Abstract:With the relocation of coal production capacity to the western regions,an increasing number of new coal mines are being es-tablished in Xinjiang.The carbon emission sources and carbon reduction pathways in coal mining,production,processing,and utilization were analyzed.Based on clarifying the connotation of low-carbon design in the general layout,the No.7 mine in Dananhu,which was se-lected as one of the first green mines in Xinjiang Uygur Autonomous Region,was taken as an example.Considering its characteristics of having salty soil and a fragile ecological environment,low-carbon optimization of the industrial site was carried out in terms of site lay-out,hardening,and greening.While extracting resources,the ecological environment is protected and its carbon sink level is enhanced,which is of great significance for building a"green mine"that aligns with the dual carbon concept,providing a reference for industry general layout design of the region.

Abstract:The integrated excavation and anchoring machine is one of the important equipment for modern mine operations.However,as the mining depth increases,the equipment may face adaptability issues under extreme conditions of high stress and strong impact in mines.To address this issue,the Zhengtong Coal Industry's integrated excavation and anchoring machine was taken as the research ob-ject.Through the analytic hierarchy process,an adaptability evaluation model was established to assess the adaptability of integrated ex-cavation and anchoring machine in complex environments.The evaluation results indicate that the adaptability evaluation score for the No.3409 haulage roadway is 84.64,indicating good adaptability.Tunneling operations under high-stress and strong-impact mine condi-tions are closely related to factors such as the stability of coal seam roof and floor,faults,folds,and the impact of rockbursts.These fac-tors directly affect the adaptability of equipment for underground excavation.Conducting adaptability evaluation before excavation opera-tions can help select anchor excavators with goodness-of-fit for excavation projects,which can improve excavation efficiency and reduce risk factors.

Abstract:To enhance the cutting efficiency and safety of steel wire rope conveyor belts,and to achieve automation,safety,and efficiency in cutting steel cord conveyor belts,an efficient and movable steel wire rope conveyor belt cutting device has been designed and manu-factured.Based on the study of its working principle,a finite element analysis model for tooth cutter and steel wire cutting was estab-lished.The rake angle,relief angle,and tip angle of the tooth cutter were taken as research variables,and the influence of each variable on cutting torque was studied using orthogonal experiment combined with simulation analysis.The parameters of each tooth cutter were optimized using range analysis.The research results indicate that the tool rake angle has the greatest impact on cutting torque,followed by the tool nose angle,and the tool relief angle has the least impact.The optimal angle combination is a rake angle of 6°,a relief angle of 22°,and a tool nose angle of 51°.Through the cutting experiment of steel cord conveyor belts,the feasibility of the high efficient and movable conveyor belt cutting equipment and the cutting effect of optimized cutting tools were tested.The results showed that the equip-ment has good cutting performance and can achieve the goal of reducing manpower,improving efficiency,and enhancing safety in con-veyor belt cutting.

Abstract:Taking the boiler flexible regenerative system added by a certain thermoelectric company as the research object,the role of flexible regenerative system in improving the efficiency of unit and solving the problem of low-temperature corrosion of air preheaters was analyzed.Through theoretical calculations and analytical comparisons,the technical solution of using a six-stage steam extraction and air heater system for steam turbines was demonstrated,and its economic benefits were evaluated.The results indicate that this scheme can reduce coal consumption of the unit,enhance the cycle thermal efficiency,effectively ensure the safety of the unit during low-load operation and winter operation,and exhibit significant energy-saving and environmental benefits.

Abstract:Fully-mechanized top coal caving with gob-side entry retaining differs from traditional gob-side entry retaining technology for thin coal seams.The greater thickness of the top coal caving seam results in more severe deformation of roadway roof and floor,as well as the coal ribs.The pressure on the retained roadway can be effectively alleviated by roof cutting and pressure relief.Taking the No.3309 fully-mechanized top coal caving face in Sangshuping No.2 mine of Hancheng Mining Area as the engineering background,the displace-ment variation characteristics of roof after cutting and pressure relief were theoretically analyzed and demonstrated.The optimal cutting height was calculated to be 8 meters.Furthermore,by utilizing numerical simulation software,the stress-displacement variation laws of the roadway roof,floor,and coal rib after cutting were analyzed.The results indicate that the roof cutting and pressure relief technique has a-chieved remarkable effects.The stress concentration phenomenon on the goaf side of roadway has been effectively relieved.The peak stress has decreased by 16.6％compared to the situation without roof cutting,and the subsidence of adjacent roof has reduced by 28.6％,which is align well with theoretical calculation data.After adopting the roof cutting and pressure relief technology for the gob-side entry retaining roof,the stress environment has been improved,and the displacement of the surrounding rock in the entry has been significantly reduced.

Abstract:A systematic analysis was conducted on typical coal gangue from seven coal mines and fly ash/ash residue from three power plants affiliated to Huaihe Energy Holding Group Co.,Ltd.The results show that the coal gangue from Huaihe Energy Holding Group has high compressive strength,and the fly ash/ash residue has good activity index,which can be used as aggregates and admixtures re-spectively to prepare permeable concrete.Analysis and testing were conducted on permeable concrete prepared using coal gangue and fly ash.The results showed that this permeable concrete not only achieves a certain degree of permeability(porosity of 15％to 20％)but also possesses sufficient strength(21.0 to 44.8 MPa).It exhibits high technical and economic feasibility and can be widely used in va-rious applications such as road hardening in mining areas,slope stabilization,and sponge city construction.

Abstract:Addressing the issues of poorly sealed goaf areas,severe air leakage,and coal seam spontaneous combustion in the application of"110 method"in spontaneous combustion coal seams,the study focuses on the prevention and control of coal spontaneous combustion un-der the conditions of"110 method"roof cutting roadway in No.13403 fully-mechanized mining face of Zhuji west coal mine.By conduc-ting air leakage tests,numerical simulations of"three zones"of residual coal spontaneous combustion in the goaf area,and tests on charac-teristic gases indicative of coal spontaneous combustion,the study analyzes the law of coal spontaneous combustion in the self-forming roadway face without coal pillars and determines the critical values of graded early warning indicators for coal spontaneous combustion.The results indicate that air leakage in working face and the goaf is primarily due to inflow from the air intake corner and support No.1-No.10,with most of the leakage occurring from supports No.44-No.61 at the tail end of working face.A ventilation method was selected that facilitates fire prevention,involving air intake through the No.13403 haulage roadway and the return air connecting roadway,and air return through the track roadway.Additionally,the distribution of the"three zones"of coal spontaneous combustion in the goaf was determined.CO gas volume fraction was chosen as an indicator to measure the stage and degree of coal spontaneous combustion.Based on experimental test results of characteristic gases of spontaneous combustion in the 13-1 coal seam,the early warning levels,temperature ranges,and early warning thresholds for each stage of spontaneous combustion in the 13-1 coal seam were divided.The research findings can serve as a ref-erence for the prevention and control of coal spontaneous combustion in self-forming roadway without coal pillar working faces.

Abstract:The development height of water-conducting fracture zones in shallowly buried thick coal seams is closely related to the safe mining of coal mines in western mining areas.To investigate the development height of water-conducting fracture zones in overlying strata during shallow mining of thick coal seams,the No.1016 working face of Yushuquan Mine in Xinjiang was selected as the research object.The development height of water-conducting fracture zones in the overlying strata was predicted through a combination of empiri-cal formula calculations,numerical simulation experiments,and field measurements.The development heights of water-conducting frac-ture zones in the overburden strata obtained by the three methods are 46.93,63.40,and 50.08 meters,respectively,with fracture-min-ing ratios of 13.76,15.85,and 15.70,respectively.The results indicate that,based on the field measured data,the fracture-mining ratio obtained from numerical simulation is close to that measured on-site.Taking the maximum value of the two,the fracture-mining ratio for shallow-buried thick coal seam mining in Yushuquan Coal Mine is determined to be 15.85.The research findings can provide a scien-tific basis for the prevention and control of roof water hazards in coal mining in similar mining areas in western China.

Abstract:In order to effectively control the gas emission in underlying stress-relief coal seam at close range,a coupled model of diffu-sion,seepage and deformation of coal dual pore media was established.The stress and multi factor coupling gas outburst law of underly-ing stress-relief layer induced by the first coal seam mining were analyzed,and the influence mechanism of the original stress,original gas pressure and initial permeability on the gas pressure change in the stress-relief layer was further explored.The results show that the stress field redistributed after the first mining layer is symmetrically distributed in the middle of working face.The closer the area is to the roof and floor of working face,the greater the degree of stress relief,and stress concentration occurs at both ends of working face,re-sulting in a significant increase in permeability value of damaged coal body.Gas pressure in stress-relief layer decreases,and the de-crease in gas pressure in most areas is similar.Along the parallel direction of working face,gas pressure change curve shows a"W"shape distribution.The gas pressure shows a pattern of first decreasing and then increasing from both ends to the middle of working face;gas pressure in the stress-relief layer at about 10 meters from both ends of working face has the largest decrease(approximately 9％).The original stress,original gas pressure,and initial permeability are all positively correlated with the decrease in gas pressure of stress-relief layer.The influence of initial permeability on gas pressure changes is higher than that of original stress and original gas pressure.Research results can provide reference for efficient gas extraction in underlying close range stress-relief coal seams,in order to reduce gas emission and ensure coal mine safety production.

Abstract:To study the influence of the position of the open-off cut and the spacing between the lower coal seams on the roadway under close range coal seam conditions,taking the No.105 working face of Liuta Coal Mine 1-2 upper coal seam as the engineering background,by combining theoretical analysis,numerical simulation,and on-site application,the failure characteristics of the plastic zone of the sur-rounding rock in the goaf floor of the upper coal seam working face and the lower coal seam roadway were analyzed at different open-off cut positions.The results show that with the increase of the distance between the open-off cut position and the lower coal seam,the plas-tic zone of the roadway and the plastic zone of the working face floor change from the through state to the separate state,and the deform-ation of the surrounding rock of the roadway group rapidly decreases;when the position of the open-off cut is selected at the layer spac-ing of 8 m,the plastic zone around the roadway does not go through to the working face floor,the height of the elastic zone is greater than 2 m,and the maximum deformation is 13.8 mm,at this time,the mining of the upper coal seam working face has the least influence on the lower roadway.The field measurement shows that when the open-off cut is selected at the layer spacing of 8 m,with a displacement of 10-16 mm between the two sides of the roadway and 8-15 mm between the roof and floor,the surrounding rock control effect meets the production requirements.

Abstract:The combination of gob-side entry retaining technology and Y-shaped ventilation mode has been widely practiced in coal mining field.The"two intake and one return"working face and the goaf tail roadway area often face the challenge of gas accumulation.When the gas concentration exceeds the safety threshold,it will increase the risk of accidents such as gas explosions.In order to improve the gas control effect in coal mines,the No.81118 working face of Wenjiazhuang Coal Mine in Shanxi Province was taken as the re-search object.Fluent simulation software was used to construct a mathematical model,and the basic laws of gas migration and diffusion under the Y-shaped ventilation mode of goaf were analyzed.The influence mechanism of different ventilation conditions on the spatial distribution pattern of gas concentration was expounded.The results show that the optimal air volume ratio of 2∶3 between the transpor-tation roadway and auxiliary transportation roadway has the best effect,which can ensure the safety of working face while achieving ef-fective management of gas in gob-side entry retaining area.

Abstract:When installing the main control system of the main shaft hoist in Zhangshuanglou Coal Mine,the safety protection system of hoist was improved in accordance with the relevant requirements of"Coal Mine Safety Regulations",but there were no specific require-ments for dynamic monitoring of tension of wire rope.To ensure the safe and stable operation of the lifting system,it is urgent to dynami-cally monitor the tension system of existing main shaft lifting wire rope,in order to solve problems such as overload,coal stagnation,un-balanced tension of lifting rope,and high maintenance costs,and ensure the safe operation of lifting equipment.

Abstract:In response to the time delay problem in the output feedback control of the dense-medium separation suspension density sys-tem,in order to reduce the occupation of network bandwidth,improve communication efficiency and control performance,based on the e-vent-triggered protocol,the dense-medium separation suspension density system was transformed into a time-delay system,solving the problem of information transmission delay in various links of the system.At the same time,an output feedback control law and sufficient conditions for performance were designed to ensure the stochastic stability of the closed-loop system by forwarding some parameter de-pendent sufficient criteria,and its effectiveness and applicability were verified by a sorting system example.

Abstract:Taking the No.210107 working face of a certain mine as the research object,a cantilever rectangular elastic thin plate model in the form of a regenerated roof was established to simulate the stress and strain laws of the regenerated roof during mining.The critical conditions for the bending and breaking of the regenerated roof during mining were analyzed,and the prevention and control methods for roof collapse were proposed.The results indicate that the smaller the thickness of the regenerated roof,the greater the tensile stress on the roof,and the longer the mining advance distance,the greater the tensile stress on the regenerated roof.During the process of regener-ated roof,the displacement of roof will first suddenly increase and then gradually decrease until it tends to stabilize,and the displace-ment of floor heave will diverge in an elliptical outward increasing state.The peak stress of the lower layer working face gradually de-creases until the fluctuation stabilizes,and the relationship between the advanced support stress of working face and distance from the working face shows a trend of first increasing and then decreasing.In terms of the management of recycled roof,it is necessary to strengthen the monitoring of activity of the recycled roof and timely release pressure,and adopt effective support methods to prevent the danger caused by large-scale activity of roof.

Abstract:In the process of coal mining in our country,especially in the coal mining in western mining area,the phenomenon of repeated mining in multiple coal seams is a common occurrence.The development mechanism and law of water conducted zone in multi-seam mining are very complex,and the research on it is of great significance for the prevention and control of water damage in working face roof.Taking Changcheng No.5 Coal Mine in Etuokeqian Banner,Inner Mongolia as the research object,based on the analysis of its multi coal seam structure,a combination of empirical formula calculation and numerical simulation methods were used to calculate and analyze the height of mining induced fractures during individual and repeated mining of each layer.The research shows that the development law of mining-induced fractures in repeated mining is related to the spacing of coal seams,when the spacing is less than the height of the caving zone,repeated mining will lead to the increase of the overall guide height;when the overlying coal seam is located under the wa-ter conducted zone of the underlying coal seam,the repeated mining of the coal seam is the highest elevation of the two-layer guiding height;when the overlying coal seam is located above the water conducted zone of the underlying coal seam,the repeated mining of coal seam does not make the water conducted zone communicate with each other,but it still affects the formation and development of the frac-ture;in the case of repeated mining of multiple coal seams,the overburden roof has the phenomenon of"weakening",which leads to the decrease of the cumulative cracking and mining ratio after repeated mining of multiple coal seams.The research results have certain guiding significance for the prevention and control of water damage to the working face roof under repeated mining conditions.

Abstract:Under high-intensity mining conditions,the safety status of working face is affected by the coupling effect of single or multi-ple factors,and there is a certain degree of uncertainty in evaluating the overall safety status of working face and obtaining its main con-trol factors causing disasters.The study extracted the constituent elements of coal mine safety risks and conducted a coupled multi factor analysis of potential coal mine risks using information entropy theory,effectively identifying their main controlling factors.By using at-tribute recognition method,the scientific division of neighborhood values of various safety indicators under coal seam geological condi-tions and disturbance effects has been achieved.A multi factor coupled working face risk assessment model based on entropy weight was constructed,which achieved a horizontal comparison of disaster prone environments and safety conditions under strong coal mining with different coal seam occurrence conditions.This provides a more scientific method for identifying and preventing the main controlling fac-tors of working face disasters under multi factor coupling.

Abstract:In order to study the characterization of tectonic coal pore structure with different destruction types and its influence on gas desorption and diffusion,the micro-pore,transition pore,meso-pore,and macropore pore structures of three types of coal samples,namely cataclastic coal,granulated coal,and mylonitic coal,were tested by using mercury intrusion porosimetry and low-temperature liq-uid nitrogen adsorption method.Combined with gas desorption and diffusion experiments,the ultimate gas adsorption capacity and de-sorption Langmuir pressure of different coal samples were calculated,and the influence of different types of tectonic coal pore structures on gas desorption and diffusion laws was analyzed.The results show that as the degree of structural coal damage increases,the pore vol-ume and pore volume ratio of coal samples show the characteristics of macro-pore increasing,meso-pore increasing first and then de-creasing,and transition pore and micro-pore continuously decreasing;the pore specific surface area and pore specific surface area ratio show the characteristics of macro-pore and meso-pore increasing,transition pore increasing first and then decreasing,and micro-pore decreasing;the ultimate gas adsorption capacity and desorption Langmuir pressure show the characteristics of gradual increase,and the adsorption and desorption capacity of coal samples increases correspondingly with the degree of tectonic coal.

Abstract:In coal seams with high gas,high crustal stress,high outburst risk,and low permeability,implementing regional pressure relief and permeability enhancement to eliminate outbursts has become one of the important measures to achieve sustainable development of coal mines.Based on the problems encountered in the application of pressure relief,permeability enhancement,and outburst elimination tech-nology,a combination of theoretical research,RFPA2D—Flow numerical simulation,and field testing was used to study the initiation mecha-nism and propagation law of directional hydraulic fracturing fractures through layers.Research has shown that the initiation of hydraulic fracturing through layers depends on factors such as the magnitude of axial and radial horizontal stresses in fracturing hole,the physical and mechanical properties of coal rock,and the weakest layer inside.Single-hole hydraulic fracturing can achieve a pressure relief radius of 7-8 meters,but there is a stress concentration zone on the outer side,which is not conducive to regional pressure relief and permeability enhancement.Multi-hole directional hydraulic fracturing forms a nearly cylindrical compression fracture zone,and a through crack surface is generated in the centerline direction of the fracturing hole and directional hole,effectively eliminating the phenomenon of stress concen-tration in non-directional hydraulic fracturing.The results showed that the gas content in coal seam of No.2238 auxiliary roadway test area in a certain mine decreased by about 42.3％,effectively reducing the risk of coal and gas outbursts.

Abstract:In response to the problem of spontaneous combustion of residual coal in goaf of irregular working faces in deep mines,taking No.21914 working face as an example,combined with its geological conditions and complex environment of goaf,key technologies for fire prevention and extinguishing in irregular working faces were studied.By analyzing the tendency of coal seam spontaneous combus-tion,the distribution of residual coal in goaf,and the characteristics of changes in working face morphology,a comprehensive fire preven-tion and extinguishing system was constructed,effectively reducing the risk of spontaneous combustion and providing reference for safe mining of working faces under similar conditions.

Abstract:The surface deformation caused by coal mining can cause serious damage to ground infrastructure.Taking the No.4 thin seam mining of Fujiayan Coal Mine as the research object,a fusion interferometric synthetic aperture radar(InSAR)technology was pro-posed,and using FLAC3D numerical simulation and probability integration comprehensive method to predict the surface deformation caused by thin coal seam mining.The results show that when using InSAR historical deformation data to invert rock mechanics parame-ters in numerical simulations,the simulated estimated surface deformation is basically consistent with InSAR data and probability inte-gration model results,verifying the reliability of the simulation results.Using this method,it is estimated that the No.4 coal seam of Fu-jiayan Coal Mine will experience a settlement deformation of 0.68 m during mining.Comprehensive prediction method effectively im-proves the accuracy of surface deformation prediction under mining action.Research results can provide reference for predicting surface subsidence during coal seam mining under similar geological and mining conditions.