The stability control of roadside support body is the key to keep gob-side entry retaining stable. In the case of determined filling material characteristics and roadway height, the width of roadside support body has become the key factor .The article is based on gob-side entry retaining of soft-rock roadway in some one mine for engineering background, using the method of combination of theoretical analysis, numerical simulation and field test to conclude the method to determine the reasonable width of roadside support body, namely using theoretical calculations of width of roadside support body, simulating the relations of the stress distribution and deformation between of roadside support body, surrounding rocks and the width of support body, and finally comprehensively confirming that the reasonable width of gob-side entry support body is 3m .The field test indicates that the roadside support body width ,which is identified by this method ,become stable after the roof movement, and the roadway surrounding rocks and backfill body is also stable. It proves that determining the roadside support body width by this method is scientific and reliable .It is certain instructive significance for gob-side entry retaining in practice.

In recent years, the power supply security requirement has increased, the emergency power supply to the local ventilator become more and more hotter for the scholars, while there are still some problems from the existing scheme more or less. The paper analyzes and compares several different connection types for the emergency power supply, and proposes a new scheme, aiming at the safety and reliability operation of the local ventilator. In the scheme, the emergency power supply is fully independent of the double-loop system program, and has some advantages as simple switching control when power off, and less faults. The paper also analyzes the battery management system and the main controller of the proposed scheme, and the proposed scheme has been made into the model machine. The test result proves to be high promotion value in the locale experiment.

The paper introduces a design survey of Ningdong Energy and Chemical base the first stage project which is one of key national and local projects.The designs of processing capabilities, coal tipping system, Coal storage and blending system,coal conveyance system,expert system for coal blending and civil engineering are included.A lot of information about the design parameters,characteristics and the operate approach of each system is given in detail.The completion and entering into production of this project provides theoretical references and experience for designing other large coal storage and blending project.

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Based on technical problems in controlling surrounding rock of roadway affected by overhead mining, combing with the engineering practice of roadway affected overhead mine face WIII5110 in Yangzhuang coal mine of Huaibei mining group, the damage reason is analyzed, concluding that the original supporting method can't bear the drastic crossing influence. Aiming at the engineering geological characteristics of floor roadway, the parameters of reinforcement scheme is optimized through theoretical analysis, by using the key technology of sparging and anchoring net + lag grouting, with high strength bolt and anchor, the roadway is effectively reinforced. In the industrial test, the expected results are attained, the largest amount of convergence between roof and floor is 73mm, and the convergence between roadway ' s sides is 38mm, the shape of roadway is in good condition, and that ensure the normal production safety.

Abstract: According to the mechanism of gas outburst prevention of hydrofracturing and the numerical simulation by use of RFPA2D-Integrated software, draw the conclusion about the start pressure of hydrofracturing and the range of pressure relief area. In the field of industrial test, compared the concentration and the flow between the drainage hole of the hydrofracturing and that of common, and found that increased about 20times and 27times separately, greatly increased the speed and efficiency of gas drainage. So hydrofracturing technology can play a significant role of gas outburst prevention in low-permeable coal seam .

Under solving gas extraction, water gushing when tunneling and geological anomalous body, the horizontal directional drilling in coal mine has played a promoting role for high-efficient coal mining. Firstly，this paper analyzes the main factors of the horizontal directional drilling in the underground coal mine, and then elaborates the performance and application condition of assembly drilling tools and screw drill tools, at last, on the base of analysing advantages and disadvantages of bottom hole assembly which is used by these two kinds of horizontal directional drilling, refers to best combination and development trends. The conclusions in this paper can be the basis for optimization of bottom hole assembly on horizontal directional drilling.

This article introduces the successful application of big cutting height fully mechanized mining equipment in Huangling No.2 mine of Shaanxi Mining Group Company Limited. It effectively solved the problems of coal wall spalling, gas outburst , fire disaster and some other issues under complicated geological conditions, which provides some reference for safe and highly efficient mining in the similar mine conditions.

Summary：High gas mine using comprehensive mechanized coal caving mining technology, make face per unit area yield is greatly improved, coal production is more concentrated, but the prevention and treatment of gas has become one of the biggest problems in safety production. Laohutai mine in practice for many years, the successful use of the preliminary drainage of gas, gas and draining while mining goaf gas drainage technology, solves the fully mechanized caving face gas gushing problem, ensure the fully mechanized caving face of successive safe production, and make full use of the gas resource.

Have introduced that the Peigou Coal Mine of Zheng coal group in" Three Soft" coal seam fully mechanized working face and transport routes within the existing comprehensive prevention and dust reduction technology system application foundation, according to the principle of preventing dust, and focused attention to prevent dust reduction system the application in underground the feasibility of targeted research and reform, further optimization of the underground comprehensive prevention and dust reduction system, to ensure the normal and reliable operation of the system, and greatly improve the dust rate, for coal mine safety production and laid a good foundation.

Abstract; Shanxi province LiLiu mining area is the largest coke base in China , at the east part of which is the Shuangliu coal mine.Arrange the process of XiaZu coal mining ,the major challenge is the water burst threat of Taiyuan limestone aquifer upper and lower parts of high pressure Ordovician limestone aquifer and the floor to withstand a maximum pressure of Ordovician limestone up to 5 - 6Mpa.This paper is at the basis of the region hydrogeological condition ,make an analysis of the aquifer and confining layer with water filling and the mine water filling factor，offer an measure of water prevention about XiaZu coal mining of ShuangLiu coal mine and the technique basis of ensure the mine safety protection.

In order to explore relationship between shallow strata types and the roadway roof caving hidden danger level, using RFPA software, To simulate the roof deformation and failure characteristics at the condition of different types of rock. The results of the study show that the strength index of shallow strata determine the destroyed scale of roadway, directly affect roof caving hidden danger level, the roof fall risk decreased according to the order of Soft-toughening type rock、 Soft-brittle type rock、 Medium-toughening type rock Medium strength-Medium stiffness type rock, Hard-toughening type rock. Rock stiffness determine roof rock failure mode, rock stiffness on the roof caving hidden danger level influence power is not important than rock strength; When the shallow roof type is medium strength-Medium stiffness type rock or Hard-toughening type rock, using bolt support only can ensure the roadway do not occurred roof fall accident.

Taking extension traffic Shaft of Xieyi coal mine as the research target, the paper analyzes surrounding rock pressure appeared characteristics of the influence of the shaft and tunnel by protective coal pillar mining 4271B8 mining face. According to the observed data, it has been analyzed the deformation rule and destruction features by mining shaft and tunnel moving influence. With the help of numerical simulation, the stability characteristics of shaft and tunnel affected by cross mining in 4271B8 mining are analyzed and obtain the surrounding rock stress and plastic zone range.

There are 140~440m incompact alluvium overlaied on Linnancang coal field. This paper analysed quaternary Loose Soils’s thickness distributing character, aquifer and aquifuge’s distribution within incompact alluvium and also the its bottom layer’s waterproof capability by statistically analysing the main geological drills. Then confirmed the permeable fractured zone’s height after mining the close coal seams by numerical simulation. On the basis of intending adequately the permeable fractured zone’s height, confirmed reasonable water-repellent pillar’s height. The 8-1、9、11 and 12 coal seams’ mining limit were increased by 30m、30m、30m and 15m separately. This adds 3.726 million tons coal resource.

As the Critical Deformation Angle is the main parameter when we retain coal pillar,it directly determines the safety of the surface construction and the resoure recovery rate.Therefore,how to determine the various parameters of surface movement is very important for mining. Based on the measured data in Huainai and Huaibei,this article analyzed the influence of the geological and mining conditions on the Critical Deformation Angle and the Boundary angle,and found that logarithmic relationship exists between the two angles and alluvium.the Critical Deformation and the Boundary angle will be smaller if the thickness of the alluvium get bigger;an empirical formula of the Boundary Angle and the Critical Deformation Angle in thick alluvial mining has been established by mathematical statistics,which will provide a reliable angle parameter for retaining coal pillar to protect the structions in Huainan and Huaibei.

A site mine pressure measurement and analysis were conducted in No. 42202 fully mechanized high cutting coal mining face in Wanli NO. 1 coal mine. The results showed that the initial roof pressurized distance of the coal mining face was 19.9 m, the periodical roof pressurized distance was 10~16.5m, and the roof pressurized at the middle of the coal face was 2~5m in advanced than the two ends of the coalmining face; the influent distance by the induced abutment pressure was 15 m generally, but increased to 20 m during the periodical pressure or mining face closing to the connecting roadway; and the setting load of the powered support was too low to meet the requirements of support resistance in the middle and at the end of the mining exploration. To counter the current support and disaster situation, the improving measures such as the increasing of the setting load of support were put forward. This research can play a guidance role for the safe mining in a fully mechanized high cutting coal mining face of shallow-buried coal seam with the similar condition.

The 2209 coal face of Shen Jia Zhuang Mine,Hbei Cixian has special storage conditions,and there is little experience to learn from.In orde to achieve safe and efficient production,taking upward caving with light support face under double inclination and high inclined angle condition of Shen Jia Zhuang Mine as the example, the similar simulation test and the site test and combined with theoretical analysis method are applied to the study on the top coal caving technique. The study results shows that the coal caving distance would be 0.6 m and the coal mining recovery rate could be reached to 93%.

Abstract: Choosing scientific, reasonable and effective warning index，and establishing integrated pre-warning index system are the premise and foundation of accident warning. This article, takes the safety system theory as guide and the time dimension of incubation, occurrence and evolution of coal and gas outburst danger as breakthrough point，presents the method for establishing pre-warning index system which includes various influence factors originated from natural history conditions, realistic and real-time status in the danger forming course of coal and gas outburst. Based on the above, this article discussed the index constitute of danger-warning index system, as well as the construction of dynamic pre-warning index system through the computer system application. The practice testified that this method improves system popularity, field applying flexibility and the pre-warning accuracy of coal and gas outburst.

With the increasing intensity of coal mining activities in the western region, the contradiction between the destruction of the shortage of water resources in the western region and coal mining activities on the environment is becoming more prominent. To achieve the sustainable development of the coal mining region, through the analysis of the groundwater system, combined with the law of groundwater movement, water for open pit mining methods, Within the row of open-pit can be achieved through the reconstruction of key stratigraphic techniques to achieve the reconstruction and recovery of the groundwater system can not restore the groundwater system by way of the reconstruction of groundwater recharge areas within the row of open-pit.; target for water conservation, dump the process to do the appropriate adjustments.

Abstract: through the analysis of the Classification Float-and-sink test of each product of TBS at liangbei coal preparation plant, TBS almost have no separation effect on -0.25mm size fraction, the fate of most of the high-ash fine slime is TBS overflow. therefore high-ash fine slime pollutes sorted coarse clean coal, how to reduce or remove high-ash fine slime is The key of guarantee quality of clean coal, Liangbei coal preparation plant utilizes original TBS on the coarse slime second classification before sorting and utilizes Derrick Screens to remove slime in clean coal after sorting , finally, ash of clean coal is not above 11%.

Abstract: The main circuit of driving and regenerative braking for coal mine trackless rubber tire electric vehicle is designed based on permanent magnet DC motor. The model of regenerative braking is built with two quadrant DC-DC type DC chopper structure. Comparing with the maximum feedback power braking, the maximum feedback efficiency braking, constant torque braking and constant feedback current braking, the constant feedback current regenerative braking who can not only ensures maximum energy recovery, but also protects the battery is obtained. The energy efficient operation of coal mine trackless rubber tire electric vehicle is provided as a reference, has some practical value.

The compensation of capacitive current is always an important problem about the coal mine safety. This paper analyzed the current status and exeisting problems of arc suppression coil, and then the working principle of phase-controlled arc suppression coil is presented. By pointing out the imperfection of extreme-method, this study combined the symmetry-method and phase-method to detect capacitive current in power network, and introduced a new mathematical explanation. MATLAB was used to establish the simulation model of Z-Transformer and phase-controlled arc suppression coil, and its basic performance was also studied. The results show that the phase-controlled arc suppression coil could trace capacitive current exaclty, and has good compensation effcet without using damping resistance. So it is meaningful for us to use the phase-controlled arc suppression coil in power network.

In order to reduce the input shaft breaking accident occurred in gearbox of belt conveyor in coal mine enterprise。In this paper ，the author provides detailed analyses of the input shaft breaking for gearbox of belt conveyor in underground mine。The analyses were made on the design calculation 、manufacturing process、installation、usage。The author found out the reason of shaft breaking and provided effective solutions according to the reason of shaft breaking。

Abstract: According to coal production needs, a PLC-based high-pressure explosion-proof feed combination switch was designed. Its system functional unit of the design ideas, working methods and the main parameters of the design specifications was description. The actual research shows that: The system could help improve the efficiency of large-scale mine production, reduce production costs and easy to use and flexible.

The remote-controlled platform bridge of spanning scraper conveyor was specialized equipment of workers through face scraper conveyors on return gateway of working face, the need for the development of the device was described in this paper, the main structure, the function and main technical parameters of the equipment were introduced, working principle and operation was expounded, and the structure characteristics were analyzed and summarized.

In view of the current communication and production demands of coal industry and combining technology advantages of TD-SCDMA, the solution of the communication and dispatching system for coal industry is proposed in this paper based on TD-SCDMA enterprise network system, and the differences between this solution and existing solution of coal mine are compared and analyzed. The comparison and analysis showed the obvious advantages of the solution of the special engined enterprise network and relay connecting with operators. Finally applicability of this solution in coal mine is proved by the analysis of applications, the results showed that the solution of enterprise network can solve the communication problems of current coal mine effectively, and fully satisfies the development requirements of future communication in coal mine.

Evaluation of Coal Mine Safety is an important issue in coal mine safety research. Based on current situation of the study, the scholars mainly studied the assessment of the possibility that cause coal mine accidents by hazards from the perspective of risk. But this article select from a relative point of view, that is, from a security perspective, evaluate the level of coal mine safety control, aims to improve the deficiencies and shortcomings of coal mine safety.

In this paper, a new project cost management model, workflow process dynamic cost management program mode. First of all for coal mining area the inherent characteristics of the construction project, the contrast analysis of domestic and international cost management mode, and then separately from the construction project design phase, bidding stage, construction stage, settlement stage four stages cost control mode is analyzed, and the mode analysis after the concrete implementation process problems, finally discusses the future of the implementation of the mode reform thinking, and puts forward some Suggestions.