EBH315 Roadheader is a hard rock roadheader specially used for large cross-section roadway drivage. In order to test whether it has reached the design level and actual cutting ability, and is better used in actual roadway excavation in coal mine underground, a simulation test of false rock wall cutting was carried out. During the test, the cutting motor power, hydraulic system pressure and flow change curve, vibration of the whole machine and stress change in key parts of the machine under different cutting parameters were recorded. Through sorting and analyzing the test data, the measured data of the whole machine parameters of the roadheader are obtained, so as to verify the design parameters of the roadheader. At the same time, valuable experimental data are provided for the design and research of the roadheader, which can effectively guide the subsequent improvement of the design work.

The industrial system of coal resource-based cities is a coal-based industrial system that is gradually evolving and forming a coal industry. The transformation and upgrading of the coal industry will have a strong ripple effect, and comprehensively consider the components and structural factors of the coal-based industrial system. The effective transformation of the coal industry is of great significance. Based on the theory of industry chain and industrial network, this paper puts forward the concept of coal industry tree and builds a coal industry tree model through analogy analysis. Then, it analyzes the tree structure and function of coal industry and the evolution mechanism. Finally, the coal is briefly described. The Application Value and Path of Industry Tree in Discriminating the Direction of Coal Industry Transformation .

According to the occurrence characteristics of coal resources in Shendong mining area, it is often with drift of long distance or inclined shaft with gentle slope development way, and it needs to study adaptability of long distance inclined shaft with gentle slope development new technology in need of safe and efficient condition, In this paper ，with Ordos region of the large mine actual development situation, analyzes the potential factors affecting shaft development way, using fuzzy decision method, with the help of experts to determine the potential adaptability of inclined shaft with gentle slope development way in Ordos area ，and it provides technical support for safe and efficient mining of coal resources in Ordos region and other mining areas with suitable conditions.

Aiming at the problem of water discharge and drainage in working face and goaf in large water mine, this paper introduces the application technology of the centralized drainage tunnel at the bottom of the working face, taking Gao Jia Bao coal mine as an example. In this paper, the layout, quantity, horizon, section and slope of the centralized drainage roadway in the working face are mainly discussed, and the main advantages and applicable conditions of the centralized drainage roadway in coal seam floor are summarized. It further shows that the layout of the centralized drainage roadway is an effective way to solve the water inrush and drainage in the coal mining face and goaf of the large water mine, which has important practical significance for ensuring the safety production of such mines.

Abstract: Based on the laws of strata behaviors in gob-side entry retaining under the thin coal seam and hard roof, model of roadside support is built, that the roof of filling space is supported by the method of flexible support and the free subsidence of roof is reserved to avoid filling body being crushed. By comparing the scheme of the Gob-side Entry Retaining, both single props and gangue belt are used in the support of the early roof , gangue belt was used as the inner template of filling body and put the concrete mixer machine in the underground track lane, which simplify filling system greatly. As pumping concrete to the working surface directly after stirring the concrete in the 16701 working face of Quan Shang coal mine, , the practice shows that the effect of gob-side entry retaining is good, and the production needs of the next working face are basically satisfied.

In Houbu mine full mechanized mining in JH waste in wellbore and wellbore, analysis of the existing tunnel and the roof and floor mining technical conditions on the basis of the fully mechanized face reinforcement technology scheme of cross abandoned wellbore, namely in wellbore and coal seam at the confluence of the bottom by the well type of wood, anchor beam and concrete pouring strengthening support. At the top of the anchor beam and anchor + arc steel beam, steel beam, steel beam type row tile roof and concrete pouring strengthening support, the formation of active support and passive support coupled to the overall support, and technology at the top filling Ma Li powder comprehensive scheme. The engineering practice proves that the scheme can guarantee the fully mechanized mining face efficient, safe and stable across the shaft and can increase the recovery rate, and provide technical support and construction for the similar mine waste recycling or cross shaft mining shaft coal column.

As a result of the limitation of open-pit mine external conditions and the demand of production and operation mode, some open-pit mines use hydraulic backhoe as the main mining equipment. The article takes linear parameters and operating features of 7m3 hydraulic backhoe- 60 tons dump trucks as the examples, and reveals operation methods of hydraulic backhoe and confirms the working face parameters of bench group mining.

Water saving and optimization of cooling water system are extremely significant for coal chemical projects. This paper studies the water consumption , electricity consumption, total investment and operating cost of 6 kinds of water cooling system, and builds two tech-economic analysis models about minimum total cost and industry water consumption threshold. Then, the paper sorts the total cost of water cooling systems and improves the solutions to meet the requirement of water consumption standard. At last, the paper makes recommendations for process water saving by sensitivity analysis.

The unascertained measure theory is applied to the risk assessment of freezing method. Aiming at the uncertain risk factors, the risk assessment model is established according to the unascertained measure theory and the information entropy theory, and the rank of risk hazard is forecasted. According to the actual situation, 19 critical risk factors were selected as the evaluation index, the evaluation index system was established, the single index measure function was established according to the qualitative and quantitative data, the measure of the rating of each index was calculated, the weight of each evaluation index was calculated by the information entropy theory, To avoid the subjectivity and preference of expert judgment. Finally, the comprehensive risk rating of the freezing method is calculated based on the multi-index comprehensive measure of the evaluation vector and the confidence criterion. This model is applied to the Wanfu coal mine in Shandong province. The practical application results show that the predicted results are scientific and reasonable and consistent with the actual situation in the field, which shows that the method is feasible and has strong adaptability for the coal mine freezing method. New ideas, at the same time for other similar projects to provide reference.

There are many problems of coal mining in China, such as large waste of resources, low utilization rate and so on. Gob-side entry retaining technology has advantages in non-chain pillar entry protection and green safe mining. It is an important improvement of gob-side entry retaining technology to study the large-span fracture characteristics of critical block and select reasonable strength and width of filling wall. Taking Xingwu coal mine in Shanxi Province as an example, the long-span fracture mechanism of key blocks in medium-thick seam is analyzed, and the static load formula of filling wall is derived theoretically. UDEC2D software is used to simulate and analyze the deformation law of filling wall with different width and strength. Based on the criteria of lateral displacement, axial displacement, axial stress and economic benefit, the different schemes are compared and analyzed. The results show that the surrounding rock of roadway can be controlled stability when the filling wall strength is 12 MPa and the width is 1.2 m.

In this paper, the adhesive tape transportation of 11041 working face in Liushuwan coal mine is taken as the engineering background. The numerical simulation method is used to analyze the influence of stress on the roadway anchor The scheme of joint support of rod + metal mesh + anchor + steel ladder beam determines the scientific support scheme and parameters and has significant technical and economic benefits. It not only brings valuable experience to tunneling under similar conditions in the future, but also gives Surrounding coal mines and even similar conditions provide a valuable technical reference.

Tai'an Coal Mining 11# coal seam and 12# coal seam, the distance between two layers of coal seams in some sections is about 3m, study 12# coal seam working face roadway distance extended into 11# coal seam coal pillar and roadway support technology is necessary. Carried out geomechanical testing, numerical simulation of the stress distribution of surrounding rock of 12# coal seam after mining of 11# coal seam face, the roadway support technology was put forward in a targeted manner, and the field test was carried out. The results show: the average strength of 12# coal seam roof siltstone is 66.00MPa, the average strength of 12# coal seam is 14.34MPa, the axial direction of the roadway differs from the optimal arrangement by 10.9°, roadway deformation is affected by the direction of the maximum horizontal principal stress; after 11# coal seam working face mining, the area with high stress concentration in 12# coal surrounding rock is about 2m; roadway support technology adopting “timely support, high pre-tightening force and strong protection table”, supporting W steel guard plate with high strength rockbolt with diameter of 22mm; the results of mine pressure monitoring show that the roof subsidence is less than 35mm, The distance between the two groups is less than 80mm considering that the roadway has to withstand two mining effects, the support scheme is reasonable and reliable.

In order to solve and reduce the impact pressure phenomenon caused by the failure of near-vertical roof rock in the mining process of the coal seam, in view of the danger of the slope rock, the craft lane has been constructed inside the rock, and the high pressure water injection method was used to weaken the rock layer. In the engineering, the microseismic monitoring and the PASAT-M detection method were used to observe and statistics the weakening effect. The results show that high-pressure water injection changes the internal structure of rock mass and reduces the initial strength of rock mass. Microseismic monitoring revealed that the number of high-energy events decreased, the low energy events increased, the energy accumulation decreased and the impact risk decreased. The PASAT-M detections show that the peak of high stress zone in rock mass decreases and the peak of low stress zone increases, but the overall stress concentration coefficient decreases. Water injection softening engineering has obvious effect on reducing stress concentration of vertical rock layers, and can effectively mitigate or prevent the impact of vertical rock formations.

In order to analyze the rock pressure law of thick coal seam caving mining in Qinshui coalfield, the author took the 3309 caving mining face in Wangpo coal mine as an example, and used the roof pressure on-line monitoring system to record the periodical weighting, the change of the working resistance of the hydraulic support column, the force of the vertical column and the opening of the safety valve. In this paper, the periodic pressure law of the roof of the caving mining face in thick coal seam was analyzed, and the safety protection measures for the working face before the periodic pressure were put forward, which provided the basis for the roof pressure control in the mining face of the coal mine in the adjacent coal mine in the Qinshui coalfield.

In order to solve the problem that under U type ventilation the gas concentration in the upper corner of the fully mechanized caving face was overrunning due to gas emission of the left mine in gob, the CFD bistable computing model of gas emission of the left mine in gob was builded.and By numerical simulation method the air-flowing field and the gas-concentration field in gob under U-tube ventilation system, U+I-tube ventilation system, inclined to Y type ventilation system and Paratactic double U-shape ventilation system were simulated. With different air quantity of coal face, gas-concentration in upper corner, gas-concentration in return airway, gas-concentration in the wind drainage roadway in the gob and total gas quantity of air-flow were analyzed and compared. The results showed that under U+I-tube ventilation system, inclined to Y type ventilation system and Paratactic double U-shape ventilation system, the gas-concentration in upper corner was well controlled, but gas-concentration in the wind drainage roadway in the gob had a high probability of exceeding the limit. The research results had important reference value for controlling gas emission of the left mine in gob by air quantity of the fully mechanized caving face.

In order to solve the problems of slow updating of coal mine maps, difficulty in sharing and sharing, and diversification of mine map software, Shen dong Coal Group cooperated with scientific research institutions to develop a “coal mine map” online collaborative working system. Through the drawings commonly used by the system coal mine can be updated on a map and on-line viewing. The “Coal Mine One Picture” system was subsequently successfully applied in the Daliuta Coal Mine of the Shendong Coal Group. The various types of mine maps in the mine have been integrated and managed, and the updating has also become more convenient and timely, breaking the barriers between different systems and mining areas and realizing Information sharing.

Abstract: It is comprehensively introduced that the design characteristics, versatility, efficiency and output power quality, reliability and maximum availability, etc. of the cell-series multi-level medium-voltage converter, and the advantages and development trend of the inverter is illustrated. Through the application in the large belt conveyor of main inclined shafts in the mines with 10Mt capacity at datong coal mine group, the function and advantage of variable frequency drives in the belt conveyor has been introduced, and the importance and necessity of localization and coal mine customization of the converter is illustrated. Furthermore the future development trend of the variable frequency drives on the application in the belt conveyors is pointed out, and indicates the role and significance for coal mine development.

In order to improve the ability of gas extraction in low permeability coal seam, different kinds of gas extraction methods are applied in engineering practice, including relief to increasing permeability by high pressure water jet slotting, strengthening pre-extraction method, displacing and driving gas method by air injection, and inhibiting gas desorption method by water injection. To increase the permeability of coal seam, the high pressure water jet slotting method is applied through boreholes in the rock under the floor of coal seam. Then the high pressure gas is extracted by pre-extraction method. After reaching the limit time of pre-extraction method does not work, the air injection method is taken. When the air injection method becomes invalid, the new method that inhibiting gas desorption by water injection is applied to increase the moisture of coal seam and inhibit desorption of residual gas in coal seam. Field tests show that the permeability of coal seam increases more than 100 times after taking the multiple gas strengthening extraction methods and the gas extraction efficiency is increased from 16.4% to 58.6%. The flow ability of gas-injected air-water has a succession of theses multiple processes. In other words, the later sub-process seepage commences just when the former sub-process seepage comes to an end. The new conception of multi-process seepage is introduced to study the whole process for the first time. The multi-process seepage equations are also built taking the seepage pressure distribution in the former sub-process as the initial condition of the following seepage sub-process. Then these equations are solved. These numerical solutions are more practical and reasonable, especially for the multi-process and multi-fluid seepage. The results show that the gas pressure curve is a parabola form in the first sub-process and the final state of this stage can be expressed by power function; in the following sub-process, the injecting air pressure curve decreases first and then increases in a trough form at initial state and decreases in a power function form; in the last sub-process, the injecting water pressure curve decreases in a power function form. All these results will provide theoretical and engineering references for multiple process gas strengthening extraction practices.

This paper introduces the basic principle of microseism CT inversion and three CT evaluation indicators firstly, and then analyses the correlation between the three CT evaluation indicators and electromagnetic radiation strength with the result of microseism CT inversion and the monitoring electromagnetic radiation data in field, determining the apparent relationship existing in them. Furthermore, three principal components corresponding to the three CT evaluation indicators are calculated by principal component analysis method, and with the contribution rate value of different principal component, it is determined that the first principal component Y1 can replace the three single CT evaluation indicator effectively. Finally, the first principal component Y1 was used to re-evaluate the impact of risk on the work face and finds a new 2# danger area, indicating that the new comprehensive evaluation indicator Y1 is more general and reliable and has a great significance to the risk evaluation of rock burst.

Wind farm construction and operation are dependent on the weather service. In the early days of wind farms, wind farms should monitor the wind resources and meteorological conditions in real time, and then assess the regional wind resources. In order to realize the regional wind resource assessment of wind farm, this paper designed a kind of multifunctional monitoring system of wind parameters. From the point of high reliability and strong expansibility, PLC is adopted as the core to design the hardware connection, data acquisition and monitoring interface. The monitoring system has user management, real-time monitoring, trend diagram, report display and alarm functions. The system is characterized by the acquisition of voltage and current signals, Modbus protocol signals with two monitoring methods of IPC and touch screen. The system uses the industry's common OPC server which is compatible with other systems of data information. Experiments show that: The system is fully functional, both in situ and remote monitoring, with good reliability and monitoring results.

Abstract: In order to study the feasibility of preventing and controlling coal spontaneous combustion by priming inhibitor solution ,taking the 3 upper coal seam in Nantun mine as an example ,selecting four kids of inhibitors through the inhibition experiments and carrying out pre-injection experiments of inhibitor solution by using a self-made device.The pre-injection effect of several inhibitor solution was compared by testing the moisture increment of the coal samples .The coal spontaneous combustion characteristics comprehensive test system was used to test the shortest spontaneous ignition period of the coal samples before and after the pre-injection of the inhibitor solution, and the coal quality before and after the pre-injection of the inhibitor solution was analyzed. The results show that the pre-injection effect of the inhibitor solution is affected by the type of inhibitor and the concentration of the inhibitor solution. The experimental shortest spontaneous ignition period of coal can be effectively prolonged by pre-injection of the inhibitor solution. The four inhibitors extended the experimental shortest spontaneous combustion period of coal by 12.6%, 10.7%, 9.3% and 8.1% respectively. The effect of the pre-injection of the inhibitor solution on coal quality was acceptable.

Coal mine gas concentration sensor directly collects on-site data, which is an important tool for analyzing underground gas hidden danger and judging the trend of gas disaster. According to the data of gas monitoring and monitoring since 2017 in Bijie coal mine, the time, place and reason of gas monitoring are statistically analyzed. It is found that the number of alarm times is concentrated in 7, 8, 9, November, and 8~17 in one day, and the coal mining face and coal mining face are the most easy to exceed the limit of gas concentration. There are 49.7% and 27.6% of the total alarm times, and the main reasons for sensor alarm are sensor failure and underground stop wind, and the field construction, such as blasting, drilling and roof collapse, is also an important cause of sensor alarm. According to the time, place and reason characteristics of gas monitoring and alarm, the train of thought for coal mine safety supervision and coal mine gas monitoring and management is put forward.

Thermodynamic parameters are important parameters to describe the state of substance in the adsorption process. The methane adsorption isotherms of coal samples with different metamorphic degrees were measured using a high-pressure isothermal adsorption instrument. Combined with the standard Gibbs free energy change (ΔG°), enthalpy change (ΔH°), and entropy change (ΔS°), to study the methane adsorption state on the coal surface under different temperature conditions. The results show that the methane adsorption on the coal surface is a exothermic and reversible physical process. Under the low-temperature condition, the methane adsorption capacity decreases obviously due to the temperature increase, and the adsorption capacity decreases slowly after the temperature exceeds 40°C. The adsorption process is mostly thermodynamically spontaneous. Under the high temperature and pressure conditions, the gas in the coal surface is more likely to desorb into a free gas state.

The hydrogeologic condition of the aquifer from the Fengfeng formation within the south of the Taiyuan Xishan coalfield are studied using the water pumping experiment and water quality analysis results with the aim to find out the reason for the discrepancy between the Ordovician limestone karst water level within the area and regional groundwater level. The results reveal that the aquifer of the Fengfeng formation might have been connected to the aquifer of the Taiyuan formation through the normal faults in the northwestern region, so that it received the vertical supply from the aquifer of Taiyuan formation in some part of the area, resulting in the inconsistency between the Ordovician limestone karst water level obtained from water pumping experiment and regional groundwater level.

A set of hydraulic-brake system is designed for monorail braking,establishing the brake mechanism of three-dimensional model and the principle is introduced.The full hydraulic braking system is analyzed in the monorail,using the hydraulic mechanical system modeling and simulation software AMESim to built up the whole hydraulic braking circuit, set the main parameters of the model elements and simulate the response time and force of the strokeravel braking and emergency braking of the mechanism. The results show that when starting the full hydraulic system, the stroke braking force increases approximately linearly; When the locomotive is in emergency braking, the response time is 0.65 second, the stroke cylinder output force is 14310 Newton and the emergency braking cylinder output force reaches 36510 Newton.The braking performance meets the requirement.

In this paper，all of factors which include vehicle parameter, Explosion-proof power battery ,Explosion-proof drive system and transmission type affect the range of Explosion-proof pure electric Vehicle are analyzed. The methods and results which can improve the range of Explosion-proof pure electric Vehicle on the condition of lower energy density of battery. And based on a certain type of explosion-proof pure electric Vehicle, complete the combination property test by vehicle test stand and the VehSpy3 upper system, calculation of the range of equal speed and the range of working conditions in Wang-jailing subsidiary transport. The results show that the method can effective promote the range of Explosion-proof pure electric Vehicle and provide the theoretical Basis for the development and popularization of Explosion-proof pure electric Vehicle.

As an advanced technology, Positron Emission Particle Tracking (PEPT) technology has been used in mineral processing industry. Mechanism and application of PEPT in mineral processing were outlined in present work. Application prospect of PEPT technology in mineral processing was also discussed. Results show that PEPT has proved to be an advanced technology in tracing particle trajectories in spiral concentrator, forth floation, hydrocyclone and milling processes, which has a remarkable influence in understanding mechanism and optimizing equipment. Future work should be done in tracing particle moving behavior in TBS, table concentrator, conditioning, etc, which would be a better understanding of these processes.

Abstract :Soil organic carbon (SOC) is a key indicator for characterization of soil quality and ecological characteristics. The study of restoration and distribution of SOC is of great significance for assessing the changes of soil quality and guiding the reconstruction of soil. The selection of gangue-filled reclamation and restoration area in Xinzhuangzi Mine, Huainan City as the research object. the study was divided into 10 sampling plots according to different topsoil cover thickness and vegetation type. The soil samples at 0-20 cm and 20-40 cm soil from different depths of reclaimed soil profile were collected to determine their bulk density(BD), water content (WC),pH value ,and soil organic carbon (SOC). Thus, the authors studied the effect of topsoil thickness and vegetation type on SOCsoil organic carbon (SOC) spatial distribution, and the correlation between SOC and soil physical and chemical properties .The results showed that: (1) The SOC content in different vegetation types was significantly different.In the 20-40 cm topsoil ,the order of SOC content from big to small is that grassland> chestnut woodland> soybean field> corn field> metasequoia forest land. In the 20-40 cm soil, the order of SOC content is from small to large grassland> chestnut woodland> corn field> metasequoia woodland> soybean field . (2) In the 20-40 cm soil layer, the SOC content varies significantly with different soil thickness, and increases with the thickness of the overlying soil layer. The highest value is the sampling area with cover soil of 81-100 cm (4.06 ~ 5.87 g/kg). As the sampling depth increases, the SOC content gradually decreases, and as the thickness of the overlying soil layer deepens, the overall rate of decline is faster. (3) The effect of overlying vegetation type on the SOC content in the study area was greater than that of the soil thickness; there was no significant difference in the content of SOC under the interaction of the existing vegetation type and soil cover thickness in the study area. (4) There has a significant positive correlation between SOC and pH, a significant negative correlation with BD, and a positive correlation with WC (P>0.05).

As the core part of the mine hoist, the mechanical analysis and calculation accuracy of the head sheave shaft is related to the safe production of the whole mine. The mechanical properties of the head sheave shaft is analyzed by the one-dimensional beam theory. First of all, the second-order displacement field of the element is established using the Carrera Unified Formulation. Then the mechanical model of the head sheave shaft was established by employing the principle of virtual displacement. At last, the accuracy and the practicability of the one-dimension high-order model is demonstrated by comparing ANSYS simulation results. Compared with the traditional beam theory, this method has obvious superiority, which can provide theoretical support for the design of the head sheave shaft.

In order to solve the problem of highly concentration of dust during transport and unloading in the belt conveyor,taking the rectangular straight chute structure as an example,combining with the precipitation mechanism and airflow characteristics of dust, analyzing the force of coal under transporting, obtaining the impact factors on the spread of dust transfer chute structure parameters.Take Zhuan-Longwan Coal Preparation Plant as the background,using the FLUENT software within Euler - Lagrange method to simulate the gas-solid two-phase flow couple,drawing the track of coal in different chute structure parameters.The result shows that:When the chute inclination is bigger, the induced wind is larger;When the cross-sectional area of the chute is the same and the aspect ratio is different, the cross-sectional width is proportional to the chute effect gas-solid area, the number of particles acting, frictional resistance between the particles on the surface and the chute.Through comparing with the actual measurement results, verified the reliability of simulation results,this research can provides the theoretical basis and data support for the structure optimization design of the repeater chute dust control to further improve the development of green production on mining equipment.

Affected by the large voltage fluctuation range of the overhead line in underground coal mines, wire trolley can not often operate efficiently and safely. Applying traction and feedback operation characteristics of bidirectional converters and combining structure and control strategy of bidirectional converters to achieve the use of bidirectional converters and diode rectifiers, which realizes the purpose of a stable DC net pressure and effectively solves the problem of inefficient and unsafe operation of wire trolley. The research results showed that the use of bidirectional converters could quickly feed the excess energy generated by the electric brake of wire trolley back to the high-voltage grid, which could suppress line voltage rise too high and protect the safety of vehicle inverter. The application of bidirectional converters could also compensate for system reactive power and improve power factor, which guaranteed the safe and efficient operation of wire trolley.

during the third years of the 13th Five-Year plan, the capacity and adjustment structure of the coal industry were gradually deepening. This paper has combed the historical development of China's coal policy, focusing on the analysis of the policy text of the coal industry from 2010 to 2017, and mastered the main change trend of the coal industry policy in recent years: while maintaining the important position of safety production, the policy tendency is changed from production to production control, from heavy production to attention. Environmental protection, from production technology to the Internet, big data accession, policy changes also reflect the impact of the changing era on the industry. Finally, the future policy trends and industry development directions are analyzed.

Replacing business tax with value added tax (VAT) has been the most important tax reform in China in recent years. The construction industry is the pillar industry in our national economy. It is of great significance whether the replacing business tax with VAT in the construction industry can achieve the design goal. Starting from the background ofreplacing business tax with VATand the main points of VAT system, this paper expounds the problems of VAT in construction industry in the aspects of the special invoice obtaining, Party A supply projects, labor outsourcing, time of tax obligation and so on.In accordance with the characteristics of the construction industry, this paper puts forward to draw lessons from the policies ofVAT on agricultural products. This paper raises that part of the input tax should be allowed to deduct, construction enterprises should be allowed to deduct a certain percentage of loan cost expense, and at the same time, effective measures should be taken in the Party A supply project to eliminate tax differences due to different material suppliers.