Middling coal, which is mainly composed of coal gangue, is a very valuable and scarce resources, in order to recycle the scarce resources, first of all, coal and waste rock will be fully disintegrate. A new vertical crusher with two－stage crushing, whose can effectively reduce the middling coal crushing rate and improve the yield of clean coal, has been designed. To better understand the performance of the grinding machine, with its as the research object, the simulate of the working process of the grinding machine is carried out by using discrete element software EDEM. Using the number of broken bonding of middling coal as a measure of material crushing effect, the influence of different coarse crushing speed to broken bonding is obtained. On the basis, an optimal coarse crushing speed is selected, and the experimental prototype is trial-produced. On the test model, the accuracy of the simulation results is validated by the test of coarse crushing speed condition test. By the analysis, it is concluded that when the rough frequency is 50?Hz, the crushing effect is the best.

Fully mechanized mining, has been using the adjacent working face roadway layout of roadway system in the same layer, usually rectangular setting between working face coal pillar, the coal industry project generally set up 5 meters of coal pillar for mining without coal pillar. The end of the system to solve the long-standing lost coal in the top coal roadway layout, is not conducive to driving, broken top coal and gas easily lead to fire difficult problems, in order to achieve complete mining without coal pillar in the true sense,it based on the design principle of stagger gateroad mining method, put forward to the negative coal pillar design technology, according to the different angle of coal seam conditions for two types of negative stagger coal pillar design and scheme has been successfully applied.The results show that the negative stagger coal pillar design, is conducive to the realization of non coal pillar caving mining technology, the mining technology realize the upgrade.

The Hejiade tunnel segment of Kunming Shanghai high-speed rail from east to west through Shangzhichang coal mine northern area, and its scope of land overlaid part mining rights of Shangzhichang coal mine. According to the relevant approved documents, standards and regulations and on-site verification, analysis determine the amount of mineral resources and the scope of coal mine loss which all caused by overlaid minerals, and comprehensively verified the quantities of projects and real assets within the scope of coal mine loss. Through economic analysis, to assess the value of overlaying mineral resources, real assets, other current assets and long-term expenses within the scope of coal mine loss, to determine the economic loss and provide the necessary basis for compensation due to overlaid minerals.

In order to more convenient to determine coal seam gas drainage radius, gas extraction rule of basic assumptions in the same geological unit consistent condition, proposed the use of gas quantity and gas drainage with each section drilling amount and extraction time conform to the quadratic equation of superposition function relationship, get in any gas content area of the geological unit of gas drainage radius, gas extraction radius of dynamic measurement, the method in the determination of 3207 company return air along the trough results close to radius of pressure drop method extraction result, the result is good.

Abstract: In order to improve the efficient of the coal transportation, the main transportation roadway inNo.53 mining area is needed to be arranged in the isolated coal pillar. Then surrounding rock structure and stress distribution law is analyzed firstly. With the using of Flac3d, a software, the roadway position is located in the position which is 4m away from the 5401 gob by the contrastive analysis of the coal pillar’ stress, strain, roadway’ displacement and the stability of the isolated coal pillar. Besides, the the anchoring force near the narrow coal pillar is guaranteed by the determination of the ressonable length of the anchor through the pull out test. As a result, the deformation of surrounding rock is controlled successfully with the combined support of high pre-tension and high-strength anchor under the 4m width of coal pillar in practice.

The current research on combination of excavator and truck failed to integrate the technical and economic factors, as well as various options cannot be quantitatively compared. To this end, this paper introduces equipment combination ability index and annual conversion cost, by calculating the cost efficiency, it is come true to integrate the technical and economic factors and quantify the results, so as to ensure the best match of excavator and truck.

Through the long-term detection of Inner Mongolia Hongqinghe coal mine product warehouse in prestressed steel strand prestress,anddraw lessons from code for design of concrete structures and highway bridge rules in JTG D62-2004 which focus on the bridge of the prestress loss ,we were obtained the calculation formula of the large diameter prestressed concrete silo long-term prestress loss,and severally reached the theoretical value and the experimental value. Through the comparative method between the theoretical value and the experimental value, it is concluded that the formula of the rules is applicable to the silo and safer, at the same time, according to the measured data can be analyzed that the rules of the prestress loss of large diameter silo changes along with the passage of time and proportion of long-term loss in total loss.

Abstract: An important guarantee system of the green cycle was set up based on the concept of "high starting point, high standard and demonstration”, The system is constituted by four parts as " green production, energy saving and emission reduction ","mining to nurture agriculture、environmental protection"，" resource utilization, recycling economy " and “ecological civilization, trinity". To ensure the normal operation of the system, enterprise must build perfect institutions and monitoring and control system.

Main workshop equipment for coal preparation plant, the structure arrangement complex, large equipment (sieve, centrifuges, etc.) are often dynamic load and vibration caused by the operation problems, combining with a project example, for the problems caused by equipment vibration, adopts the traditional simplified calculation (single beam) and the finite element method are compared, the analysis found the cause of the equipment vibration. Results show that the equipment into the material end and discharge end bearing elevation, could be real using finite element method to compute the overall response of the structure of the natural frequency; In addition, from the perspective of reducing equipment for vibration of equipment layout should be decorated on the low side of the building

Coal and outburst accident alarm system requires convenient operation, real-time refresh, with cross platform capabilities, able to adapt to the complex deployment environment. For the solution of the original C/S architecture outburst accident alarm system deployment is not convenient, maintenance workload and other issues, the space based on OpenLayers open-source Web GIS library, supplemented by OSGeo web, GeoJSON.NET and other data conversion library, and JavaScript, Ajax and other web client technologies, relying on the ASP. Net environment design research and development of the outburst accident alarm site, and in the popularization and application of the Hong-Yang Coal Mine of Shenyang Coal Group, with expansion of good, easy to deploy, maintenance workload is small, browser compatibility, map the user experience is good wait for a characteristic, explore an open source WebGIS library design and development of coal mine special small web mine map management system feasible technology scheme based on.

In view of the existing three-dimensional mining software functions, Combined with the characteristics of underground coal mining, proposed the Underground Mine Three-dimensional Information Modeling System, Constructing "BIM" which suitables for underground mines. The system finally and comprehensively achieve the visualization, digital and intelligent work from whole strata geological modeling, underground mining system design, construction management, production management and other, to promote the three-dimensional informatization construction process of underground mine.

Multiplex roadway of large mining height has a large deformation, it is difficult to be controlled. analysis the deformation law of multiplex roadway through filed measurement, explain the action mechanism between surrounding rock deformation and grouting support opportunity, apply new grouting material and used to twice grouting support test. Results show: Multiplex roadway can be divided into ahead impacting zone、starting deformation zone、serve deformation zone 、tending to stable zone、stable zone; coordination support theory think that grouting support should be applied at deformation starting stage, apply twice grouting support before and after face; multiplex roadway’s deformation decreased more than 50% after twice grouting support.

Multi mining effect of roadway surrounding rock has become an urgent problem to be solved in coal mine safety mining under the condition of extra thick coal seam fully mechanized caving mining.According to the technical problem of mining influence in extremely thick coal seam by sub-level caving mining in Buliangou coal mine, using structural mechanics theory to set up the mechanics model of the overburden strata structure and analyze of the stability of surrounding rock under the influence of mining. Get the overlying rock the key block subsidence in the analytical formula of breaking. Three dimensional numerical model was established to study the displacement and plastic zone distribution of surrounding rock, and the deformation and failure law of surrounding rock under mining influence were obtained. Field measurements show: F6103 face rear 15~25m roadway is affected by the first mining effect, and the mining disturbance has little influence on the stability of surrounding rock. F6103 face rear 15~25m roadway is affected by the second mining effect, the rock pressure of the surrounding rock is more severe, and the deformation is obviously increased.

In the mining process for extra thick coal seams with close range, rib spalling and floor heave of crossheading of coal seam beneath often happen. Based on this background, the methods of theoretical analysis and field monitoring were used to investigate the deformation and fracture behaviors of floor roadway. Fracture depth of floor of working face under the action of mining and influence sphere and extent that abutment pressure has on floor roadway were obtained. This research can provide some references for layout and support design of floor roadway under the effect of mining closed coal seam with extra thick.

Abstract: To find out the distribution of small structure inside the coal mining face is an important part of the hidden disaster factors, the ISS transmission method is a suitable and relatively mature technique, but it has its limitations. In order to find out the distribution of the fault and collapse pillar in 5316 working face of Zhaozhuang coal mine of Jincheng coal industry group, and study application of ISS transmission method and reflection method in detection of small structures, in this paper, detectors and explosive source are arranged in two parallel grooves and open-off cut, the joint of ISS transmission method and reflection method is carried out. It has been proved to have good geological effect. This paper shows that as long as the design of the observation system is reasonable, ISS transmission method and reflection method can complement each other and the interpretation accuracy greatly improved, also can provide safety guarantee for coal mine production.

In order to solve the problem of full mechanized mining face crossing fault is difficult, low security, disaster prevention ect. Take 4236 fully mechanized working face of Huashan coal over F1 oblique fault as an example, this paper introduce the determination of abnormal area by fixed point method, remove water drilling, the encryption technology to control gas drainage, advance grouting reinforcement fault near the top of the roof, palisades and special falling coal during passing through fault, supporting, antiskid, anti flying, channeling rock, the end support mobile technology, floor supporting roof control technology. Conclusion: 4236 fully mechanized mining face successfully through the fault, improve the recovery rate of high-quality resources, and achieve good economic benefits, accumulate rich experience in production safety.

This paper introduces a kind of coal dust inhibitor in the fully mechanized coal face mining process played in the process of dust removal effect, in 1327 fully mechanized coal mining face spray nozzle in proportion to adding coal dust inhibitor in the face of the drum cutting process through The coal dust can be controlled and suppressed by the internal and external spraying of the shearer. At the same time, the use of coal dust inhibitor in the process of water injection in the 1327 face, effectively improve the dust removal efficiency.

Abstract: According to great dust problem occurred from a mine mechanized heading face during mining process,a dust control and colledtion integrated technology was applied. The paper introduced the compositon ande the main features of the system. An investigation was conducted on the site application and the dust control&collection effect of the system applied in Anju Mine. ，The totall dust collection was over 97% , the respirable dust collection also was above 94%. The successful applocation of the sustem in Anju Mine could provide the technical support to the dust pollution control of the mine mechanized heading face and could provide favorable protection to the occupational health of the coal miners and the mine safety production.

Abstract: The source of mine water, the water quality characteristics and the pollution effect of discharge on the environment are analyzed in this paper. The application of water treatment technology of different types of mine water and new technology such as desalt by electrosorb technology were expounded. Taking Huainan mining area as an example, according to the characteristics of water quality, the method of mine water treatment in Huainan mining area was put forward, which can improve the utilization rate of mine water and achieve the purpose of energy saving and emission reduction.

In order to study the application of CO2 phase-transforming fracturing technology on coal seam roof weakening, the technology of fracturing on coal seam roof was analyzed and engineering experiments were conducted. The effect of fracturing was observed by the change of pressure monitoring system of fully mechanized mining support and explosion proof camera and drilling peep instrument. The results show that the effect of CO2 phase-transforming fracturing technology was significant, the distance of first step of the working face to press the step advanced for 18 meters comparing with the average distance of the mine. The safety factor increases comparing with traditional explosive technology. This technology provides references for other mines to mine safely in fully mechanized caving face.

As the extra thick compound roof is quite thick and easy to bed layer and damage, the improper maintenance of roadway can extremly easy to cause casualty accidents by large roof fall. Therefore,its design requirements is stricter on bolt angle.Firstly, this paper refers to the concept of stress ellipse from numerical simulation and analyzes and summarizes the laws of roof damage from shear stress ellipse. Secondly,by theoretical analysis, the paper proposes a new method of calculation bolt support angles. Research results are as follows: The simulation results show that both sides of the tunnel roof are mainly shear failure, and the shear stress was significantly greater than the shear stress in the middle;The paper calculates the specific trajectory equations of shear stress ellipse by caving arch equation and finds the calculation method of bolt inclination angle based the trajectory equation of stress ellipse; The paper calculates the angle of bolt support and puts it compiled into two data tables. This provides the basis and guidance for similar projects support.

To study the relationship between abutment pressure and the gas permeability of xinan coal mine 二1 coal seam，in-situ test study were carried out. By analyzing the change rule of abutment pressure, fitting to get the gauss distribution, using face of front position, the relationship between the abutment pressure and gas flow is established, Through the analyzing found that the abutment pressure has significant effects for the gas permeability, abutment pressure for gas permeability has a certain impact, gas flow rate is reduced, as the bearing pressure increased in the minimum, the abutment pressure peak abutment pressure is reduced, the gas velocity increased. This also for the gas extraction from borehole layout provides a theoretical basis.

To solve the problem of the gas consistence exceeding limit at the upper corner of working face. The distribution law and charicteristis of overburden strata “three zones” during mining are studied by physical simulation experiment aim at the situaton of (4-5)04 working face in Liu Huanggou Coal Mine. High level borehole is designed by the experiment result for drainage gas in upper corner of working face and its drainage effect is observed and analyzed in real time. The results shown that caving degree is about 71°and there are a lot of fracture in overburden strata. The height of caving zone and fractured zone are 25~26.8m and 109.2~110m. Its first weighting interval and average periodic weighting distance is 36m and 16.6m. The width of cracked is 40m near cut hole. It is about 30m near reture airway and airflow airway. It is from 20m to 40m near working face during mining. Reasonable air supply of working face is 1100m3/min and drainage subpressure is 30~40kPa from the results of numerical simulation and field observation. It is 7.00~26.03% that the drainage concentration of high level borehole from the field observation. Average effective distance of borehole is 54.5m. The value of gas concentration of upper corner and working face are is controled under 0.27% and 0.32%. The working face is mined safely and effectively.

For underground roadway surface irregularities, bolts tail tension, torsion, bending combination of stress rupture phenomenon, theoretical analysis and numerical simulation methods used to study the effects of different spherical washers on bolts tail of the force. Analysis of the impact of the angle θ, the coefficient of friction between the tray and the spherical washer on bolt tail stress and deformation, air obtained spherical washers can be a good improvement in the force bolt tail. Obtain spherical washers can be well optimized force bolt tail. Preload force 30kN, bolts tail force reduced by 66% by used spherical washers; the larger of the angle θ, the smaller of friction coefficient, bolts tail bending angle is smaller; when the angle θ take 30 °, ball pad aligning Range Max.

Coal-bed gas content is an important indicator of coal reservoir comprehensive evaluation, it also has guiding significance for coalbed methane resources calculation and exploitation of coal-bed methane. Paper based on Ordos Basin L block as the research object, adopting Adsorption Isotherm method, respectively establish the relationship between coal industry components with and ,and then predict the coal seam gas content; In addition, combine logging curve data, integrate the influences of density, neutron, and gamma on coal-bed gas content, using multiple regression analysis, get the formula on the calculation of coal-bed gas content for the region, summarize the applicable condition of different forecasting methods, On the basis of gas content forecast, then classification evaluate the coalbed methane content by related parameters.

To ensure the safety and efficiency of mining on soft an low permeability flat coal seam with high gas content, we take the X10901 working face in Dawan mine west well as the studying object. In this paper, research was made on stress change law and damage of coal and rock mass and the deformation distribution law of protected seam in upper protective layer mining by using Flac3D numerical software, and carrying out the inspection certification of protective effect on site. The results show that the coal and rock mass around the stope has experienced a transformation from initial stress area to stress concentrated area, depressurized area, stable area and new compaction area in the whole process of excavation. With the advance of working face, the depressurized area which formed by upper protective layer mining is gradually enlarge from “V” type to “U” type. After the protective layer mining, the amount of maximum swelling deformation of protected seam can be 12.2mm (the relative swelling deformation is 4.52‰), and forming the distribution of “three zones” and floor heave of overburden in the vertical direction. Combining with the inspection certification of protective effect on site, protected coal mass has been fully protected after upper protective layer mining. All of these has not only almost eliminated coal and gas outburst danger, but also provided a strong foundation for the high production and high efficiency of mine.

Abstract : In ord to control the surrounding rock with roadway driving along goaf of which overlying strata is unstable. Based on analysis of Influencing Factors for mechanical environment in coal plillar with gob-side entry, Taking the return roadway of NO.1342(1) workface in Gubei mine as the engineering background, a comprehensive technical scheme of surrounding rock control based on coal pillar pre-reinforcement was proposed. Supporting effect of the scheme is studied by numerical simulation and the field engineering practice, The results show that roadway driving along goaf with the adoption of the comprehensive technical scheme when the overlying strata of last section was unstable, the bearing capacity of coal pillar was improved and the stability of coal pillar was maintained, the deformation of surrounding rock was reduced obviously, the supporting effect was improved obviously.

According to the complex hydrogeological conditions and frequent occurrence of water inrush accidents in China’s coal mines, through the consolidation of National Coal Mine Safety Supervision Bureau and the National Bureau of statistics data from 2000 to 2015, in line chart, histogram, pie chart and other forms to make annual classification of coal production, coal mine accidents and water inrush accidents in the last 16 years, and analyze the relationship between the three, reveal the level characteristics of water disaster accidents, discuss the relationship between the time of the accidents and relevant national policies and regulations. The results show that the water inrush accident is still the second largest killer of coal mine accidents, the number of major and grave water disaster accidents and deaths accounted for 18.7% of the total number of coal mine accidents and the deaths during the 12th five-year plan. Single grave water inrush accident has the largest number of deaths and must be paid more attention to, which will offer theoretical support for the "13th Five-Year" during the development of coal industry in China.

To explore the coupling relationship between the mining goaf coal spontaneous combustion and the gas explosion, according to the different characteristics of the three stages of spontaneous combustion and taking a constant volume reactor as a model, the numerical simulation software CHEMKIN was used to simulate the diversification of key reaction basis of before and after gas explosion under different stages and different conditions of spontaneous combustion. Calculation results of comparative analysis showed that: the gas explosion was inhibited in the slow oxidation stage; the gas explosion was promoted in the accelerating oxidation stage; the gas explosion was slightly promoted in the violent oxidation stage.

In order to study the desorption characteristics of coalbed methane in the middle and high rank coal reservoir,this paper analyzed the characteristics and laws of coal seam gas desorption based on the data of desorption of coal and rock in Hancheng mining area.And discussed the relationship between the characteristics of coal and coal, the degree of metamorphism of coal and rock, the micro component of coal and the classification of coal and rock industry groups.The results show that the desorption rate of coalbed methane in the study area is between 13%~72%,the desorption rate of NO.5 coal is the largest.The desorption of coalbed methane has stage character,and the decrease of desorption rate is mainly caused by the change of gas content in coal reservoirs. The initial desorption rate and its attenuation characteristics are related to the pore structure and connectivity of coal and rock.The influence of the rate of desorption in the area is more complex, which the data is more discrete.But the desorption rate was not significantly correlated with the degree of coal metamorphism, but decreased with the increase of ash yield, and increased significantly with the increase of water content.The increase of the content of vitrinite mirror can increase methane desorption rate, while the content of vitrinite inertinite is on the contrary.The desorption rate of coal No. 5 and No. 11 coal in Xue Feng area , No. 5 coal in South of Wang Feng area and west of Wei Dong area , No. 11 coal in the southern part of Wei Dong area was higher,which is more than 50%,conducive to the development of coal-bed methane.

Abstract: Research on coal slurry pipeline transportation has been carried out since 1980s in China, and its industrial application has been carried on in a project by Shaanxi Coal and Chemical Industry. Before pipeline transportation, the coal must be made as coal water slurry in order to use pipeline hydraulic transport because of the long distance, and large volume in pipeline transportation. In this paper, to ensure the safety of the coal slurry pipeline, the standard of qualified coal slurry pipeline transportation is suggested, in order to provide a scientific basis for pipeline coal slurry production. In addition, through the study of particle suspension mechanism in coal slurry pipeline transportation process, the resistance loss parameters in coal pipeline transportation and semi-theoretical and semi-empirical formula for the critical non-deposition velocity are derived. This empirical formula is verified with operation data ofthe 400-kilometer-long Black Measa coal pipeline in the United States, as well as test data of domestic and international indoor circulation pipe coal. It is found that this formula has relatively high precision. Finally, taking the newly built Shaanxi coal pipeline as an example, the design parameters of the pipeline are calculated, the calculation results of which show that the Shaanxi coal pipeline design is safe and reliable.

This paper studies the internal flow field and the performance of the contra-rotating fan of four different distances between two impellers FLUENT. The results show that when distance raising，the efficiency increased first and then decreased; the interference between two impellers reduces the axial distance increasing at a certain range, which helps to homogenize airflow; The mutual interference of the two impellers is mainly reflected in the interference of the first stage impeller to the second stage, the effect of the second stage impeller to the first stage is not as much. The decrease of the axial distance could cause serious vortex in the axial spacing, and increase the eddy current loss. But a large axial distance not only increases the axial size of the fan, but also Increases the energy loss, resulting in the decrease of fan pressure, flow and efficiency .

By taking cylindrical nozzle used for descaling in pipelines as research object, the fluid field of nozzle is simulated by Fluent software. The flow characteristics of nozzle jet are analyzed by changing the jet pressure, impact angles, environmental media and target distance. The simulation results illustrate that the maximum impinging pressure and shear stress of target surface become larger with higher jet pressure, and presents a linear relation. The jet cleaning has preferable performance when the impact angle is equal to 〖60〗^°. Under the two conditions of non submerged and submerged jet, different hydraulic parameters correspond to an optimum target distance. The cleaning ability of nonsubmerged jet is better than that of submerged jet when the jet pressures are the same. The results provide a theoretical basis for the application of pileline water jet cleaning engineering.

In the coal mine under special conditions, high-speed power head sealing and temperature problems highlighted, constraining the performance and reliability of the coal mine rig. The main factors leading to the heat generation of the oil seal are theoretically analyzed. By comparing the temperature rise of the bearing, the box, the system and the sealing ring under the different rotational speed, three groups of laboratory test data are presented. The new sealing structure of the system oil circuit is discussed. The concrete measures to solve the problem of sealing and temperature rise are discussed, and verified in the industrial test.

Abstract: Due to the braking torque un-adjustable and the large impact force during the braking process of conventional electro-hydraulic brake, the fluid dynamics theory is applied to analyzing the thrust mechanism caused by electro-hydraulic pusher. It shows that the thrust of the pusher can be adjusted by changing the rotational speed of the impeller, and then the different braking torque can be obtained to realize controllable braking process of the mechanical load. This conclusion is verified on the experimental platform of the electro-hydraulic brake performance.

A low rank coal possesses poor flotability due to its high hydrophilic character。A satisfactory result is difficult to achieve when using the tradition flotation method. Ultrasonic pretreatment on the low rank coal was carried out to enhance its flotation performance. The particle size analysis、contact angle analysis and infrared spectrum analysis was used to characterize the change of coal sample properties before and after ultrasonic treatment. The results indicated that the yield of clean coal increased by 5.41% while the ash content almost keep unchanged after ultrasonic pretreatment of 4min under the ultrasonic frequency of 20kHz and ultrasonic power of 135W. The particle size distribution of the coal sample changed significantly、contact angle increased and the amount of oxygen-containing functional groups decreased after ultrasonic pretreatment. Therefore, ultrasonic treatment can enhance the hydrophobicity of low rank coal and improve its flotation behavior dramatically.

It is significant to optimize and design scraper conveyor's headstock for the improvement of transportation performance. However, traditional optimization method can't obtain ideal optimization results. This paper introduces the particles and computational model of DEM. By using the software EDEM, the dynamic simulation and analysis of scraper conveyor's headstock are completed. The DEM modeling analyzes scraper conveyor performance in terms of particles' power and force analysis due to changes in the operating conditions, providing evidence for optimization of scraper conveyor' headstock.

In view of the situation in the coal industry, washing center actively reduces costs and keeps innovating. Lean management gets effective implementation in the washing center. Lean management runs through the whole process of production organization, equipment operation, cost control, coal quality improvement work. Lean management strengthen the production efficiency, special coal yield, activity-based management, equipment protection, equipment maintenance, circuit transformation, mechanical and electrical faults, tons of coal consumption, repairing and recycling, and quality improvement. Through the above measures, washing center income about 5 billion yuan.

In the coal mine safety production, “One Ventilation and Three Prevention” work is especially important. Coal mine workers’ uneven master of the vast laws and regulations, directly affect their safety consciousness and behavior in the work. So, from the improving of coal mine workers’ vocational skills and professionals, put forward “One Ventilation and Three Prevention” ubiquitous learning pattern, meshed learning resources, used network to sense and transmit information, through multi-terminal sharing and real-time pushing cooperation, built ubiquitous learning’ dynamic loop framework, designed and developed ubiquitous learning platform, to provide coal mine workers an efficient and convenient way to learn safety technology, making a great significance to improve the workers’ professional skills and to ensure the safety of coal mine production .