring and detection of CO2 storage in deep coal seam","dynamic sealing evaluation of physical en-ergy storage in deep underground space under multi-field disturbance"can provide scientific and technological support for the implementation of national deep underground strategy.

Abstract:Under deep mining conditions,the failure mechanisms of coal gas compound dynamic disasters are highly com-plex and involve strong multi-factor coupling,so accurate early warning is critical for ensuring safe mine production.This study proposes a deep learning-based early-warning approach driven by multi-source information fusion and develops an SCSSA-MSDA-TFT time-series intelligent early-warning model.In this framework,an Sine-Cosine and Cauchy-en-hanced Sparrow Search Algorithm(SCSSA)is employed to adaptively optimize the model hyperparameters,Multi-Source Domain Adaptation(MSDA)is introduced to align the distributions of heterogeneous monitoring data and achieve unified feature representation,and a Temporal Fusion Transformer(TFT)is used to efficiently extract the dynamic evolutionary characteristics of multi-source time-series indicators,thereby enabling risk-level early warning.For multi-source informa-tion such as microseismic monitoring and gas-related parameters,a data-driven risk-level calibration procedure for coal gas compound dynamic disasters is constructed.Taking a Composite Risk Index(CRI)as the core,the CRI series is tem-porally smoothed,and the high-risk threshold is determined based on Receiver Operating Characteristic(ROC)curve ana-lysis.Cluster validity evaluation is then used to assess the consistency between the calibrated risk levels and the intrinsic data structure.Furthermore,a compound dynamic disaster early-warning indicator system is established:an XGBoost multi-class baseline model is trained and global Shapley Additive Explanations(SHAP)importance is computed,which,combined with sliding-window robustness checks and subset selection criteria,yields a compact indicator subset that bal-ances physical interpretability and discriminative efficiency.The results show that the proposed model achieves a macro-averaged Fl-score of 0.965 and an accuracy of 0.961 on the test set,significantly outperforming the comparison and abla-tion models.The model can accurately capture multi-scale precursory signals of coal gas compound dynamic disasters and realize precise prediction and early warning of risk levels.The proposed deep learning fusion early-warning approach ef-fectively integrates multi-source information and establishes a coherent risk-level calibration and indicator system,offer-ing substantial engineering application value for improving the accuracy and reliability of risk-level early warning for coal gas compound dynamic disasters.

Abstract:The investigation into the evolution mechanisms of fractures in high-stress-sensitive coal under external load-ing and their controlling effects on permeability is crucial for understanding gas migration in deep coal seams.To address the limitations of traditional image analysis in characterizing fractures in coal CT images,this study employs a deep learn-ing algorithm to automatically segment fractures.Based on in-situ CT experimental data under confining pressures ran-ging from 0 to 25 MPa,the three-dimensional structure and topological model of the fracture network were reconstructed,and the evolution of structural parameters was quantified.In terms of theoretical modeling,unlike conventional methods that average fracture properties,a penny-shaped fracture assumption was introduced to equivalently characterize the pro-gressive closure of fractures under stress.A critical stress model was subsequently developed to reflect the fundamental closure stress conditions of the fracture system.Based on this theory,a permeability evolution model applicable to high-stress conditions was further derived.The results show that the deep learning model achieved a prediction accuracy of 84.14％on out-of-distribution images,significantly outperforming the traditional method(40.96％),thereby effectively im-proving fracture extraction accuracy.As the confining pressure increased from 0 MPa to 6 MPa,the average fracture aper-ture decreased from 136.96 μm to 75.29 μm,the average tortuosity increased from 2.87 to 3.32,and the average coordina-tion number-a key indicator of connectivity-dropped from 2.45 to 1.21.At a confining pressure of 25 MPa,the fracture porosity decreased by an average of 98.99％,indicating near-complete closure of the fractures.Based on hydrostatic com-pression test data and a trial-and-error iterative algorithm,the critical closure stresses were determined to be 24.16 MPa and 23.86 MPa,with corresponding permeabilities as low as 8.78×10-7 μm2and 4.20×10-6 μm2,respectively.The conver-ted diffusion coefficients matched the magnitude measured in coal particle desorption experiments,indirectly confirming that the critical-stress condition exerts a sealing effect on seepage pathways.Compared to traditional models,the proposed permeability evolution model,which accounts for both fracture closure and elastic compression,significantly improved prediction accuracy-reducing the average error by 51.14％,particularly under high-stress conditions above 20 MPa.

Abstract:Coal burst is a sudden dynamic disaster that occurs under the superposition of dynamic and static loads,charac-terized by a violent failure process,concentrated energy release,and complex occurrence mechanism,posing a serious threat to mine safety.To reproduce the failure process of coal burst and reveal its dynamic essence in laboratory condi-tions,conventional physical simulation methods based on static similarity principles are inadequate to fully capture its dy-namic characteristics.Therefore,with the dynamic disaster mechanism of coal burst as the research focus,a coal-rock dy-namic similarity criterion system centered on the acceleration similarity ratio is proposed,aiming to establish a theoretical framework for physical simulation that can realistically reflect the dynamic response characteristics of coal burst.Through dimensional analysis,the key parameters involved in the coal burst process were systematically analyzed.Using the accel-eration similarity ratio as the primary control parameter,a theoretical equation set of dynamic similarity criteria for coal burst was derived,and a system of dynamic similarity coefficients was constructed,including the stress similarity ratio,elastic modulus similarity ratio,time similarity ratio,and strain rate similarity ratio.By introducing the dynamic similarity coefficient,the coupling relationships and constraint conditions among various similarity ratios were analyzed,and a sim-ilarity criterion system describing the impact tendency of physical models was established.Furthermore,based on the de-rived theoretical relationships,the evolution laws of model strength curves under different geometric similarity ratios were summarized,and the applicable range and parameter intervals of the dynamic similarity criteria were clarified.The results show that the dynamic similarity coefficient is the key parameter governing dynamic similarity relationships,and its value directly determines the similarity of inertia response and energy transfer between the model and the prototype.The optim-al geometric similarity ratio and wave velocity similarity ratio for the dynamic similarity criteria were determined.The proposed coal-rock dynamic similarity principle for coal burst breaks through the limitations of traditional static similarity theory,achieves quantitative characterization of inertia effects and energy release behavior,and provides an operable the-oretical basis for dynamic physical simulation experiments of coal burst.

Abstract:In response to the"intelligence-capability disconnect"paradox in intelligent coal mining manifests as:insuffi-cient operational environment perception,poor adaptability of smart equipment,and limited collaborative capacity,result-ing in the dilemma of"intelligence without capability,capability without intelligence".The collaborative control theory and technological applications in intelligent coal mining were thoroughly investigated,with systematic analyses conduc-ted on the integration challenges between autonomous systems,environmental perception,and multi-agent coordination.Based on the ternary space fusion theory(HPC)and from the perspective of secondary production space,the fundamental definition and characteristics of intelligent mining have been systematically clarified.The principle of intelligent mining collaborative control has been systematically constructed.The characteristics of multi-agent systems have been thor-oughly analyzed.A data-driven multi-agent collaborative control strategy encompassing task allocation,path planning,and resource optimization has been explicitly defined.The key technologies of intelligent mining collaborative control,includ-ing environment pre-perception,autonomous operation decision-making,and equipment self-organization,have been sys-tematically analyzed,specifically involving GNN-based multi-environmental perception fusion,SOM-driven autonomous operation matching,and large-scale graph computing-enabled equipment self-organization,achieving multidimensional perception fusion,adaptive parameter adjustment,intelligent decision-making,and precise control.The relevant technolo-gies have been implemented in engineering practices at both the intelligent fully-mechanized mining face of Huangling Mining Area and the 5G-based intelligent mining operations of Bala Su Coal Mine under Yanchang Mining Group.These applications have significantly enhanced the intelligence level of coal mining operations,optimized resource allocation,and achieved breakthroughs in the intelligent production model characterized by"remote control,automated extraction,manned inspection,and guard-free operation".This provides both theoretical guidance and practical references for the col-laborative control of intelligent coal mining.

Abstract:Intelligent mine ventilation,as a crucial component of coal mine digitalization,has been faced with three major challenges for a long time:Inaccurate and slow environmental sensing in underground production sites leading to unreli-able production status information;inefficient and imprecise ventilation network calculations causing safety management decisions deviating from the reality;and slow and costly disaster prediction simulations resulting in delayed forecasting.These issues hinder effective guidance for on-site operations.Quantum computing,with its advantages such as parallel ex-ponential acceleration,offers a novel breakthrough path to address these core challenges of"inaccurate measurement,slow computation,and time-consuming simulation".The strengths of quantum computing in model fidelity,global optimiza-tion and computational acceleration,and quantum computing power has been analyzed.And,for the first time,a mapping framework for quantum measurement,quantum algorithms,and quantum simulation have been established to tackle the"inaccurate measurement"of underlying data,the"slow computation"of network solutions,and the"time-consuming sim-ulation"of disaster prediction in intelligent mine ventilation.as well as catastrophic events.Based on a quantum mi-croservices architecture,a preliminary framework for a cloud-edge-end collaborative intelligent mine ventilation service platform has been established,which simultaneously examines current technical bottlenecks in quantum computing devel-opment,highlighting practical challenges for its engineering application in mine ventilation:Maintaining quantum states amid environmental interference,deploying complex systems in harsh environments,verifying quantum measurement out-comes,mapping multi-parameter quantum states,achieving robust quantum algorithms,and reducing high economic costs.A hybrid quantum algorithm combining the Quantum Newton's Method(QCGA)and Variational Quantum Linear Solver(VQLS)was applied to mine ventilation network calculations,achieving speedups of 11.9 and 12.8 respectively.This demonstrates the feasibility of quantum computing acceleration for solving problems in intelligent mine ventilation,and provides theoretical guidance for leveraging quantum computing to drive technological transformation in intelligent mine ventilation and advances smart mine construction.