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    25 July 2022, Volume 38 Issue 7
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    Applicability Analysis of Mobile Learning Mode in the Field of Enterprise Safety Education and Training
    WANG Wenxu
    2022, 38(7):  1. 
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    With the development of mobile Internet technology and the needs of the post-epidemic era，traditional face-to-face learning and electronic learning methods can no longer meet the needs of en⁃ terprises，students and regulatory authorities.Through the comparison of face-to-face learning，traditional electronic learning and mobile learning three existing learning modes，the problems existing in the first two modes are analyzed from multiple angles.And the applicability of mobile learning mode in the field of safety education is analyzed and summarized from the characteristics of safety education and training，policies and systems，technical equipment，and training needs of all parties，and it is believed that mobile learning mode can better meet the needs of enterprise safety education and training.
    Time Management Mode of Iron Mine Production Process
    XU Xiaodong, FU Mingyu, ZHAO Jian, JIA Yongqiang
    2022, 38(7):  4. 
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    In order to build the mine production process of data analysis and time control mode，aim⁃ ing at the main process of "perforation，blasting，mining and loading，transportation，crushing，grinding and separation，concentrate transportation and tailings discharge"，a variety of innovative methods and tools are used to carry out lean production management，so as to eliminate bottlenecks，equipment failures，stagna⁃ tion，type change，information blockage and other problems existing in the process.By promoting the time control mode，the efficiency of the production processes of mining，selection and transportation is signifi⁃ cantly improved.The working time of mining system accounted for 66.04%，increased by 8.04% year on year，and other non-working time decreased synchronously. The grinding and separation system accounted for 90.86% of the operation time，0.69% higher than last year.Piping system time accounted for 97.2%，up 0.4% from the same period last year.The "blasting instead of breaking" project was fully implemented.The efficiency of mining equipment and the platform efficiency of crushing area were significantly improved.The platform efficiency of coarse crushing was 2 485 t/h，up 6.1% year on year.
    Application of Soil Geochemical Survey in the Mineral Exploration in Zhalaite Banner， Inner Mongolia
    GONG Hongliang, ZHANG Weidong, WANG Chunyu
    2022, 38(7):  7. 
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    The mid-segment of the Greater Khingan is a very prominent copper polymetallic metallo⁃ genic belt in China. In order to provide guidance for the prospecting prediction study in this region，a total of 388 single element anomalies and 40 combined anomalies are identified，through 1∶50 000 soil geo⁃ chemical survey in the Zhalaite Banner area of Inner Mongolia that selected as the mineral exploration area. In which，key combination anomalies are checked，and 4 ore（mineralization）occurrences are discovered in the exploration area.A general exploration is carried out on the Dengjitun copper ore occurrence.Total 171 copper ore（mineralized）bodies are found，with copper grades mainly ranging from 0.2% to 1.0%.Ac⁃ cording to its ore characteristics and zoning features of mineralization alteration，it is concluded that this deposit has the genetic characteristics of porphyry copper deposits.And the mineral exploration direction is pointed out for next stage in the working area.Due to the factors such as geochemical characteristics and metallogenic geological conditions，the exploration area is divided into two metallogenic prospective areas in grade I and one metallogenic prospective area in grade II，as well as four prospecting target areas are de⁃ termined in these metallogenic prospective areas，which lays the foundation for the regional mineral explo⁃ ration.
    Mineral Characteristics of Tin (Tungsten) Polymetallic Deposit in Xiwukou Mining Area
    ZHOU Xuefei, YU Jianghua, LI Tongpeng
    2022, 38(7):  11. 
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    Combined with the polished section and thin section of ore minerals and gangue minerals under the polarizing microscope，and adopt the field geology and drilling core sampling methods，the charac⁃ teristics of the ore minerals in Tin (Tungsten) Polymetallic Deposit in Xiwukou mining area is summarized， and four alteration zones are divided as silicification，angle lithization，greisenization and muscovitization. According to the mineral assemblage，mineral paragenetic sequence，metasomatism relationship，metamor⁃ phic degree，the analysis indicated that the orebody is mainly distributed in greisenization and muscovitiza⁃ tion zone.The study results show that the deposit is the typical magmatic period after pneumato-hydrother⁃ mal deposit，namely high temperature gas topaz quartz vein tungsten tin deposit，accompanied by copper， molybdenum，bismuth，beryllium polymetallic deposits，metallogenic form are high temperature quartz vein tungsten ore，tungsten tin and granoxite series composite deposits.
    Provenance and Depositional Environment of The Hanjiga Group in Adegenbulage area， Wenquan County，Xinjiang
    DU Xiaoliang
    2022, 38(7):  15. 
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    Devonian sedimentary strata are widely developed in the hot spring area of West Tianshan. The Hanjiga Group in the Adgenbulag area of Wenquan County，Xinjiang is characterized by conglomerate， lithic sandstone and a small amount of marbleized crystalline dolomite limestone.The clastics of sedimenta⁃ ry rocks are mainly acidic volcanic rocks and clastic sandstones，mainly from the island arc transition zone， and some may come from the uncut oceanic active island arc area.Through field detailed profile surveying and sedimentary environment analysis，combined with the identification of the rock and mineral in the labo⁃ ratory，the depositional environment and provenance characteristics of the Hanjiga Group are comprehen⁃ sively analyzed.It is considered that the Middle Devonian Hanjiga Group was a turbulent coastal sedimenta⁃ ry environment，and its main tectonic environment was close to the active continental margin environment.
    Neoproterozoic-early Carboniferous Ocean-land Transformation in the North of Heilongjiang Province
    ZHANG Tie'an, ZHAO Yusheng, GAO Hongyan , LIU Yuqi , LIU Yuwei , DU Bingying
    2022, 38(7):  20. 
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    Aiming at the important scientific problem of the location and tectonic evolution of the northeast micro-block group in Northern China，based on the ocean-land conversion and continental dy⁃ namics theory，the types and tectonic environments of ophiolite in the erguna-Songnen block are identified by systematic analysis of the material composition of Xinlin-Tayuan-Xinglong subduction accretion com⁃ plex belt of Neoproterozoic to Early Cambrian and Nenjiang-Heihe subduction accretion complex belt of Early Carboniferous，and the types and tectonic setting of ophiolite in subduction accretion complex zone are identified.The study results show that：The ophiolite types of neoproterozoic Xinlin-Tayuan-Xinglong subduction accretion complex mainly include SSZ type ophiolite-niobium-rich basic volcanic rocks，mantle plume type ophiolite-ultramafic rock and gabbro assemblage，and ophiolite ultramafic rock and gabbro as⁃ semblage related to arc-basin evolution.The ophiolite type of the Nenjiang-Heihe subduction accretion complex in the Early Carboniferous is mainly composed of ultramafic and gabitic assemblages related to arc-basin evolution.Based on the material composition of Xinlin-Tayuan-Xinglong subduction accretion complex belt of Neoproterozoic and Early Cambrian，and the spatial distribution of magmatic arcs and re⁃ gional molasite formations of Nenjiang-Heihe subduction accretion complex belt of Early Carboniferous， the oceanic and continental transition process of Neoproterozoic and Early Carboniferous between Erguna Block and Songnen Block is summarized.
    Metallogenic Geological Conditions of a Lead-zinc Polymetallic Deposit in Longmen Basin， Guangdong Province
    QIU Mingxiang
    2022, 38(7):  26. 
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    Through the summarize of the working results of geological survey，soil geochemical survey and soil profile survey carried out in Longmen Basin prospective area，the distribution characteristics of geo⁃ logical body，structure and mineralized alteration zone related to mineralization in the area are analyzed， and the metallogenic regularity of the deposit is summarized.Based on the above analysis results，a prospect⁃ ing target area is preliminarily delineated.The main type of deposit is contact metasomatic skarn pb-Zn polymetallic deposit.The analysis results have certain reference value for the subsequent prospecting work in the basin.
    Geological Characteristics and Ore-controlling Factors of Laer Iron Deposit in Yuexi County
    LIN Shouhai
    2022, 38(7):  30. 
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    After years of exploitation，the amount of iron ore resources in the mining right of Laer Iron Mine in Yuexi County is small，so it is necessary to increase exploration investment to find replacement re⁃ sources.Through comprehensive analysis of metallogenic geological background，geological characteristics and ore-controlling factors of Laer Iron Mine，the results show that: ①The deposit has the same metallo⁃ genic geological background as the iron ore deposit in this area.The iron ore body occurs in the clastic rock of sandstone and shale of Qingmen Formation of Middle Devonian，and is produced in bedding.②The de⁃ posit is stratified and controlled by cheromu syncline.③The palaeogeographic environment in the west of Yuexi is favorable to the formation of iron deposits，which belong to Ningxiang-type sedimentary iron de⁃ posits.④The genesis of the deposit belongs to the sedimentary colloid chemical mineralization of shallow Marine facies.The research results have certain reference value for the prospecting of the same horizon and adjacent area in the region.
    Geological Characteristics and Evaluation of the Geological Remains of Boron Deposits in Liaoji Active Belt
    HU Yanchun, LI Tingting, FENG Yuanyuan, SHI JIAN
    2022, 38(7):  34. 
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    Liaoji active belt is one of the most representative Paleoproterozoic active belts in North China block.It not only records the important information of the dynamic process of early supercontinent ag⁃ gregation and fragmentation，but also develops many typical Precambrian geological relic landscapes. Through a brief analysis of the boron deposits and related geological relics developed in the active belt，it is considered that there are mainly basic geological types of geological relics developed in the area，including stratigraphic section，rock section，structural section and important rock and ore producing areas.Based on the above analysis results，the the geological characteristics，genesis and formation and evolution process of boron deposits are discussed.Combined with the development of a large number of geomorphic and land⁃ scape geological relics in the area，it is indicated that the integration of them will be of great value to region⁃ al economic construction，scientific popularization and tourism economy.
    Geological Features and Genesis of Geothermal Resources in Ziwei District，Yinjiang County， Guizhou Province
    ZHANG Xuedong, WAN Jiang, HOU Jiangping
    2022, 38(7):  38. 
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    Based on the analysis of regional geological background，geological characteristics，hydro⁃ chemical characteristics and heat storage conditions of the geothermal resources in Ziwei district，Yinjiang County，Guizhou Province，the characteristics of the geothermal resources in the area were analyzed by means of nodule geophysical prospecting，drilling and laboratory tests.It is considered that the geothermal resources in this area are fracture convection type geothermal resources and the circulation of geothermal water in crustal rock mass is a very complicated circulation system.In the study area，atmospheric precipita⁃ tion，surface water and groundwater along the fault zone and voids in rock mass (fractures and caves，dis⁃ solve gap，karst pipeline，etc.) into underground migration channel infiltration，constantly in the process of infiltration migration for underground heat water temperature rising，and dissolve and leached in the sur⁃ rounding rock mineral composition，under the action of gravity is controlled by deep fracture do large cycle. The study results show that the geothermal water，which is mainly derived from rainfall，is heated by circu⁃ lation under the action of recent faults and karst fissures，and finally forms rich geothermal water resources in the research area.The wellhead water temperature is 49 °C，the water inrush water is 1 104.68 m3/d，and the water quality is SO4—Ca—Mg type when the pressure reduction is 0.5 MPa (depth 50.0 m).
    Engineering Investigation and Treatment Measures of Geological Hazards of HonggaoliangLandslide in Xin County
    ZHANG Junjie
    2022, 38(7):  42. 
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    Taking the geological disaster control engineering of Honggaoliang landslide in Xin County as an example，on the basis of geological exploration，the topographic and geomorphic characteristics，stra⁃ tum structure and geological structure characteristics of landslides are analyzed，and the cause，deforma⁃ tion mechanism and stability of landslides are analyzed，and scientific and reasonable prevention and con⁃ trol measures of landslides are put forward.Practice results showed that the proposed technical measures are technically feasible，economically reasonable，eliminate geological hazards，social and environmental ben⁃ efits are good，and have certain reference value for similar engineering practice.
    Research on Underground Mining Method of Gently Inclined Orebodies in No. 2 Mine of Kunyang Phosphate Mine
    HUANG Jie, LI Shujian, XIA Gangyuan, WANG Menglai, ZHANG Bin, LIU Yinghui
    2022, 38(7):  45. 
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    The multi-layer gently inclined thin-medium thick ore body is recognized as a difficult ore body in the mining industry. The deep ore body outside the open-pit mining boundary of the No. 2 min⁃ ing area of Kunyang Phosphate Mine has more special geological conditions. It is produced by double-layer phosphate rock with waste rock，and the hanging wall rock and interlayer have poor stability. Firstly，the mining technical conditions are analyzed，and the rock mass quality is classified by Proctor classification method and RMR classification method respectively. It is concluded that Kunyang Phosphate rock belongs to poor rock mass-general rock mass. Combined with the mining technical conditions，the underground mining scheme of the ore body is studied，and a variety of mining methods suitable for the underground mining of the deep ore body outside the open-pit mining boundary of the No.2 mining area of Kunyang Phosphate Mine are proposed. Qualitative and quantitative comparisons are carried out，and the advantages and disadvantages of different methods are analyzed from the perspective of safety，technology and econo⁃ my. Finally，the room pillar subsequent filling mining method is recommended，and the non explosive con⁃ tinuous cutting and mining process of tunneling machine is adopted，It provides support for the conversion of open-pit mining to underground mining in the second mine of Kunyang Phosphate Mine.
    Application of FAHP in Mining Method Optimization of Jianshan Mine
    CHEN Shulin, LI Liang, XUE Lijuan, ZHOU Keping, YUAN Danling
    2022, 38(7):  51. 
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    Mining method is very important for mining，and the selection of mining method is a com⁃ plex and systematic work. In order to consider the influence of uncertainty and quantifiable factors on min⁃ ing method selection，a fuzzy analytic hierarchy process（FAHP）method suitable for mining method deci⁃ sion of underground metal deposits is proposed. Taking Jianshan Mine as an example，four alternative min⁃ ing methods are analyzed by fuzzy analytic hierarchy process，and the comprehensive optimization degrees of the four methods are 81.09%，78.19%，93.67% and 92.30% respectively，so as to determine the opti⁃ mal stage of sublevel drilling and subsequent filling method. The application of FAHP in the selection of mining methods effectively improves the decision-making efficiency and provides a reliable method for the comparison and selection of mining methods for underground metal deposits.
    Study on 3D Scanning and Filling Scheme of Old Goaf in a Small Mine
    XIA Gangyuan, LI Shujian, LIU Ping, WANG Menglai, LU Yugen
    2022, 38(7):  56. 
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    Aiming at the unidentified goaf area of a small fluorite mine，endangering the safety of the main shaft and the surface，three-dimensional laser scanning technology was used to scan the empty area， and the accurate shape of the empty area was obtained.It is found that the empty area continued to fall up⁃ wards.The nearest point of the main shaft is less than 20 m.Aiming at the problem of the lack of tailings and other filling materials in the mine's non-concentration plant，the ultra-high water filling technology was studied.The filling system has the characteristics of low construction cost，flexible layout，less occupation， high automation and good filling effect. A set of ultra-high water filling station can be laid at the wellhead， the filling hole can be drilled from the surface to the goaf after determining the filling position，and the slur⁃ ry is mixed and then lowered to the goaf by filling drilling.The practice results showed that the two major mined-out areas that affect the safety of the surface and the main shaft were filled in less than 2 months， the safety of surface structures and personnel were ensured.
    Analysis of the Impact of Open-pit Blasting on the Safety of Railway Industrial Facilities in Biandanshan Mine
    LOU Guangwen, FAN Qing, XIA Yong
    2022, 38(7):  59. 
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    On the north side of Biandanshan Mine，there are buildings and structures such as Anqing branch line of Hefei Jiujiang Railway and civilian houses. In order to protect the safety of railway and civil⁃ ian houses，the types，distribution，severity and potential accident hazards of seismic effects，blasting fly⁃ ing stones，blasting air shock wave，blasting and production dust and other dangerous and harmful factors produced in the blasting process are analyzed，and the safety and reliability of relevant blasting parameters for the operation of Hefei Jiujiang Railway are analyzed. According to the geographical relationship be⁃ tween the open-pit mining area and Hefei Jiujiang railway and the on-site operation conditions，blast um blasting vibration tester is used to conduct blasting tests on the test points arranged on the site. According to the blasting test results，the blasting attenuation coefficient is calculated by regression，the blasting engi⁃ neering level is determined，and the blasting vibration speed，blasting impact and blasting flying stone and other safety distances produced by the open-pit blasting operation are calculated. According to the relevant technical standards and specifications，the safety impact analysis of the open-pit blasting mining in the northeast of the mining area on Hefei Jiujiang Railway is carried out. According to the analysis results，the safety allowable vibration speed of blasting operation，the maximum detonating charge，the safety allow⁃ able distance of blasting and blasting vibration meet the requirements，and will not pose a safety threat to Hefei Jiujiang Railway.
    Study on Optimization of Stope Approach Parameters in Caving Method Ore Drawing Test of Rongguan Mining
    PENG Minjie, LU Yugen
    2022, 38(7):  64. 
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    In order to study the entry size suitable for the sub-pillar-free sub-caving method of Rong⁃ guan Mining，and verify whether there is a scientific basis for expanding the size and width of the approach after optimizing and increasing the distance between the approaches，a study on the optimization of stope ap⁃ proach parameters was carried out in a draw test.The ore-drawing monomer test has obtained the develop⁃ mental shape of the ore-drawing ellipsoid in Rongguan Mining at different discharge heights.The ellipsoids drawn by the single test are arranged according to the combination of different stope structure parameters currently used in the well，and it shows that when the height of the segment is 12 m，the distance between the entrances is 15 m，and the width of the entrance is 6 m，which is a more reasonable stope structure. pa⁃ rameter combination.From the 962 m subsection level below，the mine has increased the approach distance to 15 m.The analysis of the three-dimensional test data shows that when the approach distance is increased to 15 m，the width of the approach path needs to be widened to 6 m at the same time，so as to release the el⁃ lipsoids in pairs.So that，the dilution and loss are small.
    Application of Waterfall Draw Shaft in Phase II Project of Dahongshan Iron Mine
    WEI Jianhai , MA Xiangsong, WU Jianwei
    2022, 38(7):  67. 
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    Dahongshan Iron Mine Phase II project adopts 200m high and middle section develop⁃ ment，multi section inclined shaft belt relay transportation of ore，and adopts sublevel caving mining with⁃ out sill pillar. Due to the high height of the middle section，the chute after ore collection and transportation is relatively deep，and there is a level of ore collection and transportation from the uppermost unloading sta⁃ tion to the crushing station at the bottom. In order to ensure the operation safety of the deep ore pass and the unloading station，and the simultaneous production of the two ore collection and transportation sec⁃ tions，the waterfall type ore pass layout is adopted. At the same time，the ore drawing system is combined in the waterfall type ore pass system，so that the ore pass has the function of transporting ore，and the prob⁃ lem of continuous production of the large-scale mine ore pass system is solved. The field application and the monitoring results of the chute show that，except for the influencing factors of the surrounding rock，the chute basically belongs to normal scouring damage，and the application of the waterfall chute in Phase Ⅱ project of Dahongshan Iron Mine is successful.
    Analysis of Blasting Mechanism and Experimental Study on Mechanical Properties of Frozen Rock in Alpine Region
    ZHANG Xinhe, JIA Shijie, ZHAO Guoqiang
    2022, 38(7):  72. 
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    The temperature of mines in alpine region is low，and the rocks are often frozen，and are covered with frozen soil layer. The blasting mechanism is unknown，and the blasting effect is difficult to control. Combining theoretical analysis with laboratory tests，the mechanism of rock blasting fragmentation and the variation law of main mechanical parameters of rock under low temperature freezing conditions are analyzed. Based on the basic theory of non frozen rock blasting，this paper expounds three popular theoreti⁃ cal foundations of rock blasting crushing mechanism，and analyzes the blasting crushing mechanism of fro⁃ zen rock. In addition，rock static and dynamic tests were carried out at 20 ℃，0 ℃，-5 ℃，-15 ℃ and - 30 ℃. The results show that under the same freezing temperature，the dynamic strength of rock is signifi⁃ cantly greater than the static strength. With the decrease of temperature，the dynamic and static strength of rock gradually increases，and the mechanical parameters of rock show a linear correlation. Under freezing conditions，the internal structure of rock is more compact，the overall bearing capacity is greatly im⁃ proved，and the blasting difficulty of rock is increased. The research results can provide an important basis for the technical optimization of on-site blasting parameters in alpine region.
    Stability Analysis of Open-pit Slope in a Domestic Mine
    LAN Qiuhua
    2022, 38(7):  77. 
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    Based on the results of 3D laser scanning，the structural plane characteristics of slope rock mass in an open-pit mine was identified.The mechanical parameters of slope stability were obtained by in⁃ verse analysis.On this basis，stereographic projection method and limit equilibrium method were used to an⁃ alyze the stability and failure mode of stope slope.The results showed that the differentiation degree of slope rock mass was generally breezy，the quality of rock mass was good，the mechanical index is high，and the slope was generally stable.The local stability of the slope was mainly controlled by the joint plane.Collapse occurred at the foot of the lower slide body.
    Support Technology in Fractured Rock Roadway Based on Compaction Layer Protection
    WANG Chunxian, LAN Zhou, ZHANG Yishan
    2022, 38(7):  80. 
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    Aiming at the problems of high support cost and easy to be damaged by ground pressure in fractured rock roadway，taking Baoxiu mining area of Hainan Iron Mine as the engineering background， the concept of fine support based on compaction layer protection is proposed. According to the borehole de⁃ tection image，the fractured rock roadway could be divided into internal fragmentation layer，compaction layer，external fragmentation layer and original rock layer from the surface to the inside of the rock mass. The compaction layer is formed in the process of excavation and blasting，and the internal and external cracks obtain expansion space and further develop to form internal and external fracture layers，which leads to roadway roof fall and failure. Based on this mechanism，the key of fine support of broken surround⁃ ing rock roadway is to protect the stability of compaction layer and limit the crushing and swelling space of fractured surrounding rock. The timely support form of bolt mesh shotcrete and anchor cable is proposed and tested in roadway of fragmental surroundings in Baoxiu mining area. The industrial test results show that the timely support form of bolt mesh shotcrete and anchor cable，that is，bolt mesh shotcrete closely follows the support of the working face and the secondary support of anchor cable for 3~5 cycles according to the ground pressure appearance speed，can highly adapt to the ground pressure failure law of the broken surrounding rock roadway in Baoxiu mining area and effectively ensure the stability of the broken surround⁃ ing rock roadway.
    Study on Stability Analysis and Control of Stope Roof in Liguanji Iron Mine
    FAN Zhenhua, FU Xinkai
    2022, 38(7):  84. 
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    Taking the roof support of No.3 stope in -400 m middle section of Liguanji Iron Mine as the engineering background，and comparing with the classification standard of engineering rock mass，the rock mass of No. 3 stope in -400m middle section is divided into Grade IV rock mass with poor quality. Through the analysis of the instability mode and mechanism of broken roof，it is determined to adopt the support method of resin bolt to strengthen the roof. Using FLAC3D numerical simulation method to analyze the stability of roof before and after stope support，the variation characteristics of displacement field and stress field of roof slate and the expansion law of plastic zone are obtained. The results show that after the use of bolt support，the movement and subsidence of roof strata are reduced from unsupported 32 cm to 16 cm，and the height of overburden plastic zone is reduced from unsupported 9.6 m to 6.4 m，which proves that this support method can effectively control the roof displacement，and the research results can provide reference for similar mine stope support.
    Deformation Mechanism and Control Technology of Surrounding Rock in Stress Zone of Tunneling Roadway
    WANG Haibo
    2022, 38(7):  89. 
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    When the 450~530 m section of 2305 Lane passes through the F7 fault stress area，the roof sinks，breaks，and the support fails，and the surrounding rock deformation phenomena such as side slope of the stress area and large displacement occur. The analysis shows that the surrounding rock deforma⁃ tion of 2305 lane is mainly caused by structural stress，surrounding rock characteristics，support strength， support design and other reasons. According to the actual production situation，the joint treatment mea⁃ sures of "grouting +jw anchor cable hanging shed + π steel shed" are taken for the roof，The combined sup⁃ port technology of "advance pipe shed grouting + Truss Bolt" is adopted for the roadway side of the fault. According to the actual application effect，after the comprehensive treatment technology is adopted in the roadway stress area，the roof subsidence is controlled below 0.17 m，and the depth of the roadway side slope is controlled below 0.40 m，which improves the roadway forming rate in the stress area and ensures the safe and rapid tunneling of the roadway.
    Study on the Deformation Mechanism of Kilometer Deep Roadway in Qianqiu Coal Mine of Yimei Group
    XIE Junfeng, LIU Zhili
    2022, 38(7):  93. 
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    Based on the actual situation of Qianqiu Coal Mine，the deformation mechanism of large roadway over two groups of rock strata is studied by numerical simulation .The study results show that:① The stress in the wall of a large roadway with a depth of more than 1 000 meters is large，and the maximum stress can reach about 50 MPa;②Arched roof is easier to deal with deep high stress environment than rect⁃ angular or trapezoidal roof，which is helpful to reduce the scope of plastic failure zone;③When the main roadway is located in the middle of two groups of rock strata，the rock strata with larger strength is benefi⁃ cial to the maintenance of the roadway in this part;④The shear failure zone developed along the roof and floor of a roadway is mainly caused by the shear caused by the vertical wall.According to the situation that the roadway passes through the rock strata，the sectionalized support scheme can be designed，by changing the support density and strength and designing the support scheme according to local conditions，it can avoid insufficient support strength in some sections or excessive support strength in some sections when the whole roadway adopts one support scheme，and reduce the support cost on the premise of guaranteeing the support effect to a certain extent.
    Application of Advanced Support Technology Based on New Material in Tunneling Basting
    YAN Yajun
    2022, 38(7):  97. 
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    Advance support is an important part of roadway support in mineral mining，which pro⁃ vides a certain support resistance for roadway surrounding rock，prevents the collapse of dangerous rocks， and enhances the safety and reliability of tunneling operations. Due to the deficiency of the existing ad⁃ vance support technology，several common support methods can not meet the needs of excavation blasting， and the phenomenon of roof falling and wall chipping often occurs in the process of excavation. Through the research on the support mechanism and support technology，a new material advance support technology is designed and studied. The reliability of this technology is verified from the support strength，the displace⁃ ment of the roadway surface after support and the blasting effect through tests. The results show that the support strength can reach 0.42~0.63 MPa，which can effectively reduce the damage of blasting impact on the surrounding rock，form a stable and effective artificial false roof，and enhance the stability of the sur⁃ rounding rock. The displacement of the roadway surface can still reach 3~5 mm in about 90 days，effective⁃ ly ensuring the safety of operators. At the same time，due to the role of the filling material in it，the blast⁃ ing effect has also been improved to a cer，tain extent. The utilization rate of the blast hole in soft rock has been increased by 10.4% ~11.7%，and that in hard rock has been increased by 3.8% ~ 6.7%. Each compo⁃ nent of the filling material used in the advance support is pollution-free，healthy and environment-friendly products，which will not produce other polluting gases after blasting. It has the advantages of convenient op⁃ eration，high blasting efficiency，good use effect and so on.
    Study on Process Mineralogy of an Iron Ore in Anhui Province
    WANG Huan , ZHOU Hepeng
    2022, 38(7):  101. 
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    In order to better recycle an iron ore in Anhui，the process mineralogy of the ore was stud⁃ ied. The results show that the iron grade of the iron ore is 37.85%，which is low sulfur，high phosphorus and semi-self-melting ore. The useful iron minerals are mainly magnetite，accounting for 85.19% of the to⁃ tal iron. The ore structure mainly includes massive structure and layered structure. The ore structure mainly includes granular structure，inclusion structure，metasomatic structure，spot structure，disseminated struc⁃ ture and flake and squamous structure. The useful iron mineral magnetite is fine-grained disseminated， and the distribution rate is 77.03% at -0.07 mm. The secondary mineral hematite crystal size is smaller，al⁃ most all distributed in -0.07 mm grain size. The disseminated grain sizes of carbonate and mica in the main gangue minerals are coarse，and the distribution rates at +0.07 mm are 65.28% and 55.02% respectively. The magnetite in the iron ore should be recycled by the process of discarding coarse-grained magnetic sepa⁃ ration-grinding-low intensity magnetic separation-grinding-low intensity magnetic separation.
    Analysis on the Characteristics of East Orebodies of Bayan Obo Deposit
    YU Junfang, YAN Guoying, PENG Zhangkuang
    2022, 38(7):  106. 
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    The Bayan Obo super-large ferroniobium rare earth deposit also contains various elements and minerals such as fluorite, sulfur, phosphorus, potassium, scandium, and thorium. In order to better uti⁃ lize and develop it, the strip ore of East Orebodies of Bayan Obo Deposit was collected through field work, and the observation and identification of petroglyphology and the analysis of process mineralogy were car⁃ ried out. The study shows that the main minerals in the striped ore are fluorite, fluorocarbon cerium ore, monazite, hematite, dolomite, etc., the main oxides are CaO and MgO, the F content is 7.49%~28.95%, and the iron mineral content is high, reaching 79.80%；Rare earth minerals are mainly fluorocarbon cerium ore and monazite, and are evenly distributed in banded ores, with rare earth minerals as high as 9.28% and less than 0.1% in smaller content.
    Mechanism and Study of New Chlorite Inhibitor PSSNa in Ilmenite Flotation
    YANG Hui, WANG Zhen, SAFAROV Sayfidin, ZOU Dan, XU Ying
    2022, 38(7):  110. 
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    In order to solve the problem that chlorite and other gangue minerals with certain natural hydrophobicity are easily mixed into concentrate and reduce the quality of concentrate in ilmenite flotation, the inhibition effect and mechanism of a new chlorite inhibitor sodium polystyrene sulfonate ( PSSNa ) were studied. The results of micro flotation test show that PSSNa can selectively inhibit the flotation of chlorite. Under the optimal conditions, the recovery of ilmenite is nearly 50% higher than that of chlorite, which cre⁃ ates good conditions for flotation separation. The contact angle test results showed that sodium polystyrene sulfonate could significantly reduce the hydrophobic effect of sodium oleate on the chlorite surface, but had little effect on the ability of sodium oleate to hydrate ilmenite. The results of infrared spectroscopy showed that compared with ilmenite, PSSNa had chemical adsorption with magnesium atoms on chlorite surface through its sulfonic group, showing selectivity. The adsorption measurement results showed that the adsorp⁃ tion of sodium polystyrene sulfonate prevented the further adsorption of sodium oleate on the chlorite sur⁃ face. The molecular dynamics simulation results explained the selective adsorption and inhibition of the in⁃ hibitor on ilmenite and chlorite at the molecular level.
    Experimental Study on Beneficiation Process of Magnetic-hematite Ore Dressing in a Processing Plant in Hainan
    ZHU Hailong, ZHANG Ling, WU Hongqiang
    2022, 38(7):  115. 
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    In order to explore the best beneficiation process and possible indicators for the effective recovery and utilization of iron ore in a processing plant in Hainan，on the basis of the study of process min⁃ eralogical properties，an experimental study of iron ore with a total iron grade of 39.66% was carried out. Through the use of stage grinding-low intensity magnetic separation-high intensity magnetic separation-flo⁃ tation desulfurization-anion reverse flotation process，a good index of iron concentrate grade of 63.32% and iron recovery rate of 70.38% was obtained in the experiment. The comprehensive recovery of limonite pro⁃ vides a reference for the development and utilization of similar ores.
    Experimental Study on Zinc Recovery by Ammonia Enhanced Leaching of Metallurgical Dust
    LIU Yi'nan, SUN Rui
    2022, 38(7):  119. 
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    In order to explore a new technology for the comprehensive utilization of secondary resourc⁃ es of metallurgical sediment，aiming at the problem that zinc in metallurgical sediment cannot be effective⁃ ly recycled，the metallurgical sediment containing 8.40% zinc in a smelter in Fujian was taken as the re⁃ search object，and the ammonia-ammonium chloride enhanced leaching method was used to analyze and discuss the effects of leaching agent type and concentration，stirring temperature，time and rotational speed on zinc leaching recovery. The results show that under the optimum conditions of ammonia and am⁃ monium chloride concentration ratio 1∶1，total ammonium ion concentration 6 mol/L，liquid-solid ratio 6∶ 1，temperature 65 ℃，stirring time 2.5 h，stirring speed 500 r/min，the leaching rate of zinc reaches 86.91%，and the leaching effect is better.
    Research on Optimization Test of Beneficiation Process of Chentaigou Iron Ore Mine
    CHANG Wenli
    2022, 38(7):  123. 
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    In order to achieve tail-free emission，Chentaigou Iron Mine carried out an optimized ex⁃ perimental study on the beneficiation process. By setting dry separation operation before fine crushing，wet pre-selection operation before one stage ball milling，and pre-selection operation before one stage cyclone sedimentation，+0.5 mm grain size sand was separated in advance for commercial use，and the resulting wet tailings were mixed with cementitious materials for underground filling. Through the above process opti⁃ mization，the mining-filling balance is realized and the efficient and stable operation of the production sys⁃ tem is ensured.
    Study on Process Mineralogy of an Iron Ore in Liberia
    ZHANG Yong, LIN Xiaofeng, LIU Jun
    2022, 38(7):  127. 
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    In order to find out the influence of ore properties on mineral processing indexes，the min⁃ eral composition，content and distribution characteristics of main minerals of a foreign iron ore were stud⁃ ied by chemical multi-element analysis，phase analysis and MLA analysis.The process mineralogy results show that Fe is the main target element in the ore with a grade of 39.09%，mainly occurring in magnetite，li⁃ monite and hematite.Quartz is the main gangue mineral，followed by pyroxene，garnet and other silicate minerals，and the content of other minerals is relatively low. The process particle size of useful iron miner⁃ als magnetite and limonite is coarse-grained，the disseminated particle size of hematite is fine，and the crys⁃ tal particle size of main gangue mineral quartz is coarse-grained.According to the mineralogy properties of the process，it is suggested to adopt stage grinding and magnetic-gravity combined beneficiation processing.
    Process Mineralogy Study of an Refractory Iron Ore in China
    WANG Ju, CHEN Zhou, YUAN Qidong , TIAN Yi'an
    2022, 38(7):  131. 
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    In order to rationally develop and utilize a refractory iron ore in China，the chemical com⁃ position，mineral content，structure and distribution characteristics of the process minerals were studied in detail by means of multi-element analysis，iron phase analysis and microscope identification. The results show that the main useful iron minerals are magnetite and a small amount of hematite and the main gangue minerals are carbonate，feldspar，quartz and clay. The ore and rock mainly have laminar structure，mas⁃ sive structure and disseminated structure，and the main structures are granular structure，strip structure， porphyritic structure，scale structure，veined structure and disseminated structure. There are many fine iron minerals in clay and chloritic，and the symbiotic relationship is close. There are iron minerals magne⁃ tite and hematite（brown）iron，which are very fine grained and difficult to be liberated in the ore.
    Flotation Experiment of Flake Graphite Ore in Tanzania
    HU Jun, CHEN Xiaobo, LIU Jianwen
    2022, 38(7):  135. 
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    High-quality large flake graphite has high application value and economic value. In order to prevent the fragmentation of large flake graphite，the stage grinding flotation-pre-separation process of a large flake graphite ore in Tanzania was studied. The +0.15 mm large flake graphite concentrate was ob⁃ tained by screening，and the high carbon fine-grained graphite concentrate was obtained by stage grinding and cleaning of -0.15 mm graphite. The fixed carbon grade of large flake graphite was 96.04% and the re⁃ covery rate was 55.84%. The fixed carbon grade of fine-grained graphite was 95.43% and the recovery rate was 38.73%. The total recovery rate of concentrate was 94.57%. The process effectively protects the integri⁃ ty of graphite flakes and improves the yield of large flakes.
    Preferential Flotation Experimental Research on a Copper-zinc Sulfide Ore in Heilongjiang
    ZHANG Qiang
    2022, 38(7):  139. 
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    In order to solve the problem of low grade of on-site copper concentrate in a copper-zinc sulfide mine，zinc suppression and copper flotation preferential flotation test was conducted. The open-cir⁃ cuit test results show that when the grinding fineness is -0.074 mm75%，zinc sulfate and sodium sulfite are used as zinc mineral combination inhibitors，Z-200 and butyl xanthate are used as copper mineral combi⁃ nation collectors，the copper concentrate with copper grade of 19.80%，copper recovery of 48.60% and zinc grade of 15.80% can be obtained by one roughing，three cleaning and one scavenging process. Zinc concentrate with zinc grade of 49.60%，zinc recovery of 53.01%，and copper grade of 0.92% can be ob⁃ tained by using copper sulfate as zinc mineral activator，butyl xanthate as zinc mineral collector，and one roughing and three cleaning process for zinc minerals，realizing the comprehensive recovery of copper and zinc.
    Optimization and Application of Gravity-Magnetic Process for Magnetite in Gongchangling Concentrator
    YU Ying , LIU Guoyi , DU Yanqing, LI Chunyan , ZHAO Dehui, LUAN Changqing
    2022, 38(7):  143. 
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    In order to improve the production index of magnetite working area in Gongchangling Con⁃ centrator，in view of the problems such as the fluctuation of concentrate index，the high grade of tailings and the increase of reagent consumption caused by the increase of ore processing capacity，the process opti⁃ mization and technical transformation were carried out by using the new process of two-stage grinding， one-stage magnetic separation and tailings discarding，gravity separation，coarse-fine classification and fine-grained magnetic separation. The results showed that the qualified iron concentrate with yield of 27.55%，iron grade of 67.09% and iron recovery of 73.91% was obtained after process optimization，and the iron grade of comprehensive tailings was 9.01%. The new process can efficiently separate Gongchan⁃ gling magnetite with excellent product indexes，simple process and remarkable economic benefits.
    Experimental Study on Beneficiation Process of a Low Grade Iron Ore
    WANG Youwei
    2022, 38(7):  147. 
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    In order to determine the development and utilization process of a low-grade low intensity magnetic iron ore in China and optimize the separation index，the beneficiation tests of process mineralogy and magnetic-flotation combined process were carried out for the ore.Through process mineralogy research， it is found that the particle size distribution of magnetite is relatively dispersed，mainly medium particles， belonging to medium-fine particle uneven distribution.The dissemination characteristics of magnetite in ore are complex，the dissemination particle size is uneven，and some magnetic iron minerals are associated with pyrrhotite，which brings certain difficulties to iron ore separation.The results of magnetic-flotation com⁃ bined process show that the combined process of pre-separation tailings discarding-stage grinding-stage magnetic separation-reverse flotation desulfurization has good effect on iron desulfurization，and qualified iron concentrate with sulfur content of 0.39%，TFe grade of 65.43% and TFe recovery of 71.36% is obtained.
    Process Optimization of Fine-Grained Preconcentration System in Meishan Mining Industry
    PAN Ying
    2022, 38(7):  151. 
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    In order to reduce the wet tailings and alleviate the pressure of tailings storage，Meishan Mining has carried out the process optimization research on the 0.5~0 mm fine-grained pre-concentration system of gravity separation in mineral processing，aiming at the problem that the geological grade of raw ore has decreased year by year and the mud content of raw ore has gradually increased in recent years. The research focuses on the detailed sampling，investigation and research of each section of the whole gravity separation 0.5~ 0 mm system，and analyzes the influence of the decrease of geological grade and the change of raw ore properties on the system. The data analysis results show that the iron concentrate with iron grade of about 50% can be separated from the slime of the raw ore by the gravity separation 0.5~0 mm system，which has a great effect on reducing the wet tailings of beneficiation. However，the current concen⁃ tration capacity has reached a bottleneck and needs further optimization.
    A New Biological Oxidation Process of High Arsenic and High Sulfur Refractory Gold Mine
    GAO Junlei, WU Hongqiang, XIN Jinxiu, YANG Xiaoqi, DU Shengtao, GUO Yongchao
    2022, 38(7):  155. 
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    In order to improve the recovery rate of a high-arsenic and high-sulfur refractory gold ore in Inner Mongolia，in view of the characteristics of low gold and silver grade，high arsenic-sulfur content， and fine-grained inclusion of the target minerals，the process mineralogy was analyzed，and the strains were domesticated. Bacterial heap leaching oxidation，oxidation slag gold extraction and other exploratory experimental research. The research has determined the bacterial heap leaching pretreatment-cyanide leaching process route. The refractory gold ore resource finally obtained arsenic oxidation rate of 60.45%， iron oxidation rate of 23.40%，sulfur oxidation rate of 48.32%，gold leaching rate of 77.10%，and silver leaching rate 72.73%. Compared with the conventional beneficiation and smelting process，the gold leach⁃ ing rate can be increased by more than 20 percentage points，which provides a feasible technical route for the recovery of such ore gold and silver valuable elements.
    Process Experiment Study on Improving Beneficiation Index of an Iron Ore
    LIN Xiaofeng, YUAN Qidong, ZHANG Yong
    2022, 38(7):  159. 
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    In order to rationally develop and utilize a certain hematite mineral resource and provide technical reference for the subsequent beneficiation process，a systematic experimental study on the benefi⁃ ciation process was carried out according to the properties and characteristics of this ore. The test results show that the iron concentrate with a grade of more than 55% can be obtained by using the raw ore-grind⁃ ing（-0.076mm 95%）-strong magnetic separation process; the raw ore-grinding（-0.076mm 95%）-spiral chute gravity separation process and raw ore-grinding（-0.076mm 95%）-strong magnetic-spiral chute gravity separation process can obtain iron concentrate with a grade of more than 58%.
    Study on the Promotion Effect of Lauric Acid on Flotation of Coal Gasification Fine Slag
    CHENG Yanhua
    2022, 38(7):  162. 
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    In order to separate the residual carbon and ash in the coal gasification fine slag，the flota⁃ tion test of collector dosage with lauric acid and kerosene as compound reagent was carried out aiming at the problems that there are a large number of oxygen-containing functional groups and pores on the surface of coal gasification fine slag and the traditional hydrocarbon collector is difficult to recover the residual car⁃ bon. The experimental results show that the addition of a small amount of kerosene into lauric acid as col⁃ lector can improve the concentrate yield and combustible recovery rate，and reduce the burning loss of tail⁃ ings. When the dosage of compound reagent is increased to 16 kg/t，the burning loss of tailings is reduced to less than 8%，and the combustible recovery is more than 90%. The addition of lauric acid can increase the dispersion of kerosene in water，thereby increasing the contact area between residual carbon particles and collector droplets. The synergistic effect of lauric acid and collector droplets can improve the hydropho⁃ bicity and floatability of residual carbon particles. The contact angle test results verify the relationship be⁃ tween concentrate yield and floatability when using different collectors for flotation tests. The pore structure parameters and calorific value of flotation products were analyzed by BET test and calorific value test， which provided theoretical support for product reuse.
    Beneficiation Experiment of a Maghemite Ore from Brazil
    WEI Dong, HUANG Chunyuan, TAO Fei, ZENG Zhaoke
    2022, 38(7):  168. 
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    In order to rationally develop and utilize a mixed maghemite ore with iron grade of 50.84% and fine ore particle size in Brazil，the process test was carried out on the basis of ore properties research. The results show that under the grinding fineness of -0.076 mm 60%，the comprehensive iron concentrate with the yield of 70.89%，iron grade of 63.30% and iron recovery of 91.60% can be obtained by grindinglow intensity magnetic-high intensity magnetic one roughing one scavenging process. The beneficiation in⁃ dex is good，which can provide technical reference and basis for the production and processing of such iron ore in domestic concentrators.
    Experimental Study on Reducing Sulfur Content of an Iron Concentrate from a Copper and Iron Ore of Anhui
    WAN Chao
    2022, 38(7):  171. 
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    In order to reduce the sulfur content of iron concentrate from 2%~4% to less than 1%，a mine in Anhui carried out relevant experimental research on the basis of ore properties.The results show that it is difficult to reduce the sulfur content of iron concentrate to less than 1% without activation of sulfur minerals by copper-sulfur mixed flotation process. Although the sulfur content of iron concentrate can be re⁃ duced to 0.92% by adding CuSO4 activated sulfur minerals，it also leads to the difficulty of separation of copper and sulfur，which affects the copper separation index.The iron concentrate with sulfur content less than 1% can be obtained by using on-site copper tailings resulfurization scheme and on-site iron concen⁃ trate direct reverse flotation desulfurization scheme.From the aspects of process transformation and mainte⁃ nance cost，it is recommended to adopt the on-site iron concentrate reverse flotation desulfurization scheme.
    Research on Evaluating Method of Mineral Processing Index Efficiency
    ZHU Yongtao, XIAO Yun, LI Qingheng, ZHANG Wenqian
    2022, 38(7):  175. 
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    In order to evaluate the pros and cons of beneficiation technical indicators scientifically， effectively and conveniently，analyzes and researches common problems such as the drawbacks and limita⁃ tions of the existing beneficiation industry index evaluation methods.Through the derivation of mathematical formulas，the relevant influencing factors are found out，and the objective function that is fast，simple and applicable is established，and the beneficiation index of a lead-zinc ore is analyzed and evaluated by using the new objective function.The evaluation results show that: the new objective function can overcome the disadvantages of the non-uniform evaluation system caused by the fluctuation of beneficiation index caused by the fluctuation of raw ore properties，and at the same time avoid the disadvantages and limitations of the previous evaluation methods. The scientific，effective and convenient evaluation of beneficiation technical indicators is realized，which provides a basis for scientific evaluation of beneficiation index separation effi⁃ ciency，and also provides technical reference for relevant enterprises to evaluate beneficiation indexes.
    Experimental Study on Quality Improvement and Impurities Reducing Beneficiation of a Silica Bearing Iron Ore in Brazil
    XU Jilong
    2022, 38(7):  178. 
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    In order to reduce the content of silicon dioxide in an iron ore in Brazil and improve the iron grade of concentrate，a magnetic separation test of one roughing and one scavenging was carried out. Through the separation study of Brazilian purchased raw ore samples with iron grade of 57.94% and silicon content of 11.68% under different magnetic field intensities when grinding to -0.074 mm particle size con⁃ tent of 77.0%，the iron grade is 61.50%，the yield is 91.30%，the iron recovery is 96.91%，and the content of SiO2 is 7.23% iron concentrate. The iron grade of tailings after separation is 20.60%，which meets the control target value of Meishan Beneficiation Production tailings iron grade ≤21%. The Brazilian raw ore is mixed into the beneficiation production process of Meishan self-produced ore.It is mixed according to 100 tons per hour and the grade of comprehensive iron concentrate is controlled on the premise of 57%，each ton of Brazilian raw ore can produce 1.10 tons of Meishan comprehensive iron concentrate with an iron grade of 57.00%.
    Experimental Study on Comprehensive Recovery of Copper，Zinc and Sulfur in a Mine
    WANG Junhao, WANG Fei , LIN Yuanyuan
    2022, 38(7):  182. 
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    In order to reduce the zinc content in copper and sulfur concentrate of a magnetite contain⁃ ing copper，zinc and sulfur，aiming at the problem of high zinc content in raw ore，according to the ore properties，the process of mixed flotation，mixed concentrate regrinding，preferential separation of copper， zinc and sulfur separation process was used to comprehensively recover copper，zinc and sulfur in magnetic separation tailings. The final grade of copper concentrate was 30.03%，and the recovery rate of copper was 95.58%. The grade of zinc concentrate was 46.36%，and the recovery rate of zinc was 70.27%. The grade of sulfur concentrate was 45.80%，and the recovery rate of sulfur was 94.12%. The zinc content in copper and sulfur concentrates was significantly reduced，and copper，zinc and sulfur were effectively recovered.
    Analysis and Optimization of 20~2 mm Preconcentration Process before Grinding in Meishan Iron Mine
    ZHANG Zugang, CHENG Lei, ZHOU Run, WANG Qiulin
    2022, 38(7):  185. 
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    In In order to improve the pre-concentration accuracy of 20~2 mm grain size before grind⁃ ing in Meishan Iron Mine，in view of the problems existing in the existing pre-concentration process，such as gangue inclusion in concentrate and large loss of tailings metal，the separation test was carried out on the raw ore of this grain size. The test results show that the concentrate with iron grade of 48.96% and iron recovery of 83.97% can be obtained by pre-concentration of 20~2 mm magnetic pulley concentrate before grinding，and the iron grade is increased by 5.86 percentage points. The average iron grade of concentrate reached 36.79% and tailings grade is 11.01%，respectively，using a new type of high magnetic field force 2RTGX0612 cylindrical permanent magnetic separator. Compared with the existing roller high intensity magnetic separator concentrate iron grade increased by 2.59 percentage points，tailings iron grade de⁃ creased by 2.19 percentage points，separation efficiency improved significantly; under the premise that the metal recovery rate is 0.93 percentage points higher than that of the roller high intensity magnetic separa⁃ tor，the concentrate quantity (grinding quantity) of the roller high intensity magnetic separator is reduced by 4.09 percentage points.
    Experimental Study on Recovery and Utilization of Copper and Sulfur Resources from a Tailing
    LU Yongsen, ZHANG Hao
    2022, 38(7):  189. 
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    In order to improve the recovery and utilization rate of resources，improve the concentrator and the surrounding environment，and realize the energy saving and emission reduction of the concentrator， aiming at the problems of a large number of valuable resources in the tailings of the concentrator are not ef⁃ fectively recycled，and a large number of tailings are piled up to pollute the environment and occupy land， the tailings properties are analyzed and the experimental study of copper sulfur mixed flotation-copper sul⁃ fur separation flotation-copper concentrate flotation is carried out.The experimental results show that the copper concentrate with copper grade of 10.34% and copper recovery rate of 45.67%，and the sulfur concen⁃ trate with sulfur grade of 38.22% and sulfur recovery rate of 75.69% are finally obtained. The copper and sulfur resources are effectively recovered，and the recovery and reuse of valuable resources in tailings are re⁃ alized.
    Typical Applications and Potential Prospect of Nano-ceramic Ball in Fine Grinding Circuit in Metal Mines
    ZHOU Hong Lin
    2022, 38(7):  192. 
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    In order to reduce the production cost of metal mining enterprises and improve the utiliza⁃ tion rate of resources，in view of the material and fine grinding characteristics of nano-ceramic balls，com⁃ bined with the application case of nano-ceramic balls replacing traditional steel balls in the fine grinding of metal mines，the economic indicators of“energy saving and consumption reduction”obtained by using na⁃ no-ceramic balls as the grinding medium of ball mills and tower mills，and the positive effect of reducing overgrinding and iron pollution on the separation of useful minerals are briefly described. In addition，the optimization design direction of ball mill and tower mill suitable for the application of nano-ceramic balls was discussed，and the broad application prospect of nano-ceramic balls in fine grinding of metal ores was prospected.
    Analysis of Influencing Factors of SLon Vertical Ring and Pulsation High-gradient Magnetic Separator
    FU Guohui, XU Junfeng, LI Gang, SONG Changchun, WANG Ziyang, HOU Ying
    2022, 38(7):  197. 
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    In order to explore the influencing factors of obvious aboriginality on high-intensity mag⁃ netic separation of hematite，the influencing factors of SLon vertical ring pulsating high gradient magnetic separator were analyzed，and the influence of structural parameters，working parameters，ore feeding prop⁃ erties and daily production management on high-intensity magnetic separation of hematite was discussed. The backwashing results show that the structural parameters such as the outer diameter of the rotating ring， the structure and material of the medium box，the working parameters such as the pulsating stroke，the pul⁃ sating stroke，the background magnetic induction intensity，and the rotating speed of the rotating ring，the feeding property parameters such as the feeding concentration and the feeding particle size，the daily pro⁃ duction management such as the level of the separation tank and the cleaning of the magnetic separator will significantly affect the separation effect. At the same time，the control direction of the influencing factors of the SLon vertical ring pulsating high gradient magnetic separator in the process of high magnetic separation of hematite is pointed out. It is clearly pointed out that the automation technologies such as the liquid level monitoring of the separation tank and the intelligent control of the feed concentration need to be strength⁃ ened and popularized in practical application.
    Reliability Analysis of Gravity Conveying of Full Tailings Paste Filling in a Mine
    ZENG Wenxu, LI Pengcheng
    2022, 38(7):  201. 
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    In order to explore the reliability of pipeline gravity conveying of full tailings-filled slurry in a mine，the slump，consistency，stratification，yield stress and plastic viscosity of each ratio of full-tail⁃ ings-filled slurry were tested. The critical flow rate and filling ratio of the recommended ratio of full tailings slurry under the current filling system conditions are calculated. The results show that when the mass con⁃ centration of the slurry is 70%~74%，it exhibits better flow properties. The actual working flow rate of the full tailings filling slurry with a lime-sand ratio of 1:4 and a mass concentration of 74% is more than the critical flow rate，and the filling multiplier in most stopes is less than 4.74. Based on comprehensive judg⁃ ment，the whole mine tailings can be used as filling slurry aggregate.
    Technical Transformation Practice of Hydraulic System of Engineering Equipment in Sijiaying Iron Mine
    GUO Xin
    2022, 38(7):  205. 
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    As an important part of the production of mining enterprises, the working conditions of en⁃ gineering equipment are directly related to the normal production and operation of enterprises. In order to improve the management level of engineering equipment, Sijiaying Iron Mine adopts a series of measures such as technical transformation, invention and innovation management ideas for the hydraulic system of en⁃ gineering equipment, improving the radiator of the hydraulic system of engineering equipment and installing pressure relief oil pipe through practice.Then the service life of hydraulic components of engineering equip⁃ ment is prolonged, the recovery rate of hydraulic oil during maintenance of hydraulic system of engineering equipment is improved, the use cost is reduced, and the normal operation and safe maintenance of equip⁃ ment are realized.
    Design and Development of Real-time Processing System for Ground-based Interferometric Radar
    LI Yifan, DU Bailin, FU Yuhan, YANG Honglei
    2022, 38(7):  208. 
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    Ground-based Interferometric Radar has the characteristics of high spatial-temporal reso⁃ lution monitoring，and is widely used in small-scale landslide monitoring，but the efficiency of data acqui⁃ sition will affect the timeliness of landslide monitoring and early warning. GPRI-II equipment is currently commonly used ground-based Interferometric Radar Equipment，but the supporting data processing soft⁃ ware has no image interface，and can only realize post-processing of data acquisition，not real-time pro⁃ cessing. In view of the problems existing in the supporting software，the functions of the existing software are investigated，and a real-time processing flow of ground-based Interferometric Radar image data is pro⁃ posed. On the basis of the supporting software，the function of the real-time processing software is de⁃ signed，designed and redeveloped with Python language，and the ground-based Interferometric Radar re⁃ al-time processing software is compiled. The developed software has a good human-computer interaction in⁃ terface，and adopts the grouping method for time series analysis，which overcomes the problem of high hardware requirements for overall calculation. Taking the slope monitoring of Malanzhuang mining area in Hebei Province as an example，the results show that the processing time of single scene data in real-time processing is better than 25 seconds and less than the data acquisition time. The accuracy of the monitoring results is better than 1mm，which meets the needs of deformation monitoring and early warning.
    Design and Application of Underground Drainage Automatic Control System in Wangpo Coal Mine
    YANG Xiaodong
    2022, 38(7):  213. 
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    In view of the problems that each pump room in the multi-level drainage system of Wang⁃ po Mine depends on its own drainage to control，the drainage equipment is not updated in time，the mainte⁃ nance cost of drainage equipment is high，and the drainage efficiency is low，in order to minimize the pow⁃ er consumption of the system on the basis of safely and efficiently completing the drainage task，a set of drainage control system is developed according to the principles of information exchange and centralized control The system composition，main equipment and sensors are introduced，and the realization functions are described. The application results show that the system realizes single-level automatic drainage and multi-level coordinated and optimized drainage control. The operation of the water pump is safe and reli⁃ able，with strong anti-interference. The system data can be transmitted to the ground monitoring center through the underground ring network，the phenomenon of pump stop water hammer can be alleviated，the water leakage fault can be avoided，and the drainage efficiency of the mine can be improved by more than 10%，which can provide technical reference for similar mine drainage.
    Design and Application of Hidden Danger Management System Based on PDA in Open-pit Mine
    PENG Huazhi
    2022, 38(7):  217. 
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    Open-pit mines have large coverage，complex working conditions and many safety blind spots. In order to improve the level of mine information safety management，through the analysis of a large number of hidden danger accidents that have occurred，a three-dimensional dynamic model of hidden dan⁃ ger sources is established，and the basis for hidden danger identification of open-pit mines is obtained; On this basis，a multi-dimensional risk assessment and closed-loop treatment process is designed to form a hidden danger troubleshooting and governance model; Establish the wireless Internet of things architecture based on information layer，transmission layer and application layer，introduce offline data storage and au⁃ tomatic retransmission technology with the help of intelligent PDA terminal equipment，integrate end cloud service sharing，and realize the intelligent collection，processing and application of hidden danger informa⁃ tion; The function modules of hidden danger identification，processing and data analysis system are con⁃ structed，and the system software platform is developed，which provides a good idea for the discovery， treatment，prevention and accident traceability analysis of hidden dangers in open-pit mines. The results show that the system operation can significantly improve the screening rate of fixed hidden danger points in open-pit mines，enhance the risk identification ability of employees，promote the preparation of targeted plans，facilitate the establishment of a convenient and effective hidden danger screening and treatment sys⁃ tem，and realize the normalization and scientific management and control of hidden dangers in open-pit mines.
    Application and Practice of Occupational Health Enterprises Creation in Metallurgical Mines
    LI Gengchen
    2022, 38(7):  220. 
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    In order to actively respond to the national "13th Five-year Plan" for Healthy China，ad⁃ vocate healthy production and lifestyle，prevent and reduce occupational diseases and related disease haz⁃ ards，improve occupational health management，and achieve sustainable and harmonious development of enterprise development and personnel health，Miaogou Iron Mine aiming at the problems of strengthening the implementation of the occupational health management system，beautifying and improving the healthy production and living environment，forming a mature and healthy cultural overall atmosphere，and build⁃ ing a three-in-one modern health management enterprise，research on creating an occupational health en⁃ terprise was carried out，and finally formed a complete occupational health management system. Through the construction of occupational health enterprises for nearly a year，the awareness and ability of front-line employees exposed to occupational disease hazards have been significantly improved，the beautification of occupational health environment has given the majority of employees a higher sense of gain and happiness， and the cultural literacy of occupational health has gradually improved; There was no occupational health injury accident in the whole year，Establishing occupational health enterprises has become an essential long-term mechanism for Miaogou Iron Mine to improve the level of occupational health management.
    Inversion Analysis of Stope Roof Caving Based on Microseismic Monitoring
    YUAN Jinfeng, DONG Ya'ning, JIA Wei, LIU Bo
    2022, 38(7):  224. 
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    Luohe Iron Mine adopts the panel stage open stope and subsequent filling mining method， which retains a large number of panel interval pillars. At the same time，in the mining and filling cycle of a single ore block，the exposed area of the roof of the goaf in one step is large and the exposure time is long， and the stress of the overlying strata is transferred and redistributed in the filling cycle. In order to ensure the safety of dynamic mining，a high-precision microseismic monitoring system is established. From the pa⁃ rameters of event occurrence time，event rate，microseismic moment magnitude，b value change，event cluster and so on，the roof caving of a goaf in Luohe iron mine is inversely analyzed. The results show that the microseismic monitoring system can monitor the dynamic change process of rock mass fracture and send out early warning information 3~7 days in advance，which can help the safety supervision of mines.
    Research and Application of Fog Removal and Dust Reduction Technology in an Underground Mine
    REN Jiaze, JIAO Peng, JIA Mintao
    2022, 38(7):  229. 
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    In order to eliminate the surface environmental pollution caused by the discharge air out⁃ side the return air shaft of an underground mine，in view of the formation of white fog column at the well⁃ head of the return air shaft of an underground mine in winter，and the environmental pollution caused by the discharge water mist，dust and harmful gases，the investigation of the discharge intensity of the pollution factor of the return air shaft and the study of the emission reduction technology were carried out. Through 24 h continuous sampling and analysis of the waste air in the return air shaft of underground mine，it is con⁃ cluded that the waste air outside the return air shaft has the characteristics of large flow，low concentration and high total amount，and the concentration reaches the peak value 1 h after underground large blasting. The test results show that the defogging effect of the mesh mist eliminator is better than that of the corrugat⁃ ed plate mist eliminator，and the combined mist eliminator is better than the mesh mist eliminator. The thicker the wire mesh demister is，the better the demister effect is.According to the test results，a combined mist and dust removal scheme is proposed. The engineering practice shows that the scheme can effectively eliminate the white mist column in the return air shaft. The system resistance is less than 200 Pa，and the air volume of the ventilation system is reduced by 3.2%，which has little effect on the ventilation system.
    Simulation Analysis of the Influence of Roadway Crossing on Air Flow Stability
    SU Xiangli
    2022, 38(7):  233. 
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    In order to study the influence of underground roadway crossing on the stability of air flow in the roadway，the numerical simulation method is used to establish the relevant mine roadway crossing model，and the Fluent software is used to simulate the model. Taking the wind speed at the entry of road⁃ way crossing as 1m/s，3m/s and 13m/s as examples，the air flow field of the crossing roadway under three different wind speeds is simulated，and the air flow distribution cloud diagram and static pressure cloud di⁃ agram of the roadway under each wind speed are obtained. The results show that the roadway intersection has a significant impact on the air flow distribution of the roadway. When the air flow inlet end is close to the roadway intersection，the central wind speed will increase and the wind speed on both sides will de⁃ crease. The air flow of the roadway passing through the roadway intersection and the direction of the road⁃ way at the inlet end is the smallest to be disturbed，and the roadway perpendicular to the inlet end is the largest to be disturbed，while the wind speed at the inlet end has no significant impact on the air flow distri⁃ bution through the roadway intersection. The research results provide theoretical guidance for the layout of monitoring points of mine underground ventilation system，and are of great significance to improve the ac⁃ curacy of ventilation monitoring under corresponding conditions.
    Study on Treatment Technology of S91 Loose Collapse Column in 18502 Working Face of Malan Mine
    LUO Yongqing
    2022, 38(7):  237. 
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    In order to prevent water damage accidents caused by delayed water diversion with the ac⁃ tivation of mining collapse column，comprehensive detection means were adopted to analyze and explore S91 loose collapse column of Malan Mine，grouting reinforcement was adopted for S91 collapse column in 18502 working face of the mine，and 684 m downhill hole and 676 m uphill hole in 18502 gas identifica⁃ tion roadway were peeped by drilling peeping means.The control effect of 18502 gas identification roadway before and after grouting is compared and analyzed.The research shows that there are many cracks in the hole before grouting，and the hole wall is rough. After grouting，there are basically no cracks and the hole wall is smooth. This time，the loose collapse column is treated by grouting，the grouting effect is obvious， the grouting purpose is basically achieved，and the safe mining conditions of 18502 working face is formed.
    Investigation and Analysis of Soil Pollution in an Electroplating Site
    WANG Bingbing
    2022, 38(7):  240. 
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    A preliminary investigation was conducted on the soil environment of an electroplating site. Point sampling and sample collection were carried out for possible heavy metal pollutants (arsenic， cadmium，chromium (hexavalent)，copper，lead，mercury，nickel)，volatile organic compounds and some semi volatile organic compounds. A total of 6 soil sampling points and 2 groundwater sampling points were arranged. The analysis results show that the concentration of heavy metals and volatile and semi-volatile pollutants in the soil of the site does not exceed the screening value standard of class II Land in“standard for soil environmental quality control of soil pollution risk of construction land”(GB 36600—2018)，which does not belong to the polluted land，so there is no need to carry out further detailed investigation of the site soil environment and health risk assessment.
    Investigation and Research on Waste Volume in an Informal Landfill Area
    LIU Wenqiang, DANG Weimin, MOU Yelong, WANG Jiaqi, ZHENG Guolei, MA Wei
    2022, 38(7):  244. 
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    Through the systematic investigation of an informal waste landfill in northern North China， the relevant geological data of the site area and the physical property test results of the laboratory test were carefully collected，and the buried depth，shape and volume of the waste in the site area were investigated by using the method of combining high-density electrical method with engineering survey，and a three-di⁃ mensional geological model was established.The study results can provide reference for the landfill composi⁃ tion，volume investigation and related environmental management of the same type of landfill.
    Geological Disaster Control and Mountain Greening Design of a Waste Stone Factory in Suzhou City
    ZHANG Wei , GAO Shan
    2022, 38(7):  247. 
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    The geological environment problems of abandoned mines left over by history are promi⁃ nent.In order to effectively control the geological environment problems of abandoned mines，taking an abandoned stone factory in Suzhou City as an example，through the investigation and analysis of geological environment background conditions and the current geological environment problems，combined with the characteristics of mine geological environment，the practical and feasible geological disaster management scheme is proposed，including slope management，backfilling and overfilling，drainage，green and other projects.Through the treatment can improve the control area and surrounding environment，green，beautify the landform landscape，eliminate "visual pollution"，environmental benefits are very significant.The study results have certain reference value for environmental restoration and treatment of similar abandoned mines around.
    Partition of Ion Bank Based on the Piper Diagram and Dynamic Transformation and Discrimination of Mine Water Inrush Source
    YANG Fei, SHI Zhiyuan, ZHENG Shitian, WANG Qi, XU Zhimin
    2022, 38(7):  250. 
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    After the occurrence of water inrush accident in coal mine，it is of great significance to identify water inrush source for formulating rescue plan.In order to quickly realize water inrush source iden⁃ tification，20 groups of water sample data collected in Xuzhuang Mine history were selected，and their Ca2+， Mg2+，SO42- and other conventional ions were divided into four groups，A，B，C，and D based on cluster analysis and concentration difference analysis.And it is determined that they are derived from L4 limestone aquifer of Taiyuan Formation，sandstone aquifer of Lower Shihezi Formation and sandstone aquifer of No.7 coal roof .Using the ion concentration range of each aquifer as the database，the ion library partition based on Piper diagram was plotted.In order to further verify the accuracy of ion library partition map，the water in⁃ rush process of working face 7331 of the mine was analyzed.By analyzing the position changes of water sam⁃ ples at different time points in ion bank partition diagram，it is confirmed that there is dynamic transforma⁃ tion of water inrush source in the process of water inrush.Based on the ion conservation，it is calculated that the water proportion of sandstone in No.7 coal roof is 26.96% and that of sandstone in Upper Shihezi is 73.04% in the mixed water inrush source.It is basically consistent with the actual observation that the water proportion of No.7 coal roof sandstone is 20%~25% and that of upper stone box sandstone is 75%~80% in water inrush source.
    Research on Low-cost Wind Power Sintering Process of Nd-Fe-B
    SUN Hongjun, ZHOU Jun, ZHENG Dawei, XU Peng , ZHAI Houqin, NIE Kai , HUANG Wenhuan
    2022, 38(7):  255. 
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    In order to obtain low-cost and excellent performance NdFeB products sintered by wind power，aiming at the problem of unstable performance of this type of products in different production batch⁃ es，advanced processes and equipment such as non-heavy rare earth dual alloy process，multi-channel tar⁃ get pulverizing，grain refinement，automatic powder mixing system，forced stirring and continuous sinter⁃ ing furnace were studied. By optimizing and curing the key process parameters of the whole process，the μ，δ，and γ phases with high magnetocrystalline anisotropy field are stably formed in the grain boundary phase，and high-performance products such as 50H and 52H are stably produced. The production process adopts the intelligent one-bond operation to implement and monitor the process parameters，which greatly reduces the production cost，reduces the interference of human factors on process control，and greatly im⁃ proves the quality and consistency of products.
    Technical Transformation of High Efficiency Utilization of Filtrate of Filter Press in Yangquan Minmetals Coal Preparation Plant
    FENG Zhibin
    2022, 38(7):  259. 
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    In order to adapt to the current environmental protection requirements and reduce the use of clean water in the disc root or mechanical seal of the cooling pump in the pressure filter workshop of Yangquan No.5 Mine Coal Preparation Plant of Lu’an Chemical Industry Group, aiming at the problem that the filtrate separated by the pressure filter in the pressure filter workshop of the coal preparation plant is not completely separated from the coal slime, and without changing the slime water system in other work⁃ shops, the on-site test verifies the moisture content of the coal slime and the concentration of clean water. The clean water meeting the requirements is separated from the coal slime filtrate and is used for the me⁃ chanical disc root or mechanical seal of the cooling pump in the workshop by adding the separation plate to the filtrate tank, adding pipelines and electric valves in the system and adding automatic charging devices. The loading of low-moisture coal slime that meets the requirements not only ensures the water content of coal slime to reach the standard, but also reduces the use of water, achieving the purpose of efficient utiliza⁃ tion of filtrate and saving tap water.
    Research on Influence of Nd-Fe-B Nickel Plating Process on Magnetic Properties
    FU Shinan, DAI Jian, CHEN Jing
    2022, 38(7):  263. 
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    In order to expand the application of nickel plating process in rare earth permanent magnet Nd-Fe-B devices，the influence of bottom nickel plating layer on the magnetic properties of products was studied in view of the attenuation of magnetic properties of Nd-Fe-B magnets caused by nickel plating pro⁃ cess. By adjusting the process of nickel plating on the bottom of Nd-Fe-B magnetic devices，the thickness of nickel plating on different bottom layers is obtained. The magnetic flux attenuation of magnetic devices is used as a measure to judge the influence of nickel coating thickness on magnetic properties. The test results show that when the bottom nickel layer is too thin，there is excessive corrosion on the product matrix，re⁃ sulting in serious magnetic flux attenuation. As the thickness of the bottom nickel layer increases to a cer⁃ tain appropriate range，the magnetic flux attenuation has the minimum value ; after the thickness of the bot⁃ tom nickel layer continues to increase，the magnetic output is shielded due to the ferromagnetic property of nickel，which further leads to the magnetic flux attenuation. The influence of bottom nickel plating thick⁃ ness on flux attenuation shows a trend of nonlinear gradient increase.
    Design and Application of Explosive Blasting Combined with Static Crushing Scheme for Rock Deep Foundation Pit under Complex Conditions
    ZHANG Changtai, ZHANG Qijun, ZHANG Xiaochuan, WANG Yonghong, BAI Xiaoyu, LIU Yongxin, LI Xuefeng
    2022, 38(7):  266. 
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    On the premise of ensuring the safety of the foundation pit and the normal use of the sur⁃ rounding environment，in order to maximize the scope of explosive blasting and make the stone excavation the fastest and most economical，firstly conduct a detailed investigation of the surrounding environmental conditions of the foundation pit，reasonably determine the safe vibration velocity of the buildings (struc⁃ tures) and pipelines to be protected and the side wall support structure，and find out the key protected ob⁃ jects that are most sensitive to explosive blasting. Through the on-site explosive blasting test，the safe dis⁃ tance between the controlled blasting range and the key protected objects is analyzed，and the static crush⁃ ing excavation method is adopted for the stonework that has a safety impact on the protected objects. The test results show that when the distance from the most sensitive side wall support structure is more than 3 m，the blasting vibration speed can be controlled within 10 cm/s without damaging effects when using the town shallow hole hole by hole loosening blasting technology to control the single detonating charge and mil⁃ lisecond staged blasting. The static expansion and hydraulic hammer crushing excavation are used within 3 m near the side wall of the foundation pit. The deformation monitoring of the foundation pit shows that it is safe and stable. This scheme greatly accelerates the construction period of rock excavation of foundation pit and controls the cost，which has reference value for similar projects.
    Comparative Study on Dry Stacking Scheme of Tailings of an Iron Mine in Hubei
    YU Yunlong, GUO Meiling, YE Pingxian, SUN Haozhan
    2022, 38(7):  272. 
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    In order to solve the problem that tailings cannot be continuously piled up due to insuffi⁃ cient storage capacity of an iron ore tailings pond in Hubei Province，an economic and reasonable process is used to treat the tailings of the concentrator. In view of the commonly used classification dehydration pro⁃ cess and the whole tailings pressure filtration process in the domestic tailings dry pile，a comprehensive analysis and comparison are carried out from the perspective of investment and operation cost. The compara⁃ tive analysis results show that the classification dewatering process has less investment and lower operation cost. The analysis results are consistent with the commonly used tailings treatment process in the industry， and can provide useful reference for similar tailings dry heap mines at home and abroad.