The coal bunker is the key part of the continuous transportation system of coal mine. In order to improve its service life and reduce the shutdown maintenance time, the wall structure and closing position of the lower entrance of the coal bunker are improved, which not only improves the impact resistance of the wall, but also make sure the safty of workers and equipments when loading room has been brokendown. In order to ensure the normal use of the air gun, according to the flow characteristics of the coal flow in the bin and the production experience, the layout and protection mode of the air gun are improved, and solve the problem that the air gun shutdown when its broken. Through continuous improve design of coal bunker, it has been proved that the structure is reasonable, safe and reliable, and the maintenance period is prolonged after years of use, which has guiding significance for coal bunker design.

In order to solve the problem of strong pressure in the mining of island working face of hard roof in fully mechanized top-coal caving mining with large mining height of extremely thick coal seam, based on the research background of 8102 working face of Tongxin coal mine, the stress distribution in the mining of island working face was simulated and analyzed. And on this basis, the safety production technology guarantee system of island working face is put forward, which is based on the core of " small coal pillar of gob-side entry driving + high working resistance hydraulic support + hard rock hydraulic fracturing in the ground + roadway pressure relief borehole ", and the rationality of the security system is verified by field measurement. Field application shows that: 21000kN high working face resistance hydraulic support has large supporting capacity and good adaptive effect ;The roadway USES 6m small coal pillars to dig the roadway along the goaf . Roadway with 6m small coal pillar of gob-side entry driving, during the mining, the maximum displacement of roof and floor of roadway is 700mm, and that two sides of roadway is 1020mm. The surrounding rock deformation of the roadway is controllable, which can meet the actual production requirements of the working face.

In order to solve the problems of stress concentration, roadway surrounding rock control difficulty and excavation replacement tension when retaining coal pillars, combined with the actual geological conditions of gob side entry retaining in 1604 fully mechanized caving face of Guhanshan mine, the directional presplitting blasting technology is proposed to be applied in gob side entry retaining. The principle of directional presplitting blasting is analyzed, and the test results of different blasting methods are compared and analyzed by means of theoretical analysis and field test. The research results show that: the directional presplitting blasting technology can effectively cut off the mechanical connection between the basic roof above the roadway and the basic roof rock above the goaf; when the directional presplitting blasting is adopted and the charge structure is "8 + 6 + 4 + 2", the cracks in the blasting hole expand well and the formation rate is high; after the blasting is carried out on site, the average displacement of the top and floor of the roadway retaining section is 624mm, and the average displacement of the two sides is 338m m. It meets the requirements of the later use of the roadway, and the effect of retaining roadway is good.

Whether the mining procedures of the open-pit mine can be optimized directly affects the overall economic benefits of mining. In order to solve the problem of mining procedures in the case of passing the Luzigou anticline during the mining of the first mining area of Anjialing open-pit mine, through Based on the analysis and calculation of geological conditions, production status, and dumping space, three technically feasible mining schemes are proposed: "direct push in the current mining area", "direct push + northern advance" and "L-shaped fan steering"; Based on the analysis of various economic and technical indicators in the above schemes, the Analytic Hierarchy Process and the TOPSIS method are combined, and the weights of the nine selected evaluation indicators are determined through the AHP, and then the TOPSIS method is used to sort the three schemes , And finally determined "direct push + northern advance" as the optimal mining plan.

The process of super-magnetic separation has some advantages such as high efficiency to separate suspended solids in mine water，small area coverage, etc, and is applied to treat mine water to a certain extent as a new type of mine water treatment technology. In order to increase mine water use rate, to resolve the problems of sump clean underground and equipment wear severity, the coal mine uses the process of super-magnetic separation to reform the original process of treating mine water underground, according to the result of process operation in recent years, The process of super-magnetic separation is stable operation and better effluent quality, resolving the problem of mine water low use rate because of high suspended solids, the cost low, has certain reference significance to coal mine water treating and using underground.

Heat exchanger is the core device of mine return air waste heat recovery system. The choice of heat exchanger directly determines the utilization efficiency of mine return air waste heat. This paper relies on the selection of heat exchanger of Wanfu mine return air waste heat recovery system. A three-dimensional discrete gas-liquid two-phase flow model was used to simulate the heat transfer and resistance characteristics of the air flow in the spray heat exchanger. And the characteristics of flow velocity, pressure and temperature in heat pipe heat exchanger were analyzed based on the standard k～ε turbulence model. The heat transfer effect and resistance of spray heat exchanger and heat pipe heat exchanger are compared and analyzed, the results show that spray heat exchanger has less resistance to the return air, while heat pipe heat exchanger has better heat transfer effect. The economic analysis shows that the annual investment of heat pipe heat exchanger is only two-thirds of that of spray heat exchanger. The research results have some practical guiding significance for the selection of heat exchanger for waste heat recovery system in Wanfu mine.

Based on the inclined shaft concrete lining occurred fracture, spalling, leakage and other serious corrosion problems under sulfate erosion environment, this paper took the inclined shaft of Gansu Wan Sheng Mining District as the research object, did indoor simulation experiment, explored that various content of the fly ash had an impact on the corrosion resistance of concrete, and researshed the strengthening technology of inclined shaft. The results showed that the fly ash had great influence on corrosion resistance of cement mortar specimens, and the corrosion resistance coefficient from large to small is 20%, 10%, 30%, 0%, 40% fly ash content, providing theoretical basis for grouting reinforcement behind wall; Adopting intensive I-Steel well curb and lay 2mm waterproof and anti-corrosion soft materials synchronously to repair and reinforce the inclined shaft, and grouting the reserved waterproof and anti-corrosion grout filling area and wellbore wall , the effect of strengthening and anti-corrosion is good; Dealing the surface of new jetted concrete with silicane impregnant can reduce the diffusion and infiltration of sulfate ion and other harmful substances efficiently.

The transportation of coal gangue is one of the key technical links of the tunneling system based on the tunneling machine. This article introduces two coal transportation methods：the continuous transportation and the interrupted transportation and finds out the advantages and disadvantages, applicable conditions and scope of application by a detailed comparative analysis of the two transportation methods in terms of safety, transportation efficiency, labor cost and equipment use.The research results show that: compared with interrupted transportation , the continuous transportationhas fewer hidden dangers, high transportation efficiency, low labor cost, and low equipment failure rate. It is suitable for the supporting transportation system of the fast tunneling system of the windlass. However, the selection of the transportation system requires comprehensive consideration of factors such as the installation of working face equipment,, the duration and period of moving downside,gas prevention, the company’s existing equipment, safety management, and production organization.

In view of the difficulty in forming the roadway with broken roof, roof hollowing out, separation and subsidence, etc., the boreholes were drilled to peep at the roadway, and the actual measurement showed that the roof was basically broken, and the scope of roof loose circle was about 5.0 m. The main factors of roadway deformation and failure are low strength of roadway surrounding rock, large range of roof broken rock mass and unreasonable roadway support parameters; in order to improve the surrounding rock structure of roadway, the integrated support technology of "bolting and shotcreting" is proposed, which is the combination of advanced grouting, roadway shotcreting, lengthening anchor cable and lag grouting. The support verification is carried out through numerical simulation, and the results show that After the improvement of the support scheme, the plastic zone and deformation of the roadway are significantly reduced, and the surrounding rock reinforcement technology of "bolting, shotcreting" is feasible; through the field industrial test, the deformation of the roof and the two sides and the roof separation are small, the broken rock mass of the roof is effectively controlled, and the surrounding rock control effect is good.

Abstract：The mining of No.11 Coal Seam in Sangshuping Coal Mine of Hancheng mining area is facing the threat of Ordovician limestone water hazard from coal seam floor. In order to ensure the safe mining of 3109 working face, directional drilling grouting technology was used to explore and control the upper Ordovician aquifer in the coal seam floor of 3109 working face, and the permeability of the upper Ordovician aquifer in the coal seam floor of 3109 working face was identified and transformed. Through the water pressure test, it was found that the fractures in the upper part of Ordovician limestone aquifer in the floor of 3109 working face are not developed and the water permeability is poor. Through drilling and grouting, the permeability of Ordovician limestone aquifer in 3109 working face floor was further reduced. After the completion of grouting project, 3109 working face has realized safe mining, which proves the effectiveness of directional drilling grouting technology in the prevention and control of floor Ordovician limestone water hazard in study area.

Shenfu Dongsheng coalfield has complex terrain conditions, and there are many small coal mines. The accumulated water in the goaf has caused great potential safety hazard to the adjacent existing coal mines. Using ground to air transient electromagnetic to explore the accumulated water in the goaf can not only solve the impact of terrain on the construction, but also improve the work efficiency. According to the overall longitudinal geoelectric characteristics of "low resistance, high resistance, low resistance in Shenfu-Dongsheng Jurassic coalfield, the K type geological model is established, and its ground-airborne TEM curve characteristics in the presence of low resistance body are studied by three-dimensional finite difference time domain method forward modeling. A constrained inversion method with independent adjustment, discrete logarithm interval layer thickness, and upper and lower limits constraint inversion of resistivity values is adopted to obtain the response characteristics of low resistance body. This method was applied to the exploration of water-filled goaf in Jurassic coal field, and two abnormal areas with low resistance were successfully detected, which were verified as water-filled goaf by drilling.

Single event energy and daily total energy are the two most commonly used microseismic early warning indicators in coal mines, but their initial values are often not accurate enough and need to be optimized combined with a large number of monitoring data. Based on the actual monitoring data of cucurbitacin 21103 working face, the early warning effectiveness of the initial index is analyzed. The analysis shows that the initial design of strong impact risk index of single event energy, moderate and strong impact risk index of daily total energy is unreasonable. The optimization method of microseismic early-warning index based on energy level and frequency analysis is further developed: firstly, the energy level frequency curve of microseismic events at mine scale is studied and divided into exponential distribution section, linear distribution section and discrete distribution section; secondly, the energy level of the last two migration points of linear distribution section is taken as the early warning index of medium and strong rockburst risk, the energy level of the slope shift point is taken as the early warning index of weak rockburst risk. Finally, the rationality of the energy level and frequency of the total daily energy index divided based on the statistical data is tested. Finally, the accuracy of the new early-warning index is significantly improved, and the early-warning of four high energy events is basically accurate.

Abstract: In order to solve the problems of hard coal and low lump coal rate in 5-2 coal seam of Shiyaodian coal mine, the Weakening Mechanism of hydraulic fracturing combined with deep hole blasting for hard coal body was studied by theoretical analysis and field test. The results show that: the hydraulic fracturing technology mainly weakens the coal through tensile failure and shear failure; on the one hand, hydraulic fracturing has the advantages of making a large number of fractures in advance, reducing the coal strength, increasing Poisson's ratio and so on to realize the coal body in-situ modification; on the other hand, it increases the water filling between the fractures in the coal body, which greatly weakens the scattering effect of blasting stress wave attenuation The results show that the effect of blasting weakening is improved by the effect of stress and friction; the coal breaking by deep hole blasting is mainly divided into two stages: shock fracture and gas wedge expansion. Blasting in the coal body with hydraulic fracturing weakening and in-situ modification can increase the radius of blasting crushing area and fracture area. Combined with the actual situation of Shiyaodian coal mine, the weakening scheme of hydraulic fracturing combined with deep hole blasting for hard coal body is formulated. Through electromagnetic wave CT detection and comparison of lump coal rate before and after weakening, the effect of combined weakening technology scheme is verified.

The geological structure of Hancheng mining area is complex, and the controlling effect of structure on coalbed methane is obvious. In order to reveal the influence of structure on the enrichment, accumulation and development of coalbed methane in Hancheng mining area, the basement subsidence history of Hancheng mining area is excavated, the genesis of coalbed methane is determined, the plane distribution of coal rank is divided, and the relationship between gas content and structural style and buried depth of coal seam is analyzed. It is found that the shallow part of Hancheng mining area is affected by base uplift and tectonic stress, coalbed methane is secondary biogenic gas superimposed thermogenetic gas, and deep metamorphism is a typical high coal rank thermogenetic gas. Controlled by different structural styles and present burial depth, the gas content of the structural coal caused by the layer slip structure in the north is higher than that in the south, and the gas content in the middle and deep part is higher than that in the shallow part. Based on the analysis of the occurrence characteristics of coalbed methane controlled by structure, the complexity analysis of coal body structure and stress environment, the shallow structural coal is developed, the gas content is low and the permeability is poor, which is the unfavorable area for coalbed methane development; the middle transition zone is the sweet area for coalbed methane development with high coalbed methane content and good permeability; the deep slope zone in northwest China is a relatively favorable area for coalbed methane development because of its high gas content but poor permeability. On the basis of the above, the mining modes of coalbed methane (mine gas) in different mine fields are put forward at last.

Aimed at the situation that the coal seam in the fully mechanized mining face has unstable distribution and different thickness of gangue sandwiched layer with dense and hard characteristics, which has poor cutting performance and pollutes the coal quality, through the mechanical experiment of gangue sandwiched and numerical simulation of rock drilling presplitting, a large area classification presplitting method of hard gangue sandwiched layer is proposed. The new technology of presplitting and crushing, which is the integration of high-pressure water jet presplitting, gas gathering blasting, high-pressure fracturing and acidizing, is adopted to solve the effective crushing problems of different types of gangue sandwiched layers. The engineering practice shows that the analysis of actual mining data is basically consistent with the conclusion of experimental simulation. The research of this technology provides a reference for the high-efficiency mining of coal seam under the same geological conditions.

Studying the development law of water-conducting cracks in mining is an important foundation for realizing water-preserving mining. The 2304 working face of a mine in northern Shaanxi is used as the research object. Through theoretical analysis, theoretical calculations, similar simulation tests and other methods, the dynamic development of water-transmitting cracks in shallow coal seam mining with thick alluvium is studied. By establishing a prediction model for the dynamic movement and deformation of the mining rock and soil layers, the basin-wide subsidence and horizontal deformation prediction formulas are given. The study established the development height of upward water-conducting fractures with the subsidence of the key stratum as critical parameter and a calculation method for the development depth of downward water conducting cracks with the movement and deformation of the impermeable layer as critical parameter. The dynamic development of upward cracks and downward cracks during the advancement of 2304 working face is analyzed and predicted. The similar simulation experiment phenomenon is basically consistent with the predicted result. The research can provide reference for the prediction of mining fracture development under similar geological conditions.

In order to obtain the overburden water-conducted fracture height under the condition of large mining height of shallow buried coal seams in Wanli No.1 Coal Mine, the method of combining theoretical prediction with field drilling engineering detection was carried out. Basing on the “Key Strata theory”, the prediction method of the height of water-conducted fracture zone was researched which refers to the multiple-coal mining condition. With the method, it was discovered that, whether mining 3-1 coal seam alone or 3-1 coal seam and 4-2 coal seam repeatedly, the height of water flowing fracture zone in overburden rock is basically the same, and the water conducting cracks are developed into the surface sand outside the top interface of bedrock; the field drilling engineering detection results verify the accuracy of the theoretical prediction. Combined with the leakage of flushing fluid and the change of water level in the borehole and the borehole TV observation, it is found that the water flowing fissures caused by repeated mining of 3-1 coal seam and 4-2 coal seam have developed to the surface, corresponding to the height of water fracture zone is 170m; the height of overburden caving zone caused by 3-1 coal mining and 4-2coal mining is 21m and 18m respectively, and the corresponding overburden caving ratio is 4.2 and 3.8. The research results can provide the basis for the practice of water retaining coal mining under similar mining conditions.

Abstract：In order to analyze the influence of multi slot arrangement on the antireflection mechanism of hydraulic slotting (punching) gas efficient drainage technology, the consistency verification experiment based on uniaxial compression digital speckle pattern experiment and particle flow PFC simulation of rock deformation was conducted. Based on the results of the consistency verification experiment, PFC was used to simulate the mechanical damage behavior of coal and rock samples with 3 slots under uniaxial loading. The influence of the angle between the central line of the slot and the horizontal plane and the distribution level of the slot on the strength, crack development and crack propagation of the specimen were analyzed. And the effect of slot distribution on coal seam permeability was studied. The simulation results are verified by acoustic emission experiment of rock samples in laboratory. The results showed that it is feasible to simulate rock deformation by PFC and the distribution of slots has a significant effect on the damage characteristics of the specimens. When the angle between the slots is acute, the specimen is more likely to be damaged and the cracks are more likely to sprout and develop. When the angle is between 0°and 90°, the influence range between the slots can be increased. When the angle is 90 ° and the fracture surface is parallel to the main stress, the permeability enhancement effect of coal seam groove is not good.

Muli mining area is located in the birthplace of Datong River, an important tributary of the Yellow River. It is an important part of water conservation and ecological security barrier in the Qilian Mountains region, and its ecological status is very important.Disordered and predatory mining has led to a series of ecological and environmental problems, such as the destruction of landform landscape, the destruction of vegetation, the destruction of land, the degradation of permafrost, the destruction of river wetland, the slope instability (landslide, collapse), etc.In this paper, the ecological characteristics and damage characteristics of Muli mining area are deeply analyzed, and taking Jiangcang No. 1 Well as an example, the treatment ideas of "geology + ecology" and "natural recovery + engineering management" are put forward in the combined mining of open pit. The treatment mode of "mining pit backfill gentle slope + slope and slag hill regulation + soil reconstruction and vegetation greening + wetland and rock wall landscape shaping" was established.

In order to meet the requirements of indoor simulated grouting reinforcement for fractured rock mass and rock mass with different damage degrees, a new grouting reinforcement system is developed. This system is mainly composed of five parts: hydraulic pumping device, slurry storage tank, grouting reinforcement test device, pressurized water pump, slurry storage cylinder and vacuum pump. Grouting reinforcement system is made for the standard rock sample size of φ50× H100 mm required for the test. The system can control the grouting pressure and confining pressure by itself to meet the grouting requirements under different pressure conditions. Meanwhile, the system can realize the new grouting technology combining "injection and pumping" to improve the grouting efficiency. The development of the grouting reinforcement system solves the problems of difficult grouting reinforcement or unsatisfactory grouting effect in fractured rock mass, and has the advantages of good sealing, simple operation and wide application range.

In view of the high gas content, high pressure, and low extraction efficiency in the M9 coal seam of Jiaozishan Coal Mine, the liquid CO2 phase change fracturing technology was applied to the coal seam anti-reflection project test.The principle of CO2 phase change fracturing and permeability enhancement was explored from multiple angles. Through grouped comparative tests, the focus was on the effects of different construction sequences of fracturing holes and different liquid loadings (crackers) on the effective extraction radius. The gas content index method was used to study The law of the change of gas drainage radius at different pre-drainage time is described. The results show that: 1) When the pre-drainage time is the same, more fracture channels will be provided when the auxiliary drilling is constructed first, and the resistance will be reduced when the stress wave propagates, so that the effective radius of gas drainage will be larger;2) Within 90 days of pre-draining time, the effective radius of gas drainage from fracture holes is positively correlated with the amount of liquid (fracturer).When the pre-drainage time is 90 to 150 days, under the action of tectonic stress, the borehole deformation is large, and the effective radius of gas drainage in the fracture hole with more liquid (fracturer) is smaller;3) After fracturing, the effective radius of gas drainage in boreholes is larger, 3.6-4.2 times that of ordinary holes. The net gas flow rate of single-hole drainage increases by 2.9-5.8 times on average, and the gas drainage concentration increases by 2.3-3.1 times. The pre-pumping time is shortened by more than 65%. The research results provide a basis for the reasonable layout of gas drainage boreholes, thereby improving the efficiency of coal seam gas drainage.

In order to effectively prevent the roof water damage of the main coal seam in Dafosi mine field. The current situation of roof water damage is fully analyzed, and based on the full analysis of the water samples of each aquifer, the mine water chemical characteristic database is established to analyze the recharge, runoff, and drainage conditions of each aquifer and the hydraulic relationship between them. Compare the water inrush samples with the water chemistry database to determine the source of the water inrush, and use cluster analysis to complement and verify each other. The research results show that the water chemical characteristics of the shallow aquifer and the deep aquifer of the well field are obviously different; the upper clay aquifer of the Xiaozhanggou Formation cannot completely block the hydraulic connection between the loose layer phreatic water and the Neogene aquifer; the Cretaceous aquifer does not directly receive the replenishment of atmospheric precipitation, and the replenishment is dominated by the area outer flow. And it is judged that the water inrush sample No. 1 is from the Cretaceous aquifer, and the water inrush sample No. 2 is from the Jurassic aquifer, which is in line with the actual production situation, indicating that the combination of water chemical characteristics comparison method and cluster analysis can accurately distinguish the source of water inrush.

To solve the problems of low positioning accuracy, serious environmental interference and large equipment cost, an RSSI algorithm for locating underground personnel in coal mine is proposed based on improved weighted hybrid filtering. Firstly, Gaussian filtering was carried out to remove the small probability and large interference signal value received by each position point through the signal collected off-line at the fixed point, and then the maximum weighted processing was introduced to get the signal values of each position point. Secondly, an improved Kalman filter with equivalent weight function was designed to smooth the calculated signal value of each position point to suppress the errors caused by noises in the environment. Finally, the least squares were used to determine the path loss index Xσ and environmental parameter n in this environment, resulting in the establishment of the wireless signal transmission model which conforms to the special environment in the underground coal mine. And the location of mine workers was obtained by calculating the distance from unknown nodes to beacon nodes. The simulation results show that the proposed method may reduce the RSSI ranging and positioning errors effectively, which lays a theo-retical foundation for the better application of the RSSI ranging and positioning technology in coal mine personnel positioning.

In view of the poor positioning effect of the shearer in the fully mechanized mining face affected by the environment, a positioning method of "inertial navigation + odometer" is proposed. In this method, the difference between the displacement measured by ins and the displacement calculated by odometer is taken as the measured value. The closed-loop Kalman filter is used to establish the combined positioning model, and the system error is corrected in real time to measure the attitude and position of the shearer. The results show that the measurement error of advancing direction is less than 3cm, and the measurement error of height direction is less than 2cm. The reason of error is analyzed and the accuracy and stability of positioning method of "inertial navigation + odometer" shearer are verified.

Abstract: Local ventilator in coal mine is the main equipment of coal mine safety production,in order to solve the problem of wind speed adjustment in advance according to the demand of air volume at the next moment, an improved genetic algorithm to optimize Elman neural network algorithm of IGA - Elman (Improved based algorithm - Elman) was proposed to predict the required air volume. The improved algorithm of the strategy to improve the selection operator of genetic algorithm, by copying excellent individuals and selecting better methods according to proportion, the average fitness of population is improved and the ability of operator selection is improved.Compared with the IGA-Elman neural network and the traditional GA-Elman neural network, the IGA-Elman network can improve the predictability and has the advantage of fast convergence speed, and realizes the accurate prediction of the air demand of the local ventilator, it has important practical significance for coal mine safety production.

In order to solve the problem of ambiguity and uncertainty of index factors in the integrated assessment of occupational hazards in coal mine workplaces, the cloud model theory is introduced and combined with the combination of assignment techniques to build an occupational hazard assessment model for coal mine workplaces. Using a coal mine's general mining face as the research background, a total of 20 influencing factors in five aspects, such as operator condition, dust and toxic substances, physical factors, equipment factors, and management factors, were selected as evaluation indicators, and the determinacy of belonging to different levels was calculated using a forward cloud generator, and the combination weights of each indicator were calculated based on Euclidean distance combination using AHP and EWM to reduce the subjective influence of decision makers, and the occupational hazard level of the coal mine workplace was determined based on the characteristic parameters of the evaluation indicator cloud model. The results of the study show that the comprehensive assessment grade of the coal mine workplace is C4, which is basically consistent with the actual assessment situation and has certain reliability and operability, and provides new reference and ideas for the assessment of occupational hazards in coal mine workplaces.

The separation process of interference bed separator (TBS) was numerically simulated by the coupling technology of computational fluid dynamics (CFD) and discrete element method (DEM), and the flow field, particle movement characteristics and separation effect of TBS were studied. The results show that the axial flow is the main form of flow field in TBS. With the increase of the height, the difference between the axial velocity and the radial velocity of the flow increases gradually, and the flow finally develops into a stable uniform flow; Vortex ring and short-circuit flow will be produced in the separation drum. With the increase of the rising water velocity, the position of vortex ring will gradually increase, and the flow of short-circuit flow will also increase. The movement characteristics of particles with different sizes are different in TBS separation. When the particle density is the same, the larger the particle size is, the longer the trajectory is and the longer the residence time is; The smaller the particle size is, the longer the residence time is. When the diameter of the discharge port is 150 and 200 mm, the EP values are 0.110 and 0.107 respectively, and the separation effect is better. When the opening rate of TBS distributor is in the range of 14% to 16%, the distribution rate curve is close to coincidence, and the Ep value is 0.107 and 0.109, so the separation effect is the best.

Aiming at the technical problem of the low efficiency of 3 mm dry screening for viscous-moist steam coal and the short service life of screen surface, the structural design and kinematic characteristics test of screen surface and parameters optimization of 3 mm screening were carried out. The time-frequency characteristics of the inner and outer screen frame and screen surface were analyzed by using vibration testing technology. The material formula and structure design of screen surface were optimized. And the variable thickness cross section arc transition screen surface was developed. And the influence of vibration frequency and processing capacity on screening effect were explored. The results show that: after the material formula and structure design of screen surface optimized, the y-direction vibration intensity of the center point of the screen surface decreases from 36.50 g to 21.63 g, which significantly reduces the movement speed of the material group on the screen, prolongs the screening time, and has a service life of more than 6 months; With the increase of the working frequency, the screening efficiency first increases and then decreases. With the increase of the treatment capacity, the screening efficiency decreases. When the frequency is 9.33 Hz and the treatment capacity is 400 t/h, the 3 mm screening efficiency and the ＜0.5 mm slime removal rate reach 92.85% and 95.67%, respectively. Compared with the original screen surface, the screening efficiency is increased by 11.18%, which significantly reduces the amount of slime entering the system. It is of great significance to reduce slime production and improve production efficiency in coal preparation plant.

In order to reduce the mine water disaster in the heading face effectively, the ZDY2-3200LF narrow-body split crawler drilling rig with twin boom was developed, which was based on the construction requirements of the heading face and the problems of the split drilling rig.The overall design ideas, structural composition and hydraulic system of the drilling rig were introduced. The test shows that the structure design of the drilling rig is reasonable and the performance is stable and reliable. The technical indexes of each test also meet the requirements of design. It can provide a strong equipment support for improving the speed of roadway excavation and ensuring safe production.

In order to solve the problems of low dust removal efficiency, and easy clogging of internal nozzles and filters in the existing wet dust collectors of Chinese coal mines. Based on the characteristics of the air flow generated by the radial impeller moving in the radial direction under the action of centrifugal force, a radial mixing impeller that integrates dust extraction and purification was proposed, and a radial mixing cyclone dust collector for mine was developed, which is composed of water inlet pipe, radial mixing impeller, motor, guide vane, and dewatering grid. The equipment achieves the purification of polluted air through the three-stage dust collection process of water distribution, primary atomization and secondary atomization. The radial mixing cyclone dust collector for mine was tested in the coal preparation plant of Shandong Jining No. 2 Coal Mine. The results show that the dust removal efficiency of total dust and respirable dust in the manned work area was above 96%, the dust concentration was reduced to below 4.2 mg?m-3, the water consumption was 0.9～1.35 m3/d, and the working environment in the work area has been significantly improved, the application effect is remarkable.

The construction of smart mines has had a huge impact on the production and operation of coal companies, and it has also brought huge challenges to the management of quotas for coal companies. This article believes that the traditional quota preparation method cannot meet smart mining enterprises' needs in terms of quota accuracy, change cycle, and scope of adaptation. This paper uses the LUBA model to analyze coal enterprises' actual consumption and the relationship between the various quota elements and proposes the quota management framework and quota preparation requirements under the smart mines' background. Combined with big data analysis, a coal enterprise quota preparation method suitable for smart mining background is proposed, and it strives to systematize and intelligence the quota preparation of smart mining enterprises.

Trust is the prerequisite for the establishment of a cooperative relationship within the organization. In the organization and management, the lack of employees' trust in the leader will bring greater management costs to the organization. To help the coal mine solve the trust problem between the mine manager and subordinates， Leader-member Exchange theory is the theoretical basis to construct an adjusted intermediary model,and the structural equation model is used to analyze the influence path of the behavioral integrity of mine managers on employees' trust in mine managers. and in-depth exploration of the subordinates' trust tendency and the consistency of values between the manager and the subordinates in the influencing mechanism. The intermediary effect of the hierarchical linear regression analysis method is used to test the adjustment effect of the superior-subordinate guanxi，and the bootstrap method is further used to test the adjusted intermediary effect model. The research results show that the behavioral integrity of coal leader has a positive effect on the cognitive trust and emotional trust in leader in coal mines; the trust tendency of subordinates partially mediates the influence of the behavioral integrity on the cognitive trust and emotional trust in mine manager; Consistency of values between subordinates and mine manager Part of the intermediary mine manager’s behavioral integrity affect the emotional trust in manager's, and the higher the quality of the superior-subordinate guanxi,the stronger the indirect effect of the trust tendency and the consistency of values. The above studies further improves the influence of leaders' behavioral integrity on trust in leadership，and provides practical references for coal mines enterprises to rebuild leadership.

Aiming at the engineering problem that the frozen wall cannot be closed on time during the construction of the auxiliary shaft of the Libi Mine, it was judged that there was a water inrush "gap" in the sand and gravel layer of the frozen wall between 30, 31, 32, 33 freezing holes, by analyzing the field temperature measurement hole data and the hydrogeological conditions of the mining area. Based on the hydrothermal coupling mathematical model, combined with the actual forming position of the freezing holes, the evolution mechanism of the freezing temperature field of the sand and gravel layer was studied by numerical calculation. By comparing the contour of the frozen wall and the temperature data of measuring holes, it was judged that the groundwater velocity of this layer reached 9m/d. If the current freezing scheme was continued, the closure time of the frozen wall would be as long as 132 days, far exceeding the expected construction period. Based on the technical principle of reducing groundwater flow rate, reducing cooling loss and strengthening local freezing, a fast composite technique of "control", "injection" and "freezing" was proposed for water inrush "gap" of the frozen wall. Based on the current development of the frozen wall and considering the influence of groundwater velocity and flow direction, the positions and quantity of the grouting holes and the enhanced freezing holes were determined. The closing process of the water inrush gap of the frozen wall was predicted by numerical calculation. The results of the project implementation showed that the hydrological hole of auxiliary shaft of Libi mine started to gush water 21 days (17 days predicted) after the completion of the frozen wall bridging construction. This case study could provide a useful reference for future vertical shaft freezing projects with similar hydrological and engineering geological conditions.