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    25 October 2022, Volume 38 Issue 10
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    Analysis of Development Strategy of Gaotan Geological and Cultural Village in Jiangxi Province Based on SWOT Method
    FENG Naiqi, YANG Xiaoling, ZHANG Yongkang, WANG Hongjie, WANG Panxi
    2022, 38(10):  1. 
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    Research Center for Utilization of Industrial Minerals; 3. Zhengzhou University of Aeronautics） Abstract Gaotan Village in Jiangxi Province has rich geological relics and selenium-rich geological resources，and strives to build a geological and cultural village with the model of‘geology+ecological agri⁃ culture’. Through the SWOT situation analysis method，this paper systematically analyzes the advantages， disadvantages，opportunities and risks of the development of Gaotan geological culture village，and puts forward the development mode of excavating the development potential of geological science tourism re⁃ sources，strengthening the integration and publicity of tourism resources，and improving the management system of geological culture village to realize the sustainable development of Gaotan geological culture vil⁃ lage.
    Research on Postgraduate Training Based on Coal Chemistry - Quantum Chemistry Interdisciplinary
    DU Shuangli, ZHAI Ruicong , ZHU Ying
    2022, 38(10):  7. 
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    Interdisciplinary integration is a major feature of current scientific and technological devel⁃ opment and an effective path for cultivating innovative talents. The cross-integration of different disciplines can fill the knowledge gaps in the marginal areas between independent disciplines，greatly promote the in⁃ novation and development of the profession，and then improve the quality of talent training. According to the current situation of postgraduate training in the field of coal chemistry majoring in safety engineering， the problems existing in the interdisciplinary cultivation of coal chemistry and quantum chemistry are ex⁃ plored and analyzed，and the management system of standardized interdisciplinary postgraduate training， the establishment of interdisciplinary tutor groups，and the strengthening of interdisciplinary training are put forward in a targeted manner. Measures such as the construction of subject faculty and the establish⁃ ment of interdisciplinary postgraduate scientific research creation and exchange and innovation platforms， strive to achieve new breakthroughs in thinking methods and scientific research and creation capabilities for postgraduates in the interdisciplinary field of coal chemistry and quantum chemistry.
    Study on Cost Control in the Whole Process of Mine Construction Project
    ZHAO Fangfang, SUN Yongmao
    2022, 38(10):  11. 
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    Due to the particularity of mine construction projects，compared with the construction in⁃ dustry，its project cost control management is at a low level. The whole process of mine construction project is divided into four stages : decision-making，design，bidding and construction. According to the character⁃ istics of each stage，the control method of project cost is studied. The study suggests that in the decisionmaking stage，enterprises should fully examine the market environment，production scale，and actively co⁃ operate with consulting units to improve the quality of feasibility study and the confidence of project cost. In the design stage，the standard design should be adopted，and the competition mechanism should be intro⁃ duced to improve the design quality. At the same time，the quota design should be vigorously promoted to control the project construction cost from the source. In the bidding stage，enterprises should improve the professional level of project cost personnel and introduce advanced bidding management system. In the con⁃ struction phase，do a good job before，during and after the construction of the three parts of the quality con⁃ trol，standardize the relevant management system，ensure the best interests of enterprises.
    Analysis and Countermeasures of Environmental Protection Tax Rlief Collection Mechanism Taking a State-owned Coal Mine Enterprises in Henan Province as an Example
    WANG Xiangling
    2022, 38(10):  15. 
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    Analyze the policy of environmental protection tax rlief for state-owned coal mining enter⁃ prises，and fully grasp the proportion of exemption and tax savings. Combined with the main collection of dust production points in coal mine environmental protection tax，the countermeasures of installing bag dust removal device and dry fog system device are adopted. Through the comparative analysis of the tax sav⁃ ing amount of the environmental protection tax after the transformation，more than 3.8 million yuan was saved throughout the year，and very considerable economic benefits were achieved. The analysis results have important guiding significance for state-owned coal mining enterprises to strive for more preferential policies.
    Geological Characteristics and Prospect Analysis of KANUNKA Copper-cobalt Deposit in Congo(DRC)
    DANG Weimin
    2022, 38(10):  18. 
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    Through the analysis of the ore-forming geological conditions such as strata，structure， geophysical anomalies，ore body characteristics and ore types of the KANUNKA copper-cobalt deposit in Congo(DRC)，it is considered that the ore-bearing strata in this area are Luoan group，and the ore-con⁃ ducting and ore-bearing structures are clear. The magnetic anomaly shows the structural framework of the mining area，the electrical anomaly is consistent with the known mineralization location，and the folk min⁃ ing remains are abundant. Various prospecting indicators are obvious and have good prospecting prospects. The deposit is controlled by strata and faults. The Luoan group strata have experienced three mineralization stages: sedimentary stage，hydrothermal transformation stage and supergene enrichment stage. The genetic type belongs to the sedimentary-transformation-secondary enrichment layered copper-cobalt deposit.
    Geothermal Resource Reserves Calculation and Development and Utilization Suggestions of Yonghan Geothermal Field in Longmen County
    WANG Xiaoliang, ZHANG Guo
    2022, 38(10):  23. 
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    The Yonghan Geothermal Field is located in Yonghan Town, Longmen County, Guangdong Province. It is divided into two thermal anomaly areas, Maxing and Gebei. Through geological survey, geo⁃ physical exploration, geothermal drilling, depressurization test and temperature measurement, the geother⁃ mal geological conditions of the Yonghan geothermal field were basically identified. It is calculated that the geothermal resource reserve of Yonghan geothermal field is 9 925 m3/d, and the average water temperature is 57.8 °C.The concentration of metasilicic acid and fluorine in the geothermal water resources of the local hot field reaches the standard of named mineral water concentration, which can be named as silicon water and fluorine water, and has medical value. It is proposed that the development and utilization direction of geothermal resources in this geothermal field is mainly hot spring physiotherapy and bathing. The design, production and construction scale is 8 932 m3/d, and the service life is tentatively set as 10 a. The scope of the three-level protection zone of the local geothermal field is delineated, which provides a geological basis for the development and utilization of geothermal resources and the protection of geological environment.
    Geological Characteristics and Prospecting Direction of Deep Orebody in Xianglushan Tungsten Deposit
    WANG Yi
    2022, 38(10):  29. 
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    The Xianglushan Tungsten Mine is mainly developing the shallow main ore body at this stage，and the retained resource reserves are declining year by year. In order to ensure the smooth opera⁃ tion of production and prolong the service life of the mine，it is imperative for the mine to find continuous resources in the deep. Through in-depth discussion of mineralization，main ore-controlling factors and orecontrolling rules，it is found that the ore-hosting structural belts such as interlayer stripping structural belts，bundled network vein-like fracture zones，internal contact zones of surrounding rock and rock mass and rock branch xenolith alteration zones formed by fold structure development in the deep part of the min⁃ ing area are the main direction of deep prospecting. The deep interlayer stripping tectonic belt and rock dendritic xenolith alteration zone are the most favorable ore-forming parts of the ore body，and are the main output parts of the rich ore body.
    The Genesis and Prospecting Prospect of Qianshan Iron Deposit in Fanchang County, Anhui Province
    QI Weiwei
    2022, 38(10):  33. 
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    In order to analyze the geological prospecting potential of Qianshan iron mine, according to the exploration results, the geological characteristics of the mining area and deposit are analyzed in detail from the perspectives of stratum, structure and magmatic rock. The results show that the ore body is con⁃ trolled by skarn and mainly occurs in the contact zone between limestone and skarn. The comprehensive analysis shows that the ore-forming potential is good in the area where the fold and fault tectonic activities are strong and the granite and dioritic porphyrite rock mass are well exposed, which is the favorable part for further prospecting and exploration in the mining area.
    Geological Characteristics and Prospecting Potential of Magnesium Clay Deposits in Huze-Fengyang Area，Fenyi County，Jiangxi Province
    XIAO Junjun
    2022, 38(10):  36. 
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    In order to systematically summarize the prospecting results of magnesian clay deposits in the Huze-Fengyang area of Fenyi County，Jiangxi Province，and provide reference for the prospecting of magnesian clay deposits in the area，four areas of Bailutang，Shibaoshan，Shangshanbei and Guishan were taken as the research objects. The basic geological characteristics of the study area were investigated，and the distribution range，scale，occurrence and ore quality of magnesian clay deposits were analyzed. The re⁃ sults show that the magnesian clay ore bodies are mostly ( like ) layered，and the mineral components are mainly talc，quartz and calcite. The average content of beneficial chemical composition MgO was 22.35%. The natural type of ore is talc-type magnesia clay，and the industrial type is magnesia clay ore for ceramic raw materials. The genetic type of the deposit is weathering residual type.
    Application of High Precision Two-dimensional Seismic Exploration in Polymetallic Ore Exploration
    DU Hongjie
    2022, 38(10):  40. 
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    In order to find out the complex structure and deep extension of polymetallic ore body， high precision two-dimensional seismic method is selected for exploration test. Firstly，the appropriate ex⁃ citation parameters were selected in the experiment，and then the high-quality data were collected by us⁃ ing the high coverage times and double-line reception. Finally，the fine processing was performed to reveal the underground structure. The two-dimensional seismic method correctly delineates the distribution range of volcanic institutions，reveals the tendency and depth of cryptoexplosive breccia pipe，identifies the over⁃ all structure，and explores the deep extension of ore bodies. The application effect is good.
    3D Digital Modeling of Hadamengou Gold Mine in Inner Mongolia Based on Surpac
    ZHANG Biao, CHEN Guangbo, WANG Lu
    2022, 38(10):  43. 
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    Taking the Hadamengou Gold Mine in Inner Mongolia as an example，the original geologi⁃ cal data are classified and sorted，and Surpac is used for 3D digital modeling to realize the digitization of mine resource information. Through the established solid model，four vein groups including 11 ore bodies are circled，the surface of the mining area is visually displayed by surface model，the occurrence state of gold grade in different vein groups is displayed in three-dimensional form by block model and grade model. The 3D digital model supports the next mining work.
    Analysis on Geothermal Geological Conditions of Geothermal Field in Gaosha Area of Guangdong Province
    QIU Mingxiang, QIN Haiwei , BAI Chunyan
    2022, 38(10):  47. 
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    In order to increase the scale of geothermal water production, to meet the long-term supply of high sand area of geothermal water, the organization of high sand area of geothermal resources reserves verification work. Geothermal geological survey, audio magnetotelluric sounding, high density resistivity measurement, geothermal geological drilling, borehole temperature measurement, depressurization test, rock and mineral identification, water quality analysis and other work were carried out in the high sand area. The geothermal geological conditions of the geothermal field in the high sand area were basically identified, and the geothermal anomaly area of the geothermal field in the high sand area was delineated to be 1.33 km2. The relationship between the occurrence conditions of geothermal fluid and lithology is clarified. The main burial depth of geothermal reservoir is 40.00~121.00 m. It is determined that the channel of geothermal flu⁃ id is near north-south fracture and fissure karst cave development zone. The study provides an important basis for reserves calculation, exploration and development and long-term planning of geothermal resources in Gaosha area.
    Geochemical Characteristics and Genesis of the Sanchaya Graphite Deposit in Hubei Province
    XIA Jinsheng, WANG Junzhu, YAN Hong, PENG Youju, WANG Yang, CHEN Shenghua
    2022, 38(10):  50. 
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    The Sanchaya crystalline graphite deposit in Yichang，Hubei Province is located in the northern part of the Huangling fault dome in the upper Yangtze platform. It is one of the important crystal⁃ line graphite deposits in China. In order to further explore the genesis of the deposit，through the geological characteristics of the deposit，graphite carbon isotope characteristics，ore fixed carbon content analysis and testing，it can be seen that the ore body mainly occurs in the Huanglianghe Formation strata，and the ore type is mainly graphite schist. The fixed carbon content of graphite ore is 14.75%~19.22%，large flake graphite 85%，small flake graphite 15%. The test value of graphite δ13C‰ is -10.62‰~-11.69‰. It is speculated that the source of graphite carbon in Sanchaya graphite ore mainly comes from organic carbon and a small amount of inorganic carbon.
    Geological Characteristics and Ore-controlling Factors of the Zhongfu Fluorite Deposit in Yongfeng, Jiangxi Province
    ZHOU Zhanwei, MENG Pinghong
    2022, 38(10):  54. 
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    The Zhongfu Fluorite Deposit is a large-scale fluorite deposit discovered in Jiangxi Prov⁃ ince in recent years. Its geological characteristics and ore-controlling factors are poorly studied. By analyz⁃ ing the geological characteristics of Zhongfu Fluorite Deposit, the ore-controlling factors are analyzed. The results show that the shape and occurrence of the ore body of Zhongfu Fluorite Deposit are controlled by the structural fracture zone, and the thickness of the ore body at the wide fracture zone tends to increase. Ore minerals are fluorite and gangue minerals are mainly quartz. The ore structure is mainly broken structure and porphyroclastic structure, and the structure is mainly block structure, strip structure and breccia struc⁃ ture. Ore types include fluorite type, quartz-fluorite type and fluorite-quartz type. The mineralization of flu⁃ orite deposits in the study area is closely related to the strata, magmatic rocks and structures in the area, and its trinity jointly controls the formation, precipitation and enrichment of fluorite ore-forming fluids. There are many faults in the study area, and magmatic rocks are well developed. These factors are condu⁃ cive to the formation of fluorite deposits in the area.
    Influence Study of the Corner Effect of Roof Breaking on the Periodic Pressure Characteristics
    WU Chengzhe, LIU Changwu, YUAN Xun, WANG Ding
    2022, 38(10):  57. 
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    During mining，due to the corner effect of the roof breaking，the roof often breaks in an arc shape at the intersection of the supporting boundary when it fails，leaving two small arc-shaped blocks. At present，when applying the thin plate theory to study the characteristics of the roof pressure，the influ⁃ ence of the small arc-shaped blocks is ignored and the rectangular elastic thin plate model is used for cal⁃ culation. In order to analyze the influence of the corner effect of plate breaking on the periodic pressure characteristics of the roof，the maximum stress of the elastic thin plate considering the arc-shaped blocks was solved by the difference method，and it was compared with the maximum stress of the rectangular thin plate model. Through comparison，it can be seen that the maximum stress of the roof considering the corner effect of plate breaking can reach up to 1.27 times the maximum stress of the roof without considering the effect，but when calculating the periodic weighting step，the difference is small. Therefore，when estimat⁃ ing the maximum stress of the roof，the corner effect of plate breaking should be considered，and when esti⁃ mating the periodic weighting step of the roof，the influence of this effect can be ignored.
    Rational Over-depth Research on Blasting Excavation of Open-pit Benches
    MA Donghua, ZUO Chun, LI Zhimou, QU Honglue
    2022, 38(10):  62. 
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    Reasonable over-depth can effectively avoid the bedrock and improve the blasting effect. In order to study the influence mechanism of over-depth on blasting effect and the reasonable over-depth value of bench excavation blasting，based on the actual situation of a negative excavation project，the three-dimensional model of open-pit bench was established by ANSYS finite element software，and the stress field distribution law of bench excavation blasting was simulated by LS-DYNA post-processing soft⁃ ware. According to the effective stress time-history curve and damage diagram obtained by numerical simu⁃ lation，the reasonable over-depth of open-pit bench excavation blasting under the combined action of mul⁃ tiple factors was explored，and the optimal blasting parameter scheme suitable for the project was selected. Finally，the blasting engineering effect is the best when the hole network parameter is 2.5 m × 2 m，the ap⁃ erture is 90 mm and there is no over-depth.
    Feasibility Analysis of Winter Ore Drawing Method for Tailings Reservoir in Winter in Severe Cold Area
    CHEN Rongjian, WANG Weiming, LIU Tao, ZENG Xiaoxiang
    2022, 38(10):  68. 
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    Luming Mining Co., Ltd.；2.Sinosteel Maanshan General Institute of Mining Research Co., Ltd.） Abstract Improper ore drawing method of tailings reservoir in severe cold area will produce ore drawing frozen layer in sedimentary beach, which will affect the normal seepage and anti-sliding stability of tailings dam. Taking the ore drawing method for a tailings reservoir in a cold area as an example, the tem⁃ perature drop distance and freezing distance of the slurry flow are theoretically calculated, and the state of the drawing beach surface and the monitoring of the drawing parameters in winter are carried out. Accord⁃ ing to the exploration sampling and the temperature measurement in the hole, the occurrence of the frozen layer in the tailings accumulation and the temperature change law are determined. The results show that the freezing distance of pulp flow is far greater than its temperature drop distance, and the flowing pulp will not freeze before entering the ice cover. Concentrated ore drawing can quickly form a drawing flow channel, which flows along the flow channel to the ice sheet and enters the water. The flowing slurry plays a role in melting the surrounding frozen layer. The frozen soil layer below the dam surface has completely melted. The frozen soil layer in the reservoir area is distributed about 20 m below the sedimentary beach, and the maximum frozen soil thickness is 2~3 m. There is no frozen layer below the frozen layer, and the tempera⁃ ture inside the accumulation gradually increases to about 10 °C with the increase of depth. The results show that the ore drawing method of the tailings reservoir in winter is feasible. Before recovering the ore drawing in front of the dam at the end of the freezing period, the ice breaking operation is carried out on the surface frozen layer of the beach in front of the dam to destroy its integrity, accelerate its melting rate, and reduce the adverse effect of the frozen layer on the seepage and stability of the dam body.
    Optimization of Mining Scheme in East Mining Area of Longmenshan Mine Based on FLAC3D
    GAO Xinghong, CAO Shuai, LI Tongpeng
    2022, 38(10):  73. 
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    The eastern mining area of Longmenshan Copper Mine adopts the method of subsection goaf and subsequent filling. Now some stopes have been mined，forming a large goaf. In order to economi⁃ cally and efficiently mine the ore bodies around the eastern goaf of Longmenshan Copper Mine and avoid large-scale collapse accidents，the three-dimensional model of the ore body was established by taking the unmined E3 north and E4 stopes in the eastern mining area as the research object. The numerical simula⁃ tion of five filling mining schemes was carried out，and the advantages and disadvantages of each scheme were ranked from the perspective of safety. The results show that the scheme of cemented filling all the ex⁃ isting goafs is the most safe，but the cost is also the highest. Without dealing with the existing goaf，the safety factor of the scheme of retaining pillars in the stope and partially filling after mining is higher，and the mining cost is slightly lower.
    Study on Selection and Application of Mining Method in Deep Steeply Inclined Thick Gold Mine
    QU Yan, TU Xudong, MA Haoji
    2022, 38(10):  77. 
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    With the increase of mining depth in Sifang Gold Mine，the continuous use of non-pillar sublevel caving mining will face the problems of goaf safety and poor technical and economic indicators. In view of the occurrence conditions of deep ore bodies and the change of ground pressure，considering the technical and economic indicators，the safety conditions of surrounding rock and the occurrence conditions of ore bodies，the sublevel open stoping with subsequent filling mining method and the large diameter deep hole stage open stoping with subsequent filling mining method are compared. The depletion index of sublev⁃ el open stoping with subsequent filling method is better than the latter，and the mining safety is better un⁃ der the condition of unstable surrounding rock. Finally，the sublevel open stoping with subsequent filling mining method was adopted and industrial tests were carried out，and good results were achieved.
    Practice of Open Pit Fixed Side Step Hanging Wall Ore Reverse Mining Method
    XIE Daihong
    2022, 38(10):  81. 
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    Aiming at the recovery of hanging wall ore in fixed side bench after pit closure in open pit， taking the 1 270~1 210 m fixed side bench after pit closure in Lanshan stope as an example，the hanging wall ore was recovered step by step from bottom to top by reverse mining method. The blasting vibration is reduced by layered charging and reduced the hole network parameters by small aperture drilling rig. The practical results show that it is feasible to recover the fixed side step hanging side ore by reverse mining method under the condition of ensuring the stability of the slope in the mining area by selecting reasonable mining technical parameters and backfilling the inner dumping slope toe in the mining area. The scheme has reference significance for similar mines.
    Selection of Mining Methods for Deep Thick Large Ore Based on AHP-TOPSIS Evaluation Model
    LIANG Yaodong, GAO Feng, LI Xin, LUO Zengwu, SONG Shouyang, HUANG Shiding
    2022, 38(10):  85. 
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    In view of the requirements for the improvement of production capacity and production effi⁃ ciency in the mining of deep steeply inclined thick orebody in Gaofeng Mine，the optimization of mining scheme was studied. Firstly，a comprehensive evaluation model based on AHP and TOPSIS is established， and three mining schemes are selected according to the technical conditions of orebody mining. Using AHP-TOPSIS model，11 indexes were selected from three aspects of technology，economy and safety for comprehensive evaluation，and the optimal mining method was segmented open stope subsequent filling mining method.
    Analysis of Causes for the Bedrock of Open-pit Bench Blasting
    LI Haichao, JIA Chengjie, ZHANG Yongbing, MU Jianlin, QU Honglue
    2022, 38(10):  89. 
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    Bedrock has a great impact on the production process and the safety of personnel and equipment. In order to reduce or eliminate the bedrock，taking open-pit bench excavation blasting as the research object，the generation mechanism of blasting bedrock phenomenon are analyzed. Combined with specific cases，LS-DYNA numerical simulation software is used to analyze different factors，and the most intuitive display is given through the effective stress curve. It is found that in a reasonable range，reducing the hole network parameters，setting the ultra-deep，and increasing the aperture can reduce the root rate.
    Mining-cutting Engineering Layout and Supporting Technology of Bottom Ore Drawing and Subsequent Filling Mining Method
    WANG Sheguang , YANG Zhiqiang , WANG Fuquan , HE Wei
    2022, 38(10):  93. 
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    The surrounding rock of an iron ore is broken and the stability is poor. It is planned to use the bottom ore drawing and subsequent filling mining method. For this reason，the optimization research on the layout of the mining and cutting engineering and the support scheme is carried out. Firstly，aiming at the complex broken ore body，combined with the requirements of the bottom ore drawing and subsequent filling mining method，on the basis of the existing excavation roadway，the engineering layout forms such as-230 m bottom structure，-215 m induced bottom pulling，-185 and-170 m cutting side are proposed. Secondly，combined with the stability of surrounding rock，engineering importance and mining conditions and other factors，it is proposed to strengthen the support technology of mining roadway under the geologi⁃ cal conditions and the use conditions of general broken surrounding rock，local broken surrounding rock and obvious deformation. Finally，the excavation method and blasting parameters are optimized. It has been proved by practice that the layout and support of mining roadway have achieved good results，and the re⁃ search results can provide reference for similar mines.
    Optimization of Development Transportation Scheme of Miaozigou Iron Mine
    ZHAO Jinglin, ZHANG Chunyang, WANG Xing
    2022, 38(10):  97. 
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    It is very important for mine to develop transportation system，and its layout is related to the economic benefits of the whole mine. In order to expand and integrate the production of Hongge Iron Mine and Miaozigou Iron Mine in west of Panzhihua，two schemes of crushing + belt transportation and au⁃ tomobile transportation were first proposed，and the preliminary design of the scheme was carried out. Sub⁃ sequently，for the transport of ore and waste rock，the cumulative present value of investment cost compari⁃ son method to carry out technical and economic comparison program. The results show that the present val⁃ ue of cumulative investment cost of crushing + belt transportation system in stope is lower than that of auto⁃ mobile transportation system. The research results can provide reference for similar mines.
    Optimization of the General Layout Plan of an Open-pit Building Material Mine with Difficult Land Use
    PENG Leping
    2022, 38(10):  101. 
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    Aiming at the problems of complex surrounding environment and land shortage in an openpit building materials mine，through the analysis of mine topography and transportation conditions，mining technology，crushing processing technology，etc.，based on the rational selection of production technolo⁃ gy，comprehensive utilization of stripped materials，reasonable setting of internal dump，and partition lay⁃ out of crushing processing plant，the area occupied by the mine is reduced，so as to optimize the general layout. The scheme reduces the land requisition area，facilitates the transportation of raw ore and products， and saves the mine cost，which has important reference value for similar mine general layout design.
    Study on Influence of Mountain Wind on Mine General Layout
    SU Gaofei
    2022, 38(10):  104. 
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    In order to minimize the impact of mine production on the environment，from the perspec⁃ tive of mine general layout design，the influence of mountain local wind on the environment in the mine general layout design and the influence of mine general layout on the energy consumption in the production process are analyzed，and the outdoor wind environment of the site is scientifically calculated and analyzed by numerical simulation. The results show that in the mountainous area with complex terrain，it is obvious⁃ ly inappropriate to use the local wind direction rose diagram to judge the wind，and the airflow direction should be reasonably judged according to the terrain. It can not only fundamentally alleviate the impact of mine production on the plant environment，but also has a positive impact on energy consumption such as ventilation and warmth.
    Study on Ore Breaking Response under Different Constraint Conditions under Blasting Load
    MA Dong , HU Shichao , GONG Guohui , LI Zongwu, HAN Xuejiao , LI Dong
    2022, 38(10):  108. 
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    In mine blasting mining，the constraint conditions of ore rock have a great influence on the blasting effect. Through indoor experiments，the influence of constraints on the degree of ore fragmenta⁃ tion under explosion load was studied. In the experiment，gravels with different particle sizes are used to simulate the constraints of free surface. The ore fragmentation after blasting is screened and counted，and the three-dimensional fractal dimension of fragmentation is calculated. The results show that the constraint conditions have an important influence on the blasting fragmentation distribution. In the case of the same amount of explosive，with the increase of the particle size of the constrained crushed stone，the non-uni⁃ form coefficient of the blasting ore fragmentation and the block rate show a trend of decreasing first and then increasing，and the fractal dimension value of the fragmentation shows a trend of increasing first and then decreasing. There is an optimal boundary condition，which makes the blasting ore block smaller and more uniform.
    Research and Analysis of Open-pit to Underground Wedge Transition Collaborative Mining Tech⁃ nology
    FAN Xiaoming, WANG Hongqiang , ZHAO Qiang , ZHANG Zhao, HUANG Qichong , ZHAO Wenlong
    2022, 38(10):  111. 
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    For large deep open-pit mines entering the end of mining，they will face problems such as difficult capacity continuation and poor safety production conditions when transferred from open-pit mining to underground mining. The wedge transition cooperative mining mode is constructed by using the techno⁃ logical advantages of open-pit and underground mining，and the technical points of cooperative mining and induced caving first mining area are sorted out and verified in Dagushan Iron Mine. The results show that the wedge transition collaborative mining technology can maintain the stability of mine production capaci⁃ ty，and has a significant effect on the safe and stable development of open-pit to underground mining in su⁃ per-large iron mines.
    Optimization of Support Parameters for Rapid Excavation of Large Section Coal Roadway
    ZHAO Pingping, ZHAO Xiangzhuo, LIU Qi, LU Jianping, WANG Haohao
    2022, 38(10):  114. 
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    In order to further improve the efficiency of excavation-anchoring integrated machine for large section rectangular roadway, the 2102 auxiliary transportation crossheading of the first mining face coal mine in Yuheng mining area is taken as the engineering background. The influence of bolt spacing and anchor cable layout on the stability of roadway surrounding rock is analyzed by field investigation and nu⁃ merical simulation. Combined with the support characteristics of the integrated machine, the support optimi⁃ zation scheme of rapid excavation of large section coal roadway is proposed on the basis of the original sup⁃ port scheme. The test shows that after the support optimization scheme is adopted, the surrounding rock of the roadway is safe and stable, and the efficiency of excavation and support is increased by 20%.
    Study on Deformation Failure Characteristics and Damage Mechanism of Phosphorus Dolomite under Uniaxial Compression
    LIU Qiang, CHEN Songwei
    2022, 38(10):  119. 
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    To study the deformation and failure characteristics of phosphorous dolomite stratum in the process of mineral mining，uniaxial compression mechanical tests were carried out on Phosphorous dolo⁃ mite with different water content in laboratory，and the internal damage mechanism of rock deformation and failure was deeply analyzed through acoustic emission test. The study found that : ①During the deformation and failure process of phosphorus-containing dolomite，the release of acoustic emission signal is mainly concentrated in the pre-peak failure stage，while the signal is not active in the compaction and elastic stage. ②As the water content of the rock increases，the compressive strength of the phosphorus-containing dolomite continues to decay，and the acoustic emission signal intensity gradually weakens. The research re⁃ sults provide some data support for phosphate mining in China.
    Dynamic Response Analysis of High Fill Subgrade under Train Loading
    ZHUANG Yunxia, WANG Jinlu, WANG Weiqing, LI Ruifeng, QU Honglue
    2022, 38(10):  122. 
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    Railway subgrade is one of the important components of train operation. In the past study of train dynamic load，the height of subgrade is generally less than 15 m，and the dynamic response law of subgrade up to 20 m has not been explored. Based on the Yungui railway project，FLAC3D numerical simu⁃ lation is carried out to explore the dynamic response characteristics of train loads. The results show that un⁃ der the action of train load，the dynamic stress is consistent with the change trend of plastic deformation， and gradually decreases from the surface of the foundation bed. The effective influence depth of train load is within 8.8 m. With the increase of the number of dynamic load cycles，the total settlement of subgrade in⁃ creases with fluctuation. Within a certain depth below the ground，the growth of subgrade settlement gradu⁃ ally slows down. During the 20 years of train operation，the maximum cumulative settlement reached 18.15 mm，which met the 30 mm required by the embankment section in the high-speed railway design code.
    Prediction of Uniaxial Compressive Strength of Granite Based on P-wave Modulus
    ZHAO Chao, LIU Changwu, ZHOU Pengkun, MIAO Yichen
    2022, 38(10):  126. 
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    Uniaxial compressive strength is an important physical and mechanical parameter of rock， which is especially important for engineering design and on-site construction. The conventional methodolo⁃ gy for obtaining uniaxial compressive strength of rock is mechanical test，the process is complicated. There⁃ fore，it is of great significance to explore the rapid prediction methodology of rock uniaxial compressive strength by establishing the relationship between uniaxial compressive strength and rock physical parame⁃ ters.The P-wave modulus of granite is obtained based on its density and wave velocity. At the same time， the uniaxial compressive strength of granite is obtained through testing. Adopting regression analysis，the fitting relationship between uniaxial compressive strength and P-wave modulus is established，thus obtain⁃ ing the methodology for deriving mechanical parameters from physical parameters. It has been proved that the significance of the regression equation is good and can better predict the uniaxial compressive strength of granite.
    Study on Stability Analysis of Near-top Pillar Ore Rock in Hemushan Iron Mine
    LI Guoping, ZHANG Ji
    2022, 38(10):  129. 
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    In view of the safety hazards such as the deformation of roof and two sides caused by min⁃ ing and ground pressure in some roadways and mining areas in Houguanyinshan section of Hemushan Iron Mine，the stability of ore and rock in this mining area was investigated and analyzed. Combined with the ac⁃ tual situation of the mining area，Q system classification，RMR classification and national standard BQ classification were used to classify the survey results. The results show that the overall stability of the rock in the Houguanyinshan mine section is deviated，and the failure modes of some rocks are different. It is necessary to propose corresponding roadway support countermeasures. The research results are of great sig⁃ nificance to ensure the safe and efficient mining of the mining area.
    Study and Application of Reuse Roadway Support Technology in Wangpo Coal Mine under Dynamic Pressure
    SHI Jiebo
    2022, 38(10):  133. 
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    In order to minimize the damage of dynamic pressure to the reuse roadway，four support optimization schemes are designed for the geomechanical parameters of the reuse roadway based on the analysis of the current support methods. Through numerical simulation，the roof subsidence，floor heave and side displacement were analyzed，and the economic cost was considered to determine the optimal sup⁃ port scheme of the reuse roadway. Through the actual monitoring，the roadway surface displacement of the new support scheme is reduced by about 50 % compared with the original support method，and the sur⁃ rounding rock deformation of the reuse roadway is effectively controlled.
    Stress Evolution Law and Preventive Measures of a Tunneling Roadway Crossing Fault
    YANG Yang, GUO Lei, ZHANG Heng, LI Aobo, HUANG Yizu, ZHANG Jitao
    2022, 38(10):  136. 
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    The FLAC3D numerical simulation method was used to study the stress distribution charac⁃ teristics of the 2-216 working face of a mine during the tunneling through the fault，and put forward rele⁃ vant decompression and risk reduction measures were put forward. The results show that when the working face reaches 40 m from the fault，the stress concentration phenomenon begins to form near the fault，and the closer the distance to the fault，the more obvious the stress concentration phenomenon. In response to this result，a countermeasure was proposed based on the method of pre-relief drilling，which achieved good pressure relief and anti-shock effect.
    Research Progress on Preparation of Calcium Sulfate Hemihydrate Whiskers
    CAO Yongdan, ZHAO Tianyue, CAO Zhao, ZHANG Jinshan, DONG Hongjuan
    2022, 38(10):  139. 
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    Hemihydrate calcium sulfate whiskers is a kind of modified reinforcement material with wide potential application and excellent performance. However，the quality and yield of hemihydrate calci⁃ um sulfate whiskers are limited to a wide range of applications. In order to promote the solution of the prob⁃ lem，based on a brief summary of the preparation methods of hemihydrate calcium sulfate whiskers，the re⁃ search progress of hydrothermal synthesis method，atmospheric salt solution method，organic reagent meth⁃ od and microwave heating method were emphatically introduced. And the advantages and disadvantages of different preparation methods were compared. The growth mechanism of hemihydrate calcium sulfate whis⁃ kers was elaborated，including the nucleation mechanism of hemihydrate calcium sulfate whiskers and reg⁃ ulatory mechanism of additive to hemihydrate calcium sulfate whisker. Meanwhile，the hydration process of hemihydrate calcium sulfate whiskers was introduced，which is of certain guiding significance for the prepa⁃ ration research，industrial production and application of hemihydrate calcium sulfate whiskers.
    Exploratory Experiment on Preparation of Ultrafine Particle Mixed Materials by Tower Mill
    MA Chao , HAN Cheng , XU Haiyang
    2022, 38(10):  145. 
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    Tower mill is a vertical mixing and crushing equipment，which has the characteristics of low energy consumption and high efficiency. It is widely used in the crushing process of various materials， and ultrafine particles whose the average particle size is less than 1 μm can be prepared by the equipment. Through the experiment of crushing ultra-fine mixed materials by tower mill，the influence of crushing time on the particle characteristics of products was explored，and the influencing of defects of mixed materi⁃ als generated in the compression molding process were analyzed. It is considered that when preparing ultrafine mixed materials by tower mill，the differences of physical properties of various materials should be ful⁃ ly considered. The particle size distribution span of mixed materials would be reduced by reducing the "dead zone" of equipment crushing and controlling the crushing time，so as to improve the qualified rate of products in dehydration pressing molding stage.
    Experimental Study on High Pressure Roller Mill of Ore in Nanfen Concentrator
    ZHANG Xichao, XIAO Qifei
    2022, 38(10):  149. 
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    In order to understand the effect of high pressure roller grinding for magnetite ore in Nan⁃ fen Concentrator，the high pressure roller grinding test was carried out on the basis of the analysis of ore sample properties，and the wet magnetic separation test was carried out on the closed-circuit roller prod⁃ ucts under the determined conditions. The results showed that the ore samples with TFe grade of 33.25% and mFe grade of 21.87% were rolled at 20~0 mm. When the working pressure of high pressure roller mill was 8.0，10.0 and 12.0 MPa，the cumulative yield of 5~0 mm grain size of rolled product was 70.60%， 74.83% and 76.61%，respectively. The grain yield of - 0.074 mm accounted for 7.50%，8.28% and 8.50%，respectively. When the working pressure of high pressure roller mill was 8.0，10.0 and 12.0 MPa with feeding particle size of 15~0 mm，the cumulative yield of 5~0 mm grain size was 71.65%，75.51% and 77.24%，respectively，and the yield of -0.074 mm grain size was 7.84%，8.96% and 9.28%，respec⁃ tively. When the screen width was 3 mm and 5 mm，the cyclic load was 71.90% and 38.70%，and the yield of -0.074 mm was 15.41% and 14.29%，respectively. The concentrate from the wet magnetic separa⁃ tion test of high pressure roller grinding closed circuit rolling product（3~0 mm） has a TFe grade of 37.50%，mFe grade of 26.73%，TFe recovery rate of 91.38%，mFe recovery rate of 99.03%，tail casting yield of 18.98%，TFe grade of 15.10% and mFe grade of 1.12%.
    Beneficiation Test of Coarse Iron Concentrate Obtained from the Coarse-particle Dry-preconcentration of Asbestos Tailings
    ZHOU Jian, LI Tianshu, LONG Feifei
    2022, 38(10):  152. 
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    The preconcentration coarse concentrate obtained from the dry magnetic separation for as⁃ bestos tailings is similar to low-grade magnetite ore. While it is with features such as easy to adsorb water， pulp stick-slip and hard to grind and classify.The TFe grade of the products was 32.46% and the main iron mineral was magnetite ore with magnetic iron content of 30.85% and distribution rate of 93.48%.The main gangue minerals are serpentine and quartz. The content of SiO2 and MgO in the ores was high，which were the main impurities need to be removed.In order to determine the grinding and beneficiation flowsheet，the beneficiation test were carried out with wet preconcentration，stage grinding and single magnetic separa⁃ tion process.With grinding fineness of -0.074 mm accounting for 60%～65% and -0.043 mm accounting for 85% for the first stage and second stage separately，the iron concentrate with TFe grade of 58.43% and recovery rate of 89.84% was obtained by once wet preconcentration magnetic separation，once thickening and desliming using dewatering tank，once low-intensity magnetic roughing and twice low-intensity mag⁃ netic cleaning.The recommended process including wet preconcentration，staged grinding and single mag⁃ netic was simple，and has good adaptive capacity with the variational ore properties，appearing low benefici⁃ ation cost.
    Experimental Study on Chromium Extraction and Silicon Reduction for Chromite Ores in Pakistan
    LI Wenhui
    2022, 38(10):  155. 
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    A chromite ore in Pakistan contains high silicon with Cr2O3 content of 50.46% and SiO2 content of 3.80%. Chromite is the only useful metal minerals in the ore（mainly in the form of chromium spinel，distribution rate of 99.53%），and mainly appeared coarse grain（particle size greater than 0.1 mm accounting for 93.90%）with mainly allotriomorphic granular texture and massive structure. Most of the bro⁃ ken chromite is zonal distribution，and the transparent mineral quartz is filled between the chromite masses. In order to reduce the silicon content in the ore，the beneficiation test was carried out. The results showed that the ore was treated by the process of gravity separation and middle ore regrinding and reseparation， and finally four concentrate products were obtained. The comprehensive concentrate has Cr2O3 grade of 54.90%，Cr2O3 recovery rate of 88.40%，and SiO2 content of 1.25%.The content of SiO2 in all concentrate products meet the requirements，and the effect of chromium extraction and silicon reduction is achieved.
    Experimental Study on Beneficiation of Panzhihua Taiyangwan Vanadium-titanium Magnetite Ores
    WANG Yong
    2022, 38(10):  158. 
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    After decades of mining in Zhulan stope of Panzhihua Iron and Steel Group，the produc⁃ tion capacity is gradually declining. In order to ensure the sustainable development of Panzhihua's main mining area，the development and utilization technology of similar ores in the north extension ore body of Zhulan stope—Taiyangwan ore section was tested and studied. The results showed that the TFe，TiO2 and V2O5 grades of the ore are 21.49%，10.54% and 0.17% respectively，which belongs to high sulfur，acidic， low iron and high titanium type primary vanadium-titanium magnetite ores. After two-stage grinding and low-intensity magnetic separation，iron concentrate with yield of 18.56%，TFe grade of 54.06%，TiO2 grade of 11.66% and TFe recovery rate of 46.69% could be obtained. After two-stage high-intensity mag⁃ netic separation + flotation processing for tailings from low-intensity magnetic separation，titanium concen⁃ trate with yield of 9.54%，TiO2 grade of 47.00% and TiO2 recovery rate of 42.54% could be obtained. Tai⁃ yangwan vanadium-titanium magnetite ore has high development and utilization value. The development and utilization of Taiyangwan ore resources can improve the resource support capacity of Panzhihua head⁃ quarters and extend the stable production service life of the mine.
    Study on Comprehensive Recovery of Copper and Iron in a Copper Smelting Slag
    ZOU Liping, YANG Youzhi , DENG Hongfei , CAO Enyuan , JIANG Huxia , ZENG Suqin
    2022, 38(10):  162. 
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    The contents of Cu and Fe in a copper smelting slag in Hubei are 2.11% and 40.07%，re⁃ spectively.The content of main impurity component SiO2 is 30.89%. Copper mainly exists in the form of cop⁃ per sulfide，and iron mainly exists in the form of magnetic iron. In order to recover copper and iron in the sample efficiently，an efficient and reasonable recovery process was studied. The results showed that under the condition of grinding fineness of -74 μm accounting for 85%，the copper concentrate with copper grade of 24.78% and recovery rate of 88.55% and the iron concentrate with iron grade of 64.12% and recovery rate of 82.52% can be obtained after twice low-intensity magnetic separation for flotation tailings treated by one roughing，one cleaning and one scavenging，and the medium ore are returned to the process in se⁃ quence. Adopting twice low-intensity magnetic separation，the iron concentrate with iron grade of 64.78% and recovery rate of 85.91%，and the copper concentrate with copper grade of 24.86% and recovery rate of 62.33% were obtained after one roughing，one cleaning and one scavenging the medium ore are returned to the process in sequence for the low-intensity magnetic separation tailings. The copper recovery rate of the pre-flotation and post-magnetic process is significantly higher，so it is an ideal recovery process for copper and iron.
    Experiment of Magnetization Roasting and Low Intensity Magnetic Separation of Iron in a Flotation Tailings
    LIANG Juming, ZHU Hailong, WANG Kaiyang, LI Zhiming
    2022, 38(10):  166. 
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    High intensity magnetic separation preconcentration concentrate from flotation tailings of a domestic iron concentrator has an iron grade of 30.63%，and the content of main impurities SiO2 is 40.78%. The content of main harmful components like phosphorus and sulfur is low. Hematite-limonite，magnetic iron，carbonate iron accounts for 62.79%，17.59%，12.23% of the total iron，respectively. Magnetic roasting and low intensity magnetic separation process was studied in order to efficiently recover iron. The results showed that under the conditions of total gas volume of 600 mL/min，H2 concentration of 20%，reduction roasting temperature of 520 ℃ and reduction time of 20 min，the iron content of roasted clinker increased to 33.00%，and iron mainly existed in the form of magnetic iron. Hematite-limonite and carbonate iron in the samples were mostly converted to magnetic iron. Under the condition of grinding fineness of -600 mesh accounting for 87.04% and magnetic field strength of 119.43 kA/m，low intensity magnetic separation was carried out. The iron concentrate with iron grade of 64.12% and recovery rate of 71.81% was obtained and iron recovery from the sample was well realized.
    Test Research on Iron Improvement and Silicon Reduction by Magnetic Field Screening Separator for an Iron Concentrate in Liaoning
    DONG Dong, ZHANG Yingxin, WANG Erfeng
    2022, 38(10):  169. 
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    The main iron mineral in an iron ore in Liaoning is magnetite，followed by specularite， and the main gangue mineral is quartz. The concentrate with iron grade about 65% and SiO2 content above 8% was obtained on site，which is difficult to be sold because of higher SiO2 content. In order to solve the problem efficiently and inexpensively without changing the main structure of the process，the on-site iron concentrate from the second stage magnetic separation was treated as test sample with the process of mag⁃ netic field screening separation，screening of magnetic screen concentrate，regrinding of combinated medi⁃ um ore，low intensity magnetic separation，magnetic field screening cleaning，screening of magnetic screen concentrate and combinating medium ore. In the end，comprehensive iron concentrate with TFe grade of 66.73%，rocovery rate of 88.46% and SiO2 content of 5.67% was obtained，indicating significantly effective for iron improvement and silicon reduction and achieving prospective experimental target.
    Industrial Experiment Study on Flotation of a Copper-Cobalt Oxide Ore in Democratic Republic of the Congo
    WANG Jinliang , ZHUANG Guofeng, BA Hongfei
    2022, 38(10):  172. 
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    A Copper-cobalt oxide ore from Democratic Republic of the Congo contains a small amount of sulfide ore，and the oxidation rates of copper and cobalt are above 83% and 89%，respectively. In order to determine the suitable development and utilization technology of the ores，flotation and leaching test was carried out. The results showed that the flotation concentrate with copper grade of 12.16%，cobalt grade of 1.37%，copper recovery rate of 80.48% and cobalt recovery rate of 61.07% was obtained in indus⁃ trial test with raw ores containing copper 1.31% and cobalt 0.201%. The leaching rates of copper and cobalt from flotation concentrate reached 85.45% and 86.38%，respectively. Compared with the direct leaching process for the ore，the acid consumption of the beneficiation and smelting combined process is significant⁃ ly reduced. Therefore，the floatation and leaching process is a reasonable process for the development and utilization of the ore.
    Experimental Study on Comprehensive Recovery of Copper and Cobalt from a Copper and Cobalt Tailings Abroad
    YU Futao , WANG Hongjie, LIU Jie, ZHANG Chengxin, LI Yong, MENG Wenfei , ZHOU Kuanda
    2022, 38(10):  176. 
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    In an aged copper and cobalt mine tailings abroad, the grade of Cu and Co are 0.97% and 0.080%, respectively. The copper mainly exists in the form of copper oxide, accounting for 88.66% of the to⁃ tal copper. For the ores, -0.074 mm particles accounted for 77.31% and -0.038 mm particles accounted for 53.01%. And Cu and Co obviously enriched in the fraction of +0.15 mm. However, the distribution rate of Cu and Co was not high in the fraction due to its low yield. In order to determine the appropriate recovery process of copper and cobalt from the tailings, preconcentration of copper and cobalt by flotation was car⁃ ried out, and then the roughing concentrate was leached in sulfuric acid at room temperature. The flotation results showed that the roughing concentrate is with Cu grade of 5.37%, Co grade of 0.325%, Cu recovery rate of 63.99% and Co recovery rate of 48.88%. The acid consumption in acid leaching is 7.53 t/t, and Cu and Co leaching rates of the rough concentrate were 80.16% and 69.87%, which indicating the better pre⁃ concentration effect. The acid comsumption in acid leaching after preconcentration decreased compared with direct acid leaching, which had remarkable economic and environmental benefits.
    Experimental Research on Copper Extraction Optimization with Copper-Sulfur Separation Reagents for a Gold Mine in Central Asia
    HE Yuanpeng
    2022, 38(10):  179. 
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    A gold ore in Central Asia contains 0.21% copper and 6.32 g/t gold. Primary copper sul⁃ fide and secondary copper sulfide account for 96.22% of the total copper. The exposed gold and sulfide en⁃ crusted gold accounted for 90.07% of the total gold，and the sulfide encrusted gold was mainly chalcopy⁃ rite. In the field，copper-sulfur mixed flotation using one roughing，one cleaning and one scavenging，and copper-sulfur separation using two roughing and three cleaning when the mixed concentrate was ground to - 38 μm accounting for 90% was carried out，while the grade of gold and copper concentrate was only 4.72%. In order to obtain gold and copper concentrate with copper grade over 20%，the separation reagent of copper and sulfur of mixed concentrate was optimized. The results showed that gold and copper concen⁃ trate with copper grade of 22.39%，gold grade of 602.61 g/t，copper recovery of 85.34%，gold operation re⁃ covery rate of 63.68%，and sulfur gold concentrate with gold grade of 13.28 g/t and gold operation recovery rate of 36.32% were obtained by the process of separation of copper and sulfur with two roughing and three cleaning and middling return in sequence with collectors of Z-200 and lsoamyl xanthate. Compared with the on-site production concentrate，the gold grade of gold and copper concentrate increased from 139.50 g/ t to 602.61 g/t，the copper grade increased from 4.72% to 22.39%，and the Cu recovery rate increased by 9.35 percentage points. In the closed circuit test，the gold leaching rate of sulfur-gold concentrate was 69.49%，the gold grade of leaching residue was 4.08 g/t，and the final comprehensive recovery rate of gold was 88.92%，which reached the ideal experimental effect.
    Study on Process Mineralogy of An Copper Oxide Ore
    LYU Chao, ZHANG Jing, JIAN Sheng
    2022, 38(10):  183. 
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    For a copper ore in Yunnan，a systematic process mineralogy study was carried out in or⁃ der to provide a basis for the formulation of reasonable beneficiation and smelting process. The results showed that，the ores contains copper of 0.45%，copper sulfide of 55.56% and bonded copper oxide of 36.44%. The main copper minerals are chalcopyrite，chalcocite，arsenic-calcium copper，and the main gangue minerals are quartz，calcite，tourmaline and mica. The structures and textures of the ores are com⁃ plex and composed of many structural types. The copper minerals are characterized by fine disseminated grain size，complex symbiosis and low minerals content，which are unfavorable for monomer dissociation of useful minerals and extremely difficult for effective separation. Therefore，it is suggested to recover copper minerals in the ores by means of a combination of beneficiation and metallurgy，that is，to recover part of copper sulfide minerals by flotation，and then to recover copper oxide minerals by acid leaching.
    The Beneficiation Processing Transformation for Copper-cobalt Oxide Ore Replacing Copper-cobalt Sulphide Ore in Democratic Republic of the Congo
    ZHUANG Guofeng, WANG Jinliang, CHEN Bingyu, WEI Hongbo, LIU Bang
    2022, 38(10):  187. 
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    A copper-cobalt sulphide ore Dressing plant in Democratic Republic of the Congo altered to treat copper-cobalt sulphide ore，so the beneficiation process need to be adjusted widely. The specific retrofit content and production indexes situation were introduced so as to extent the successful transforma⁃ tion experience. The retrofit content was introduced as followed: ① The reform of grinding workshop is mainly to increase the size of 15 mm，reduce the filling rate of the steel ball of the semi-self-mill from 10% to 7.5%，adjust the steel ball addition of the ball mill from a single ϕ60 mm ball to ϕ60 mm and ϕ80 mm ball half and half，and reduce the amount of steel ball addition of the ball mill. ② The transformation of flotation workshop is mainly to change the independent process of one roughing，two scavenging，three cleaning and middling return in order in the upper and lower working areas into a two-stage process of six open circuit roughing，namely，three consecutive roughing processes after dosing centralized stirring，and three consecutive roughing processes after tailings dosing centralized stirring. At the same time，dosing was changed from each operation to each flotation machine，and a stirring drum was added to adjust the direc⁃ tion of slurry pipeline according to the flow. ③ The transformation of dehydration workshop is mainly to ad⁃ just the speed of thickener，flocculant and its dosage. The grade of copper and cobalt in oxidized concen⁃ trate after transformation is 10.74% and 1.07%，and the recovery is 83.40% and 66.65%，respectively， reaching the expected production indexes.
    Industrial Application Test of the Cassiterite Collector CS-6 in Chehe Dressing Plant
    ZHANG Nian, HUANG Yan, HUANG Runzhi, LIANG Shihua, LIANG Jiarong
    2022, 38(10):  190. 
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    The dissemination granularity of tin polymetallic ore treated by Chehe Dressing Plant of Dachang Tin polymetallic Mine is getting finer，thus the metal amount of fine fraction in the process in⁃ creases. Therefore，strengthening the flotation recovery of tin minerals with fine particle is of great signifi⁃ cance. Firstly，comparative test on two kinds of new and old collectors were carried out. Based on it，indus⁃ trial application test was proceed. The results showed that the laboratory test with CS-6 as the collector，tin concentrate with grade of 18.43% and recovery rate of 88.58% was obtained. When the concentrate grade is the same，the recovery rate is significantly higher than 80.94% with BY-9 used as collector. The dosage of CS-6 in industrial production test was 171 g/t，which was lower than that of BY-9 (185 g/t). The grade of total zinc concentrate with CS-6 was 45.90%，which was higher than that with BY-9 (45.35%)，and the re⁃ covery rate was increased by 0.17 percentage points. The usage of new collector CS-6 for fine particle cas⁃ siterite flotation has achieved an annual economic benefit of 1.794 9 million yuan per year. Therefore，CS- 6 is significantly better than BY-9 in the flotation of fine particle cassiterite.
    Control and High Efficient Recovery of Powdered Carbon in the Process of Extracting Gold with Carbon Slurry
    HU Shitong
    2022, 38(10):  193. 
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    High gold powdered carbon is inevitably produced in the process of extracting gold with carbon leaching. Aiming at the problems，the measures of reducing carbon loss，optimizing powder carbon collection and adopting multi-stage leaching were put forward by Jiangxi Sanhe Gold Industry Co.，Ltd. based on sysmatically analyzing the cause of production of powdered carbon. The practice showed that the implementation of these measures reduces the carbon loss，improves the recovery effect of powdered car⁃ bon，and realizes the high-efficiency recovery of gold in powdered carbon，indicating remarkable econom⁃ ic and social benefits and providing a reference for gold smelting enterprises which adopting carbon slurry process.
    Study on New Process of Purification and Impurities Removal for a Quartz Sand Ores in Malaysia
    XIE Zhifeng, DING Li , WAN Peng
    2022, 38(10):  196. 
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    A quartz sand ore from Malaysia has SiO2 content of 79.45%，Fe2O3 content of 1.48%， TiO2 content of 1.04%，which belongs to a common quartz sand raw material. In order to obtain super stan⁃ dard quartz sand products with high efficiency，low cost and no pollution，purification research with new process was carried out. The results showed that the super standard quartz sand products with Fe2O3 content of 0.007 8% and SiO2 content of 99.90% can be obtained after treated by crushing，washing，intelligent separation and waste disposal，grinding，one roughing and one cleaning in high-intensity magnetic separa⁃ tion process for the ores. The new process has the characteristics of simple process，conventional equip⁃ ment，low cost and no pollution，which has popularization and application value.
    Research on Influence of Flocculant and Feed Concentration on Sedimentation Characteristics of Full Tailings
    WU Fuhe, XIONG Changran
    2022, 38(10):  199. 
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    In order to understand the influence of flocculant and feed concentration on the perfor⁃ mance of full tailings backfill of a copper mine，research on the natural sedimentation and flocculation sedi⁃ mentation law of tailing slurry with different mass concentrations were carried out after analyzing density， particle size and chemical composition and other performance characteristics. Meanwhile，the performance analysis of field backfill was conducted. The results showed that with the increase of slurry concentration， the sedimentation rate decreases and the bottom flow concentration increases，and the maximum bottom flow concentration can reach 68% in the natural sedimentation. Flocculant can significantly improve the sedimentation rate of the full tailings. When the concentration of tailings slurry is 20%，the sedimentation rate of the full tailings increases by 4.7 times after adding flocculant ZYDY of 20 g/t. While the bottom flow concentration decreases by 6 percentage points. In flocculation sedimentation，the sedimentation rate of full tailings slurry decreases and the concentration of bottom flow increases，and the concentration of bot⁃ tom flow in flocculation sedimentation is 49% to 61% with the increase of feed concentration. The effective coring rate，integrity and effective sample of the natural sedimentation backfill are not as good as those of the flocculation sedimentation backfill，and the effective sample strength of the two kinds of backfill pro⁃ cesses all meet the strength requirements of the backfill.
    Study on Microstructure and Properties of Steel Knot Cemented Carbide Composite Wear Resistant Plate
    SHI Yali, HUANG Zhiquan, TAO Wenjia
    2022, 38(10):  203. 
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    A kind of steel knot cemented carbide/Q235 steel composite wear resistant plate was pre⁃ pared by vacuum sintering process. The interface microstructure of the composite plate was analyzed. The shear strength and impact toughness of the composite plate were tested，and the wear resistance was com⁃ pared with that of the surfacing wear resistant plate. The results showed that there is a mutual dissolution zone with a width of 140~160 μm at the interface between steel knot cemented carbide and Q235 steel， and there is atomic diffusion in the mutual dissolution zone. The interfacial shear strength is 340~382 MPa，and a metallurgical bonding is formed between steel knot cemented carbide and substrate. The Rock⁃ well hardness of the composite wear resistant plate is 55~60 HRC，and its wear resistance is about 18.6% higher than that of the surfacing wear resistant plate. The impact energy of the composite plate is 7~10 J， which can be used in the harsh wear conditions under impact load.
    Optimization and Application of Mine Hoisting System Based on EML-DEMATEL-CA Method
    ZENG Weifeng
    2022, 38(10):  208. 
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    In order to scientifically identify the restrictive factors of mine hoisting transportation sys⁃ tem, targeted system optimization is carried out. Taking a lead-zinc mine as the research background, com⁃ bined with the actual production of the mine, the expert meeting method was used to analyze and construct a multi-level index system of influencing factors of the hoisting system. On this basis, the decision-making experiment and evaluation laboratory method are introduced into the identification of key restrictive factors of the lifting transportation system for the first time. By establishing the direct influence matrix and the com⁃ prehensive influence matrix, the influence degree, the affected degree, the centrality and the reason degree of each index factor are calculated, and the causality diagram is drawn according to the calculation results. The research shows that low efficiency of multi-level lifting, low degree of mechanization, low efficiency of middle transportation and lack of unified design are the key restrictive factors of the mine hoisting system. Finally, the optimization measures of transportation system are put forward, and satisfactory application re⁃ sults are obtained.
    Influence of Installation Azimuth of Magnetoelectric Speed Sensor on Test Data
    ZHANG Mengqiao, XIAO Dingjun, PU Chuanjin, ZHANG Jin
    2022, 38(10):  213. 
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    The deviation of the installation azimuth of the magnetoelectric velocity sensor during the on-site blasting seismic wave test will affect the acquisition of correct test and regression parameter values， and then affect the safety judgment of the project and the determination of the blasting vibration law. Four sets of measuring points were arranged at different positions from the blast source with different horizontal installation angles，and blasting vibration tests were carried out on the field open-air deep hole bench blasting，so as to obtain blasting vibration data at different distances and different sensor installation azi⁃ muths. The analysis results show that the blasting vibration velocity peaks are also different at different sen⁃ sor installation azimuths at the same distance. The radial and tangential vibration velocity peaks have the greatest impact，and the maximum deviation can reach 184.68%. The vertical vibration velocity peak has little effect，and the maximum deviation is only 7.02%. At the same time，the regression value is also af⁃ fected by the installation azimuth of the sensor，and the tangential direction is the most obvious，followed by the radial and vertical directions.
    Open-pit Slope Monitoring System Based on MSR Real Aperture Radar
    WANG Hao, CHANG Jian, WANG Liwen
    2022, 38(10):  218. 
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    In order to study the slope monitoring and early warning effect of the MSR open-pit slope monitoring system，the detection effect was analyzed based on the actual application of the soft rock slope in an open-pit mine，combined with the cause of the landslide. The results show that MSR real aperture ra⁃ dar can realize real-time monitoring of open-pit slopes and is effective in early warning of imminent slid⁃ ing. It can make early warning of landslide information such as location，displacement，speed and time of landslide area in time，and can minimize the adverse effects of landslide disaster on mining area.
    Research on Field Work Layout of Real Aperture Slope Radar System
    DING Hui
    2022, 38(10):  221. 
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    In order to ensure the stable operation and accurate monitoring of the real aperture radar system，the composition and equipment limitations of the real aperture radar system are analyzed. The de⁃ termination principle of the optimal layout range of radar equipment in a variety of key monitoring areas is proposed，and the basic requirements for the layout of communication system and monitoring center plat⁃ form are discussed. The practice in the northern slope monitoring case of Zhahanaoer Open-pit Coal Mine shows that the strict layout of the real aperture slope radar monitoring system according to the principle can obtain accurate and effective monitoring data，and the monitoring operation is stable and reliable.
    Optimization of Underground Filling Drilling and Drainage Facilities in Zhangzhuang Iron Mine
    LIU Zhiyong, WANG Zhang, WANG Yufu, TIAN Qizhi, SUN Chao
    2022, 38(10):  225. 
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    Due to continuous filling in Zhangzhuang Iron Mine，the accumulated water in the goaf is not easy to discharge，and the filling boreholes are damaged repeatedly due to long-term abrasion. There⁃ fore，it is necessary to optimize the underground filling boreholes and drainage facilities. Combined with the particle size characteristics of tailings in Zhangzhuang Mine，a new type of drainage pipeline is select⁃ ed to improve the drainage efficiency and roof-contacted filling speed. The causes of filling borehole failure are analyzed. Combined with the actual work，the filling pipeline is extended，the resistance of slurry along the way is increased，and the liquid level in the vertical pipeline is maintained on the erosion datum sur⁃ face，which effectively prolongs the life of filling borehole.
    Investigation and Analysis on the Present Situation of Dust Control of Typical Dust Sources in the Underground of Baixiangshan Iron Mine
    WANG Ronglin, LI Gang
    2022, 38(10):  228. 
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    Baixiangshan Iron Mine has taken dust suppression measures such as wet operation，mine ventilation，water spraying and dust collection with wet dust catcher in the process of underground mining and production. In order to evaluate the dust suppression effect，it has jointly investigated and analyzed with Sinosteel Maanshan General Institute of Mining Research Co.，Ltd.，pointed out the existing prob⁃ lems，and finally proposed targeted improvement measures.
    Study on Induced Burst Law of 40111 Working Face in Dafosi Coal Mine Based on Inversion Analysis of Microseismic Data
    ZHAO Sen
    2022, 38(10):  231. 
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    Based on the engineering background that the 4上coal seam of Dafosi Coal Mine is used as the protective layer of 4 coal seam for mining，in order to explore the law of induced burst of working face in this special area，the relationship between mining speed and microseismic 'time-space-strength' character⁃ istic parameters is analyzed by means of existing microseismic monitoring equipment. The results show that the mining of the 4上coal seam as the protective layer of the 4 coal seam can effectively reduce the micro⁃ seismic energy of the working face，and the scheme has played a better pressure relief role.Through the cor⁃ relation between microseismic spatial distribution characteristics and mining speed，the reasonable mining speed is determined，which provides data support for the design of rockburst prevention system.
    Numerical Analysis of Dam Break Impact of Tailings Pond Based on DL Breach Model
    NING Wei, LI Yu, WU Mengmeng, YANG Chao
    2022, 38(10):  234. 
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    The risk of dam-breaking accidents in tailings ponds is high，and there is still no effective prediction mechanism for dam-breaking sand flow. Based on the DL Breach model，a calculation method of dam-break sand flow in tailings reservoir is proposed. According to the nature of sand flow discharged from tailings reservoir，combined with the engineering experience and specifications of dam-break of tailings reservoir，the movement model of dam-break sand flow is established，the main influencing parameters in the process of dam-break are calculated，and the evolution law of submerged range and submerged depth of discharged sand flow is analyzed. The results show that the accumulation depth of the sediment discharge flow under the dam break increases first and then decreases. The submerged depth of the sediment dis⁃ charge flow in the drilling channel valley is large，and the deposition is more，and the maximum accumula⁃ tion depth is 2.48 m. As the distance from the initial dam gradually increases，the maximum submerged depth at the downstream 3# bridge does not exceed 1 m，and the overall safety risk is controllable. The nu⁃ merical simulation of tailings dam break using this model can predict the possible disasters caused by tail⁃ ings dam break，which has guiding significance for the safe operation of tailings dam.
    Application of UAV Aerial Survey Technology in Mine Geological Environment Monitoring
    YOU Kunpeng, TU Xudong
    2022, 38(10):  239. 
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    With the gradual strengthening of the state's supervision of the geological environment of mines，monitoring of the geological environment of mines has become an important daily work of mining en⁃ terprises. Taking the geological environment monitoring of Sifang Gold Mine as the background，this paper proposes a monitoring method that combines UAV PPK image-free aerial survey technology and data visual⁃ ization technology，which provides a new idea for mine geological environment monitoring. The results show that the current UAV PPK free image control aerial survey technology can meet the accuracy require⁃ ments of geological environment monitoring under complex terrain conditions. The monitoring results can be expressed in rich data visualization using GIS software to provide decision-making basis for disaster preven⁃ tion and control.
    Detection of Development and Expansion of Water Flow Fracture Zone in Underground Coal Mine
    MA Guofeng
    2022, 38(10):  244. 
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    The development and expansion of water flow fracture zone in coal mine plays an impor⁃ tant role in safe mining. Taking Yuandatan Coal Mine as an example，in order to achieve the goal of protect⁃ ing groundwater system while coal mining，three detection boreholes were carried out，and the develop⁃ ment and expansion of water flow fracture zone in coal mining face were judged by using the consumption of drilling flushing fluid. The results show that the fracture zone length of No.2 coal seam is 104.36~110.37 m. When the mining height is 3.2 m，the fracture-mining ratio is 32.61~34.49 m. The top of the water flow fracture zone is within the Zhiluo Formation，about 151~157 m from the bottom of the Cretaceous strata， and about 189~195 m from the bottom of the Quaternary Salawusu Formation. Mining did not cause distur⁃ bance and damage to the Cretaceous aquifer and the Salawusu Formation aquifer. The prevention and con⁃ trol of formation water in Zhiluo Formation within the development and extension range of fracture zone should be strengthened.
    Analysis and Prediction of Ground Subsidence under Mining of Soft and Broken Ore and Rock
    HUANG Xiaozhong, LI Guoping
    2022, 38(10):  247. 
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    The surrounding rock of an iron mine is extremely soft and broken，and the filling condi⁃ tion is not good after mining. After years of mining，the ground has different degrees of subsidence. Based on the statistics of land subsidence monitoring data in mining area，the variation law of land subsidence in subsidence area is studied. The results show that the mining area has experienced two stages of slow defor⁃ mation and surface subsidence basin，both vertical subsidence and horizontal expansion are accelerating. The maximum cumulative settlement in vertical direction is 1 078 mm，and the maximum settlement veloci⁃ ty is 1.56 mm/d. Horizontal displacement is mainly in the northeast direction，the maximum cumulative dis⁃ placement of 1 168.5 mm，the maximum expansion rate of 1.73 mm/d. Weak surrounding rock，large min⁃ ing disturbance，poor ore body occurrence conditions and poor filling process are the main factors leading to land subsidence. By establishing a mathematical statistical model to predict the cumulative settlement of the last month，the highest accuracy is 99.5%.
    Research Progress on the High-value Utilization of Iron Tailings
    ZHOU Yidi, WANG Lijuan, MIN Xin, MI Ruiyu, WU Xiaowen, LIU Yan'gai, FANG Minghao, HUANG Zhaohui
    2022, 38(10):  251. 
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    In view of the problem that the massive accumulation of iron tailings not only occupies land，but also causes harm to ecological environment，the general idea to realize the utilization of iron tail⁃ ings is to take iron tailings as secondary resources，use iron tailings to prepare high value-added materi⁃ als，so as to give products with larger market radius and utilization value. Based on the description of iron tailings components，the main methods of high-value utilization of iron tailings are reviewed，and the re⁃ search progress of high-value ultilization of iron tailings in valuable components recovery，ceramics prepa⁃ ration，porous materials preparation，insulation wall materials preparation and other functional materials are summarized，as well as the problems existing in the process of high-value utilization. Finally，the chal⁃ lenges of high-value utilization of iron tailings are put forward，and the direction of high value utilization of iron tailings in the future is prospected.
    Effect of Grinding Environment on Flotation Performance of Copper Sulfide Ore
    ZHANG Daoguo, LIU Shuai, LU Yuqing
    2022, 38(10):  255. 
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    In order to understand the influence of the grinding environment on flotation，the analysis was carried out on the particle size of the grinding products，the pulp chemical properties，the dissolved ox⁃ ygen in the pulp，foam characteristics，added reagents (the most common ones such as lime and cyanide， etc.)，grinding equipment and other aspects.Then，pertinent suggestions were put forward.
    Study on the Difficulties of Improving the Quality of Panzhihua and Baima Vanadium Titanium Magnetite Iron Concentrates
    CHEN Bi, LI Weiwei, WANG Yong
    2022, 38(10):  258. 
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    With the deep extension of vanadium titanium magnetite stopes in Panzhihua and Baima mining areas，the beneficiability of the ore becomes worse and it is increasingly difficult to obtain high-qual⁃ ity iron concentrate. In order to clarify influence factors and seek ways to improve the quality of iron concen⁃ trate，the quality improvement test of iron concentrate and the detailed analysis of on-site concentrate were carried out on the basis of analyzing the main factors affecting the grade of iron concentrate and the difficul⁃ ties in improving the quality.The results showed that:①The main factors affecting the grade of iron concen⁃ trate are the category and content of titanomagnetite guest crystal minerals，and the physical properties of ti⁃ tanomagnetite and associated minerals.②Titanomagnetite is a composite iron mineral that can be used in va⁃ nadium titanium magnetite.Although considerable part of the solid solution isolate can be removed by fine grinding，it is unable to remove the isomorphs in improving the quality of titanomagnetite. ③The theoretical TFe grade of iron concentrate in Panzhihua mining area is 56.36%～61.36%，and that in Baima mining area is 59.26%～60.60%.④The upper limit of TFe grade of Panzhihua iron concentrate is 57.30% and that of Baima iron is 59.58% in the improvement test of iron concentrate.⑤The quality of Panzhihua iron concen⁃ trate on site is the worst and the TFe grade of Baima 2# concentrate obtained by regrinding and reselection of Baima 1# concentrate is the highest，which conform the conclusion of theory and practice.
    Study on Process Problems Diagnosis and Optimization Measures in a Concentrator
    LIU Guoyi, LI Chunyan, WANG Shengyong, WANG Luxin, LIU Shengchen, YU Ying
    2022, 38(10):  262. 
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    Aiming at the problems existing in the production of a concentrator，the problems were an⁃ alyzed systematically based on the inspection results of the production process. The results showed the prob⁃ lems including poor grinding and grading effect，large cyclic load，low screening efficiency of fine screen， unreasonable concentration of multiple products and worse dissociation degree of grinding products. In view of these problems，a series of reform suggestions were put forward. The implementation of the reform pro⁃ posal has achieved the effect of quality stabilization，tailings reduction，emission reduction and production increase.
    Study on Activity Enhancement of a Certain Lead-zinc Tailings by Mechanical Activation
    WU Xu, XU Xiuping, LI Shuqin
    2022, 38(10):  266. 
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    In order to reduce the environmental safety risk for stockpile of a lead-zinc tailings in Si⁃ chuan, the mechanical activation effect of ball milling was studied using the tailings as sample. The results showed that the quartz and dolomite phases in lead-zinc tailings changed slightly under mechanical force, and a small amount of amorphous phase were produced. Mechanical activation can increase the specific sur⁃ face area. The specific surface area reached largest value of 1 781.40 cm2/g with being ground for 2 h. The mortar specimen was made of lead zinc tailing powder with being ground for 2 h, standard sand and cement. The 3, 7 and 28 d compressive strength and activity index were the highest, in which 7 d compressive strength was 24.3 MPa and the activity index was 61%. The possibility of large scale utilization for the leadzinc tailings was pointed out in the research.
    Research and Practice of Full Tailings Cemented Filling for Reducing Ratio of Cement to Sand in Longqiao Mining
    LIU Jinsheng
    2022, 38(10):  269. 
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    In order to reduce the cost of full tailings cement filling，research and practice on the in⁃ fluence of the reduction of the ratio of cement to sand on the compressive strength of the backfill were car⁃ ried out by optimizing cementing agent in Longqiao Mining. The results showed that under the condition of ensuring the filling strength，the optimization of the cementing agent could reduce the ratio of cement to sand from 1∶6 to 1∶8 and the amount of cement by 36.2 kg per cubic meter of filling. The cost of filling ma⁃ terials on average per year saved by 10.86 million yuan. The following studies also showed that the ratio of cement to sand can be further reduced to 1∶10，the amount of cement can be reduced by 23.04 kg per cu⁃ bic meter of filling，and the production cost also will be further reduced.
    Process Transformation Practice of Production Backwater in Longqiao Concentrator
    YANG Huibing
    2022, 38(10):  272. 
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    The overflow water from the concentration operation (also known as middling concentra⁃ tion) of magnetic separation tailings before flotation in the concentrator of Longqiao Mining Company Con⁃ centrator runs muddy seriously. In order to solve this problem，on the basis of industrial test demonstra⁃ tion，it is proposed to lead the turbid overflow water to the idle ϕ53 m thickener and flocculant was added to make the overflow water of the ϕ53 m thickener clarified. Meanwhile，the underflow is filtered by pres⁃ sure，realizing the goal of zero discharge of the enterprise's production tailings，creating conditions for the closure of the tailings reservoir in the later stage and ensuring the sustainable development of the enter⁃ prise. The quality of backwater has been greatly improved and the consumption has been significantly in⁃ creased，which has greatly reduced the operation time of the three-stage pump and reduced the annual wa⁃ ter cost by 3 million yuan. The volume utilization rate of the high-level pool has been greatly improved， and the human and financial consumption of desilting has been reduced to zero. The sanitation of the work⁃ ing environment of the concentrator has also been significantly improved.