In the article, production status of Pangpangta mine and existing problems in system were pointed out. Making full use of underground system of Pangpangta mine design was optimized and related project was improved. Meanwhile, safety guarantee level of mine was improved and the period of recombination and integration was shortened. Thus, the mine put into production in commission and then production become effective earlier. The cost of recombination and integration for Pangpangta mine was saved, the related requirements were satisfied by Chinese and Shannxi province government.

Abstract: Using power electronic transformers can transformer 660V/127V voltage as lighting power. In order to simplify the structure of power electronic transformer and reduce the circuit losses, this paper introduces a new kind of single-stage high-frequency isolated three-phase AC/DC converter and its control method--using a power conversion stage to complete the PWM rectifier and high-frequency isolated DC/DC converter. And then we tested the fesibility of the topology through software simulation. Finally, on this basis, we completed a low-power circuit design testing and analysis of relevant conclusions. The results show that the converter can be applied to the design of lighting power supply underground coal mine.

Due to the limitations of yard belt conveyor tripper itself, the design of concave arc curve segment cannot adopt the curve segment design method of universal belt conveyors. According to the analysis, when the tripper was designed to only one concave arc, there is a defect that the curve segment is relatively short when the tripper works under full load condition. In this paper, a new design method which has 3 section curves in the tripper is proposed. Through the analyses of deformation and transient dynamics, it demonstrates the advantages of using 3 section curves. Further, the design constraints and the specific design steps of the curve are also proposed.

The support patterns in roadways with 20m coal pillar was used in 0922 coal face ventilation roadway of Qipanjing Mine, strata behaviors was violent between roadway driving, the phenomenon of large area roof caving and floor heave have appeared, the roadway was too difficult to maintain. The instability mechanism of ventilation roadway was researched and analysised by the method of theoretical analysis. The results showed that: stress concentration caused by the unreasonable width of coal pillar, low anchor support strength and low anchor pre-tightening force were main influence factors of instability of 0922 coal face ventilation roadway. On the basis, the reasonable width of coal pillar was determined, and put forward anchor support technology of high strength and high pre-tightening force. The technology was applied to engineering practice, achieved the good engineering test effect.

According to Jining No.3 coal mine commonly employed in driving roadway along gob prepared by gob area influence present situation,utilization of mining face measured small profile, calculate the goaf water quantity, water area and depth of water. Developed using parallel roadway drainage and long distance ahead of roadway driving along Gob with driving while on the program, through the construction of the drainage chamber,The borehole layout was optimized, There were 6 boreholes of horizontal 100m long distance,a total of drainage in gob area 444000 m3, working surface stoping period did not appear a lot of gushing water.

Scientifically to carry on “daily output determination matched with the fan actual ability”, is important guarantee and one of premises that carries out the safety production of high gas mine. On the basis of designating the relatively stable time of mine ventilation system as the approving time. Through calculating the mine needed air volume, confirm the needed air volume in excavation face，mine cavern and reserve workplace. According to the calculation of mine ventilation capacity, to determine the reasonable ratio（1:3）of mining and tunneling in Anxing coal mine, the mine ventilation capacity is 120 million tons. Verified from mine ventilation capacity, effective air in the needed site, mine ventilation network capacity and dilutuing gas ability, the mine ventilation capacity is 120 million tons. The air flow in each place of the mine is stability, air volume, air speed, tair resistance all meet the demands, mine ventilation network capacity can meet the requirements of production safety.

With the extension of the mine continues to develop, Installed along the face longer transport routes， in order to fundamentally solve the installation Workface distance transport, tight installation schedule, installation equipment, and other adverse conditions ，Through scientific analysis， reasonable choice transport routes and transport modes, coordination and command, to achieve a safe and high quality face quick installation, as the mine face similar conditions to provide a successful installation experience. Jining No.3 coal mine 163 next05 installed with a non-polar face rope winch and WC40Y (B type) a combination of stent van transportation, to achieve the face of the safe and efficient installation, the successful application of mechanized mining face Quick Installation won valuable time, effective mitigation of mine succeeding tension

With systematically analysis on factors of spontaneous combustion in 6205N working face chain pillar under complex air leakage conditions of Danhou coal mine, and the actual situation, we studied and adopted the comprehensive fire preventing and extinguishing technology, which based on three-phase foam with fly ash and combined with optimizing ventilation system and water sealing tunnel. We eliminated spontaneous combustion hidden danger on chain pillar and realized the safe mining in 6205N working face. It can enrich the experience of fire preventing and extinguishing technology in chain pillar.

By analyzing Hydrogeological Conditions, observing the water-level of the ordovician limestone rockwater and testing the water in new Yima coal, we judge 12011 new Yima coal face roof water burst water main for the water sandstone, ordovician limestone broke into a small amount of water. Its recovery water guide channel for the face to form the roof and floor with hydraulic conductivity crack damage zone. Its water channel guide is the lead roof and floor with water damage with a crack. By using the sparse-based, supplemented by other control measures to ensure normal production flexible coal face.

This paper is in the background of the main inclined shaft frozen construction of Huozhou Pang Pang Ta coal mine, by using ANSYS finite element software, the three–dimensional model of temperature field of inclined Shaft bottom was established, and the development law under typical parameters was researched. Bottom freezing temperature field was uneven in time and space, the thickness and average temperature of the frozen wall in each position were both different and constantly grew and changed with time, affected by thermal fluid in formation ,they developed downward slowly.

The phenomenon of underground pressure of the coal caving face was affected by the coal rock angle in slope fully mechanized top coal caving. The roof of the longer face usually showed O-X broken; the asynchrony characteristics were arisen on face direction and its both ends was broken ahead. Based on the on-line monitoring of the pressure of the face both ends in the 3301 coal mining face, in combination with the strata pressure behaviors of the coal mining face, the roof pressurized features was analyzed, and the law of the roof motion, periodic weighting length and the both ends was obtained. Meanwhile analyzed the working state of the powered support and tested the support quality, which could provide the guidance reference to improve the roof management and the subsequent production.

Through the analysis of geological and hydro-geological conditions of Wangwa coal mine,we discussed mine water infilling factors，considering that phreatic water aquifer of the quaternary system was widespread in the area.Because the thickness was too small，the maximum destructed height had not reach the aquifer, the aquifer had rather small impact on coal mining.Main aquifer impacting on coal mine water inflow were Ordovician system、Trias System、Jurassic System、Third system、Cretaceous system. We carried out mine inflow by using large well method,long and narrow level drift hydrodynamic method and virtual discharge of water method.Through balancing and appraising each methods,finally we considered result of large well method is reasonable.

Abstract: Analysis the present situation and the gap with foreign technology on the China's full-mechanized mining face power supply system. Puts forward that the power supply system is gradually developing to High Voltage，integrating，Intelligent and so on. The research is significant for driving the progress of mechanized mining face power supply system.

Abstract：The existing hole-sealing materials fail to seal the gas drainage borehole completely, so the PD series materials is put forward. The material and coal wall’s combination level and the infiltration to the around coal are observed and analyzed under the help of FEI QuantaTM 250 environmental scanning electron microscope. The model of gas leakage through apertures around the holes is established, and a sealing effect investigation test for gas drainage borehole is carried out at the Changcun mine of Luan Group. The test results show that: PD series material than the original hole sealing materials (such as polyurethane), the former can effectively improve the drainage negative pressure, increase the gas concentration and pure gas flow mean, and it can greatly reduce the two indexes decay rate, and achieve the requirement of high-quality sealing, so as to realize the continuous and efficient gas drainage.

Through analyzing the data of coal mining area in Ordos City, this paper adopts analytic hierarchy process to quantify 13 factors from regional geological background, mining geo-environment and human activities and constructs a model for environmental quality assessment of coal mining area. The environmental evaluation results of five major mining regions in Ordos City have been given by using the model. Evaluation results are basically in accordance with the actual situation. The study indicates that this kind of assessment is practical and effective for the environmental quality assessment of coal mining areas in Ordos City.

In order to study the coal flotation process under the conditions of different energy input, high-ash tiny coal slime of Tangshan mining area was taken as sample.In the experiments, the coal flotation process was divided into the two phases of mixing and flotation, their respective flotation power experiments of different rotate speed were done.The results showed that: the optimal speed of the mixing and flotation processes were 2400r/min; with the increasement of mixing speed, ash and recovery of concentrates increased firstly and then decreased; with the increasement of flotation power, concentrates ash increased firstly and then decreased, recovery gradually increased; low stirring intensity was not conducive to the mineralization of slime, while too strong mixing would affect the stability of the foam layer. According to the mineral flotability change, the energy in the flotation process is need to be allocated, at the last the better flotation index is got by lowest power consumption.

With coal mining gradually downward, water-filled conditions became more complex during mining. Water-bursting sources of lower coal group include upper golf water , Quaternary aquifer, surface water, sandstone crack groundwater and deep Ordovician aquifer.Under the condition of complex constitution, mine groundwater inflow occur unusual, but water level monitoring data of target aquifer did not change significantly, then accurately determining main water source of mine gushing water is essential for mine water prevention and control. By analysis of examples application, it is proved that integrated identification model of hydro-chemical characteristics consisted of conventional hydrochemical cluster analysis and environmental isotope analysis under complex conditions is effective obviously to discriminate water source of coal mine, and can provide important basis for mine water bursting accidents prevention and safety production.

This paper takes the fly ash of Panzhihua Power Plant as raw material, preparation of activated fly ash cement-based waterproof coating. Mixed ratio of fly ash, water-cement ratio, sand cement ratio of the specimen at different times of water absorption and compressive strength were researched. According to orthogonal table experiment theory, the experiment data were analysed in variance and ranged to obtain the optimal techniques parameters. The experimental results showed that fly ash has a good waterproof coating waterproofing effect, The optimal techniques parameters:the cement-based waterproof coating fly ash is mixed with the best ratio of 0.8, 0.38 water-cement ratio, sand cement ratio 0.2, 5h water absorption is only 2.38% and compressive strength could be up to 36.MPa, thus provided a new way for comprehensive utilization of fly ash.

In joint development slope of open pit coal mine, landslide probability is significantly increased. Making and taking effective measures for prevention and control has important significance forassure the safety and high effective product. The paper is for research background in the north wall of jointed rock slope a large surface mine. Based on AHP method by qualitative and quantitative analysis, comprehensive consideration safety, economy and so on, the paper build comprehensive evaluation model control deformation of joint rock slope. And put forward the optimal the control schemes. Then the paper tests the effect of engineering application of research case. Finally, the paper reveals that bolting-grouting is more successful, compared with other measures. The result of this research is of important reference significance for governance similar mines.

Abstract: Being used in a tough environment, belt conveyor may often suffer from corrosion, wear and tear, insolation and drench, which brings great risks for the running of belt conveyor, even to cause significant casualties. This application of new steel cord conveyor belt X-ray online detection device deals with how to prevent the rupture of steel cord conveyor belt with heavy loads, providing an effective technical approach to defects monitoring.

Abstract：Understand the drainage equipments operation state, realize the drainage system of centralized control and management, this paper puts forward the mine pump room remote monitoring system, and analyses the working principle, this paper introduces the structure of the system, using the configuration software monitoring software design, for monitoring of drainage equipment operation state and guarantee the safe operation of the efficient drainage equipment is important.

The land surface temperature of Wuda coalfield was retried by Landsat images in 2001,2003,2007,2010.Coal fire spatial distribution and extend direction were analyzed, and the vegetation cover change was monitored. The results show that coal fire areas retried are consistent with its true distribution. The area declined in 12,13and14 coal fire zones, others extend around and form some new coal fire burning belts. The vegetation index reduced from 0.0926 to -0.0378. Monitoring the coal fire by remote sensing can provide assistant decision for fire extinguishing engineering and mining area sustainable development.

Based on the field survey and literature research, according to deep research into the influence factors of security concept and work happiness of coal miners and mathematical description of coal mine safety behaviors, this paper constructs the influence model on security concept, work happiness and safety behavior choice of coal miners.

According to the large coal methanol project risk characteristic, it determines that the main risk factors of the effects of coal to methanol project dynamic income are the coal price and the price of methanol, it develops the prediction mathematical model of the coal price and the methanol price, and verifies the feasibility. We designed to provide a higher reliability of risk assessment for investment companies, and made them propose the reasonable investment decision.