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Table of Content

    15 October 2017, Volume 46 Issue 10
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    Mining Subsidence Information Extraction Based on Uncertainty Analysis of LiDAR DEM
    YU Hai-Yang, YANG Li, ZHANG Chun-Fang, NIU Feng-Ming, WU Jian-Peng
    2017, 46(10):  1-7. 
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    Airborne LiDAR system can quickly obtain 3D point cloud data of large-scale surface with high-resolution,high-precision and can be used for extraction of mine subsidence data.But the error of LiDAR data,surface cover and data processing method will lead to the uncertainty of DEM.Based on the analysis of LiDAR DEM accuracy and uncertainty of the two airborne LiDAR point cloud data in 2009 and 2012 in the study area,an error-related surface based on slope,point cloud density and surface roughness was established by using fuzzy reasoning method.The surface can be used to detect the minimum change threshold of DEM and measure the uncertainty of DEM.With the Bayesian estimation determination and correction based on weight window,the surface deformation information in the study area was obtained.Based on the analysis of the slope correlation,the terrain change information caused by the non-mining subsidence was removed by the mask,and the more accurate subsidence basin information was extracted.Experiments show that this method is suitable for large area mining subsidence monitoring,which can quickly determine the location of subsidence area,obtain the information such as the distribution range,area and volume of subsidence area accurately,and provide a new technical means for mining subsidence monitoring.
    Research on Mining Subsidence Similarity Criterions Based on Rayleigh Theory
    ZHANG Wen-Zhi, REN Xiao-Fang
    2017, 46(10):  8-11. 
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    It discusses the key problems with similarity criterions of rock movement parameter.Bing based on π theory，as well as extending dimension M、Lx、Ly、Lz、T instead of traditional dimension M-L-T，it deduces similarity criterions of mining subsidence by Rayleigh method，and establishes trend、up、down function models with similarity criterions for prediction parameter and angular parameter.These models provide basis for calculation of rock movement parameter and analysis of similarity experiment.
    Study on Dynamic Subsidence Model of Mining Subsidence and its Parameters
    ZHANG Jin-Man, XU Liang-Ji, LI Jie-Wei, SHEN Zhen, YU Li-Ren
    2017, 46(10):  12-15. 
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    According to the shortage of Knothe time function of the sinking speed in describing the dynamic subsidence process,the improved two-parameter Knothe time function was adopted to establish the dynamic subsidence model,where the decision coefficient c of overburden rocks and exponent k value were resolved by using the least square method,and the maximum subsidence of W0 was determined through the surface movement observation station by fitting the measured data;R2 coefficient evaluation precision was adopted and applied in a mine in Huainan and in 1242 (1) working surface movement observation station data model to verify the accuracy of the model.The maximum subsidence point,MS29 and ML44 in the fitting decision coefficient of each observation period were 0.983 6 and 0.975 7.The fitting decision coefficients of the observation value and the expected value of each observation point in dip and strike observation line were 0.995 3 and 0.958 2 separately as the advancing is half (328 d).The calculation results show that the dynamic prediction of two-parameter Knothe time function model on the whole process of mining subsidence of 1242 (1) working face is accurate and reliable.
    Research on Dynamic Precise Prediction Method of Mining Subsidence Based on Aged Knothe Function
    WEI Tao, WANG Lei, CHI Shen-Shen, LI Nan, 吕Tiao-
    2017, 46(10):  16-22. 
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    Aiming at the problem of inaccurate prediction of current mining subsidence,the dynamic precision prediction method of mining subsidence based on aging Knothe function with methods of measurement analysis and theoretical research is put forward.The main achievements obtained are as following:①The values of parameter C are negative exponential decay,and finally tend to a certain value after the end of the mining.②The experimental results of the prediction of the Knothe function C value showed that:In terms of holistic prediction,the integrity of the AR model is the best,while the traditional GM (1,1) model has a large error,and the prediction results of the cubic exponential smoothing method are gross errors.In the case of single-stage prediction,the predictions of C with the traditional GM (1,1) model and the AR model are unstable,and the errors of the three-order exponential smoothing method are all small and stable.The research results are of reference significance to the dynamic precise prediction of mining subsidence.
    Monitoring Method of Surface Subsidence in Mining Area Based on D-InSAR
    LI Nan, WANG Lei, CHI Shen-Shen, WEI Tao, 吕Tiao
    2017, 46(10):  23-27. 
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    Based on two scenes ALOS PALSAR data,the surface subsidence field of mining area during the period from 2007-12-10 to 2008-01-25 is obtained by using D-InSAR technology.Then,the D-InSAR monitoring value is used to extract the advance influence angle of the mining working face in the mining period and compare with the measured data.The experimental result shows that it is feasible to obtain the advance influence angle of the mining working face by using D-InSAR technology.The probability integral parameter inversion method which is based on simulated annealing algorithm (SA) is adopted to obtain the probability integral parameters of the mining working face under the incomplete mining.The result shows that it is feasible to calculate the probability integral parameters of mining working face by using parameter extraction method of probability integral parameter based on SA.The research results play an important rule in movement and deformation monitoring in mine areas by D-InSAR technology.
    Research on Optimization Method and General Model of the Adjustment of the Underground Equilateral Straight-extended form of Connecting Traverse
    CHI Shen-Shen, WANG Lei, WEI Tao, LI Nan, 吕Tiao
    2017, 46(10):  28-32. 
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    In order to solve the problem of the optimization of the observed peg-top azimuths position and the adjustment of the direction connecting traverse，in this paper,the theory and simulation analysis method are used to carry out the research on the optimization method and the general model of the adjustment of the underground equilateral straight-extended form of connecting traverse.The main conclusions are as follows：①Based on Lagrange's extreme value method,it is proved that the equal distance is the best form to measure the observed peg-top azimuths，and obtain the law of the position of the observed peg-top azimuths with different types and different orientation accuracy.②Based on the adjustment of the condition observations,this paper establishes the model of the Direction connecting traverse adjustment of the peg-top azimuths，and verifies the correctness of the model with the simulative example of a direction connecting traverse.The results of research have important reference for the optimization of the underground direction connecting traverse connection and data processing.
    Interpolation Model of GPS Tropospheric Delay Based on RBF Neural Network
    MA Jian-Wu, TAO Ting-Ye, YIN Wei-Song
    2017, 46(10):  33-35. 
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    In order to improve the accuracy of tropospheric delay interpolation,a model of delay tropospheric delay interpolation based on RBF neural network is established.Taking the coordinates and tropospheric delay of ten CORS base stations in Anhui Province as the modeling data,among them,the coordinates and tropospheric delay of the six CORS stations are taken as the modeling data,the coordinates and tropospheric delay of the other four CORS stations are used as test data to verify the reliability of the model.The experimental results show that the tropospheric interpolation accuracy of the test data reaches the millimeter level.
    Surface Deformation Prediction and Building Damage Analysis of Coal Mining Under Buildings
    KUAI Yang, LIU Hui, ZHENG Liu-Gen, CHEN Yong-Chun
    2017, 46(10):  36-38. 
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    In order to conduct the development and utilization of coal under buildings，while protecting the safety of ground buildings,taking the industrial square of the 2103 working face of a mine in Handan mining area as the study area,the surface deformation is predicted by using the probability integration method,and the evaluation of the main building damage grade is done,besides that,some relative suggestions about reasonable exploitation are given.The study results show that the main buildings of the industrial square are affected by the surface deformation in different levels,the damage grade of dormitory is Ⅲ level,the damage grade of canteen and coal bunker is Ⅱ level,and the damage grade of the machine repair shop is Ⅰlevel.The above evaluation results is basically consistent with the surface monitoring results,which further indicated that the evaluation results of this paper is reliable.
    Dynamic Evolution Prediction of Surface Subsidence Ponding Caused by Multi-layers Coal Mining in the High Groundwater Level Area
    GAO Xu-Guang, LIU Hui
    2017, 46(10):  39-42. 
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    Some distinct characteristics of mining subsidence caused by multi-layers coal mining under thick alluvial is analyzed.The distribution prediction method of the surface mining subsidence ponding is proposed by combing the mining subsidence prediction with initial terrain,and the mining subsidence software is developed.The spatial and temporal evolution of mining subsidence ponding caused by multi-layers coal mining in Panji Mine in Huainan City is discussed.The relationship between the the distribution of the surface mining area,shallow ponding and deep ponding between mining process is studied.The above analysis results in this paper is good to improve the prediction precise of mining subsidence.
    Study on GPS Elevation Abnormal Fitting Method
    FANG Yi
    2017, 46(10):  43-46. 
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    The elevation used in the current engineering survey is normal height,while the elevation obtained by GPS surveying is geodetic height,the elevation anomaly between them is existed.In order to deal with the height anomaly value,the method of GPS height fitting method based on the powerful data processing function of Matlab sofware,and combing with the engineering examples,by using the programming function of Matlab software to realize the GPS height anomaly fitting.The results show that:①if the test area is with distributed with planar shape,the quasigeoid characteristics of the test area can be reflected effectively by using the surface fitting method;②the fitting effects of the BP neural network fitting method is good,the fitting efficient precise of the combined fitting method is superior to the one of single fitting methods;③the external and internal coincidence precises of the surface fitting method,curve fitting method,BP neural network fitting method and the combined fitting method can meet the requirements of four geometric level.The study results further indicated that it is feasible and effective to apply Matlab software to conduct GPS hight fitting.
    Study on the Scale Effect of Slope Length in Xiannangou Watershed Based on ANUDEM
    FAN Yu, GUO Wei-Ling
    2017, 46(10):  47-51. 
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    Slop length is one of the most important terrain factors in the quantitative assessment research of regional soil and water conservation.Taking Xiannangou watershed area in loess plateau region for example,DEM data with 5~100 m resolution is established based on 1∶10 000 digital topographic maps using ANUDEM software,and the surface of slop length was extracted by LS_TOOL,to analyze the changing regularity of slope length with DEM resolution.The results indicated that the slop length values of these terrain feature points are changing regularity with DEM resolution reduction.The changing regularity of mean slop length in different classifying areas appears difference,and the area ratio is increasing in all classifying areas except the 100 m.The mean slop length of Xiannangou watershed is expanded with DEM resolution reduction,and the short slope length is decreasing and the long slope length is increasing.The mean value appears linear growth with DEM resolution variation.
    Comparison of the Stochastic Model for Single-epoch Baseline Resolution of IGSO/GEO/MEO Triple-frequency
    YAN Chao, YU Xue-Xiang, XU Wei, DU Wen-Xuan, LIU Yang, WANG Tao, ZHANG Guang-Han
    2017, 46(10):  52-58. 
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    High-precision positioning jointed by three satellites of Beidou MEO,IGSO and GEO have an impact on the structure of the positioning model.Based on the sinusoidal elevation angle model,the tangent elevation angle model,the combination model of the elevation angle and the distance from the satellite to the ground station and the combination of the elevation angle,the distance from the satellite to the ground station and the signal-to-noise ratio,these four stochastic models are used to solve the short baseline with different length difference and different elevation difference.The effects of different stochastic models on the ambiguity resolution success rate and positioning accuracy of the short baseline with different length difference and different elevation difference are contrasted and analyzed.The result shows that for the baseline with short distance and small elevation difference,the sinusoidal elevation angle model have the highest ambiguity success rate and positioning accuracy; For baseline with long distance and large elevation difference,The tangent elevation angle mode have the highest ambiguity success rate,while the combination of the elevation angle,the distance from the satellite to the ground station and the signal-to-noise ratio have the highest positioning accuracy.
    Efficiency Analysis of Clock Error Resolution in Multi-satellite Navigation System
    MAO Ya, WANG Qian-Xin, YU Wei-Xuan, HU Chao, ZHANG Ming-Bin
    2017, 46(10):  59-62. 
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    With the number of satellites and ground monitoring stations increasing，a lot of GNSS observation data will be produced every day.Making the use of all data to determine the precision clock error will certainly affect the efficiency of its solution.In order to determine the precision clock error by the use of different stations,and clarify the effect of the precision clock error on the calculation accuracy and computation speed jointly by GNSS multi system,the observation data from MGEX station and iGMAS station with receiving ability of four systems are adopted to calculate the satellite clock error.According to the calculation results,the relationship between the number of stations and the solution efficiency and the relationship between different solution strategy and the solution efficiency are analyzed.The results show that when the number of stations increases to 50,the time-consuming is maximumly increased by 39%,and the precision of corresponding clock error is only improved by 10.5%.The two-step solution strategy is improved by 48.02% compared with one-step method,while the time-consuming is reduced by 41.82%.
    Design and Optimal Analysis of Topological Reliability to Remote Real-time Monitoring of Coal Mine With IoT
    TIAN Li-Qin, MA Ya-Nan
    2017, 46(10):  63-66. 
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    Internet of Things (IoT) is very suitable for remote real-time monitoring on coal mine,however its reliability needs to be further studied and improved.Based on the characteristics of coal mine,such as long and narrow tunnel and severe interference,a 3D uniform IoT sensor deployment method which is suitable for the major hazards monitoring is proposed.Furthermore,the related mechanisms to improve the topological reliability of IoT are studied on the basis of accurate monitoring data,such as the distance redundancy between nodes and the unequal redundancy of cluster head.At the same time,several relevant parameters are quantitatively analyzed.From the view of theoretical analysis and simulation results,the method have characteristics of high coverage,balanced energy consumption,and flexible scalability,which have significant effect on improving the topological reliability of coal mine major hazards remote monitoring with IoT.
    Research on Boundary Extraction of 3D Laser Scanning Point Cloud
    DU Qiu, GUO Guang-Li
    2017, 46(10):  67-71. 
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    In the process of digital mine construction，3D laser scanning is used to obtain point cloud data of surface or buildings quickly.The point cloud boundary is not only an important geometric feature to represent surface，but also serves as a model to solve the domain of the surface，which plays an important role in reconstructing the quality and precision of the surface model.It is necessary to extract the boundary points from the mass data in order to model the laser point cloud data.In this paper，a method is proposed to automatically extract the boundary features of the point cloud by discussing the geometric distribution of the local point set projection onto the micro-tangent plane fitted by them.This algorithm could be applied to various point cloud data in complicated surface with its rapid processing speed and accurate extraction result.
    Research on Engineering Volume Calculation for Open-pit Mine Based on UAV oblique Photogrammetry
    WANG Guo, SHA Cong-Shu, JIANG Rui-Bo, HAO Li-Kun
    2017, 46(10):  72-75. 
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    he volume calculation of open-pit mine is one of the key technologies in open-pit mining，however，the amount of engineering is difficult to be accurately calculated by traditional methods because of the complicated geometry of open pit mine influenced by natural conditions and mining process.A method for calculating the volume of open-pit mine based on tilt photography of unmanned aerial vehicle (UAV) is proposed，which adopts the unmanned aerial vehicle equipped with digital oblique cameras for image sequence acquisition in open-pit area.Through feature extraction，aerial triangulation，multi-image dense matching，3D point cloud are generated.Based on this，through irregular triangular gridding and texture mapping，3D model of open-pit slope are reconstructed automatically，and finally grid method is used for volume calculation of open-pit mine.An open-pit aluminum mine in Mianchi，Sanmenxia，is selected for experiment，and the results show that the engineering volume of open-pit can be rapidly obtained by using this method，with the characteristics of high efficiency and low cost.It provides a new method for rapid calculation of open-pit mine volume under complicated conditions.
    Surface Damage Regulation based on Fracture Theory of Beam under Non-uniform Load
    ZHANG Wen-Jing, HU Hai-Feng, LIAN Xu-Gang
    2017, 46(10):  76-80. 
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    To study the mining damage regulations of the ground surface under the geological conditions of thick loess and thin bedrock in mountain areas,Hezhai coal mine,in the south of Shanxi province,is chosen as the study case.Based on the field investigations,the numerical simulation software of UDEC is employed to obtain the relationship between strata fracture and surface displacement.The numerical tests show that the most serious surface deformations happen upon the fracture positions of the rock strata.A fracture model of overlying strata is established as the beam structure under non-uniform load,from which the span equations of the primary fracture and periodic fractures are deduced.The comparison between the calculated results and the locations of surface fissures measured by investigation shows the method developed in this study is available.The study shows that it is feasible to predict the surface crack spacing by using the non-uniform load beam structure fracture model under the condition of thin bedrock geological condition in the thick loess layer in the mountain area.
    Fractal Character of Coal Resources Distribution and the Spatial Distribution Law of Coal Thickness based on S-A method
    LIU Xing
    2017, 46(10):  81-88. 
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    With the use of global coal resources distribution and coal resources data of China, the fractal character of the spatial distribution of coal resources was confirmed; Based on self similarity principle of coal depositing, 10 coal seam thickness data from 168 boreholes in a Huaibei coalfield were treated through normal transformation and Kriging interpolation. The contour map of coal seam thickness was divided into background map and anomaly map by multi fractal filtering with S-A method. The background map represents the trend of coal seam distribution, where the distribution rule indicates that the underlying sands have a good corresponding relationship with sedimentary facies, under the sedimentological laws. The anomaly map showed that the variation of thickness level of coal seam corresponded to the sedimentary environment. Compared with the trend graph and residual plots obtained by the trend surface analysis, the multifractal distribution method described seam thickness more clearly. It indicates that spacial distribution of the coal seam thickness conforms to the multifractal distribution law, also show that the multifractal distribution method is effective in treating and analyzing the geological data.
    Coupling Grouting Control Technology of Instable Surrounding Rock in Large-scale Geological Anomalous Body
    XU Yan-Fei, CHEN Yong-Chun, AN Shi-Kai, LI Cui, BI Bo
    2017, 46(10):  89-98. 
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    Combined the analysis of special geological features and engineering features that appear in the construction process of level -780 m south wing conveyor roadway of Guqiao coal mine，Huainan mining area，that the grouting position and grouting range should adapt to the bearing performance of surrounding rock is considered to explain the connotations of coupling grouting.Mechanism of surrounding rock control via coupling grouting is elaborated based on FLAC3D numerical simulation software;the results show that for the same thickness of grouting，the smaller grouting depth，the better control effect of surrounding rock;for the same starting grouting position，the greater the range of grouting，the better control effect of surrounding rock.Grouting in the surrounding rock between the position of stress peak and the roadway surface can inhibit the development of the plastic zone effectively，grouting in the rupture zone of surrounding rock can control the deformation of the surrounding rock obviously.In order to achieve effective control of the roadway with instable surrounding rock in large geological anomalous body，a coupling grouting method of “overall grouting-regional grouting-partial grouting” is proposed;Method for determining the optimal grouting range in step grouting of coupling grouting is given.The conclusion is that:the grouting range of overall grouting should be greater than 2 times of the stress peak depth，and the grouting range of regional grouting and partial grouting can be determined by solving elastic-plastic mechanics of surrounding rock.Under the guidance of the coupling grouting concept，surface pre-grouting technology，advance pre-grouting technology and short-grouting and short-tunneling technology were combined to manage roadway construction in Gugui geological anomalous body，with the desired effect of surrounding rock control achieved.
    Study on Coal Pillar Reinforcement Methods and Application of Strip Mining under the Buildings
    DAI Hua-Yang, LIAO Meng-Guang, TIAN Xiu-Guo
    2017, 46(10):  99-104. 
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    In order to improve the extraction rate of strip mining,the method of coal pillar reinforcement and reducing the width of pillar is proposed.By analyzing numerical simulation,it is revealed that the strip coal pillar can optimize the strip mining and the coal pillar reinforcement.The results show that the coal pillar reinforcement can reduce the width of remaining coal pillar and improve recovery rate of strip mining.Combined with special geological and mining conditions of a certain coal mine in China and the thought of coal pillar reinforcement with roadway shores,the joint reinforcement technology of shed and wood crib was used in the test area with the width and interval of reinforcement bodies composed of shed and wood crib 1.5 m and 2m separately.Analysis on data of the underground displacement monitoring of coal pillar and the surface settlement monitoring indicated that the maximum vertical displacement of underground pillar reinforcement body is 361 mm,and the maximum subsidence of surface is 217 mm.Coal pillar reinforcement can effectively prevent from the destruction of the coal wall,control ground surface deformation,and ensure the safety of the building.So,the thought of coal pillar reinforcement with roadway shore can provide important way and reference for coal mining under buildings.
    Design and Effect Evaluation of the Filling Strip Mining Scheme under Buildings
    ZHANG Qi, LIU Hui, DI Shu-Chun, ZHENG Liu-Gen, CHEN Yong-Chun
    2017, 46(10):  105-109. 
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    In order to recover the coal resources under buildings,taking the geological mining conditions of a developing fault area in Handan mining area as the research background,and based on the super high-water material filling mining technology,and the working surface layout of the filling strip method and falling strip method was proposed.Based on the analysis of the expected parameters of surface deformation,the basic principle of probability integral method is used to predict the surface deformation,optimize the mining scheme,and propose the safety mining technology.The results show that the use of filling strip method can realize coal resources of 33017 million tons,the recovery rate of 70%,the largest surface subsidence 1 390 mm,the maximum tilt of 109 mm/m,while the use of falling strip method can realize coal resources of 21688 million tons,the recovery rate of 45%,the largest surface subsidence 1 420 mm,the maximum tilt of 109 mm/m.Therefore,the super-high water material filling strip mining method is recommended.This method provides the theoretical basis and technical reference for the exploitation of coal resources under the similar condition of geological mining.
    Study on the Remediation Effect of Coal Gangue Filling Reclamation in Datong Mining Area,Huainan
    LIU Shu-Guang, XU Liang-Ji
    2017, 46(10):  110-114. 
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    In order to study the reclamation effect of coal gangue filling and reclamation land in abandoned mining area,the reclamation land of Datong abandoned mining area in Huainan City was selected as the test area,and the soil physical and chemical characteristics of the reclaimed land and the surrounding unconventional land in Datong mining area were studied.The contents of total chlorophyll,soluble protein,proline and catalase in leaves of four kinds of seedlings including erigeron annus,humulus,tribulus terrestris and abutilon were studied,and the growth status of each plant was comprehensively and quantitatively analyzed by principal component analysis (MA).The results showed that soil bulk density,water content,trace and medium elements were different in the reclaimed land and non-subsided areas of Datong mining area,and the soil organic matter in Datong reclamation area and non-subsidence land were all at level 6.The available nitrogen and available phosphorus in Datong reclamation area was at level 6,and the available nitrogen content was at level 5;The available nitrogen content in non-subside area was at level 5,and the available phosphorus and available potassium were at level 4;The growth condition of humulus,tribulus terrestris and abutilon in the non-subsided area is better than that of the reclaimed area,while the growth position of erigeron annus in the non-subsided area is lower than that in the reclaimed area.
    Safety Evaluation Procedure,Content and Method for the Expressway Passing through the Old Goaf
    YANG Feng, GUO Guang-Li, GUO Qing-Biao-3吕Xin
    2017, 46(10):  115-120. 
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    In order to ensure the safety of the expressway on the old goaf and to standardize the operation process of the safety evaluation of the expressway construction on the old goaf,a general procedure for the safety evaluation of the expressway on the old goaf of coal mine was put forward.Also a detailed summary and analysis of the commonly used methods for evaluating the construction of expressway on the old goaf of coal mine was given,which provides a theoretical basis for the selection of safety evaluation methods.After analyzing the governance countermeasures of the expressway on the old goaf,it was pointed out that the grouting filling is not necessarily the best way to control the old goaf in the coal mine.The appropriate old goaf management program and highway pavement design countermeasures should be selected by combining with the results of the determination of the stability of the old goaf.The research results provide a technical reference for the safety evaluation of freeway passing through the old goaf of coal mine.
    Effects of Different Low Molecular Weight Organic Acids on Nutrient Release from Coal Gangue
    WANG Meng-Tian, YU Jian, FANG Li, ZHOU Guang, ZHU Kai-Qun, XU Zhan-Jun
    2017, 46(10):  121-127. 
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    In order to understand the active regularity of low molecular weight organic acids on coal gangue nutrient，different kinds and different concentrations of low molecular weight organic acid (malic acid，citric acid，oxalic acid) are added to the unweathered coal gangue，to analyze the changes and differences of pH，available nitrogen，available phosphorus and available potassium after 7 d，30 d，60 d.The result shows：compared with the control,adding citric acid and malic acid can reduce pH value of coal gangue，while adding oxalic acid can enhance the pH value of coal gangue；malic acid and citric acid have a certain release effect on the available nitrogen of coal gangue，but oxalic acid has inhibitory effect；After the treatment of malic acid and citric acid，the content of available K of gangue decreased，oxalic acid was opposite.In the aspect of available phosphorus，organic acids all increased the content of available phosphorus in coal gangue.With the increase of the concentration of low molecular weight organic acids and the prolongation of culture time，the pH value of the coal gangue treated with citric acid and malic acid basically decreased，while oxalic acid was opposite.With the increase of experimental period，the content of available nitrogen and available phosphorus of coal gangue showed an upward trend，but only the available potassium showed a downward trend.Along with the increasing concentration of low molecular weight organic acids，application of citric acid and malic acid makes the available nitrogen content of coal gangue is basically a downward trend.Adding citric acid and malic acid makes the available nitrogen content of coal gangue is basically in decline，oxalic acid showed an opposite trend.Coal gangue available potassium and available phosphorus content of organic acid concentration increased with no obvious regularity，it shows a little effect of fixation and release of organic acid concentration on coal gangue available potassium and phosphorus fractions.
    Technology Status and Development Trend of Scheelite Leaching Process
    LI Ting-Ting, ZHONG Xiang-Xi, ZHANG Wei, ZHANG Jin, SHEN Yan-Bai, WEI De-Zhou
    2017, 46(10):  128-134. 
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    Mainly current scheelite leaching processes be introduced，especially including alkaline leaching process based on generating insoluble calcium salt，acid leaching process based on generating soluble calcium salt，and other leaching processes.Alkaline leaching process is characterized by short flow，simple equipment，high leaching rate and strong adaptability to raw materials.However，alkaline leaching process is generally of high energy consumption and high cost.Meanwhile，it is carried out in the case of excessive amount of agent，which will bring some difficulties to subsequent processes.Acid leaching process，mainly used to deal with high quality scheelite with high grade and low impurities，has poor adaptability to raw materials and strict requirement for impurities in raw materials.The characteristic of acid leaching process is mainly high thermodynamics reaction trend，but can produce tungsten acid membrane in the decompositionprocess，thus affect decomposition effect of scheelite.In addition,it will lead to high corrosion of equipment and serious pollutionofenvironment.Other leaching processes are improved based on alkaline and acid leaching processes，but most of them are difficult to industrialize.Therefore，based on the disadvantages of scheelite decomposition processes,it is urgent to develop new process technologies of scheelite resource with low energy consumption，simple operation，economy and cleanliness，in order to realize sustainable development of tungsten industry resource in China.
    Simulation Study on Blasting Damage Law of Deep Rock Mass Based on FLAC3D
    LEI Gang, LI Yuan-Hui, XU Shi-Da, LU Yu
    2017, 46(10):  135-140. 
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    Under the combined action of deep high stress and blasting load，the damage of deep rock mass will be a complicated dynamic evolution process.In order to study the mechanism and influencing factors of deep rock blasting damage，the effects of different explosive peak stress，loading rate and static stress on the size of blasting damage were studied by FLAC3D nonlinear dynamic analysis method.The propagation rule of blasting damage zone with dynamic loading time is discussed，and the size of damage area after blasting is analyzed and evaluated in qualitative and quantitative way.The results show that the different peak stress mainly affects the damage area and the damage amount of the rock mass in the rising stage of the stress wave.The different loading rate mainly affects the development speed of the damage area，and different static stresses mainly affect the final form of the tensile failure zone and tensile damage.The study provides some reference for the design of deep rock blasting excavation.
    Research on Damage Rule of Blasting and Stoping Difficult-to-use Iron Ore under High Strain Ratio
    LI Xin-Ping, HONG Ji-Song-Luo-Yi, DONG Qian, XU Jia-Yun, REN Xian-Feng
    2017, 46(10):  141-148. 
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    With the continuous reduction of resources，the development and utilization of difficult-to-use resources is more and more important.In the background of safety pillar blasting stope at Western District in Chengchao Iron Mine，considering the high strain rate which will cause the dynamic hardening of the material during the blast and the impact of the rock mass from the blast，the user-defined dynamic damage constitutive model was built and inserted in LS-DYNA by secondary development.Its correctness had been verified through comparison with the blast stoping example of Western District in Chengchao; Finally，the further research was carried out on the basis of the improved damage constitutive model，the applicable stoping method and stoping sequence was obtained.The damage characteristic of the rock mass in the stope was investigated，which offered guidance for the actual construction.
    Analysis on Stability of Landslide in the Area A of Nanfen Open-pit Iron Mine Based on Geo-Slope
    CHEN Xiao-Gang, DONG Rui-Chao, TAO Zhi-Gang, PANG Shi-Hui, ZHANG Hai-Jiang
    2017, 46(10):  149-154. 
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    Based on the landslide of Open-pit Iron Mine area A in Nanfen,the stability coefficient of the slope body is calculated,and the most dangerous sliding surface and the change of the sliding surface under the action of outside influences are searched out,from the views of theory analytical and quantitative method,by using Geo-Slope software.After through analysis and research on slope stability,it is found that the slope block was basically in a state of limit equilibrium when excavated to 334-328 platform.At this time,it should stop excavating,observed closely the stability condition of the slope body,and prepared for the evacuation of personnel and equipment.It was not excavated until the sliding occurs under the effect of blasting or rainfall.In fact,the 370 platform was slid locally in a heavy rain when the excavation arrived at 340m platform on October 5.It avoided the great casualties and economic losses due to the early withdrawal.
    Shaft Deformation Prediction Caused by the Recovery of Mining Protection Pillar in Gold Mine
    JIANG Yue, ZHANG Hong-Xun, WANG Fang-Fang, JIANG Yan
    2017, 46(10):  155-158. 
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    For the "two steps" mining shaft protection pillar before closing gold mine，size of mining for small cube seam is discussed.Based on the nonlinear propagation of mining overlying strata and Knothe influence function，the shaft subsidence and deformation caused by the recovery of protection pillar is predicted.It provides a basis for shaft maintenance and reinforcement and also provides a reference method for design of deep mining protection pillar and prediction of mining surrounding orebody influencing on shaft.
    Characteristics of Core Disking and Calculation of In-situ Rock Stress in Deep Rock Mass
    ZHANG Xu, GUO Qi-Feng
    2017, 46(10):  159-162. 
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    With the Core disking phenomenon in geological exploration drilling in Sanshandao gold mine as background，the characteristics of the core disking is described in detail.Combined with the theoretical calculation formulas of various in-situ stresses at home and abroad，great numbers of contrasts with the in-situ thickness of core disking are made.Based on the stress measurements and rock test results in mining area，the optimal formulas of calculating the ground stress for thin core disking and thick disking are obtained.The drilling process and the stress distribution of core rock piles are simulated by 3DEC numerical simulation software combined with in-situ stress measurement results at early stage.According to the stress zoning and the optimal formula，the core disking thickness in different stress zoning of rock core piles is deduced.For zone Ⅰ，the maximum principal stress varies from 82 MPa to 83.6 MPa，and the disking thickness is from 7.7 mm to 7.9 mm.For zone Ⅱ，the maximum principal stress varies from 80 MPa to 82 MPa and the disking thickness is from 7.9 mm to 8.36 mm.For zone Ⅲ，the maximum principal stress varies from 76 MPa to 78 MPa，and the disking thickness is from 8.79 mm to 9.31 mm.The tolerance of core disking thickness based on the numerical simulation and theoretical calculation is within 2 mm comparing with field measurement，which provides a useful idea for investigating core disking.
    High Sulfur Tailings Backfill Properties and Effect of Chemical Additives
    JIANG Guan-Zhao, WU Ai-Xiang, LI Hong
    2017, 46(10):  163-170. 
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    The high sulfur content will reduce the strength of backfill.Adopting pyrite concentrate and sulfur tailings to control the sulfur content of tailings，the sulfur tailings effect on setting time and strength of filling body is studied，and according to the research results，two control measures of adding sodium silicate and citric acid are put forward.The results show that with sulfur content of tailings increasing，slurry setting time is longer，filling body strength reducing.The strength of backfill with less than 18% sulfur content is more than 1.2 MPa and the tailings can be used as filling aggregates.The sodium silicate is less than 4%，the accelerating effect is obvious.However，due to the formation of secondary expansion phase，the filling body 28d strength reduces gradually.When the citric acid is 0.3%，the increase of the setting time of the slurry is not obvious，and the body 28d strength reaches 1.0 MPa，and not decrease with the extension of curing time and meets filling requirements.Because the body early strength is restrained，its structure is loose，the secondary expansion phase is formed continuously to fill the pore between hydration product，making the body interior further dense.
    Influence of Blasting Action Line on the Breaking Effect of Heterogeneous Rock Mass
    CHEN Ya-Jun, CHANG Zhi-Guo, MAO Jin-Feng, WANG Wen-Ke
    2017, 46(10):  171-175. 
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    For the large-area deep hole blasting occurred in open pit mine with heterogeneous rock mass，the optimized blasting network is designed to determine the action direction of blasting.Then，good blasting effect on the heterogeneous rock mass with various structural planes can be achieved.According to the development trend of the joints and fissures in the heterogeneous rock mass，the blasting action line increase the radial tensile stress by increasing the radial tensile stress through the hole-by-hole millisecond free surface blasting.Based on the analysis of the lithology and structural plane of 3# mining area in Heishan coal mine，the theory of lasting action line is pointed out: for rocks with complex structure，blocky rocks can be lowered by increasing the free surface blasting，designing the symmetrical V type oblique interval blasting action line of nonel detonation network to realize the hole-by-hole millisecond blasting.For the heterogeneous rocks existing in some place，uniform rock breaking can be realized by determining the blasting acting line to strengthen the blasting effect，designing the oblique interval blasting action line of nonel detonation network to realize the hole-by-hole millisecond.These research results can provide some reference to resolve the problem of blasting technology for heterogeneous rocks in arid area in open pit coal mine.
    Curing and Backfilling Test of Surface Subsidence Pit by Directly Discharging Tailings in Meishan Iron Mine
    WU Rong-Gao, LIU Hai-Lin, SUN Guo-Quan, WANG Xing
    2017, 46(10):  176-178. 
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    In order to solve the problems of the insufficient shortage of tailings pond and the land waste and hidden trouble caused by the surface subsidence pits caused by the underground mining activities by adopting caving mining method,the surface subsidence pit is processed by directly charging the tailings that is conducted grading enrichment and curing agent adding in Meishan Iron Mine.As the underground mining activities continues,the subsidence pit is the active state,the stratigraphic structure of the coverage layer of caving mining method is changed after curing and stockpiling of tailings.Some regularities of the surface subsidence pit after conducting tailing curing and backfilling are discussed based on the similar simulation test of the safety structural characteristics of coverage layer and safety stockpiling technology.The above analysis results of this paper has important significance for mining engineering.
    Study on Mechanism of Local Shear Failure for Large Isolated Working Face
    WANG Yu-Xiao, JIANG Fu-Xing, WANG Yong-Bao, LIU Wei-Xin, FANG Ting
    2017, 46(10):  179-182. 
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    As isolated working face is influenced mutually by side abutment pressure of goaf at both sides, the risk of rockburst is extremely higher than that in the general working face, so it is more likely to induce rock burst with the whole instability. Although large island faces can effectively avoid such accidents, there still exists local rock burst. Aiming at study the characteristics of the local rock burst of large isolated working face, it would be able to analyze the three-dimensional stress state within coal seam through building the mechanical model, further deduce the principles of shear failure of local coal from the shear failure of infinitesimal coal and propose the criteria for local rock burst occurring in large isolated working face. The research results provide a theoretical basis for mining large isolated working face.
    Geological Characteristics and Prospecting Prediction of Lengshuikeng Ag-Pb-Zn Ore Field，Jiangxi Province
    WAN Hao-Zhang, FENG Yi
    2017, 46(10):  187-188. 
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    Lengshuikeng Pb-Zn-Ag Ore Field is the one the important ore concentration area in Wuyishan polymetallic metallogenic belt.In order to identify the geological characteristics of the ore field,combing with the regional metallogenic geological background,and based on the some related geological and exploration results in Lengshuikeng Ore Field,through deep analysis of typical ore-bodies geological characteristics,ore structures,wall rock alteration characteristics,the mineralization periods are divided and the isotopic geochemcial characteristics is summarized,besides that,the layer-body coupling metallogenic model is proposed.Based on the above discussion results,the newly geochemical exploration results of the ore field and its adjacent areas are analyzed comprehensively,and three metallogenic prediction areas are divided,they area Baojia deep prediction area,Madi-Bishan (Yanshan) prediction area and Bixi-Yangsiban prediction area.The metallogenic potential study results of the three prediction areas show that:the depth of Baojia mining area especially for the depth of the porphyry-type ore-bodies are the important prospecting target area of stratum controlling type ore-bodies;Madi-Bishan (Yanshan) prediction area is the important prospecting target area of the deep mineralization bodies buried in metamorphic rocks and volcanic rocks;Bixi-Yangsiban prediction area is the important prospecting target area of deep concealed porphyry type Ag-polymetallic and deep concealed stratum controlling type Pb-Zn ore-bodies.The above study results related to the geological characteristics and prospecting prediction of Lengshikeng Ag-Pb-Zn Ore Field can provide some reliable reference for the further prospecting and exploration works of Ag-Pb-Zn deposits in the ore field or its adjacent areas.