The protective seam mining is widely used as a treasure for prevention away from the ejection of coal and gas. This paper introduces the lower long-distance protective seam mining under the cases of the huge key layer , theoretically ,analyzes the limited span for huge key layer. By means of numerical simulation , this paper simulates the degree on the stress 、expansion deformation for protected seam around the broken of the huge key layer,analyze the “three-band”distribution regulation of overlying strata.The results indicates: because of the huge key layer, the protective effect on the protected seam ming is not good enough after the lower long-distance protective seam ming ,in a way ,huge key layer shields the protective effect on the protected seam ming .

The geological condition of the large dip angle and mining height face in Yang Chang Wan coal mine is complicated. The stability of Roof-Support-Pillar system trouble the mining safety, economic concentration and high-efficient. This paper synthesizes the geological condition and features, using FLAC3D simulation software simulate the stress distribution and evolvement laws of up and down ends, roof and pillar stress characteristic of up and down roadway, macro deformation features. The results show: with the roof collapse in mining disturbance area, the major mechanics parameters in “Roof-Support-Pillar” system has changed, and stress has redistributed, the ahead stress peak value of pillar and the range of stress reducing area is different.

By theoretically analyzing and contrasting with field measurement data, the strata behaviors of the 3101 fully-mechanized working face with large mining height in Chahasu coal mining was deeply studied.The stress and working conditions of shield powered supports with large mining height was discussed, and the adaptability of the supports is analyzed. The field observation results shows that the first weighting was 36.7m,dynamic load factor was 1.47; periodic weighting was 15.03m and its dynamic load factor was 1.44. Besides, There was a obvious time difference between mid-area and either sides of working face.The statistics showed the distribution frequency of supports’ working resistance was basically in normal, and has proved the linear increasing resistance relationship between setting load and the supports resistance towards a mining cycle end.And the supports used at present (ZY12000/28/63) can meet the demands of working face pressurization behavior. The study results could provide the references to supports choice and the safety and high efficient mining of coal mining face under the similar conditions．

Based on Gas-geology Theories and tectonic evolution, the mine field geological tectonic evolution and distribution characteristics are analyzed, the influence factors of gas occurrence, such as the geologic structure, roof and floor lithology, coal seam occurrence condition and so on are researched，by collecting the geologic and gas data systematically. On the basis of this, the mine field gas geological regularity and No.2 coal-seam gas content occurrence regularity are obtained by testing gas content and pressure, and the outburst danger of No.2 coal-seam is predicted. The research shows that: changes of tectonic coal caused by fracture structure and coal thickness and its variation are the main control factors that affect the gas content distribution and outburst happening. The result has provided theoretic guidance for coalmine coal and gas outburst controlling works.

The 3D seismic exploration is a kind of geophysical exploration methods which is high precision and low cost of.It has been widely used in geological exploration of coal mining. The quality of 3D seismic field construction affects the final geological effect directly.In the field of 3D seismic construction often encountered village, factories, river, mountain scarp and a variety of obstacles, which brings great difficulties to the field data acquisition which effect through rational design of the 3Dl seismic field special Field Setup can ensure that the first hand field data effectively.

The crude gas from underground coal gasification (UCG) containing sulfide has the corrosive effects to the steel borehole casing and gas transmitting pipeline before the purification system, which will influence the long-term safe and stable operation of UCG station. To solve this problem, an assumption that replacing the cement pipe with the steel tube is proposed, and the application of concrete pipe in the UCG project is discussed in this paper. We analyzed the stress state of the producing well casing, designed the structure of the cement pipe, and contrasted the cost of steel tube with that of cement pipeline. The results show that the pipeline made by the heat-resistant cement could satisfy the requirements of the UCG project, and has obvious advantages, compared with the steel tube, because of the corrosion resistance and only 1/3 cost of the later.

Based on the discussion of the differences between the coal pipeline transportation with other transport channels, and further studying the technology of coal pipeline transportation and analyzing the dynamic payback time of the investment for the coal pipeline transportation by technical economy, which raise the ripe time to the coal pipeline transportation as a fourth transport channel in domestic at present.

The environment pollution and ecological problems caused by long-time exploitation of coal resources have been seriously threatening the survival and sustainable development of cities dependent on coal recourses. With the guidance of ecological city theory, this paper discusses the necessity and measures of ecology-orientation for cities dependent on coal mining. Specifically, taking Tangshan as target city, this paper, based on the current environmental and ecological conditions of Tangshan, puts forward the approaches to construct an ecology-orientated city.

Abstract：Using Ansoft maxwell simulation analysis and experimental, research the overload protection problem for magnetic coupling applied to coal, and plotted the mechanical characteristics curve through experimental data。The conclusion can be gained from mechanical characteristic curve: when the output value of torque reaches the maximum torque of magnetic coupling, the output torque and speed dropped with the slip increases, motor input power was less than the power when the motor torque was at the maximum, this explained that the magnetic coupling has the function for overload protection.

Select Wuhai fat coal as research object. Screen test and float and sink test were used as sorting method. The sulfur content of each sorting product was determined. According to the results of determination of sulfur distribution of coal in different size and density components, distribution curves of sulfur were drawn. On the basis of studies of these curves, the conclusion of sulfur distributing characteristics was drawn: the content of sulfur changes in different size of coal; the content of sulfur of high-sulfur size fraction changes comply with exponential function; the content of sulfur of low-sulfur size fraction changes comply with one-element quadratic function. It provides evidence for desulphurization.

With the present phenomenon of low ash content of great amount of coal gangue and flotation tailings discharged in the process of coal washing , the necessity of tailings recleaning was analized and typical process of tailings recleaning with liquid-solid fluidized bed in WuHai area was introduced .The separation effect of the craft in Zhao Shou Cong coal preparation plant was discussed and the results show that liquid-solid fluidized bed separation could improve the calorific value of coal gangue signally and get qualified clean coal from flotation tailings , which not only has remarkable economic benefit and environmental benefit but provides a reference for tailings recleaning research .

The conventional process of sending filter liquor of pressure filter back to flotation system brought about some problems to the flotation system: the flotation system is under greater pressure when flotation feed quantity increase; flotation effect is worse with the vicious circle of fine slime in flotation system. To recover clean coal in filter liquor and improve coal slurry treating process, a new “flotation column + quick-operating pressure filter” filter liquor independent recovery process is put out. Feasibility of this process is proved through experiments, according to the results, implementation of this process can get qualified clean coal , reduce flotation feed quantity greatly and relieve flotation pressure, improve flotation effect and increase clean coal recovery.

Abstract: The relevance between associated factors of moving particles is deduced based on the dimensional harmony theorem and a correlation applied to the air dense-medium fluidized bed is found. A series of experiments were conducted to study the relationships between swelling rate function and swelling rate; origin is used to simulate the relevance and draws the conclusion. Formulaic model matches the experimental results and the correlation coefficient of reaches 0.97. As a result, the correlation is very instructive and meaningful to the calculation of association factors in air dense-medium fluidized bed.

Safety integrity is paid much attention and applied into use of in many industries, but the evaluation of safety integrity in mining industry was not well. The aim of the safety integrity scale is to master the safety integrity state of enterprises and provide advices to improve their level of safety integrity by doing survey of such state of mining enterprises. By item selection and reliability and validity analysis, a safety integrity scale including 4 dimensions and 20 elements was finally established, which is based on safety culture elements and safety conceptions. When put into practice in a mining enterprise, the scale is proved to exert the function of judging enterprise’s safety integrity level by marking safety integrity quantitatively. The scale provides a unified measurement tools for the measurement and comparison of the safety integrity within and between enterprises. Targeted safety integrity recommendations for improvement may be made according to measured results, which provide evidence to enhance safety integrity status.

The drilling pipes combined with broaching bit of large-diameter well are easily to fracture as intense longitudinal vibration,transverse vibration and torsional vibration accured during drilling down.Taking a large-diameter well drilling pipe fracture accident for example,after scientific analysis and successful treatment, this paper gives out some secure and practical plans about well accident prevention and processing measures to set up a good example using as a source of reference for dealing with similar situations.

In the study of geological conditions on the basis of the analysis Wang Hang village coal mine water inrush reason. The dynamic water pressure are measured by used ground water getting advanced detection fault location.The use of high-strength micro-expansive new grouting material for grouting and plugging water to detect the grouted effect by the water shut-off rate and coring. Through the field construction indicated that the fault is mediated water zone of the aquifer L1-4 with hydrodynamic pressure reaches 1.3MPa;To use the high-strength micro-expansive grouting material for hydrodynamic grouting, the water control rate is 100%;It is obvious that the grouting materials combined well with rock stratas, good cohesiveness , and core uniaxial compressive strength of 40MPa.The results show that, this material is very good to adapt to the dynamic pressure grouting construction,dynamic pressure water injection well block fault line and ensure that the safety of the roadway drivage.

Dahaize mine region belong to the Cretaceous and Jurassic coal-bearing strata. The compressive strength of aqueous soft rock is low, and mine shafts are constructed by full deep freezing method. This article describes the necessity and implementation of filling water shut-off technology of freezing pipe annular space in the aqueous soft rock strata in the west by combining engineering practice. This paper also propose a number of technical measures and nature points to control the quality of implementation and ensure the safety of construction and production of mine shafts. The process of slurry replacement is implemented smoothly and achieve the desired results.

In order to solve the problem of fully mechanized mining equipment installation of inclined longwall face with large mining height and large inclined angle, the Liuzhuang Coal Mine disposes assembly chamber at the top of tail entry, which can create condition for use only a no terminal rope winch to satisfy auxiliary transportation. It improves transportation efficiency and realizes safe, economic and fast installation in inclined longwall face with large mining height and large inclined angle, this method only spend 42d for installation a 350m super-long and large mining height working face. It has great significance for fast installation with similarity condition.

In order to enhanced coal resources recovery, alleviate mining and excavation, to achieve safe and high-efficient secondary mining of fully mechanized mining face,at the same time,and to provide for production practice of mining under similar conditions of mining face.The paper in detail introduced the technology of the old roadway driving security technology measures of fully mechanized mining face and safety mining technology of fully mechanized mining face crossing old roadway ,guidance of fully mechanized mining face secondary mining of the successful completion of the work.The engineering practice of secondary mining technology of old-entry goaf in fully mechanized mining face shows that: to the old-entry goaf without second mining,the recovery rate of working face have only 55.50%;If the second mining,the working face recovery rate can be as high as 96.67%.The continued improved and developed the secondary mining technology of old entry goaf could provide the scientific reliable technical access to the safety and high efficient mining in the old entry goaf.

When stope caving in working face 22305 of coal seam 2-2, the floating coal in goaf 12306 of overlying 1-2 coal seam got spontaneous combustion, resulting in overrunning of the concentration of CO gas at face 22305 in Bulianta coal mine. With the analysis of the fire area situation, a variety of methods were used for fire regional governing. However, the effects of former ways are not obvious because of the large area of fire, the serious leakage of goaf air and the fast growth of the fire zone et.al. According to the characteristics of the situation, the working face 22305 was closed later and comprehensive measures of filling liquid nitrogen and liquid carbon dioxide from the ground into under goaf were taken. It achieved good results and the high-temperature region of the face 22305 in overlying goaf were effectively controlled, which make the face safe mining after unsealing face 22305.

because of the large thickness of main roof, the dense hard, not easy caving stoping process, easy to form a large overhang. To reduce roof hanging area, to reduce the roof caving step distance for the first time, to prevent or weaken the work top corner gas overrun and preventing top-coal and roof during the preliminary extraction caused by the large area caving working face gas overrun it is necessary to weaken the roof. According to the geological and mining conditions of 1311 face and strata structure characteristics, determined the pre-splitting blasting scheme and related technical parameters. Cut the practice results show that the use of the eye as a group as a unit for construction of blast hole, by optimizing the blasting scheme makes the hole at the bottom of the uniform distribution on a straight line, through field observation and analysis to pressure indicators, pre-splitting blast proof roof can effectively weaken the first pressure strength and to realize safe mining.

Aim at the gas drainage pump long running, pump body surface and impeller serious rust and corrosion and rust, prone to card pump wait for an accident, there is even twist off pump shaft and burned the danger of motor, which has a serious impact on coal mine gas drainage system stability and safety production. Based on water quality to test and mine rust sample analysis, it is concluded that rust include carbonate and ferric oxide. Using the ratio of oxalate liquid static soak cleaning, and artificial cleaning to remove rust, from the actual effect to see, can achieve the desired cleaning purpose.

Abstract: This paper is Lee Coal 569 m shaft auxiliary shaft hoist DC motor drag electronic control system for the research object, the elevator is running too fast conversion layer, instability and other issues, combined with the actual situation and operating personnel and technical levels, and put on a hoist heavy devolution and decentralization of light load on the lift for different conditions such as velocity-depth analysis. Propose practical solutions to improve and modify the PLC program through the host computer methods for investigation and treatment, proven that this method completely solves the auxiliary shaft hoist mine too fast conversion layer problems, and achieved satisfactory results for speed control .

This paper mainly introduces the SNCG Ningdong Coal Washery plum well branch through the process control, technical innovation, improve the wash block coal rate, and ultimately increase the coal washing product benefits.

Coal mine fully mechanized coal face conveyor equipment is an important part of the coal production. Its work, reliability, security and efficiency of a direct impact on the efficiency, production safety and its related economic indicators of the coal mine production. In order to achieve the centralized monitor of transportation equipment of fully mechanized working face, this paper designs the mining face conveyor system monitoring measure flat base on PCC. This system is based on RS485 Modbus RTU communication protocol. Platform collects the monitoring parameters of the various sub-stations, and using the collected data for display, storage and fault diagnosis. If it is found abnormal, fault alarm and take the emergency manual. It shows that system is safety, reliable and practical through lots of experiments.

The working-face is the worst place in the mine. How can free the workers from the working-face is always the researcher’s direction and goals. The paper presents a digital video system which can achieve less workers on the working-face.

Abstract：Based on the problem of the mining under closed distance coal seams group of high-gas at the north of shaqu coal mine, the Strata fracture distribution and evolution, pressure-relief mechanism and the law of gas migration accumulation at goaf of the thin coal seam as upper protective seam mining was analyzed by adopted the method of combining the theory analysis and the test of practice, then the technology of gas extraction at gob-side entry retaining was put forward. This paper departures from the mining practice of the number 22201 first working-face as protective seam, then the technology of pillarless of the filling at gateway beside was introduced, and the parameters of the gas extraction is established. The results of industrial test showed that the effect is obvious about the technology of gas extraction at gob-side entry retaining, which implements the full pressure relief of the under nearby high-gas coal seam group, formed the Y shaped ventilation system of mining face, and reduced the gas of goaf into the working face, which is benefit to the safe and high-efficient mining of high-gas and outburst coal seam group.

Abstract: The temperatures is often -30-40℃ in the winter. The winter is lasting five months in Wunugetu Mountain. The large rocks that generated of upper permafrost layer impact loading efficiency and cause accident.In ore area,the large rocks are easy to plug the Gyratory crusher. Seriously, it is to cause shutdown. Experiments of blasting funnel and frozen soil blasting parameters were stuied on the characteristics of soil frozen layer and economic benefits were analyzed .

The ash of the second stage floatation clean coal is usually higher than requirement when treating high ash refractory coal slime with coal slime two-stage floatation, two-stage dewatering process, thus lump coal has to be separate at low ash level to meet the total ash requirement. To solve this problem, the author put forward the idea to use cyclone micro bubble flotation column as the second stage equipment and conduct relevance experiments. The result demonstrates that qualified clean coal can be obtained .Moreover, when compared with conventional floatation cells, clean coal ash was 3.44% lower while the tail ash and flotation perfect index was higher (1.67% and 6.54% respectively) at similar clean coal productivity, clean coal productivity is 10.27% higher, tail ash 6.91% and flotation perfect index 5.14% higher at the same clean coal ash level.

The paper summarizes the course practice of commissioning management and organization in Vietnam projects and attempts to put out how to carry out the commissioning management and what have to pay attention to in overseas project.

Aimming at high running status lasted many years and severe domestic and international coal market situation, through analyzing the data in manufacturing execution system and the diagnostic conclusion about Shendong group and Shangwan coal mine from McKinsey, Shangwan coal mine put forward the basic connotation and implementing idea of lean management system combining with the actual situation. On this basis, through fostering the typical lean culture, optimizing the operating process on production field, introducing the key performance indicator accepted internationally and using the affordable new technology, in 2012, the fully mechanized equipment operating efficiency and production capacity promoted 8.51% and 10.5% respectively, the continuous mining production time increased by 582h; the cost was effectively controlled, the electricity consumption on per ton of raw coal was reduced by ￥0.22, which ￥3,326,400 was saved on electricity bill while the production of raw coal was15.12 million tons in 2012; the number of employees was cut down, for example, the number of fleet’s authorized personnel and drainers reduced by 108 and 86 respectively, compared to those in 2010.

Internal control and risk management are two concepts both having a long evolution and development process. With the further theoretical research and practice, the two concepts learned and absorbed each other and eventually has been fully integrated in the "overall enterprise risk management framework" which issued in September 2004 by COSO Committee. This integration in turn leads the arguments on the relationship between the two concepts "internal control and risk management ", and arising some conflict and confusion in practice. Thus in dealing with the relationship between the two concepts, enterprises should be effective integrated the two concepts based on the reality from their own development goals, the resources, ability, in order to achieve the best synergy and integration effect.

The roof sandstone water has effect for borehole, drainage borehole water inflow is large, that needs install large flow automatic drainage device. Based on the principles of mine negative pressure automatic drainage device work, puts forward the simple improvement method, namely mine negative pressure automatic drainage device is used as the controller, the large volume of water storage device and a large diameter water inlet or outlet, that carries out technical reform of automatic drainage device, it achieves the objective of large capacity and flow. Through field application, achieved good results.

This paper reports the three-phase three-level voltage source inverter using the auxiliary resonant commutated pole technique in the SVG system. The purpose is to reduce the voltage stress and current stress of the switching elements, increase power density. A relationship is obtained between the soft-switching time and load current, pump current for resonant by analyzing the working process of ARCP diode clamped inverter. So the turn-on moment of the auxiliary switch is decided. The results are evaluated on the basis of the simulation and experiment results.