In order to provide reference for the water supply and drainage design of the ground buildings of the mine and the coal cleaning plant, combined with the <code for design of water supply and drainage of the coal industry>, <code for design of the coal industry mine>, <code for design of the coal cleaning engineering> combined with the actual production and design of mines and coal cleaning engineering plants, the understanding of the specific provisions of the above code and the specific application in the field of coal industry are discussed. In view of the conflict and incompleteness in the code, the paper analyzes its application and rationality in the field of coal industry, clarifies the opinions and suggestions, and puts forward the contents that need to be revised and supplemented. To provide reference for the designers of water supply and drainage in coal industry.

The lower separation limit of Ningdong mining area coal washing plant is 6mm. If the -6mm fine coal which accounts for more than 30% in raw coal is separated by dry method, the benefits of enterprises will be significantly improved. Variable-diameter pulsed airflow technology is suitable for fine coal dry beneficiation. This paper introduces the pilot scale system and process flow in detail. The effect of pulsed airflow separation and classification was investigated. According to the characteristics of high content and ash content of -1mm fine coal in Ningdong mining area, the combined process of separation and classification was designed to remove the high ash component step by step. The ash reduction of "separation and classification" and "grading and sorting" were compared and the effect of different air volume combinations of separation and classification were investigated. The result shows that the pulsed airflow achieves obvious ash reduction on 6~1mm fine coal. Constant airflow classification efficiency is higher than pulsating airflow. The combined process of “separation and classification” can improve the separation efficiency through the autogenic medium impact. Separation air volume should be around 260m3/h, and classified air volume range from 78 to 95 m3/h. The ash reduction is higher than 20% and the yield exceeds 50%. The clean coal can be used in coal chemical industry, and mixed fine coal can still be used as steam coal. Thus the product structure is optimized.

Abstract：Based on improving coal recovery efficiency, achieving normal recovery and successfully completing replacement of working face for safety production requirements, 25m coal pillar of 3-508 fully mechanized working face in Jingfang coal mine has been optimized and proposed high-strength stability support scheme. A new energy absorbing rock bolt has been developed and its mechanical properties have been investigated. A simulation model in the mining process is established by FLAC3D to study the differences of the surrounding rock stress，deformation and plastic zone distribution law under different pillar widths and different support methods．The results show that the coal pillars width can be decreased to 5-10m with supporting by the new high energy absorbing rock bolt, which means more coal resource can be exploited. The results will provides important scientific basis and instructions on the width of coal pillar and a new supporting method to keep stability of surrounding rocks in JingFang coal mine.

Due to the particularity of thetechnology, the gas drainage pump station in coal mines, with major hidden danger, may cause severe accident when struck by lightning. Based on the reality of the gas drainage pump station in Yadian coal mine, this paper determines the lightning protection level of buildings according to relevant design specifications,fixesthe scope of lightning protection with the “rolling ball method”, and carries out safety analysis of various lightning protection forms. It is found that when single / double lightning rod and single lightning wire are used as lightning arresters, they can not meet the relevant requirements of the first type of lightning protection building; preference should be given to multiple equal height lightning rods as lightning arresters; when multiple lightning rods cannot meet the requirements of lightning protection, two lightning wires should be used for protection. This paper can serve as reference for the lightning protection design of gas drainage pump stations.

Based on integrated heat pipe heat exchange technology coal mine well wellhead heating was researched as a case study in Second mine south wind well of Yangquan coal Industry Group. According to the parameters of thermal load of wellhead ventilation and the residual heat of mine air, the basic parameters of heat pipe and heat pipe resistance were calculated to analysis the temperature of the mine return air and fresh air before and after the heat exchange under typical operating conditions. The results show that the application of heat pipe heat transfer technology can meet the thermal demand of anti-freezing at the wellhead. When the outdoor temperature closing to the design value is -15℃, the inlet wellhead air temperature is 2.2℃.

In order to solve the double lane arrangement working face this section pillar of low recovery rate of coal resources, resource waste serious problems, 3304 face now stay in mulberry ping No.2 shaft section pillar as engineering background, the theoretical analysis and numerical simulation method of combining the analysis of the working face of lateral abutment pressure distribution law, the study compared the 6m, 8m, 10m and 12m, 15m, 20m, 25m and 30m different width coal pillars principal stress and displacement distribution, comprehensive consideration to ensure mine safety production and improve the recovery rate of coal resources finalized by the dual factors of reasonable section width of coal pillar for 10 m. The test results show that during the stoping of the working face, the maximum displacement of the roof surface is 21mm and the maximum displacement of the two sides is 15mm, which meets the requirements of mine safety production and proves that the width of the coal pillar is reasonable. The research results are of certain reference value to the determination of coal pillar width between roadway in the continuation working face of No. 2 well and similar mining conditions.

According to the problem of Zhengzhou mining area three soft coal seam coal roadway supporting technology , occurrence characteristics and formation mechanism of three soft coal seam has been interpreted. And the instability mechanism of three soft coal roadway supporting has been analyzed. Then put forward that the key technique mainly includes three soft coal seam anchor net support technology is mainly coal seam bolt performance, anchor preload, mesh strength, quick installation process and immediate support. On this basis, the thick coal seam anchor net supporting design had been carried out in Chaohua coal mine 22011A coal face transport roadway. The result shows that maximums roof abscission layer of shallow and deep basis points are 48 mm and 52 mm respectively, maximums of roof and floor relative motion are 372 mm and 310 mm. The effective supporting section of roadway has been ensured. So the supporting effect is good.

Aiming at the problems that the surrounding rock of 6.0m small coal pillar roadway in the third panel area of Tashan Coal Mine of Tongmei Group is complicated and difficult to control the stability of surrounding rock, the FLAC3D numerical calculation and analysis method is used to simulate and study the change of coal pillar stress during the mining process of 8311 working face Based on the support scheme for small coal pillars reinforced with roofing cables and roof support, the results of on-site monitoring and analysis show that the surrounding rock control effect of this support scheme is good, which can meet the safety production requirements of the roadway during the service period.

According to the characteristics of geological conditions in the shallow coal seam of a mine in Yulin City, the shallow two-dimensional seismic geophysical exploration technology is used to detect the goaf, and the reasonable excitation source, hammer stack number and path are selected by testing the survey area. For the construction parameters such as spacing, the 2-2 coal mining area is detected by shallow 2D seismic exploration technology in the 1.2162km2 area, and the detection results are verified in the surface construction drilling. The detection results show that: in the area where the terrain is relatively flat (the area where the heavy equipment can reach), the heavy excitation can be used, and the number of single-point sag is 14 or 16 times, and the 4m track is received; In areas with complex terrain, manual hammering excitation can be used. The number of single-point sag is 16 or 18 times, and the spacing is 2m. It is applied to the site to detect 3 anomalous areas, and 2 places are inferred as goafs. One place is inferred to be a coal seam structural change zone, and it is verified by drilling results that the shallow two-dimensional earthquake can effectively detect the shallow goaf.

This paper aimed at the large quantity and long period of crossheading buried pipe in WangPo coal mine, During the mining period, the maintenance cost of crossheading airtight wall is high, And serious gas overrun in the upper corner. This paper puts forward the large diameter borehole in coal seam gas control technology, The drilling parameter design, drilling, pipe laying, hole sealing, pipeline connection, pumping and other technological processes are introduced in detail. the test is carried out in 3310 working face, The results show that the gas in the upper corner is controlled between 0.19% - 0.61%, Gas extraction concentration increased by 1.2 times, The average concentration of drainage branch pipe is 6.85%, the pure gas extraction volume is 10.27m3/min, The construction period will be reduced by 23.53%,The number of employees decreased by 30.57%, The large diameter borehole in coal seam gas control technology, The process is simple, the pore forming speed is fast and the efficiency is high, The problem of gas overrun in the upper corner is effectively solved, It can be used for reference in gas comprehensive control of working face during mining.

In order to solve the hidden danger of gas in the mining process of the 2308 working face of the main coking coal mine, the theoretical calculation method was used to calculate the height of the fall zone and the fissure zone during mining, and combined with the microseismic monitoring technology to cover the rock during the mining Monitor and record the microseismic events to analyze the spatial position of the mining fracture zone, and then obtain the spatial position of the gas enrichment zone in the overlying strata. The study found that the height of the mining fracture zone obtained by the microseismic monitoring method is close to the theoretical calculation result, namely The height of mining fissure zone is about 38m, and the period of stepping pressure during working face mining is about 14m. Based on this, the high gas drainage borehole was designed and its drainage effect was tested. It was found that the gas drainage volume increased by 162% and the gas drainage volume fraction increased by 210%, indicating that the use of microseismic monitoring technology to detect gas enrichment the zone is reliable.

The practical development experiences of CBM horizontal wells more than 15 years for major CBM blocks in China shows that there are wide variation in development effectiveness and poor repeatability among the same technology of horizontal wells under the different geological conditions. Therefore, the optimal technology of horizontal wells needs to further be investigated. Based on typical cases data statistical analysis of CBM horizontal wells technology application. The optimized methods of horizontal wells on the well types, the well structure, the completion method, the stimulation method and the drainage equipment & technology were studied. The results show that the well types and well structure play a decisive role on the efficiently and economically developing CBM. U-type wells and L-type wells are the most valuable for extension and application among all well types. The optimization of horizontal well structure should maintain smoothing of horizontal borehole, horizontal borehole down-dip of U-type wells, horizontal borehole up-dip and setting pocket for sinking coal powder of L-type wells. The completion method is selected according to the data of ground stress, the buried depth and permeability of coal-bed. The screen completion method should be adopted for lower ground stress, relatively shallow buried depth and high-permeable coal-bed. Otherwise, The technology of “casing cementing + segmented dense multi-cluster perforation + large-scale fracturing” should be adopted in the horizontal borehole. The drainage equipment combined “Rod pump + pumping unit ” should be selected in preference. The intelligent drainage and fine drainage should be implemented to strictly control the drainage rate of the stepwise up-production stage and stable production stage of coalbed methane, in order to ensure the sustainable high production of coalbed methane wells.

The operating conditions of the downward belt conveyor are very different from those of the upward belt conveyor. The load is transported through the belt, and the kinematic and potential energy are converted into electrical energy to feed back into the grid through the four?quadrant?frequency?converter. Through long-term practice and application management, some methods for solving major safety defects or hidden safety hazards such as downward belt brake, anti-stall, anti-breaking belt, and anti-material slippage were proposed, and the design requirements of the lower conveyor belt selection were supplemented and improved, which can be used as reference for the belt conveyor design, manufacturing, installation, operation and maintenance.

In this paper, the BC800 mud pump truck for directional drilling rigs in coal mines is used as the research object, combined with the calculation formula of the instantaneous flow of the three-piston reciprocating mud pump, the flow superposition effect of the main and auxiliary mud pumps working at the same time is analyzed, Python language programming calculates and draws the flow unevenness coefficient and instantaneous flow curve of the mud pump in parallel operation, compares the effect of different initial phase angles on the flow uneven system, and proposes application measures to improve the flow pulsation for the mud pump truck, Which provides practical guidance for the design and use of the mud pump truck.

In the process of fully mechanized caving mining, the initial and periodic caving characteristics are different due to the influence of top-coal moving boundary. Taking the 12309 working face of Wangjialing coal mine as the background, the initial emission characteristics and rules of top coal in fully mechanized caving face are studied by combining theoretical analysis, field measurement and physical simulation test. The results show that: The equivalent diameter of the top coal was divided into four sections: 0~9cm, 9~18cm, 18~27cm, and 27~36cm. The mass fraction of the top coal in each section was 13.83%, 46.31%, 20.34%, and 27.36%, respectively；According to the similar simulation experiment, the correction coefficients of gravity acceleration on the left and right sides of the discharger are 1/108 and 1/92 respectively. After introducing the coefficient into the improved b-r model, it is calculated that the discharging time of 20309 working face is 33.95s, and the error with the measured discharging time is only 7.74%, which can accurately describe the discharging characteristics of top coal.

During the mining of shallow-buried coal seams, full-thickness cutting of the overburden strata produces vertical fissures, The fracture cause air leakage in the working face and the mined-out area, threatening the safety of mineral production. In order to analyze the fracture development and air leakage characteristics of overburden strata in this kind of geological conditions, the simulation and evolution of the fractures in the mined-out area were carried out through physical similarity simulation experiments. Further numerical simulation verification was carried out, and it was proposed that blocking prevention measures could effectively reduce the air leakage in the working face, and the parameters, such as viscous resistance, distance and construction period of the blocking, were determined, and get good feasibility. Based on the research of 30100 face in Nanliang Coal Mine, this paper has made a good reduction of crack development in the mining process of 30100 face, and the practice has proved the rationality of the parameters of simulation prevention measures. This research has a very good theoretical guidance significance for the prevention and control of spontaneous combustion of leftover coal and water control in coal mine production, and it has good economic benefits for the safe production of coal mines.

The microscopic pore structure of coal reconstructed by X-ray μCT is extremely complex. The pore network model (PNM) can simplify its spatial network structure from topology. In order to quantitatively characterize the space structure of coal micro-pore by this method, X-ray μCT scanning was performed on low-rank coal in the Ordos Basin. The spatial structure model of coal micro-pores was reconstructed. The PNM spatial topology structure was constructed. The structural characteristics of its pores and throats were analyzed. The results show that: larger micro-cracks are developed inside lignite. There are few micro-cracks in gas coal, but there are many pores, large volume and high homogeneity. Pores with a volume greater than 0.25μm3 in YCW lignite account for 23%, and pores with a radius of 0.1~0.7μm account for more than 90%. Its average coordination number is 7, and the average equivalent radius and length of the throat are 0.13μm and 1.69μm, respectively. However, the pore volume of XG gas coal is mainly distributed in 0~0.06μm3, and the equivalent radius is mainly distributed in 0.11~0.26μm. Its average coordination number is 4, and the average equivalent radius and length of the throat are 0.09μm and 0.63μm, respectively. Pores in lignite has larger volume and stronger connectivity. Its throats are wider and longer. This is the essential reason for its strong permeability.

In order to study the magnetic changes of coal-rock mixtures after high-temperature baking, it provides effective guidance for the application of magnetic methods in the delineation of fire zones. The magnetic susceptibility measurement system was used to determine the Nalinmiao coal. The magnetic susceptibility of coal-rock mixed samples mixed with different proportions of rock was studied respectively. The influence of temperature, particle size, magnetic field strength and coal-rock ratio on the magnetic susceptibility of the samples were studied. The results show that the magnetic susceptibility of the burnt coal-rock mixed sample formed in the whole range of normal temperature to 600 ℃ increases with the increase of temperature and decreases with the increase of the external magnetic induction intensity. When the baking temperature is less than 400 ° C, the smaller the particle size of the sample, the greater the magnetic susceptibility; the effect of high temperature baking on the composition and structure of the rock is analyzed by X-ray diffraction experiments, indicating that during the high temperature baking of the rock, Increased hematite and pyrite content is the main cause of increased susceptibility which is the main reason for the enhanced magnetic properties of sintered rocks compared to room temperature rocks. Finally, the GEM system company's GSM-19T proton magnetometer was used to detect the fire area in the key area of Nalinmiao Coal Mine No. 2 shaft. The comprehensive analysis was used to determine the suspected fire area, and the borehole temperature measurement was used to verify the magnetic detection. Fire zone reliability.

This paper designs indoor experiments for CL-C clay cement slurry, and uses a rotary viscometer to conduct experimental research on the rheological model of the slurry, the apparent viscosity and the time-varying law of shear stress. The following conclusions are drawn by analyzing the test data: 1) CL-C clay cement slurry is a non-Newtonian fluid, the ratio of the slurry affects its rheological constitutive model, the part distribution is more in line with the Bingham flow pattern than the slurry, and some are more in line Yield pseudoplastic fluid flow pattern. 2) The apparent viscosity and shear stress of CL-C clay cement slurry have a time-varying law and conform to exponential growth.3)The apparent viscosity is affected by the shear rate. At the same time, at low shear rates, the apparent viscosity The growth rate is faster and the increment is larger, while the opposite is true at high shear rates. This research has practical significance for the selection of grout ratio and grouting speed in grouting engineering, and can effectively guide the construction of grouting engineering.

In order to meet the requirements of grouting reinforcement in micro-fractured rock mass, a kind of high performance grouting material with high strength and low viscosity should be studied. Ultrafine cement, silicon powder, ultrafine fly ash and polycarboxylate superplasticizer were selected as raw materials. The slurry was modified by single factor test and orthogonal test. The results show that the stone strength of slurry can be increased by 8% ~ 34% by adding 4% ~ 12% silica powder in cement. Replacing a certain amount of cement with ultra-fine fly ash can reduce the viscosity of slurry. When the amount of fly ash is more than 20%, the viscosity of slurry will no longer decrease, reaching the limit of action. Polycarboxylate superplasticizer has a significant effect on reducing the viscosity of cement slurry, adding 0.1% ~ 0.5% superplasticizer, the viscosity of slurry can be reduced by 25% ~ 90.6%, the higher the amount of superplasticizer, the higher the water out rate of slurry, the more unstable the slurry. When the water-cement ratio is 0.8, the silicon powder content is 10%, the fly ash replacement amount is 20%, and the water-reducing agent content is 0.3%, the slurry performance is the best. The compressive strength of the stone body of the new type slurry is 22.98 Mpa on 28 d, which is 13.6% higher than that of the stone body of pure cement slurry, and the viscosity is 21.8 s, which is 89% lower than that of pure cement slurry.

Aiming at the creep deformation and bedding instability of the water-bearing soft rock slope in open pit mine, in order to determine the reasonable slope angle, taking the southern slope of the Dongming open-pit mine as the research object, on the basis of engineering geological prospecting and mechanical experiment ,the deformation and failure characteristics of bedding soft rock slope under the action of groundwater are studied by using FLAC3D,then the limit equilibrium method is used to compare and analyze the influence degree of groundwater on slope stability, finally, the slope Angle is optimized by the finite element strength reduction method. The results show that, the influence of groundwater on the stability of the southern slope of Dongming open-pit mine is obvious,the stability coefficient of the position of the soft rock surface is 20.73% lower than that under normal conditions, taking the above factors into consideration, the ultimate stability Angle of the south slope is determined to be 22°.The optimization design method of slope parameters on the basis of limit equilibrium analysis and finite element strength reduction could scientific and reliable determine the limit stable slope angle .

Aiming at the compensation of the arc suppression coil of the coal mine power grid, when a single-phase ground fault occurs, there is a problem that the fault information is weak and it is difficult to distinguish. This paper presents a method for locating fault sections in coal mine power grids based on instantaneous positive sequence current characteristics. According to the characteristic that the current signal distance value of the transient positive sequence real part on the different side of the fault point is larger, and the signal distance value on the same side of the fault point is smaller, the signal distance value at the branch node is compared in turn, Corresponding to the fault branch, to determine the fault path, the fault signal has the largest signal distance value in each section on the fault path. A large number of simulations show that the positioning method can effectively distinguish the fault section under different fault conditions and has certain applicability.

In order to increase the slurry concentration of low rank coal, the coal water slurry for gasification was prepared using low rank coal in Xinjiang as raw material. The slurry experiments were carried out by means of traditional process and gap-graded process, on this basis, the pilot-scale experiment was carried out. The results showed that the highest coal water slurry concentration of the coal was 51.01% under the traditional process. Under the condition of the mass ratio of coarse to fine was 6:4, the highest coal water slurry concentration was up to 57.08% adopting gap-graded process, we found that the slurry concentration 6% higher than the traditional process. While by using pilot-scale experiment, the highest coal water slurry concentration is 56.19%, which was 5% higher than the traditional process, but slightly lower than the gap-graded process in the laboratory. The results of pilot-scale experiment effectively verified the results of the laboratory's small-scale test, and the pilot-scale equipment can run stably for a long time.

For the purpose of comparative study and development prospection of domestic electrical haulage shearers, this paper comparatively analyses key technical parameters and the structural layout of the whole machine, the structure and connection modes of main parts (such as ranging arms, electric haulage units and wheel boxes), the overload mechanical protection ways, the hydraulic system, the materials of key parts and vulnerable parts and the corresponding comprehensive mechanical properties among MG series shearers made in China, 7LS series shearers of JOY from the United States and SL series shearers of EKF from Germany. All analysis indexes show that domestic MG series shearers are almost comparable with the corresponding imported shearers from the core technical parameters, the structural arrangement and material performance, etc. In some aspects, the design concepts and structure of domestic MG series shearers are better than imported shearers, which is also one of the rapid development achievements of the coal mining machinery in recent 30+ years. But there is still a big gap between MG series shearers and some imported shearers as far as reliability and stability are concerned. And in terms of reliability and stability, 7LS series shearers of JOY and SL series shearers of EKF are still far ahead of many domestic MG series shearers. This is also the problem that must be solved in the future development of automation and intelligence mining for domestic MG series shearers.

In order to facilitate the design of articulated transport vehicles in coal mines, the design and development of gearboxes for hydro-mechanical transmission systems are needed. The key technologies of the design of number of gears and shift control of a certain fixed-shaft power shift transmission, the determination of the transmission ratio of each gear, the determination of the center distance between the input and output, the design of the shift and reverse clutch, combination mode of each gear clutch?and the design of the structure are described. Transmission bench test transmission efficiency ranges from 96.3% to 98.5%, and the maximum temperature of transmission oil is 88.5 ℃. The average maintenance cycle of gearbox loading is 8 months, and the full life cost is equivalent to imported parts, which can replace imported ones. By changing the transmission ratio of each gear，series design of fixed shaft power shift gearbox can be used for articulated transport vehicles with different loads，it can solve the problem that the key technology of trackless auxiliary transport vehicle relies on import for a long time.

Aiming at the problems of low efficiency of semantic feature extraction and low intelligence of data collection in the information collection system of coal mine safety hazard information, this paper proposes a key semantic intelligence extraction based on improved Recurrent Neural Network (RNN) for coal mine safety hazard information system. The characteristics of the past cognition for the recurrent neural network is applied to construct the key semantic intelligent collection model of coal mine safety hazard information based on RNN. The sentence is segmented with comma as the boundary, the key semantic features are extracted step by step, and the memory of the past feature extraction is accumulated and get security risk feature keywords. The experimental results show that the system has high-precision feature extraction and semantic mapping hit rate, which realizes intelligent collection of key information of coal mine safety hazards, improves the efficiency of daily safety production hazard investigation, and reduces the occurrence of coal mine safety accidents.

To study coal consumption of China and that of thermal power, metallurgy, building materials and chemical industry, combined forecasting models of major industries are built based on GM, ARIMA, ANN and LOGISTIC. To predict the coal consumption trend of major industries in 2020-2030, the optimal models of the combined forecasting models are selected through parameter evaluation of R2, MAE, MAPE and RMSE. The results show that parameter evaluation of R2, MAE, MAPE and RMSE of the optimal models are better than those of the single models; The combined model GM-ARIMA of China coal consumption with weight of (0.32,0.68), GM-LOGISTIC-ARIMA for thermal power industry with weight of (0.28,0.14,0.58), GM-LOGISTIC of metallurgy industry with weight of (0.40,0.60), ANN-ARIMA of building materials industry with weight of (0.32,0.68) and ANN-ARIMA of chemical industry with weight of (0.79,0.21) are built respectively. It is predicted that the total consumption of coal and the consumption of thermal power industry will increase slightly in the future, reaching 4.167 billion tons and 2.210 billion tons in 2030; the consumption of metallurgy and building materials industry will be stable, reaching 660 million tons and 504 million tons in 2030; the consumption of chemical industry will increase rapidly, reaching 378 million tons in 2030.