In order to reasonably determine the location of the Goudi Coal Mine industrial site and the development plan of the mine field, four industrial site selection plans were proposed based on factors such as the terrain of the mine field, coal seam burial depth, transportation form, basic farmland, and exploration degree. The advantages and disadvantages of the four industrial sites were analyzed, finally the industrial site was arranged at the Liyuangou site. For the industrial site at Liyuangou, three mine development plans were proposed, namely: the large-diameter auxiliary shaft (T-shaped development) development , the gentle slope inclined shaft development, and the vertical shaft development plan. According to the comprehensive comparison result, the development plan of the first plan is the most reasonable.

This paper analyzed the major problems of protective layer mining in deep burst mines, and summarized the state of protective layer mining, underground coal gangue seperation technology and backfill coal mining technology. Taking the twelve mine of Ping Coal as an example, a closed-loop system of full rock protection layer mining unloading pressure - coal gangue underground separation - filling of gangue was proposed to develop the deep burst mine safely, efficiently and greenly. The concept of full rock protection layer mining was proposed, and the hard rock softening process is used to destroy the rock layer. The underground sorting system of coal gangue was established, and the integrated washing and sorting equipment was developed for underground coal mines at a depth of 1,000 meters. It also developed a new process of blocking and backfilling: the problem of ground collapse caused by mining in the quarry area has been effectively managed by blocking backfill of gangue. The independent and complete integrated system of full rock protection layer mining unloading pressure - coal gangue underground separation - filling of gangue was established in the twelve mine of Ping Coal, forming a safe and green development mode for deep burst mines and providing reference value to the development of similar mines in China.

In view of the actual on-site problems of serious deformation and destruction of surrounding rock, low construction efficiency, support cost and high labor intensity caused by the use of comprehensive excavating machine for reaming, taking geological conditions and mining parameters of 5307 fully mechanized mining face of Jiaojiagou Coal Mine as background. In this paper, the small section roadway is put forward to carry out the large section hole cutting construction by means of “permanent + temporary” support. Field tests were carried out on 5307 fully mechanized mining face with opening holes. The practice shows that the surrounding rock stability is good during opening holes, the labor intensity of opening holes support is reduced, the construction efficiency is increased by 37.5%, the number of workers is reduced by 33.0%, and significant safety and economic benefits have been achieved. It can provide reference for the opening of fully mechanized mining face under similar conditions.

nsufficient lubrication is a major contributor to head sheave malfunction. The existing head sheave bearing lubrication relies on a static mode of manual oiling, which suffers from drawbacks such as extended lubrication intervals and unreliable lubrication performance, resulting in accelerated local bearing abrasion and shortened lifespan. To lower the incidence of head sheave breakdowns, this paper identifies the essential functions of the head sheave bearing lubrication system based on the lubrication principles and conditions of the head sheave bearings. Accordingly, a head sheave bearing lubrication system with swivel wheel lubrication, rolling bearing lubrication, and waste grease recycling features is devised, and an adaptive threshold method derived from Turkey is proposed to assess the bearing lubrication status using field experimental data, achieving adaptive regulation of bearing lubrication frequency and quantity. Finally, the field application study of the lubrication system is conducted, and the outcomes demonstrate that the designed lubrication system can ensure consistent and uniform lubrication effects and attain optimal lubrication results.

Abstract: In order to quantitatively evaluate the impact of open-pit mining on grassland ecosystems, taking Yimin Open-pit Coal Mine as an example, the vegetation net primary productivity (NPP) index was selected, to calculate the long-term series of NPP using 21 satellite remote sensing data from 1985 to 2018, then quantitatively evaluate the impact of open-pit mining on the surrounding grassland ecosystem and the ecological restoration effect of the waste dump. The results indicate that, the open-pit mining has resulted in a NPP loss of approximately 10% to 30%. As the recovery time increases, the vegetation of the waste dump continues to evolve towards natural vegetation, and NPP also increases and tends to stabilize. After stabilization, the NPP of the external waste dump has reached about 90% of the average annual NPP of the unaffected area, and vegetation productivity is close to the level of natural vegetation productivity. However, the average NPP of the inner waste dump and the northern outer waste dump with shorter recovery time only reaches about 50% of the annual average NPP of the unaffected area. The ecological reconstruction and restoration of open-pit mines is a long-term process, and it takes more than 20 years for the vegetation succession of the external dump to stabilize. It must be promoted synchronously with open-pit mining activities and persisted in the long term.

In order to ensure the surface-drilled large-diameter relief well safely penetrate the roadway, we studied the factors affecting the dry hole penetration on the basis of conventional mud direct circulation and multi-stage expansion drilling in the cover layer and bedrock layer of the large-diameter well. These main factors are reverse circulation annular pressure control, reverse circulation penetration when encountering strong or weak aquifers, reserved safety distance in the penetration section, and efficient cementing completion method. By analyzing the principle of dry hole drilling technology in the reserved penetration section, the reverse circulation device, the segmented slurry and slag discharge drilling, the safe roadway penetration process, determination of the penetration position, and penetration distance, we obtained a complete set of key technology system for efficient drilling of large diameter dry hole roadway penetration, which has received good practice results, and can provide technical support for the dry hole roadway penetration of surface-drilled large diameter relief well. 

Due to the lack of distinguishing the support requirements of different strata, the design of bolting and shotcrete support is conservative and the safety factor is too high, numerical simulation method can be used to determine the improvement degree of stress and displacement of surrounding rock before and after support in different depth sections of vertical shaft, and the support design is verified and optimized by using the mechanical characteristics of surrounding rock of vertical shaft. A three-dimensional finite element model of shaft support is established based on the new return air shaft project in Anping Coal Mining Area. The stability analysis, support effect analysis and support scheme optimization of the inverted shaft wall in the bedrock section with excavation diameter of 5.3m and depth of 135m are carried out with stress and displacement indexes. The results show that the horizontal displacement of surrounding rock of the vertical shaft can be improved by up to 51.37% after the bolting and shotcrete support, the maximum principal stress of surrounding rock changes from tensile stress to compressive stress. The supporting effect of the bolt and concrete in different rock strata is different, the section with good strength and stability of surrounding rock can achieve the effect of combined support by shotcrete support, so the support method can be selected and optimized according to the actual situation. Finally, the numerical calculation results are compared with the measured results of project, and the reliability of finite element analysis in analysis of surrounding rock bolting and shotcrete support of shaft is verified.

In order to realize the rapid excavation of Arch Coal Roadway under the condition of deep buried and overlying goaf in Kailuan mining area, according to the specific working face geology and mining conditions of No. 9 coal mine in Donghuantuo Coal Mine, the maximum goaf distance of arch roadway, the stability of surrounding rock in goaf area and the influence law of different factors are studied by using the methods of theoretical analysis, numerical simulation, equipment improvement and construction technology optimization Research on supporting equipment and technology of rapid excavation. (1) Based on the thin shell theory, the mechanical model of the roof column shell in line with the arch section roadway is established. The calculation formula of the maximum empty roof distance of the arch roof is deduced by using the assumption of the moment free theory and the failure criterion of the maximum tensile stress. The influence law and weight of roadway width, tensile strength, buried depth and arch height on the maximum empty roof distance are analyzed, and it is determined that the theoretical maximum empty roof distance of Donghuantuo is 2.4m. (2) Through numerical simulation, it is found that when the empty roof distance is about 2m, the surrounding rock of the arched roadway has good stability and the roadway has no tensile failure. When the empty roof distance is greater than 4m, the two sides of the roadway have tensile failure and the stability is reduced. Therefore, the maximum empty roof distance calculated by numerical calculation is between 2 ~ 3m；The arch roof will not produce new damage with the increase of empty roof distance, which shows that the stability of arch roof is the best；Properly increasing the empty roof distance is conducive to the rapid achievement of support strength of U-shaped steel；The failure characteristics of the shallow surrounding rock of the roadway under the goaf are mainly determined by the vertical stress, while the failure characteristics of the deep surrounding rock are mainly determined by the horizontal stress. (3) Improve the combination device of self-made airborne station platform and airborne joist and the new long excavation and long support airborne temporary support device to solve the problems of low efficiency and poor safety of shed and temporary support in the 2.4m empty roof area. Cooperate with the optimized process flow for field application. The average monthly advance is more than 550 m, the peak is 846.4 m, 16 shifts are 14.1 m, and the forming quality of shed support roadway is good, It can meet the normal mining requirements of the working face, so as to realize rapid excavation.

The low efficiency of excavation and support in coal roadway is common. The unreasonable selection of excavation and support construction parameters increases the risk of heading and roof fall, which seriously affects the production efficiency. In order to solve the problem of safety and high efficiency in the process of coal roadway excavation, using theoretical analysis, numerical simulation and field test methods, combined with the geological conditions of the north wing ( 2-2052 roadway ) of Hejin Tenghui Coal Industry, the physical and mechanical model of the roof in the unsupported roof area was established by using the thin plate theory. FLAC three-dimensional numerical simulation was used to simulate the influence of factors such as unsupported roof distance, roadway width and roof support strength on the stability of the roof in the unsupported roof area, and the mine pressure appearance law and deformation characteristics of the roof in the head-on unsupported roof area of coal roadway excavation were systematically studied. The results show that the roof of the unsupported roof area is destroyed under the combined action of tension and shear. Numerical simulation is used to simulate the vertical stress of roof surrounding rock with different head-on distances ( 2,4,6,8m ) in front of the lagging support section, and considering the safety factor of the unsupported roof area, it is concluded that the limit unsupported roof distance is 4m.During the test period, the maximum settlement deformation of the roof is 62 mm, and the roof of the unsupported roof area of the heading head has not occurred. The roof stability is excellent and meets the production requirements during the whole service period.

In view of the prominent problem of high root rate in deep hole bench blasting in Jilangde coal mine, it is considered that the method of adjusting the ultra-depth of the borehole can be adopted to solve this problem through field investigation. Therefore, the reasonable range of borehole depth is firstly obtained based on the current commonly used calculation methods and theoretical calculation of borehole depth. In view of the main reason for the high root rate is serious overbreak, it is proposed to reduce the ultra-depth of the borehole from 1m to 0.8m. Then, tests are firstly carried out on 1380 and 1392 platforms. GPS is adopted to measure the elevation of the test platform and 3D elevation map is drawn to evaluate the root rate. It is found that the improved blasting scheme achieves good effect, which not only effectively reduces the root rate, but also reduces the explosive consumption and drilling workload. Finally, many repeated tests are also carried out, which shows that 85% of these achieve good blasting effect. But for some low elevation platform, such as the southwest platform1284, its blasting effect is not very ideal. It may be assumed that the rock integrity and strength increases and then the clamping force at the bottom of the borehole strengthens with the reduction of the platform elevation, and therefore the ultra-depth of the borehole should be increased.

In order to deeply explore the influence of the overlying coal column on the rock burst risk of the working face during mining. Taking the 40201 working face of Dafosi Coal Mine as the engineering background, the rock burst risk of factors such as coupling fault structure and working face square in the influence area of the overlying coal column overlying the protective layer mining was studied by theoretical analysis and on-site detection methods. The following conclusions are obtained: the mining of the protective layer is a good way to prevent the impact of ground pressure in the area, and the total energy of the microseismic events monitored by the 40201 working face during the initial mining process does not exceed 104J, and the total frequency does not exceed 100 times, which is at a low level, and the protective layer mining face is less affected by far-field dynamic load disturbance. The impact risk of the overlying coal column in the influence area of the overlying coal column of the mining of the protective layer is relatively high, and the stress concentration in the overlying residual coal column continues to be transmitted to the lower working face, which is coupled with the structural stress and abnormal roof activity caused by the fault structure in the mining surface and the square period, and the 40201 return air lane side has a higher impact risk than the transportation lane side. Up to now, the 40201 working face of Dafosi Mine has not experienced catastrophic impact when the residual coal column impact area is overlaid on the protective layer mining, which not only verifies the superiority of protective layer mining as a regional impact prevention method, but also provides a reference for the prevention of impact pressure in the same type of mine.

Aiming at the problems of long duration of periodic incoming pressure, high concentration factor of advanced bearing pressure and strong dynamic pressure appearing in the mining process of deep-buried thick hard roof face, and the defect of insufficient pressure relief in coverage of conventional hydraulic fracturing or blasting widely used at present, this paper takes Yangchangwan Coal Mine 130208 working face as the research object and determines the target fracturing layer according to the key layer theory. Based on Hubbert-Willsi formula for calculating fracture pressure of non-permeable formation, theoretical fracturing pressure is obtained. Large flow high pressure pump(1.2m3/h）and kilometer directional drilling rig capable of realizing long distance orientation are selected as fracturing equipment and regional pressure relief is carried out by means of directional hydraulic fracturing technology with long horizontal holes. The technology has a wide range of pressure relief, the interval of periodic weighting is significantly reduced after the working face enters the fracturing area, the influence range of advanced bearing pressure is reduced, the coefficient of stress concentration is reduced, and the coefficient of dynamic load is significantly reduced. During weighting, the increase resistance of support is significantly reduced and the proportion of index function resistance curve is significantly reduced. This shows that the directional hydraulic fracturing technology with long horizontal hole has good effect and has application value.

In order to investigate objectively and deeply the laws and characteristics of coal mine roof accidents in China, using mathematical statistics, origin mapping, significance test and iterative cluster analysis, the data of roof accidents published by the National Coal Mine Administration and Coal mine Safety Net from 2016 to 2022 were analyzed and discussed. The analysis shows that: Jiangxi, Sichuan and Shanxi provinces are the areas with the highest frequency of roof accidents and the highest number of deaths, accounting for 29.8% and 27.1% of the country, respectively, and should focus on prevention and control; Illegal risky operation is the main cause of roof accidents, and natural factors will aggravate the severity of accidents. In terms of specific time period, the roof accidents are more frequent in 1-2 hours before and after the shift. In terms of time distribution, March and May to August were the months with high incidence of accidents. The number of roof accidents in mid and deep Wells and deep Wells mining area has increased and accounted for more than 60%. The outdated support method and insufficient material hardness have caused many accidents, and the natural factors are more prominent. Meanwhile, it is necessary to strengthen the knowledge learning of management personnel. We should attach great importance to roof management under deep mining, adapt to the intelligent era, and develop a full-cycle safety management system.

In response to the problem of serious breakage of lump coal in the retransmission link of Harwusu coal processing plant, the characteristics of lump coal undersize fraction on the screen and carriage samples of the removal media screen were analyzed, and the drop test of lump coal was carried out to study the influence law of drop height on the undersize fraction of lump coal. Based on the mechanical analysis, a block coal anti-fragmentation mathematical model was established, and a technical solution for block coal anti-fragmentation was proposed, and the anti-fragmentation technology modification of fine coal removal media screen pre-screen chute and tape conveyor head chute was carried out. After the anti-fragmentation technology modification, the 25mm limit rate of lump coal products in the carriage was 20.31% on average, which was 16.23 percentage points lower than that before the technology application, and the sales price of tons of lump coal was increased by RMB 15 yuan /ton, which increased the economic benefit of the enterprise.

In order to explore the prevention and control technology of rock burst under the influence of spatial coal pillar, taking the Y396 and Y394 working faces of Tangshan Mine as the background, the research methods of theoretical analysis, numerical simulation, field application and test are combined to systematically analyze the main control factors of rock burst induced by working face, determine the prevention and control technology of rock burst under the influence of spatial coal pillar, and test the effect after field implementation. The results show that the main controlling factors of rock burst induced by Y396 and Y394 working face during mining are the irregular coal pillars left by the upper 5 coal seam and the irregular coal pillars of the coal seam. Through Flac3 D software, three abnormal stress rising areas of Y394 working face during mining are obtained. The main prevention and control areas are determined, and the corresponding prevention and control technologies are implemented. Through the drilling cuttings method, it is determined that the risk of rock burst in the area has been eliminated.

For the practical problem of floor heave in south wing water roadway of 33 mining area of Xutuan Coal Mine, Anhui Province, China, through TRIZ theory function component analysis, causal axis analysis, substance-field analysis, and technical conflict analysis, the conceptual design and optimization of floor heave control measures were completed. Finally, a comprehensive floor heave treatment scheme was proposed, included water-resisting layer, inverted arch lining, anchor, and polypropylene fiber concrete floor. Inspired by the flexible shell inventive principle of TRIZ theory, a three-dimensional steel grid inverted arch lining was developed. It is a semi-rigid composite supporting structure, which can have a deformation of the pressure in the early flexible support stage, and can withstand greater pressure in the later rigid support stage. The field monitoring results show that the maximum floor deformation was less than 60 mm after 60 days, and the floor heave inhibition effect was signification. This paper provide a new idea for TRIZ theory in the design optimization of roadway engineering support.

Deep roadway is prone to deformation and failure due to high stress, which seriously threatens the safety of mine production. In this paper, through the combination of theoretical analysis, numerical simulation and field test, the distribution law of plastic zone of roadway surrounding rock under different lateral pressure coefficients and different lithology is explored. The results show that with the increase of lateral pressure coefficient, the plastic zone of roadway surrounding rock gradually increases, and the change rate of the two sides is obviously small, which makes the plastic zone change from circular to elliptical. When the lateral pressure coefficient is 1.8, the plastic zone at the top and bottom plate is the largest. The plastic deformation zone of roadway under different lithology is characterized by large range of roof and floor and small range of two sides, and the plastic zone in mudstone is obviously smaller than that in coal seam. Through numerical simulation, the displacement of roadway before and after grouting reinforcement is compared. The results show that the displacement distance between surrounding rock roof and two sides is reduced by 28 % on average after grouting reinforcement. After the combined support of ' anchoring + grouting ' is applied in the field, there is basically no deformation of roadway section during excavation.

The instability of coal and rock mass is the direct cause of mine disasters. It has become an inevitable development trend to monitor and warn coal and rock mass with long period and high efficiency. The infrared thermography of transportation roadway in Hongliu Coal mine I010401 working face and I020308 working face in the observation period is studied The variation characteristics of average infrared radiation temperature (AIRT) and differential infrared radiation temperature (VSMIT) were obtained, and the VSMIT judgment threshold of the transportation lane of hongliu Coal mine I010401 working face and I020308 working face was obtained The research results show that the application of infrared radiation monitoring technology in field monitoring is feasible, which can provide reference for the application of infrared radiation monitoring technology in the stability monitoring of surrounding rock in mine.

In view of the lag of the current microseismic monitoring system in the imminent warning of rockburst, the earth sound monitoring system is applied to monitor rockburst and the time series ARIMA model is studied in data prediction. The advanced 4-channel ares-5/e geoacoustic monitoring system is installed and continuous data monitoring is carried out. First, the multi-channel geoacoustic monitoring data are cleaned to eliminate random and interference data, and then the data are tested for stationarity and data difference analysis. Then, the ARIMA data model is established and the correlation of the model is estimated. After identifying the model parameters, the validity of the model is tested, Through the verified model, the ground sound data is predicted and recognized. Through the multi-level extraction of the long-term data monitored by the geological sound equipment of a mine and the prediction of the geological sound data value in the later period, it is found that the time series ARIMA model has excellent prediction advantages in the prediction of medium and short-term geological sound data.

In the collaborative operation process of roadheader and advanced support, in order to avoid unnecessary collision between advanced support and roadheader, it is required that the rotation Angle of roadheader and advanced support should be kept in a certain range under various working conditions. Collision between advance support and roadheader under cooperative turning condition is analyzed. According to the geometric relationship of collision, the mathematical model of moving step after the advance support and roadheader rotate one angle is established, and the calculation method of changing step is deduced. Taking the maximum moving step as the index, the influence of equipment rotation angle on moving step under the premise of avoiding interference is studied. Research shows that : When only the roadheader turns to move, the larger the rotation angle of the roadheader, the smaller the movable range ; When the roadheader shovel plate lags behind the advance support and the advance support first turns to the feed, the smaller the equipment angle, the greater the maximum moving distance of the roadheader ; When the roadheader shovel plate is ahead of the advance support and the roadheader turns to feed first, the smaller the rotation angle of the equipment, the greater the maximum feed distance of the advance support.

In order to further improve the reliability and control performance of the motor as the power source in the mine pump, this paper uses permanent magnet synchronous motor to replace the asynchronous motor in the traditional mine pump. In order to ensure the safe and long-term operation of the motor in the mine, a new type of discontinuous pulse width modulation technology is proposed to reduce the loss of switching devices and ensure its control performance. In the control strategy of the motor, this paper uses the model predictive current control, and introduces the speed prediction error into the value function to optimize the performance of the predictive control. In order to improve the torque control characteristics, the extended state observer is introduced to observe the load torque, further improving the torque control characteristics of the system. Finally, simulation and experiments show that the proposed method is better than the traditional predictive control method in speed response, torque control, current harmonics and so on.

In order to further improve the performance of the spiral sludge collecting device of the coal mine sump cleaner, the simulation model of sludge collection is established by using the EDEM software, explored the torque variation trend and the aggregate effect of the spiral reamer of the sludge collecting device under the conditions of fixed speed and different transmission ratios, and fitted the obtained data to obtain the fitting curve. The results show that with the increasing of transmission ratio, the mass of materials transported in unit time is also increasing, and the distribution of scattered points is approximately a quadratic curve. At the same time, by comparing the torque of different spiral reamers, it is found that the torque of the rear end spiral reamer is significantly higher than that of the front end spiral reamer, and there is no obvious change rule. The torque of the front end spiral reamer decreases gradually with the increase of the transmission ratio within a certain range, and reaches the minimum when the transmission ratio is 1:1.1.

Abstract: The existence of coal seam anomalies in coal mine tunneling has an important impact on the safe mining of coal resources, and carrying out the detection and identification of coal seam anomalies is essential for the treatment of coal seam anomalies. In this paper, to address this problem, a two-dimensional spatial magnetic field (TM) model of coal seam was established by using the finite-difference method in time domain (FDTD), through forward simulation and theoretical analysis, the propagation law of electromagnetic wave in coal seam is studied. The research results show that the forward simulation results of coal seam anomalies with different shapes and different filling media are all hyperbolic, there are obvious differences between the hyperbolas, and these differences can be used as the conditions for identifying the shape of coal seam anomalies and filling media; the burial depth and vertical distance of coal seam anomalies can be obtained by the two-way travel time of the hyperbolic vertex, but the vertical distance of the forward simulation map of the water-bearing anomalies of the laminated coal seam cannot be accurately obtained due to the presence of multiple spurious waves. The results of the study can provide a reference basis for the actual coal seam detection data and information extraction.

Understanding and measuring miners' safety accountability pressure can provide direction for the establishment of an accountability system in coal mines. In this study, miners were used as the research object, and the scale development procedure was followed to define the connotation and dimensions of miners' safety accountability pressure and develop and validate the measurement scale based on relevant literature and miners' interview results. The research results show that miners' safety accountability pressure comes from five aspects, which are economic pressure, psychological pressure, environmental pressure, work pressure and interpersonal pressure, among which economic pressure is the main source of miners' safety accountability pressure. This study provides a measurement tool for miners' safety accountability stress and lays the foundation for further exploration of the construct.

The east side of the Anjialing Open-pit Coal Mine is facing the problem of approaching the mining boundary. In order to master the propagation law of blasting vibration and its influence on surrounding buildings, TC-4850 blasting vibration meter is used for monitoring. The linear regression analysis method is used to calculate the values of K and α, and the formula of attenuation law of particle peak vibration velocity is obtained. The reliability of the formula is verified by comparing the predicted value with the measured value. By introducing the safety guarantee coefficient and combining with the allowable value of vibration velocity of general civil buildings in Blasting Safety Regulations, the safety allowable distance is calculated, and the relationship between the safety allowable distance in three directions and the maximum single stage charge is obtained as Rx=28.484Q1/3, Ry=27.513Q1/3, Rz=27.791Q1/3, respectively, which provides a reference for the blasting parameter design of Anjialing coal mine.

In order to study the influence of grain size difference on the distribution of gangue components after crushing, taking gangue in mahuangliang coal mine as the research object, the grain size distribution law of gangue after crushing by means of screening, grinding, chemical composition testing and other means, and the change of main chemical composition of gangue under the condition of different width of discharge port and grain size were studied. The results show that the characteristic grain size of gangue grain size distribution model has a logarithmic increasing trend and the uniformity index has an exponential decreasing trend with the increase of the drainage port width. The composition of gangue with different grain sizes also changes with the grain size. With the increase of the width of the discharge port, the distribution rate of each component is affected to different degrees. Gangue particles containing CaO and MgO are enriched in coarse-grained products. The particles containing Fe2O3 gradually concentrated from fine to coarse. Particles containing Al2O3, SiO2 and C are more likely to be broken and enriched in fine-grained products. With the increase of gangue particle size, the distribution rate of each component shows a law of first increasing and then decreasing, and the enrichment ratio with the change of particle size conforms to the form of “”.

The ash control of the traditional remedia sorting process is limited by the lack of process models, and it is difficult to make breakthroughs. Although the mechanism modeling made by some studies can explain the physical parameters of the sorting system in the model, for the re-intermediate sorting control process, the mechanism modeling covers the process insufficiently comprehensively and the range of process parameters is difficult to define. After the introduction of high-precision ash analyzers in industrial sites in recent years, this problem has mainly focused on reducing ash measurement delays. Based on the random forest algorithm (Random Forest) and empirical mode decomposition, the density, magnetic content and ash data measured in the industrial site are denoised, and the mathematical model of the heavy medium sorting system is established. In order to solve the problem of high ash delay in the re-intermediate sorting process, a pre-correspondatory method for ash separation is proposed: the input at t moment (density value m magnetic content value M) corresponds to the output (ash value h) at the moment of t + T (T is the delay time) for model training. After comparing and optimizing BP neural network, random forest algorithm and algorithm based on least squares principle, it is finally concluded that the random forest algorithm has the best modeling effect. Then, the random forest estimate can be used as a guide value for coal sorting industrial sites, which is helpful to improve the efficiency of heavy medium sorting and improve the quality of refined coal.

Abstract: The battery frame car is a clean type stent carrier developed to meet the demand of coal mine working face handling, which fills the gap of the industry at home and abroad and promotes the equipment development technology of China's coal auxiliary transportation industry. In this paper, a systematic introduction is made to the vehicle, which has a compact structure, reasonable load distribution and strong adaptability. The theoretical calculation of the whole vehicle force was carried out, and a virtual prototype of dynamics simulation was built and simulated for six working conditions. The calculation and simulation results were similar, which verified the accuracy of the prototype, and the full-load over-pit working condition with the greatest force on key element parts was selected as the basis of static analysis. The static analysis of the key components was carried out in the finite element analysis software, and the forces obtained from the dynamics were added to the model in a reasonable way, and the static strength checks of the hinge pin and swing beam were carried out. The quantitative reliability analysis of the articulated pin and the oscillating beam is carried out, and they both meet the requirement of 1×10-5 failure probability. It provides reference for the design and development of the same type of vehicles.

Aiming at the problem of windlass running deviation and serious wear of its track system, taking MB670-1 windlass as the object, and taking 5-2 coal seam of a coal mine as the background, the motion analysis model of the windlass is established, and the detailed description of the windlass track system and the roadway floor is carried out using the multi-body dynamics theory and discrete element theory, Finally, the DEM-MBD coupling method is used to analyze the movement state of the roadheader and the mechanical characteristics of its track system during the driving process of the roadway floor. The research results show that the driving state of the windlass on the roadway floor is good, with the average longitudinal slip rate of 19%, the maximum vertical settlement of 20.2 mm, and the maximum lateral displacement of 20.2 mm; The tension force of the track shoe under the bearing wheel increases with the torque of the driving wheel, and the tension force of the track shoe at other positions is basically unchanged; In the track system, the driving wheel receives the largest load, with an average value of 129.6kN; The load bearing wheel located under the machine head is the largest, with an average value of 78kN; The tug wheel at the middle and rear of the fuselage bears the maximum load of 5.7kN. The research results provide a basis for improving the reliability and stability control of the windlass.