Abstract:As a consequence of the gradual depletion of high-quality iron ore resources in China,the existing iron ore re-sources exhibit the characteristics of"poor,fine,miscellaneous",which renders mineral sorting increasingly challenging.In this context,high-gradient magnetic separation is of great significance,as it allows for the improvement of the recovery of difficult-to-select iron minerals through the enhancement of magnetic field strength,the synergy of multi-physical fields,and the optimization of magnetic aggregation media.This paper reviews the application of high-gradient magnetic separators with different excitation systems(permanent magnetic,electromagnetic and superconducting)and the progress in the study of polymagnetic media.The utilization of novel permanent magnetic materials in permanent magnet high gradient magnetic separators has been demonstrated to augment the magnetic field strength and stability of the equipment,thereby effectively enhancing the mineral capture ability.An electromagnetic high-gradient magnetic separator can be classified into two categories,namely wet and dry,depending on the processing of weak magnetic minerals.A wet mag-netic separator primarily addresses the issue of media clogging through the utilization of water media,whereas a dry mag-netic separator employs airflow to enhance the sorting process and mitigate the electrostatic effect,thereby optimizing the overall sorting efficacy.A superconducting high gradient magnetic separator offers a robust magnetic field strength through the incorporation of superconducting materials,thereby reinforcing the sorting of weak magnetic minerals.However,it necessitates a low-temperature environment.In recent years,notable advancements have been made in this field,including the introduction of a novel cooling system and the development of a pulp pulsation structure.Furthermore,the magnetic permeability and durability of diverse polymagnetic media are exhaustively delineated,and the benefits and drawbacks of spherical,steel wool,toothed plate,and bar media in sorting are contrasted.The effects of media arrange-ment on magnetic field strength and capture effect are further explored,as well as the effects of media filament diameter and different cross-sectional shapes on magnetic field properties and sorting performance.In conclusion,the prospective research direction of the high gradient magnetic separator and the optimisation of the polymagnetic medium are discussed,with the objective of providing a reference for the technological progress in the field of high gradient magnetic separation.

Abstract:The water conduction fissure formed by longwall mining of coal mine leads to the destruction of groundwater system,resulting in the contradiction between the abundant water in goaf and the shortage of surface water resources,thence reasonable protection and utilization of mine water is of great importance to the safe production of coal mine and the construction of ecological civilization in mining area.Using the goaf as an underground reservoir and taking advantage of the strong capacity of broken coal and rock mass in the goaf is an important means to realize the treatment of mine water pollution and resource utilization.The water quality of most mine water in China is poor,the total dissolved solids are high,and the treatment is difficult,so the water-rock purification of broken coal and rock in goaf reservoir is conducive to the efficient in-situ treatment and utilization of mine water.At present,a series of studies have been carried out around the water-rock interaction of broken coal rock in goaf,including sample collec-tion,sample detection,simulation experiment and result analysis.Sample collection and detection is the premise of the study of water-rock interaction,which involves the basic characteristics and change rules of mine water and coal rock mass.The simulation experiment and result analysis mainly explore the action mechanism of various influencing factors.The research on water purification mechanism of reservoir in mining area mainly focuses on water-rock interac-tion.The experiments of static simulation,dynamic dripping simulation and circulating water immersion provide useful reference for exploring the water purification mechanism of water-rock interaction.Combined with the basic theories of hydrogeochemistry,rock mineralogy and water chemistry,a series of possible water-rock interactions in goaf,such as leaching-precipitation,adsorption-resolution,redox and mixing,are elucidated.The purification effect of the goaf res-ervoir is better for the concentration of suspended solids in mine water,followed by the purification effect of COD,while the purification effect of total hardness,TDS and total alkalinity depends on the mineral composition of bro-ken coal and rock mass in the mined-out area,water storage time and other factors,and the deterioration of the above indicators may occur.However,the influence factors of the design in the current indoor water-rock simulation test scheme are relatively simple,and the relevant data such as hydrodynamic field,temperature field and oxygen concen-tration in the study area are lacking.On this basis,the research and development direction of water purification technol-ogy for goaf reservoir in coal mine is proposed.Under the principle of clarifying local policies and water quality and quantity,in-depth research is made from the perspectives of goaf's own conditions and external environment to en-sure the stability,economy and safety of water purification technology in goaf reservoir.

Abstract:Coal enterprises are the main producers and consumers of energy in China.Promoting low-carbon development and green transformation of coal enterprises is a key link of carbon neutrality actions in China,which is of great signific-ance for promoting coal high-quality development and achieving the"dual carbon"goals.However,there has been a lack of systematic assessment of the strategies or technologies adopted by coal companies in response to the"dual carbon"strategy.Therefore,based on the public data of 25 listed coal companies,this study uses a fsQCA configuration analysis method to explore the multiple configuration paths and differences of business scale,investment level,technological in-novation and policy norms on the reduction of enterprise carbon emission intensity.The results show that:① Single ele-ment,such as environmental protection investment and R&D personnel,cannot constitute the necessary conditions for lis-ted coal companies to achieve high-level carbon emission reduction;② There are five configuration paths for carbon emission reduction of listed coal enterprises,and environmental protection investment,the proportion of R&D investment and the number of green patents are the core conditions to intervene in multiple configuration paths,and increasing envir-onmental protection investment,R&D investment and technological upgrading are effective measures to reduce the car-bon intensity of coal enterprises;③ There are significant differences in the configuration of carbon emission reduction ef-fects of listed coal enterprises in different regions and scales.The carbon emission reduction of listed coal companies in the eastern region is affected by environmental protection investment and policy norms.The promotion of carbon emis-sion reduction by listed coal companies in the central region is mostly dominated by a single factor,among which the policy normative drive is particularly prominent;The promotion of carbon emission reduction by listed coal enterprises in the western region is affected by the combined effect of environmental protection investment and technological innova-tion.The promotion of carbon emission reduction by giant listed coal companies is driven by multiple factors such as en-vironmental protection investment,proportion of R&D investment,technological innovation and policy norms.Regard-less of the role of operating income,the comprehensive effect of marginal conditions can also drive large listed coal com-panies to achieve carbon emission reduction,especially the proportion of environmental protection investment and R&D investment.In general,the carbon emission reduction promoted by listed coal companies is mainly driven by environment-al protection investment.This study comprehensively sorts out the complex configuration path of coal leading enterprises to cope with the dual carbon strategy,and provides a scientific basis for the green development of the whole industry.

Abstract:Establishing a resource and environmental balance system is a key pathway to implementing ecological and en-vironmental protection strategies during the development of mineral resources,achieving coordinated development between resource extraction and environmental protection,and is also essential for promoting the high-quality green devel-opment of Chinese mining enterprises.Based on the"dual carbon"goal and the gradual shift of energy consumption con-trol towards carbon emission control,optimizing the energy consumption structure and exploring the balance of energy conservation and utilization are crucial for the comprehensive green transformation of mines.Conducting in-depth re-search in this area holds significant academic value and practical significance.Firstly,this paper analyzes the various com-ponents of the energy system,including non-renewable energy,renewable energy,utilized energy,and unused energy,to draw an energy balance flow diagram for mining operations.It explains the impact of these components during the mining process and defines the concept of energy conservation and utilization balance.Secondly,based on this definition,the pa-per presents an energy balance input-output model and conducts an in-depth analysis of intermediate processes,exploring the feasibility of implementing energy-saving measures across multiple dimensions such as management,process flow,fa-cility configuration,equipment selection,and land use.It constructs a calculation model for energy balance.Finally,the paper formulates an enterprise energy balance accounting table and summarizes the technical pathways for optimizing en-ergy balance from the perspectives of optimizing energy structure,improving energy utilization efficiency,energy-saving measures,and land use,providing theoretical support for the balanced development of economic,ecological,and social be-nefits in mining operations.The strategies and ideas proposed for achieving energy balance provide an important theoretic-al basis for improving the resource development and environmental balance system and have a profound impact on pro-moting the transformation and upgrading of mining enterprises in China and the comprehensive construction of green mines.

Abstract:Due to its high alkalinity and low nutrient content,the tailing soil in the mining area are not conducive to the growth of plants and may even cause environmental pollution in severe cases.The impact of biochar and Robinia pseudoacacia on the tailing soil in mining areas was studied to provide a theoretical foundation for saline-alkaline improvement,and improve soil environment,and increase land productivity.Pot experiments were conducted,and four treatments were established according to different biochar application amounts,namely CK(no biochar ap-plied,control group),BC1(1％biochar applied),BC3(3％biochar applied),and BC5(5％biochar applied).The physical and chemical properties of the soil and the changes in survival rate,growth(seeding heigh and ground diame-ter),biomass,and root morphology of R.pseudoacacia were assessed.Results indicated that the seedling height,root length,and biomass of R.pseudoacacia reached their maximum values when the biochar addition amount was 5％.The soil pH of BC1,BC3,and BC5 significantly decreased(1.41％-7.51％)compared with CK,suggesting that bio-char can effectively reduce soil alkalinity through neutralization.The electrical conductivity increased with the rise in biochar application amount,especially with 5％biochar,which had the most significant effect,increasing the conductiv-ity content by 181.75％.Simultaneously,both the soil organic carbon content and available phosphorus content in-creased,the BC5 group increased by 42.25％and 111.67％respectively compared with CK,indicating that biochar en-hanced the content of soil nutrient elements,improved soil fertility,and was beneficial in alleviating soil impoverish-ment.The available potassium content in the soil showed a downward trend,the BC5 group decreased by 26.39％com-pared with CK,indicating that nutrient element exchange in the soil occurred.A comprehensive analysis showed that applying 5％biochar can better promote the growth of R.pseudoacacia,reduce soil pH,and improve soil fertility,there-by achieving the effects of waste resource utilization and soil improvement.This entire study and its findings were inte-grated into a single comprehensive paragraph as requested.

Abstract:In 2024,the relevant documents issued by the Ministry of Natural Resources and other seven ministries and commissions have clearly defined the relevant requirements for comprehensively promoting the construction of green mines,and made clear requirements for the number and proportion of large and medium-sized mines to be completed by the end of 2028,while the construction of small mines also requires reference to green mine management,fully reflecting the national top-level policy requirements for comprehensively building green mining.In the face of the global economic demand situation,the need to practice ecological restoration responsibilities,and the urgency to enhance the level of ecolo-gical civilization construction,how to build and manage green mines in local areas,to implement and develop local green mining,and to make characteristics and highlights.After consulting the research results,construction history and current situation of green mine,the new policy and evaluation index system of green mine construction are studied,the weight as-signment of first-level index in the latest national evaluation index is deeply analyzed,the construction and management of some local green mine is investigated,and the optimization of local green mine evaluation index can be combined with local conditions is discussed.Some challenges and difficulties still exist in comprehensive construction,such as false main responsibilities,insufficient internal impetus,lack of financial security,and need to improve the evaluation mechanism.This paper explores several ideas and countermeasures related to the overall construction and management of local green mines,such as promoting and guiding the implementation of mine policy,stimulating endogenous motivation and com-pacting main responsibility,financial security and quality control,mine control and integration innovation.The future dir-ection of green mine development and the vision of continuously improving the construction level are prospected.In order to provide a reference for the sustainable and high-quality development of green mining,optimize the evaluation system and supervision mechanism,and comprehensively promote the construction of green mines.

Abstract:As the coal industry advances towards intelligent transformation,the application of artificial intelligence(AI)technology in the entire coal mining process has gradually deepened.This study first reviews the development history of coal mining technology in China,with a focus on analyzing the evolution of AI technology at different stages and its im-pact on the intelligentization of coal mines.In response to the diverse intelligent application scenarios required throughout the coal mining process,a next-generation AI application framework for intelligent mining has been proposed,integrating sensing,decision-making,and control.Guided by scenario orientation,data-driven approaches,algorithm-centric design,and platform-based implementation,a new technical workflow for scenario-based AI applications in intelligent mining has been developed.Through actual case analysis,the effectiveness of scenario-based AI applications in intelligent coal min-ing is demonstrated.It is evident that the application of AI significantly enhances the production efficiency,safety,and sustainability of coal mines,driving the intelligent transformation of the coal industry.As the construction of intelligent mines continues to progress,the coal industry is expected to move towards a more efficient,safer,and greener future,con-tributing to the achievement of"dual carbon"goals and the optimization of the energy structure.

Abstract:The accurate acquisition of rock mass mechanical parameters is the prerequisite for the stability analysis and support design of mine roadways surrounding rock.The traditional laboratory testing method for rock sample from sur-rounding rock is difficult to meet the timeliness requirement of obtaining rock mass mechanical parameters in deep min-ing and intelligent development of coal mines.The digital drilling test technology is a method to analyze the mechanical parameters of rock mass by using the real-time drilling parameters such as drilling rate,rotational speed,drilling pressure,and drilling torque.This method provides a new way to obtain the mechanical parameters of surrounding rock of roadway in situ.The key is to establish the quantitative relationship between the drilling parameters and the rock mass mechanical parameters,and to develop intelligent drilling equipment matching with the drilling theory.The author's team designed and developed a digital analysis drill bit,obtained the theoretical solutions of rock mass cutting strength and cutting energy based on rotary cutting drilling parameters,and established the inversion model of rock mass compressive strength and elastic modulus while drilling.A true triaxial rock digital drilling test system(TRD system)and a high precision rock in-telligent rotary cutting test system(RCT system)have been developed,and a series of digital drilling tests have been car-ried out.On this basis,the intelligent drilling explore system of geology(IDE system)is developed,and the in-situ detec-tion method of mechanical parameters of roadway surrounding rock while drilling is established.The research results provide theoretical and technical support for in-situ real-time intelligent perception of roadways surrounding rock.

Abstract:China's lignite resources are abundant,it is difficult to utilize for the high oxygen content and water content.Thermal upgrading is one of the effective means to achieve clean and efficient utilization of lignite.However,the lignite in the process of thermal upgrading faces the problem of easy fragmentation and pulverization,resulting in high dust content in tar,difficulty in dust removal,and pipeline blockage,which has become a bottleneck hindering the de-velopment of lignite upgrading technology.This article takes Xianfeng lignite(XF)as the raw coal,the particle size change,cumulative distribution curve,overall particle size distribution,relative fragmentation rate and fractal di-mension of XF at different temperatures were investigated on the rotary furnace thermal upgrading experimental device,and the distribution of XF thermal fragmentation product at different temperatures was studied,and the differ-ences in ash content and mineral composition of thermal upgrading products were analyzed by X-ray fluorescence(XRF)and X-ray diffraction(XRD).The results show that XF undergoes significant fragmentation dur-ing the thermal upgrading process,with a particle size of 1-6 mm being the main generation range of fragmented parti-cles.The pulverization particle size increases with increasing temperature,with the largest increase observed at 0-0.1 mm.At 450-500℃,the relative fragmentation rate of XF increase the most,and the increase of temperature pro-motes the fragmentation,leading to an increase in fractal dimension and a more complex degree of coal particle frag-mentation.The variation of ash content with fragmentation particle size is not significant,and minerals in coal are more likely to exist in the pulverization particle size.The ash content gradually increases with the decrease of particle size of thermal fragmentation products.The ash content of the thermal fragmentation product at 550℃is higher than that at 450℃and 350℃,the Ca element content decreases with decreasing particle size,the Si and Fe element content in-creases with decreasing particle size,and the change of Al element content is not obvious.The XRD results show that quartz and calcite belong to passive distribution,while pyrite is more easily distributed to pulverization particle size due to thermal decomposition,which belongs to active distribution,and pyrite thermal decomposition leads to the formation of cracks and cavities inside the coal particles,which is one of the causes of lignite fragmentation.

Abstract:In response to the difficulties of surrounding rock instability,coal wall caving,and roof collapse in the treat-ment of near parallel transverse faults in weak coal seams with high mining height,this paper takes the 22205 working face of Yanping Coal Mine of Shanxi Huaning Coking Coal Co.Ltd.as the engineering support,systematically studies the mechanical response characteristics and dynamic instability evolution laws of coal and rock in the fault fracture zone,and proposes a collaborative treatment technology system based on"advanced cement grouting reinforcement and instant chemical grouting reinforcement".Through multi parameter optimization and refined control of the entire process,the sta-bility of the surrounding rock in the fault zone is significantly improved.Based on the"32345"comprehensive gov-ernance framework(three principles,two methods,three advanced management,four types of control,and five character policy),the stability of the surrounding rock in the fault zone has been significantly improved by optimizing the grouting parameters(pressure 15-30 MPa,water cement ratio 0.8)and construction process,combined with on-site testing and nu-merical simulation verification.The research team implemented staged infiltration filling and dynamic reinforcement on 4 large faults(YD4,YD5,YD12,and YD2 edge faults)and 13 small faults within the working face,successfully reducing the coal wall caving rate by 45％and improving the efficiency by 15％.This technology can provide theoretical support and technical reference for safe mining of weak coal seams under similar geological conditions.

Abstract:Intensive coal mining in China has generated vast underground voids,whose resource utilization holds signific-ant implications for alleviating land pressure,preventing secondary disasters,and achieving carbon neutrality goals.This paper systematically reviews current comprehensive utilization technologies for coal underground spaces,examines re-search progress in CO2 geological sequestration and underground reservoir technologies,and analyzes critical challenges and development prospects through the lens of structural backfill technology proposed by our research team.Existing stud-ies reveal that while CO2 sequestration via industrial solid waste mineralization shows promise,critical issues persist re-garding the permeability and long-term stability of carbon fixation materials,along with unclear damage mechanisms of reservoir surrounding rocks under multi-field coupling effects.Underground reservoir technology constructs water storage systems through goaf modification,yet faces critical challenges of cyclic hydraulic pressure-induced wet-dry fatigue in dam structures.Structural backfill technology establishes stable underground structures through low backfill ratio and high-stability designs,providing mechanical guarantees for functional space utilization,but confronts bottlenecks including un-defined critical backfill positions,material performance-function mismatches,unclear multi-field coupling mechanisms,and insufficient intelligent processes.Future research should prioritize functional backfill material development,cross-scale THMC multi-field coupling modeling,and intelligent perception-digital twin integration to establish a technical sys-tem encompassing"geological precision detection-functional orientation design-dynamic optimization control".Through interdisciplinary collaboration,policy support,and standardization efforts,this study aims to transform underground voids from environmental burdens into strategic resources,providing theoretical and technical foundations for green mining transition and carbon neutrality achievement.

Abstract:Fast and accurate detection of surrounding rock characteristics and efficient anchoring support technology are important guarantees for intelligent roadway excavation.Detection while drilling and efficient anchoring technology are the research hotspots in the field of mining engineering.The relationship model between rock mechanics parameters and drilling parameters is established by theoretical analysis,and the relationship between drilling parameters and rock mech-anics parameters is studied.The concrete test blocks with different mechanical properties were poured in the laboratory,and the concrete test blocks were tested while drilling.At the same time,the drilling parameters such as rotation speed,drilling speed,torque and sound pressure level were collected in real time.The relationship between drilling parameters such as rotation speed,drilling speed,torque and sound pressure level and rock mechanics parameters was analyzed,and a prediction model was established.The pre-stressed anchorage comprehensive test bench was developed,and the transfer law of pre-stress of different anchorage modes and pre-tightening force anchors was analyzed through the test of the pre-stressed anchorage comprehensive test bench.The experimental results show that the drilling speed and rotation speed have an exponential relationship with the uniaxial compressive and tensile strength of the rock.The drilling speed has the highest correlation with the uniaxial compressive and tensile strength of the rock,and the correlation coefficients are 0.9631 and 0.8718,respectively.The sound pressure level has a linear relationship with uniaxial compressive strength and uniaxi-al tensile strength.The torque work has a linear relationship with the uniaxial compressive strength and a logarithmic rela-tionship with the uniaxial tensile strength.No matter what kind of prestressed anchorage method is adopted,the axial force on the bolt gradually decreases from the beginning of the anchorage to the end of the anchorage.The increase of pre-tight-ening force will increase the diffusion range of axial force on the bolt.The full-length pre-stressed technology of anchor rod has high efficiency in the axial force transmission of anchor rod.The research results are of great significance to im-prove the detection accuracy of roadway surrounding rock parameters and the effect of bolt support,realize the safe and efficient excavation of roadway,reduce the probability of accidents and ensure the safe production of mines.

Abstract:The deep mining of mineral resources is the future direction of the mining industry,and thermal hazards in mines have become a major factor limiting safe production.Due to the working face of deep mines being located in tem-perature-increasing strata,combined with underground industrial heat sources,these heat sources exhibit characteristics such as being numerous and dispersed,prolonged duration,and high instantaneous heat release power.Current conven-tional cooling technologies such as ventilation optimization,roadway and equipment layout optimization,and isolation of heat sources cannot meet the cooling needs of deep mines,necessitating the development and application of efficient,green,and high-capacity artificial refrigeration technologies.This paper first discusses the principles of heat pumps and examines the spatial and temporal distribution characteristics of heat sources and heat sinks both on the surface and under-ground in mining areas.It summarizes the challenges of applying artificial cooling technologies to the management of thermal hazards in deep mines.The Jinfeng Gold Mine in Guizhou is currently mined to a depth of 630 meters.Using this mine as an example,the sources of underground thermal hazards were identified,and the cooling load was calculated.Cooling targets were selected based on the production characteristics of the mine,and the feasibility of using nearby water bodies as heat sinks through water-source heat pump technology for underground cooling was explored.Field investiga-tions,measurements,theoretical calculations,and numerical simulations were conducted to analyze the thermal capacity and stability of four nearby water bodies:the Lüyin Pond,Luofan River,Beipan River,and the mine diversion channel.Initial investment and operating costs were calculated for water-source heat pump schemes based on different water bod-ies,leading to a technical and economic comparison.After comprehensive analysis,the proposal to use the mine's water diversion channel as the heat source for a water-source heat pump to cool the incoming air at the mine entrance was re-commended.This scheme is characterized by good cooling effectiveness,low investment,large stable heat sink capacity,and minimal ecological impact.

Abstract:The Jurassic coal seams in northern Shaanxi contain a large number of palaeo-fire zones,which pose a serious threat to the safe mining of the underlying coal when water accumulates in these palaeo-fire zones.To effectively detect the distribution of ancient fire zones and analyze their water accumulation conditions,this study is based on the fundamental principles of direct current resistivity and the exploration mechanism of three-dimensional(3D)high-density resistivity.Using numerical simulation and engineering practices,the 3D high-density resistivity response characteristics of shallow coal seam fire zones were investigated.Multiple 3D geo-electrical models of burnt rocks were established,and forward simulations were conducted using the finite element method.The relative error between numerical and analytical solutions in a homogeneous half-space was analyzed to verify the accuracy of the forward modeling program.The 3D high-density resistivity response characteristics of geological anomalies were analyzed using pole-pole,pole-dipole,and dipole-dipole arrays in homogeneous half-space,two-layer,three-layer,and four-layer geo-electrical models.The results indicate that the pole-pole array demonstrates better sensitivity to geological anomalies but is less effective in complex stratigraphy.The dipole-dipole array shows strong responses to both geological anomalies and complex stratigraphy,offering higher lateral resolution.Compared to 2D high-density resistivity forward simulations,3D simulations improve detection accuracy through multidirectional and multilayer data acquisition,resolving the anomaly shift issues associated with the pole-dipole array.Field practices were conducted in the 2-2 coal fire zone of the northern second panel of the Hongliulin Coal Mine in northern Shaanxi using both 3D high-density dipole-dipole and pole-pole arrays.The actual exploration results aligned well with existing geological data of the area,demonstrating the feasibility of using 3D high-density resistivity to delin-eate the distribution and water accumulation of coal mine fire zones.

Abstract:China is the world's largest producer and consumer of coal,with a long history of extraction.Many coal-produ-cing regions have developed clusters of coal-related industries.With the rapid development of the coal related industry,land degradation and soil pollution caused by the expansion of coal related sites and the discharge of coal based solid waste have become increasingly severe.The proposal of identification and zoning control strategies for coal related site types is the key to achieving regional energy resources,low-carbon development,and ecological protection.The study takes the coal-related industrial area of Ningdong Coal Electricity Base as the object:Determine the information character-istics and deciphering identifiers of featured features in Ningdong Coal Electricity Base coal-related industrial area,and put forward the index system for extracting featured features at the regional scale and site scale,including coal sites,coal power sites,coal chemical sites,ect.At the regional scale,site type identification was conducted using Landsat remote sensing imagery.The analysis of land use dynamics and land use transition matrices was employed to examine the spati-otemporal evolution and differences in coal-related industrial areas.From 2003 to 2023,coal power sites emerged from non-existence,with coal mining sites increasing by 10.68%and coal chemical industry sites by 26.33%.The coal-electri-city integration area in the Ningdong Coal Electricity Base coal-related industrial area exhibits a rapid expansion trend.At the site scale,pattern analysis was conducted using Sentinel-2 remote sensing imagery with a resolution of 10 meters for the year 2023.The analysis revealed that coal mining sites covered an area of 68.38 km2,accounting for 6.88%of the total area,exhibiting a random spatial distribution.In contrast,coal chemical industry sites spanned 49.03 km2,representing 4.93%,and demonstrated significant spatial aggregation.Coal power sites occupied 24.28 km2,making up 2.44%,with a relatively concentrated spatial distribution.Used the DPSIR(Driving-Pressure-State-Impact-Response)model,a compre-hensive ecological risk assessment was conducted for coal-related industrial areas.The average ecological risk index for these areas was 0.602,indicating a low level of risk,with a 65.66%reduction in risk from 2003 to 2023,reflecting a posit-ive trend in ecological management.Five zoning control models were proposed:"dynamic restoration"modes for residen-tial aggregation areas,ecological maintenance areas,production monitoring and early warning areas,damage restoration and reconstruction areas,and other regulatory areas.This research provides theoretical and methodological support,as well as foundational data,for the identification of characteristics in coal-electricity integration sites in the Ningdong Coal Electricity Base coal-related industrial zone,which is significant for the governance of coal-electricity integration sites and regional ecological restoration.

Abstract:Using the pore structure and adsorption characteristics of gangue to pre-purify high-mineralization mine drainage provides an economical and effective technical approach for the efficient utilization of mine drainage in ecologically fragile mining areas.This paper simulates the infiltration and migration process of mine water in under-ground rock strata through a self-made dynamic leaching experimental device,and studies the influences of different li-thologies and particle sizes of gangue on the pre-purification of high-mineralization mine drainage.XRD and XRF tests show that the main mineral components of mudstone siltstone and medium-coarse sandstone roof rock samples are quartz,kaolinite,muscovite,and feldspar,with the content of clay mineral kaolinite exceeding 20%.The layered struc-ture of kaolinite can adsorb more ions from mine drainage,purifying mine drainage resources.Dynamic leaching test results indicate that under the dynamic adsorption effect of gangue,the pH of high-mineralization mine drainage tends towards weak alkalinity,and the TDS value and Ca2+concentration both decrease;the larger the gangue particle size,the smaller the decrease in TDS value and Ca2+concentration in the mine drainage sample,indicating poorer adsorption effect.Compared to mudstone siltstone,medium-coarse sandstone has a stronger pre-purification effect on mine drainage solution ions.After mine drainage leaching,numerous pores and fractures on the surface of the rock samples undergo physical adsorption under hydrochemical action,forming secondary fractures.A large number of easily soluble components dissolve into the leachate,increasing the amount of debris on the gangue surface.The in-creased pore surface area and volume accelerate the dissolution of rock sample minerals,promoting the adsorption of mine drainage ions by the gangue.

Abstract:The water resources of open-pit mines in arid areas are scarce,and the wind speed in the external dumping site is high,which leads to a decrease in plant survival rate and is not conducive to ecological restoration.To effective-ly address the impact of strong winds on plant survival rate,this article takes the Hongshaquan open-pit mine as an ex-ample and uses Fluent software to simulate the size and variation pattern of windless areas at different retaining wall heights in the external dumping site under wind speeds of 6 m/s to 10 m/s.Based on the size of the windless area,the optimal height of the retaining wall in the external dumping site is determined to be 2 m.Considering the im-pact of the retaining wall height on the dumping operation,a 1m retaining wall combined with a 1m wind and dust sup-pression network structure is adopted.At the same time,setting up a reverse flat plate structure in the external dump-ing site can effectively increase the windless area compared to the traditional horizontal arrangement of flat plates,re-duce the evaporation of water in the soil,weaken the harm of wind and sand to plants,and improve the survival rate of plants in the arid area of the external dumping site compared to the traditional horizontal layout of flat plates.Based on large eddy simulation,the range of windless areas under different wind speeds was studied under the conditions of re-verse flat plate angles of 5°,10°,15°,and 20°.The optimal angle of flat plate inclination in the external dumping site and the windless area of the third stage structure of reverse flat plate under different wind speed conditions were deter-mined.The results show that as the angle increases,the windless area first increases and then decreases at the same speed,and the influence of angle on the windless area is not significant;At the same angle,as the speed increases,the windless area gradually decreases.According to the simulation results,it was found that the maximum range of the windless area is 2.8 m when the angle is 10°,Determine 10° as the most suitable angle,the reverse design of retaining walls and dumping sites can to some extent increase the range of windless areas and reduce wind speed,which is bene-ficial for plant growth.The reverse three-level flat plate structure has a smaller windless area in the middle flat plate,and the largest windless area in the bottom flat plate.Higher plants can be planted in the bottom flat plate,while low-er growing plants can be planted in the middle flat plate.

Abstract:The assessment of ecological restoration effects in coal mining area needs to break through the limitations of traditional single indicators and construct a scientific evaluation system from a comprehensive perspective of improving ecosystem service functions.Taking the Buertai mining field in Ejin Horo Banner as the research object,based on the cur-rently commonly used ecosystem service material quantity assessment model and value calculation method,combined with GIS spatial analysis,the material quantity and value of the coal mining area(Buertai mining field)and the non-coal mining area(the area of Ejin Horo Banner except Buertai mining field)before and after ecological restoration were quanti-fied.And explore the impact of land use and vegetation coverage on ecosystem services,and evaluate the ecosystem res-toration effect of the Buertai mining field.The results show that:① The average material quantity of soil conservation per area in the Buertai mining field in 2005,2010,2015 and 2020 was 17.7,9.02,20.31 and 26.96 t/hm2 respectively;The av-erage material quantity of windbreak and sand fixation per area was 45.77,43.3,46.06 and 50.37 t/hm2 respectively.The material quantity of carbon storage per area was 9.805 4,9.795,9.805 9 and 9.814 t/hm2 respectively.During this period,there was a trend of first decreasing and then increasing.And they all show a positive correlation with grassland,forest land and vegetation coverage,and a negative correlation with construction land and unused land.② The average of the total value of ecosystem services per area in the Buertai mining field in 2005,2010,2015 and 2020 was 1 772.91,1 342.98,1 825.54 and 2 154.98 yuan/hm2 respectively.Generally,it showed a trend of first decreasing and then increas-ing,which was consistent with the changing trend of the quality of ecosystem services.③ The soil conservation and wind-break and sand fixation functions of the Buertai mining field gradually returned to a level close to that of the non-coal min-ing area after 2010,indicating a good ecological restoration effect.The carbon storage is still lower than that in non-coal mining area,indicating that the protection and restoration of the coal mining area ecosystem need to be continuously strengthened.The research results have important reference significance for regional ecological restoration.

Abstract:In recent years,due to the special working environment in coal mine,coal mine underground robot has become the focus of R&D personnel all over the world.As a kind of robot,quadruped robot has attracted a lot of attention at home and abroad because of its simple structure and high adaptability.In order to assist people to work underground and com-plete dangerous tasks,a quadruped robot system for complex tasks such as underground inspection and handling in coal mine is designed.Firstly,complete the relevant basic theoretical analysis,including quadruped robot body design,quad-ruped robot kinematics modeling and quadruped robot static gait planning;Secondly,the key technologies related to autonomous perception,autonomous decision-making and autonomous control of multi-functional special quadruped ro-bot in coal mine are studied;Finally,the virtual simulation planning system of quadruped robot,the virtual monitoring sys-tem of quadruped robot and the physical system of quadruped robot are constructed.The solid prototype of quadruped ro-bot is made,and the system integration test is completed.The results show that the quadruped robot has reasonable struc-ture and perfect function,has good adaptability to complex geological conditions underground,can complete environment-al perception and adaptive obstacle avoidance walking in unknown underground environment,and can complete complex work.The virtual simulation planning system provides information and reference for the autonomous execution of the ro-bot,and the virtual monitoring system provides three-dimensional running state monitoring and remote visual human-com-puter interaction interface for the robot.The design of virtual dimension provides digital twin platform support and solu-tion for underground complex operation,and plays a positive role in intelligent and unmanned mining of coal mine.

Abstract:The copper-molybdenum separation operation in the high-altitude copper polymetallic ore concentrator in Lhasa,Tibet,only uses sodium hydrosulfide as an metal mineral depressant.This causes the residual HS-in the re-turn water to enter the production water system,causing the pH of the water to exceed 12,which directly affects the floating of copper-bearing minerals in the front-end copper-molybdenum mixed flotation operation.When the cop-per grade is 0.948％and the molybdenum grade in raw ore is 0.032％,the annual copper recovery is only 87.17％and the molybdenum recovery is 33.79％.In order to avoid the impact of HS-in the return water in the cop-per-molybdenum separation operation on the floating of copper minerals in mixed flotation,the process mineralo-gy characteristics of the copper-molybdenum mixed concentrate were studied to screen out the inorganic and organ-ic combined depressant for copper minerals and environmentally friendly depressant for non-copper sulfide minerals in mixed concentrate.For chalcopyrite,bornite,chalcocite and multi-copper minerals,sodium hydrosulfide and sodi-um thioglycolate are used as jointly depressant,non-copper metallic minerals and non-metallic minerals are targeted to be depressed,which improves the separation effect of copper-molybdenum separation operations and greatly reduces the dosage of sodium hydrogen sulfide by 57.39％,and its unit consumption is reduced to 671 g/t.By adding 221 g/t of sodium thioglycolate for depressing copper minerals and 13.53 g/t of organic depressant AT-208 for sul-fide minerals,the impact of the single use of sodium hydrosulfide inorganic agent on front-end copper and molybde-num mixed flotation indicators was avoided.When the copper grade is 0.934％and the molybdenum grade in raw ore is 0.025％,the obtained annual copper recovery is 90.102％and the molybdenum recovery is 44.363％.The copper and molybdenum recovery have increased by 2.932％and 10.573％respectively compared with before optimization.The new environmentally friendly organic agents exert their respective targeted depressing effects,which can not only reduce agent consumption,ensure the stability of the pH value of mineral processing return water,but also a-chieve comprehensive and efficient recovery of mineral resources,providing technical support for high-quality develop-ment of enterprises and improving their core competitiveness.