In order to accurately obtain the minerals under the microscope and provide technical sup⁃ port for the fine segmentation of minerals，a multi-optimized UNet model is proposed to segment the mineral flakes to improve the accuracy of the image segmentation task in the accurate identification direction of min⁃ erals.The improved model encoder integrates the resnet50 structure，and uses the dynamic weighted channel spatial attention and multi-scale edge detection module to maximize the solution to the boundary blur prob⁃ lem of the mineral alteration transition zone.At the same time，the decoder also adds an attention mechanism to make it more accurate to interpret the features obtained by the encoder during decoding，and uses the transfer learning method to improve efficiency.By selecting common rock-forming minerals for model train⁃ ing，the experimental results show that the model can effectively segment minerals from the background ma⁃ trix. The loss rate of mineral segmentation verification value is 18%，the average intersection ratio is 82%， and the accuracy rate is 92%. It can achieve more accurate mineral segmentation and provide technical sup⁃ port for accurate mineral segmentation and recognition.

In order to improve the automation level of the preparation system of mineral processing re⁃ agents in Dongbo concentrator，the general automatic dispensing system based on Siemens S7-1200 series PLC is studied in view of the high safety risk，low efficiency，large error and easy quality problems in the manual dispensing mode. The system works together through actuators (electric / pneumatic valves，agita⁃ tors)，sensors (electromagnetic flowmeters，radar level gauges) and control modules (AI/AO，DI/DO，serial server) to realize the functions of quantitative configuration of reagent，automatic dispensing，alarm of re⁃ agent shortage and alarm of ultra-high liquid level.The application results show that the system has been running stably for 2 years in Dongbo concentrator，and the number of single-shift dispensing workers has been reduced from 2 to 1. The abnormal process time caused by inaccurate dispensing is reduced by about 60 h each year，and the annual economic loss is about 10.125 million yuan. It effectively solves a series of problems caused by manual dispensing，and the system has good adaptability and versatility in different ap⁃ plication scenarios，which has certain application value.

In order to realize the effective quantitative analysis of the color characteristics of hematite reverse flotation foam and establish the correlation model with flotation grade，the analysis of foam color characteristics based on multi-color space collaborative analysis and machine learning is carried out. By an⁃ alyzing the color characteristics of hematite reverse flotation froth，65 kinds of initial color features includ⁃ ing color moment，standard deviation and relative red value are extracted，and the key color features signifi⁃ cantly related to flotation grade are selected by correlation coefficient analysis method，including the mean value of G channel in RGB color space，the mean value of Y channel and the skewness of V channel in YUV color space，and the relative red value in gray space. On this basis，the random forest algorithm is used to construct the flotation grade prediction model and the verification test is carried out. The results of mean square error of 0.47，determination coefficient of 0.73 and average absolute error of 0.51 are obtained.The key color features extracted can effectively characterize the color of hematite reverse flotation froth，and there is a strong correlation between the color and flotation grade.It can be used as an effective tool for visual identification of hematite reverse flotation conditions，which is of great significance for the development of hematite flotation condition monitoring system based on foam color change and the improvement of flotation automation and fine control level.

In order to solve the problems of low informationization of belt conveyor operation，long dis⁃ tance along the route，high intensity of personnel work，high cost of operation and maintenance，and high frequency of equipment inspection caused by harsh environment in a large open-pit mine at high altitude in China，based on the research and development status of inspection robots at home and abroad，an intelligent inspection robot for belt conveyor system with multi-sensor fusion is proposed.Combined with auxiliary vi⁃ sion and lidar to obtain multi-source information such as image information，sound signal and environmen⁃ tal parameters of belt conveyor，fault diagnosis of key parts of belt conveyor is carried out.The application re⁃ sults show that the belt intelligent inspection system can realize the all-round monitoring and analysis of the running state of the system，and can effectively improve the accuracy and execution efficiency of the inspec⁃ tion.

In order to scientifically and reasonably compare and select the beneficiation process flow， aiming at the problems of many influencing factors of beneficiation process flow schemes，many expected targets of comparison and selection，strong comprehensiveness and difficult decision-making in the com⁃ parison and selection，taking ultra-low-grade magnetite as an example，a multi-objective decision-mak⁃ ing method is used to compare and select the beneficiation process flow.The multi-objective decision-mak⁃ ing comprehensive utility value method is used to weight and quantify the quantifiable quantitative factors such as equipment investment，civil engineering investment，energy consumption and water consumption in each stage of the process into quantitative factor utility value points. Various qualitative factors such as equipment operation efficiency，concentrate product grade，recovery rate，equipment failure rate，mainte⁃ nance cost and environmental protection requirements are given different weights according to their influ⁃ ence degree to quantify and weight them into qualitative factor utility value points.The quantitative factor utility value and the qualitative factor utility value are given different weights and then weighted to calcu⁃ late the comprehensive utility value score. The highest comprehensive utility value score is the optimal solu⁃ tion，and finally the best optimization result is obtained.By constructing a set of comprehensive evaluation index system for the selection and decision-making of beneficiation process flow scheme，the weight of each participating evaluation index is given，and the mathematical model is constructed by combining quantitative factors with qualitative factors. The incomparable factors are converted into comparable utility values for comparison，and the best scheme is selected.The results show that the multi-objective decision�making comprehensive utility value method can transform the complex process comparison and selection problem into a numerical calculation process，which is convenient for decision makers to compare and se⁃ lect，overcomes the limitations of traditional methods，and the comparison and selection results are more convincing，scientific and reasonable.

In order to realize the high value and resource comprehensive utilization of a limestone mine in Shaanxi Province，in view of the high content of SiO2，which limits the application of high added val⁃ ue，based on the study of the basic properties of the chemical composition，mineral composition and dissem⁃ ination characteristics of the limestone mine，the screening classification and photoelectric beneficiation synergistic treatment process are carried out.The test results show that the high-quality limestone products with yield of 9.07%，CaO content of 54.17%，SiO2 content of 1.62% and yield of 45.49%，CaO content of 53.50%，SiO2 content of 2.64% are obtained by grading-photoelectric separation process，as well as lime⁃ stone products used in metallurgy，desulfurization，feed，building materials and other ways. The high-value and diversified comprehensive utilization of the limestone mine is realized，which provides a low-cost and easy-to-implement technical scheme for the green and efficient development of high-silicon limestone.

In order to solve the problems of process parameter sensitive domain drift，concentrate re⁃ covery rate decrease and cost increase caused by the nonlinear dynamic characteristics of multiphase fluid�solid coupling in the beneficiation of elutriation machine，an optimization method of beneficiation process of elutriation machine based on immune genetic algorithm is proposed.The key parameters such as the opening of the electric valve，the water flow rate and the quality of the mixed ore powder are analyzed by the factor analysis method，and the synergistic model is constructed to quantify the dynamic weight of the parameters and realize the model-driven optimization.Then，based on the immune genetic algorithm，the optimization model is constructed，and the optimal combination is selected by calculating the affinity value of characteris⁃ tic parameters，so as to improve the concentrate grade. Finally，the fuzzy logic is introduced to correct the optimization error，so as to realize the optimization of the ore dressing process of the elutriation machine.The test results show that the concentrate recovery rate after optimization by this method exceeds 99.50%，the annual cost is saved by 0.750 5～1.296 8 million yuan，and the beneficiation stability is higher than 98.50%，which significantly improves the concentrate grade and process stability，and provides new ideas and methods for the sustainable development of the beneficiation industry.

In order to alleviate the contradiction between supply and demand of calcium-containing non-metallic minerals such as fluorite and apatite due to long-term dependence on a single type of ore， aiming at the separation problems caused by the similarity of surface active sites and the interaction of pulp ions between fluorite，apatite and calcite，dolomite and other calcium-containing gangues in co-associat⁃ ed ores，the efficient separation technology is studied.By analyzing the crystal structure and surface proper⁃ ties of fluorite，apatite and calcium-containing gangue，the research progress in the fields of differential separation process design of complex components，compound modification of traditional reagents and devel⁃ opment of new flotation reagents is systematically summarized. The applicable conditions and mechanism of various separation technologies are obtained，and it is revealed that the current technical bottlenecks main⁃ ly focuses on the regulation of mineral surface properties and selective adsorption of reagents.In the future， it shouldbe focused on the development of mineral surface directional modification technology，intelligent separation technology and environmentally friendly reagents，so as to provide theoretical basis and techni⁃ cal direction for the efficient development and utilization of co-associated calcium-containing non-metallic mineral resources.

Ionic rare earth ore is a mineral resource with unique characteristics in China and rare worldwide. Currently，in-situ leaching method is mainly used for the mining of ionic rare earth ore. Howev⁃ er，during the mining process，the rare earth ore body is eroded by the leaching solution for a long time， which causes continuous deterioration of its mechanical properties and thus leads to landslide disasters. Fo⁃ cusing on the mechanical characteristics of the in-situ leaching method，this study analyzes and summarizes the stress-strain behavior，deformation characteristics，evolution characteristics of mechanical strength of the ionic rare earth ore body，as well as the ore body constitutive model. Research results show that existing research results lack attention to the micromechanical properties of the ore body，the seepage erosion effect of the leaching solution，and its coupling effect with chemical erosion. The stress-strain constitutive model of the ore body still cannot fully describe the mechanical behavior of the ore body during the in-situ leaching process. To further explore the macro-micro mechanical responses of the rare earth ore body，efforts should be made to strengthen research on the numerical simulation method of the ore body，the constitutive model， and the coupling effect between seepage erosion and chemical erosion.

To reduce the surrounding rock fragmentation during the upward excavation of the 8304 high-level gas drainage roadway in Xiaotashan Coal Mine when it passes to the overlying No.4 coal seam goaf，the mechanism of surrounding rock fragmentation is analyzed from aspects of construction technolo⁃ gy，coal seam occurrence，roadway layout，and goaf. For the overlying softened rock mass in the cross-lay⁃ er section，cross-layer grouting solidification is adopted. For the broken coal mass in the roof，shallow hole grouting reinforcement is used to improve the strength of the bearing layer of the soft rock roof. Rib�penetrating cable anchors are utilized for advanced control of the easily collapsing coal pillars on both sides，and combined active and passive support such as "interlocked trapezoidal sheds + dense U29 steel sheds" is employed to strengthen the roof support. Field application effects show that after the implementa⁃ tion of the combined support，phenomena like roof cracking and subsidence caused by the softening of overlying rock layers due to water seepage are effectively controlled. The measured coal seam subsidence after support is reduced to 0.17 m，the support failure rate is lowered to 4%，the roadway repair cost is de⁃ creased to 127 000 yuan，and the excavation speed is increased to 4.8 m/d，which solves technical problems such as high support difficulty，poor effect，and severe surrounding rock deformation in roadways excavated adjacent to goafs，achievines significant application results.

In the process of metal mines mining to the deep gradualy，the range of surface movement continues to expand，and the shaft set up outside the moving range will extend the construction period of oth⁃ er development projects and increase the amount of work. The movement and deformation of ore rock is the main factor affecting the safety and stability of shaft. The measure wells are arranged in the range of surface movement，and the wellbore may be deformed and damaged by underground mining. In order to ensure the safety of the wellbore in the underground mining process of metal mines，the ore body mining scheme is de⁃ signed to extend the available period of the measure well，and the three-dimensional numerical simulation software is used to simulate the mining situation. Through the analysis of wellbore deformation，shaft sur⁃ rounding rock stress and plastic zone and other indicators，the maximum safe available time node of the mea⁃ sure well is studied. The analysis results show that according to the mining and filling scheme，in the fourth stage of the mining stage，the inclination value，curvature and vertical deformation value of the shaft wall meet the requirements. The maximum principal stress of the shaft did not change significantly after the exca⁃ vation and filling of the stope，and the maximum change value is 3.42 MPa. At the same time，the stress， displacement and plastic zone of the first five mining stages are analyzed. The results show that the shaft is in a relatively stable state in the first phase of the mining and filling plan，which can ensure the needs of mine production.

The blastability of ore rock has an important influence on the cost and efficiency of mine blasting mining. In order to comprehensively and accurately analyze the blastability of ore and rock，the in⁃ dex system of blastability of ore and rock including four indexes such as rock density and rock brittleness co⁃ efficient and the classification standard of I~VII grade of blastability of ore and rock are constructed. The in⁃ terval analytic hierarchy process is used to calculate the weight of the blastability index of the ore rock，and the interval approximation analysis model is improved to characterize and analyze the blastability index of the rock mass closer to the actual interval number，so as to determine the comprehensive grade of the blastability of the ore rock and the grade of each index. The model is used to comprehensively analyze the rock blastabili⁃ ty of multiple stopes in a phosphate mine. The rock blastability of three stopes in eight stopes is Grade IV， and the rock blastability of other stopes is Grade V. The analysis results of the rock blastability index of each stope are obtained. Based on this，the blasting scheme and parameters of the mine stope are improved，the ore removal efficiency and the qualified rate of ore block are improved，and the unit consumption of blasting explosives and blasting cost are reduced. The example proves that the improved interval approximation analy⁃ sis can make a comprehensive and scientific analysis of the blastability of ore and rock，and the results mod⁃ el can guide the design of mine blasting scheme，which can bring the effect of reducing cost and increasing efficiency for mining enterprises，and improve economic benefits and comprehensive benefits.

To address the problem of nonlinear large deformation and severe mine pressure caused by the overall external displacement of the anchor solid of the surrounding rock of the roadway side due to the influence of multiple mining dynamic stresses in the section roadway，taking the 15# coal of Xinshun Coal Industry as the research background，the methods of on-site investigation，numerical simulation，mechan⁃ ical modeling and on-site testing were adopted to analyze the overburden fracture structure model of the fully mechanized face of thick coal seams and determine the position of the fracture line. The minimum coal pillar reserved width was solved，and by using FLAC3D the optimal reserved width of the coal pillar in the section was simulated. Research shows that the final width of the coal pillar in the 15102 track chute can be optimized to 22 m，providing theoretical and technical reference for the subsequent section coal width.

Aiming at the problem of great potential safety hazards of a large number of goafs without pillars in a lead-zinc mine，the stability demonstration and treatment scheme of goafs are studied. The field investigation and laboratory test are carried out on the goaf，and the mechanical parameters of rock mass are determined by using the relevant theoretical methods，and the comprehensive evaluation of rock mass quality is carried out by using RQD，RMR and Q system classification method. The safety factor of only one pillar is calculated by using the average stress of irregular pillar bearing，and its stability is ana⁃ lyzed. Combined with the maximum unsupported span of the goaf roof and the Mathews stability diagram method，the stability of the roof is analyzed according to the most unfavorable principle. The results show that the rock mass quality under the RMR classification method is the worst，which is Grade III general rock mass. The safety factor of the pillar is 0.51，which is far less than the safety value of 1.5. The number of unstable and above empty areas is 9，accounting for 60 % of the total. Finally，the corresponding treat⁃ ment measures are put forward for these empty areas，which provides reference for solving similar hidden dangers in empty areas.

The secondary disasters of underground mines caused by the earthquake have the character⁃ istics of strong correlation and complex evolution mechanism，which are easy to safety accidents. The lack of understanding of the internal relationship of the disaster chain is the core bottleneck restricting the work of disaster prevention and mitigation. Taking the earthquake-induced disaster system of an underground mine as the research object，the disaster chain analysis method is used to systematically sort out the damage path and evolution process of the earthquake to the underground mine. Firstly，the composition of disaster events is identified，and a disaster chain evolution model with 44 nodes and 113 edges is constructed. Then，based on the complex network theory，the disaster network model is established. By calculating the key parameters such as node degree value，node subnet number and edge vulnerability，the core control nodes and vulnera⁃ ble connection edges in the disaster network are accurately identified，and the potential risk levels of differ⁃ ent disaster events are defined. Based on the above analysis，the suggestions for disaster chain breaking and disaster reduction in the mine are put forward. The research results can provide theoretical basis and practi⁃ cal reference for the construction of earthquake disaster risk prevention and control system in the same type of underground mines.

To ensure the safety of miners in the Shenggou mining area and improve their working effi⁃ ciency，aiming at the problems such as incomplete system and insufficient ventilation existing in the under⁃ ground ventilation system of the mining area，three optional schemes，namely，isolation ventilation in the - 240~280 m middle section，zone-based ventilation and unit ventilation，were proposed through on-site in⁃ vestigation，data analysis and theoretical calculation methods. Combined with the actual situation of the min⁃ ing area，The parameters such as the air volume released，air resistance and fan selection of the three schemes were compared，and the following conclusions were drawn. Scheme One is that The air volume of the east wing is 42 m³/s，and the static pressure efficiency of the fan is 72.5%，the air volume of the west wing is 47 m³/s，and the static pressure efficiency of the fan is 77.5%. Scheme Two is that the air volume of the east wing is 45 m³/s，and the static pressure efficiency of the fan is 76.0%. The air volume of the west wing is 47 m³/s，and the static pressure efficiency of the fan is 77.5%. Scheme Three is that the air volume of the main fans in the east and west wings is 41.71 m³/s，and each parameter is calculated separately during the easy and difficult periods. Through the comparison of these three ventilation schemes in terms of technol⁃ ogy and economy，the total engineering and equipment cost of Scheme Two is 645 400 yuan more than that of Scheme One and 1 353 700 yuan more than that of Scheme Three. However，its intake and return air lines are more reliable，the ventilation resistance is the smallest，and the operating cost is the lowest. Considering all aspects comprehensively，Scheme Two is selected as the optimization scheme for the underground venti⁃ lation system in this mining area. After the implementation of the plan，all ventilation technical indicators have reached the qualified standards stipulated by relevant regulations. The air quality has been greatly im⁃ proved，the ventilation efficiency has been significantly enhanced，and the energy consumption has been greatly reduced，ensuring the safe production of the mine.

To address the issue of production capacity succession in the transition from open-pit to un⁃ derground mining at Miaogou Iron Mine，a research on the transformation of the main shaft hoisting system is conducted. The diameter and width of the drum are determined to be 1 600 mm and 2.64 m，respectively. The transformation and installation methods for the head sheave platform，safety protection platform，and horizontal platform are studied，as well as the transformation methods for the unloading station pit，the seal⁃ ing of the electric locomotive repair chamber，and the drainage equipment at the -155 m level. On this ba⁃ sis，the transformation method for the main shaft tower is determined，and a tower stabilization method com⁃ bining composite reinforced piles with concrete curtain grouting is proposed，thus forming a comprehensive and integrated transformation technology for the main shaft hoisting system. The results of numerical simula⁃ tion show that significant settlement occurs on the southwest side of the main shaft tower，while the settle⁃ ment on the northeast side is relatively small，which verifies the reliability of the focused reinforcement us⁃ ing 5 composite reinforced piles on the southwest side of the tower. The maximum vertical displacement around the tower meets the requirement of less than 200 mm specified in the Code for Design of Building Foundation (GB 50007—2011)，which can effectively ensure the overall stability of the main shaft tower. The research results can provide guidance and reference for the transformation of main shaft hoisting systems in mines under similar conditions.

Aiming at the problem of surface subsidence mutation caused by shallow coal seam mining in thin bedrock，taking 3504 working face of a mine in Datong City，Shanxi Province as the engineering background，the dynamic response mechanism of overburden fracture evolution and surface movement and deformation under the synergistic effect of mining height and advancing distance is systematically revealed by combining theoretical analysis，numerical simulation and engineering verification. Through the UDEC discrete element numerical simulation software，the geological model of thin bedrock and thick loose layer is constructed，and the law of overburden fracture and surface movement and deformation under the syner⁃ gistic effect of different mining height and advancing distance is studied. The results show that the synergis⁃ tic effect of mining height and advancing distance significantly affects the stage characteristics of surface subsidence. When the mining height increases from 2.8 m to 6.8 m，the maximum roof subsidence increas⁃ es non-linearly by 106.5%~202.3%，and the corresponding surface subsidence increases sharply from 50 mm to more than 200 mm. When the mining height exceeds 4.8 m，the supporting effect of roof expansion is weakened，and the fracture penetration and caving height increase significantly，resulting in the acceler⁃ ation of surface subsidence rate. The study further shows that when the advancing distance reaches 80 m， the overburden failure enters the unstable stage，and the surface subsidence increases sharply. When the mining height is more than 4.8 m，the surface subsidence exceeds the safety threshold after advancing to 100 m. It is suggested that measures such as optimizing mining height (below 4.8 m)，adopting segmented support technology or dynamic adjustment of advancing distance should be taken to inhibit fracture penetra⁃ tion and overburden instability and reduce the risk of surface sudden subsidence.

Taking Zhangzhuang Iron Mine as the engineering background，the stability and safety of high and large stope in the mining process are systematically analyzed by numerical simulation method. Based on the COMSOL simulation platform，a refined three-dimensional geomechanical model including surrounding rock，ore body and filling body is constructed to truly reflect the geological conditions and struc⁃ tural parameters of the stope. By simulating the mining sequence of "one mining one interval" ( taking 0204 and 0507 panels as examples )，the mechanical response of surrounding rock and filling body in the process of one-step mining and two-step mining is systematically analyzed from two dimensions of stress distribu⁃ tion and displacement evolution. The results show that the stress concentration occurs significantly in the cor⁃ ner of the goaf and the pillar area. After the mining of 201~205 rooms，the maximum stress value increases from 16.3 MPa to 24.3 MPa with the advance of mining. In the process of two-step mining，because both sides are filling bodies，their strength is much lower than that of the original rock，resulting in significant roof subsidence and floor heave in the goaf. After the mining of 501~505 rooms，the maximum displacement in Z direction is up to 18 cm，and the displacement in Y direction is up to 12 cm，the filling body continues to move towards the goaf，and there is a risk of spalling. The research results provide a theoretical basis and engineering reference for the stability analysis and safety control of stopes with large structural parameters under similar conditions.

To address the rock drilling issues in the stage of super-large underground filling mines, and explore efficient rock drilling methods that can reduce costs and increase efficiency, and facilitate rapid commissioning and reaching full production capacity，by applying the comparative analysis method, a com⁃ prehensive analysis is conducted on the two mainstream rock drilling methods of large-diameter vertical deep holes and downward fan-shaped deep holes. From the aspect of the layout form of the stope, this paper deeply analyzes the differences in stope structure under different rock drilling methods and their influence on the overall mining layout. Detailed statistics and comparisons of the mining and cutting engineering vol⁃ ume are directly related to the initial construction cost of the mine. For the design of perforation blasting, in�depth research is conducted on the effects of different parameter settings on rock drilling efficiency and blast⁃ ing quality. The research finds that the downward fan-shaped deep hole drilling method has a simple field layout, high space utilization rate, deep hole blasting can achieve large-scale ore collapse, small mining en⁃ gineering volume, and the perforation blasting design is easy to standardize operation. Although the large-di⁃ ameter vertical deep hole rock drilling method is flexible under specific geological conditions, the overall mining cost is relatively high. After comprehensive analysis, the downward fan-shaped deep hole drilling method, with its significant advantages such as low mining cost and large production capacity of ore blocks, can effectively support the cost reduction, efficiency improvement and rapid production of super-large under⁃ ground mines. It is a more efficient choice for drilling in the stage of super-large underground filling mines, laying a scientific foundation for the optimization of mining plans.

The mineral composition of a gold-bearing copper ore in China is complex，and the main recovered minerals are gold-silver minerals and copper minerals. In order to efficiently recover and utilize the ore，the beneficiation test is carried out on the basis of the study of ore properties.The results show that under the conditions of grinding fineness of -0.074 mm 90%，Na2CO3 dosage of 1 200 g/t，water glass dos⁃ age of 1 200 g/t，Na2S dosage of 600 g/t，total dosage of butyl xanthate of 160 g/t and roughing flotation time of 6 min，the open-circuit flotation process test of one roughing，two cleanings and two scavengings is car⁃ ried out，the concentrate with gold grade of 67.48 g/t，gold recovery of 47.88%，copper grade of 17.22% and copper recovery of 51.60% can be obtained.Due to the high gold content of flotation tailings，up to 0.69 g/t， other beneficiation methods can be considered to extract gold from flotation tailings in the future，so as to re⁃ alize the efficient recovery and utilization of valuable minerals in ore to a large extent.

In order to recover 0～5 mm iron ore with industrial value from iron tailings in Anhui and improve the utilization rate of iron resources，a series of magnetic separation dry separation tests are carried out，and a suitable magnetic separator is determined and successfully applies in the industrial field.The re⁃ sults of industrial production show that the average grade of magnetic iron in 0～5 mm fine-grained stone powder ore feeding is 8.14%. After industrial magnetic separation，the average grade of magnetic iron in stone powder concentrate is 17.45%，the average grade of magnetic iron in stone powder tailings is 1.27%， and the recovery rate of magnetic iron in 0～5 mm fine-grained stone powder is 90.62%. The recovery and utilization of iron resources are realized，the economic benefits are remarkable，the pollution of tailings to the mining area is reduced，and the construction of waste-free green mines and the sustainable development of mines are promoted.

In order to solve the problem of poor separation effect caused by low tin grade，large mud content and fine disseminated particle size of raw ore in a tin mine in Yunnan，the beneficiation process test is carried out according to the properties and material composition of tin ore.Through the comparison of the grinding and gravity separation processes under the two conditions of desliming and non-desliming of the raw ore，it is determined that the process of grinding and gravity separation after desliming is adopted for the raw ore，and some tin minerals are effectively recovered.In order to further improve the recovery rate of tin， flotation tests under different conditions are carried out on the gravity separation medium ore，and the flota⁃ tion conditions are optimized. Finally，the combined process flow of raw ore desliming-rough grinding-mag⁃ netic separation iron removal-shaking table gravity separation-medium ore regrinding-flotation is deter⁃ mined.Under the optimum process parameters and flotation reagent system，the sorting index of comprehen⁃ sive concentrate tin grade of 48.67% and the total tin recovery of 71.58% are obtained through the whole pro⁃ cess closed-circuit test.

Molybdenum is mainly molybdenite and tungsten is mainly scheelite in a domestic molyb⁃ denum-tungsten ore. In order to determine a reasonable beneficiation process，the beneficiation test is car⁃ ried out on the basis of the study of ore properties.The test results show that the main process is molybde⁃ num-sulfur full flotation first，then tungsten flotation at room temperature，and molybdenum-sulfur full flo⁃ tation rough concentrate and tungsten rough concentrate are obtained respectively.Molybdenum concentrate is obtained by cleaning selection of molybdenum-sulfur full flotation concentrate，and scheelite concen⁃ trate is obtained by heating and cleaning selection of tungsten flotation concentrate at room temperature af⁃ ter concentration.The loss of coarse molybdenum is controlled by grinding through 50 mesh sieve.Under the conditions of raw ore WO3 grade of 0.22%，molybdenum grade of 0.43%，grinding fineness of -0.074 mm 55.21%，molybdenum concentrate with molybdenum grade of 46.85% and molybdenum recovery of 93.70% can be obtained through the whole process closed-circuit test. Tungsten concentrate with WO3 grade of 65.21% and WO3 recovery of 68.17% is obtained. The effective recovery of molybdenum and tung⁃ sten is realized，which can provide technical basis for production.

In order to make efficient use of a lithium ore resource in West Africa，in view of the fact that the ore contains both lepidolite and spodumene，multiple sets of conditional tests are carried out to de⁃ termine the optimal test parameters.The results show that the lepidolite concentrate with Li2O grade of 2.84% and recovery rate of 30.58% and the spodumene concentrate with Li2O grade of 5.20% and recovery rate of 59.21% are obtained through the whole process closed-circuit test of desliming，mica flotation and spodu⁃ mene flotation. The total Li2O recovery rate is 89.79%，which realizes the efficient recovery of lithium in this resource.

In order to efficiently develop and utilize low-grade siderite resources，the characteristics， beneficiation difficulties and application status of roasting-magnetic separation process of low-grade sider⁃ ite are analyzed. Taking a low-grade siderite ore as the research object，the roasting-magnetic separation process is studied，and the process is compared with single magnetic separation，gravity separation and flo⁃ tation process.The effects of various factors on the grade of iron concentrate and iron recovery rate are ana⁃ lyzed by experiments on siderite at different roasting temperatures，time，atmosphere and magnetic separa⁃ tion conditions.The test results show that under the optimum process conditions determined by the test，the ideal iron concentrate with iron grade of 53.09% and iron recovery of 88.65% is obtained by roasting-mag⁃ netic separation process. Compared with other single processes，the roasting-magnetic separation process has obvious advantages in iron concentrate grade and recovery rate，which can realize the effective enrich⁃ ment of low-grade siderite and provide technical support and theoretical basis for the effective development and utilization of low-grade siderite.

In order to improve the grinding efficiency of ball mill，taking magnesite from Liaoning Haimei concentrator as the research object，three key parameters of medium filling rate，ore volume and water volume are selected as the research object，and the newly generated -0.074 mm particle size product quality is used as the evaluation index. The independent influence of each parameter on the grinding effect is investigated by single factor test.The test results show that the suitable grinding medium filling rate is 40%，the water volume is 200 mL，and the ore volume is 700 g. At this time，the grinding concentration is 77.77%，the material-ball ratio is 0.067，and the utilization coefficient of the ball mill is 0.653 t/（m³·h）. Under the experimental conditions，the mass of the newly generated - 0.074 mm particle size product is 271.89 g. Compared with the laboratory grinding test of the actual production parameters，the medium fill⁃ ing rate is increased by 13.33%，the grinding concentration is increased by 3.70%，the ratio of material to ball is increased by 4.70%，the mass of the newly generated -0.074 mm product is increased by 12.07%， and the utilization coefficient of the ball mill is increased by 4.80%.By optimizing the key process parame⁃ ters，the interaction between different parameters can be effectively reduced and the utilization efficiency of ball mill can be improved.

In order to effectively improve the production efficiency of grinding operation in a mineral processing and smelting plant，ensure the product fineness to meet the standard and significantly reduce the production cost，the problems of the original two-stage grinding process such as high grinding cost，only 1.2 t/ h machine-hour processing capacity and substandard product fineness（- 0.045 mm accounted for only 83%）are studied.Through comprehensive process technology analysis，the feasibility of the new process of one-stage grinding+classifier pre-classification is demonstrated in depth. The optimal operating parameters are determined by a large number of experiments and successfully applied to the production site.The produc⁃ tion practice shows that the processing capacity of grinding machine-hour is increased to 1.5 t/h，and the production efficiency is improved. The fineness compliance rate of the product is increased to more than 90%，the grinding index is guaranteed，the comprehensive benefit is increased by 1.102 5 million yuan，the cost per ton of ore is reduced by 12.47 yuan，and the annual cost is saved by 0.249 4 million yuan.The one�stage grinding + classifier pre-classification process has high applicability and superiority，solves the prob⁃ lems existing in the original process，and has significant economic benefits. It has reference value for other similar concentrators.

In order to solve the problems existing in the production of a concentrator of Shougang， such as serious blockage of circular vibrating screen mesh，low working efficiency of crushing and grinding equipment，and poor effect of dry magnetic separation of magnetic drum，the process flow is reformed. Through transformation，the existing screening equipment is dismantled，and a double-layer banana screen is added for wet screening. The -3 mm material by the wet screening under the sieve is treated separately for wet pre-magnetic separation，and the material in the - 12 + 3 mm intermediate grade by the screening is transported to the original process by belt conveyor.After the transformation，the loss of magnetic iron in the production line is reduced by 10 700 tons per year，the iron powder with total iron grade of 66.50% is in⁃ creased by 16 000 tons per year，the total profit of the enterprise is increased by 10.538 3 million yuan/a， and the net profit is increased by 7.903 7 million yuan/a. The economic benefit of the technical transforma⁃ tion is remarkable.

In order to efficiently recover lithium oxide from a spodumene ore in Myanmar，based on the study of process mineralogy，single gravity separation，single magnetic separation，single positive flota⁃ tion and single reverse flotation process are studied.The test results show that the reverse flotation process is used to carry out the whole process closed-circuit test of one roughing，three cleaning and two scavenging of the raw ore and the gradual return of the middle ore under the determined optimal operating parameters. The spodumene concentrate with Li2O grade of 3.56% and Li2O recovery rate of 73.11% is obtained，and the Li2O grade in the tailings is only 0.12%，and the loss is small.At the same time，satisfactory production in⁃ dexes can be obtained by increasing or decreasing the number of cleaning times according to the actual de⁃ mand of concentrate.

 The uneven development of the internal dump and the adjacent stope slope in the open-pit
coal mine area is easy to induce large-scale landslides，which has become a major hidden danger threaten⁃
ing the safe mining of open-pit mines. Focusing on the slope of stope and inner dump in Zhundong Open-pit
Coal Mine，based on the field investigation and analysis of the factors affecting the slope stability，the fail⁃
ure mode and stability of the current slope under natural and saturated conditions are analyzed by means of
Phase2 finite element simulation software. The results show that groundwater and weak layer are the main
factors affecting slope stability. Due to the steepness of the deep slope，the western slope is prone to shear
failure along the coal seam floor，the southern and eastern slopes are prone to local step shear sliding fail⁃
ure，and the inner dump slope is prone to single-step circular sliding failure. At present，the slope of the
stope and the inner dump is in a stable state. In view of the above research，the prevention and control mea⁃
sures of optimizing slope shape，establishing waterproof and drainage system and monitoring and early warn⁃
ing mechanism are put forward. The research results have reference significance for similar open-pit slope
production design and landslide mechanism research.

In order to understand the variation law of the saturation line of the tailings reservoir in Yunfu Pyrite Mine and guide the production and management of the tailings reservoir，the saturation line of the tailings reservoir dam body in the upstream dam construction method is analyzed and studied.Combined with the change of monitoring data of saturation line in different periods in the process of production control and safety management of tailings reservoir，the influence of tailings reservoir accumulation dam height， drainage facilities and water level control on the buried depth of saturation line is analyzed，and the engi⁃ neering measures and effects of abnormal saturation line are summarized.Through the inspection of the con⁃ trol effect of the saturation line of the tailings dam body，it can be seen that a series of corresponding mea⁃ sures have achieved good implementation results，and this kind of method has a certain reference role in the control of the saturation line of similar tailings reservoirs.

In order to enhance the real-time performance and accuracy of the open-pit mine slope monitoring in a certain copper-cobalt mine in Africa，in response to the problems of traditional optical monitoring methods such as large workload，discontinuous and non-real-time data，and significant influ⁃ ence from environmental and human factors，a radar monitoring system was built to conduct long-distance and large-scale scanning of the monitoring area，achieving real-time，continuous，all-weather monitoring data. It effectively makes up for the deficiencies of manual point monitoring，and at the same time forms a monitoring method that combines points and surfaces，enabling mutual verification and checking of moni⁃ toring data，eliminating the limitations of a single monitoring system，and promoting the rapid implementa⁃ tion of INSAR synthetic aperture radar technology in the safe production of overseas mines.

After the closure of metal mines，the underground hydrogeological conditions have changed significantly，and the residual mineralized bodies and surrounding rocks have undergone water and oxygen reactions，which in turn affect the evolution of the groundwater chemical field and form serious heavy metal pollution water environment problems. Taking a closed mine in Tongling as the research object，the back⁃ ground point，mineralized surrounding rock and mine groundwater samples are collected and tested. Based on the analysis and test data，the groundwater hydrochemical types are divided，the characteristics of heavy metal pollution are evaluated，and the main control factors of hydrochemical genesis are clarified. The re⁃ sults show that the sulfur-containing minerals are exposed to air due to mining. The ORP test shows that the oxidation of groundwater is strong，and the hydrolysis of sulfide minerals becomes an important water-rock interaction，which controls the evolution of groundwater hydrochemical type from Ca-Mg-HCO3 type to Ca�Mg-SO4 type，making the groundwater strongly acidic ( pH<2.5 )，metal ions precipitate，TDS mass concen⁃ tration increases，and heavy metal pollution such as Cu，Cd，Zn and Ni is produced.

In order to explore the correlation between oil content and logging curve of oil shale，take Longkou Liangjia Coal Mine as an example，based on the existing logging data，the logging curves of oil shale sections in each borehole are re-contrasted and interpreted to determine their horizons，structure and thickness. Through the correlation study and mathematical statistics analysis of the logging curve and the oil content test results，the least square method is used to find out the correlation between the logging curve and the test results of the oil-bearing strata. The results show that the oil shale layer and coal seam have good reflect characteristics on the logging curve，and the corresponding geological characteristics and horizons can be clearly identified. The thickness distribution of oil shale in each layer is uneven，and the oil content of the selected research layer is high. The relative error between oil content and artificial gamma and apparent resistivity is small，and the correlation is good. It can be applied to the accurate and rapid identification of oil content of oil shale. The research results provide a simple and quick calculation method for the estimation of oil shale oil content.

The SICOMINES copper-cobalt deposit is located in the Congo (Kinshasa) -Zambia cop⁃ per (cobalt) ore belt. In order to analyze the causes of copper-cobalt enrichment in this area，the geological characteristics of the deposit and the ore body characteristics of the two main ore bodies in the mining area are analyzed，and then the enrichment and distribution of Cu and Co elements in the main ore bodies are expounded. According to the characteristics of the ore body，the characteristics of the ore，the occurrence of Cu and Co elements in the ore，the causes of the enrichment and formation are analyzed. The results show that the high enrichment area of Cu element is formed by oxidation leaching enrichment，and the me⁃ dium-high，medium and low enrichment areas are formed by early sedimentary diagenesis and later region⁃ al metamorphic hydrothermal enrichment. The low enrichment area of Co element is formed by early sedi⁃ mentary diagenesis，regional metamorphic hydrothermal fluid or oxidation leaching enrichment in the late diagenetic stage. The middle and high enrichment areas are formed by early sedimentary diagenesis，re⁃ gional metamorphic hydrothermal fluid and tectonic hydrothermal fluid enrichment in the late diagenetic stage. It is concluded that the deposit is a sedimentary metamorphic-tectonic hydrothermal transformation type deposit.

In order to improve the comprehensive utilization rate of fine-grained wrapped gold，aim⁃ ing at the problem of low flotation recovery rate of a high-sulfur and high-arsenic fine-grained wrapped gold concentrator and low cyanide leaching rate of a smelter，a systematic study on sand mill grinding and gold re⁃ covery and utilization is carried out. The test results show that the power consumption can be reduced by properly increasing the grinding concentration. The leaching rate of gold sulfide concentrate can be effective⁃ ly improved after fine grinding. When grinding to -38 μm 94% by sand mill，the gold recovery rate can be increased by 5.00 percentage points，and the comprehensive economic benefit after flotation fine grinding is remarkable.When the gold concentrate is ground to D80 of 10 μm，the gold leaching rate can be increased by 7.84 percentage points，which can provide an important basis for the rational application of sand mill in gold mining and construction.

In order to improve the operation efficiency and equipment stability of the ball mill of Longqiao Mining Industry，in view of the problems of short service life，frequent maintenance and frequent slurry leakage in the use of traditional high manganese steel liners，bimetallic composite liners have been in⁃ troduced into the one-stage grinding system since 2010，and structural optimization and installation process improvement have been continuously carried out.The production practice shows that the bimetallic compos⁃ ite liner has shown significant advantages in wear resistance，impact resistance and service life. The average service life can reach 24 months，which is nearly 5 times that of high manganese steel liner. The average an⁃ nual replacement times are reduced from 2.4 times to 0.5 times，which greatly reduces the unplanned shut⁃ down time，improves the continuity and reliability of equipment operation，and improves the beneficiation efficiency.At the same time，the maintenance cost is significantly reduced，and the annual comprehensive cost is 249 000 yuan，which promotes the construction of green mines and provides an effective path for min⁃ ing enterprises to reduce costs and increase efficiency.

According to the selection of filling cementitious materials and the design of filling material ratio parameters of a gold mine in Anhui Province，the strength comparison test of the new cementitious ma⁃ terial cemented filling body and the cement cemented filling body is carried out. The results show that under the conditions of cement-sand ratio of 1∶8，concentration of 65% and 28 d curing age，the compressive strength of the new cementitious material cemented test block is 3.3 times that of the cement cemented test block. Through the numerical simulation method，the actual strength requirement of the filling body of the bottom structure of the typical one-step stope is calculated to be 3.5 MPa and the thickness is 14 m. On this basis，the recommended filling concentration is not less than 65%，and the ratio of new cementitious materi⁃ al to tailings is 1∶8 for industrial filling test. The field sampling of field filling shows that the average com⁃ pressive strength of the new cementitious material filling body sample is 4.42 MPa，which meets the require⁃ ments of the mine for filling strength and filling quality，and reduces the amount of cementitious material by 41.8%，thus saving the filling cost.

In order to explore the change of vegetation in mining area and its influence by mining ac⁃ tivities，aiming at the problem of vegetation classification and monitoring in iron ore area around Anshan， the image data based on Landsat5 TM/Landsat8 OLI is studied.By using the relevant image data，the vege⁃ tation classification of the four major iron ore areas around Anshan in the past 40 years is monitored and analyzed. By using the random forest algorithm，combined with various vegetation spectral indices and tex⁃ ture indices，a random forest tree suitable for the study area is constructed，and the vegetation type classi⁃ fication in this area is completed. The study is divided into six categories: grassland，non-vegetation， shrub，broad-leaved forest，farmland and coniferous forest. The classification and accuracy evaluation are carried out at a time interval of 5 years.The overall accuracy of the research is above 78.69%，and the aver⁃ age Kappa coefficient is 81.97%. The highest accuracy in 1999 is 89.52%，and the lowest accuracy in 2007 is 78.69%，indicating that the overall classification accuracy of the machine learning algorithm is good.The vegetation types in the mining area are mainly transformed from natural grassland to shrub，conif⁃ erous forest and broad-leaved forest.The mining activities in the mining area have a great impact on the surrounding vegetation.

To ensure the safe production of underground metal mines and effectively reduce the "three types of violations" (command violations，operation violations，and labor discipline violations)，an intelli⁃ gent video monitoring system for underground metal mines is researched and developed to realize real-time monitoring and intelligent analysis of mine production.Functions such as high-definition video acquisition， edge or server-side intelligent analysis，3D visualization，electronic fencing，and early warning for emer⁃ gency events are organically integrated，and an architecture adapted to high humidity，high dust levels，and blasting impacts is constructed. After analysis and evaluation，target recognition based on convolutional neu⁃ ral networks ，behavior analysis based on temporal models，and a model update strategy combining transfer learning and online fine-tuning are proposed to improve recognition accuracy and reduce the false alarm rate.In view of the impact of the underground environment on image quality，equipment stability，and net⁃ work transmission，countermeasures such as equipment selection，monitoring point optimization，and en⁃ hanced maintenance are put forward.The research results show that the system has significant application value in improving the efficiency of identifying violation behaviors，shortening the response time for emer⁃ gency events，reducing the labor intensity of patrol inspections，and enhancing mine safety management and production efficiency. It also provides a feasible path and implementation suggestions for the construction of smart mines.

The stability of the slope has always been the most concerned issue in the process of open�pit mining. There are many factors affecting the stability of the slope. External factors such as rainfall and dy⁃ namic load，internal factors such as physical and mechanical parameters of rock and soil，slope height and slope gradient. Through the analysis of sensitivity，the correlation degree of each parameter to slope stability can be quantitatively judged. Taking the backfill slope in a mining area in South America as an example，the sensitivity of stability to the cohesion and internal friction angle of rock and soil in the slope is calculated and analyzed under different working conditions and different slopes. The results show that when the slope is large，the sensitivity of slope safety factor to cohesion is greater than that to internal friction angle. When the slope is small，the safety factor is more sensitive to the change of internal friction angle，and the earthquake will reduce the average sensitivity of the safety factor to each parameter，but will not change the sensitivity of the slope to each parameter. The change of the safety factor of the slope is calculated by the change law of the sensitivity，which is consistent with the actual modeling and calculation results. It helps the mining area to choose a more suitable backfill material. It will also provide great help for the stacking scheme and materi⁃ al selection of the mine dump and temporary yard，and help to promote the intelligent stacking research in the construction of digital mines.

In order to explore the influence of close-distance coal seam mining on the deformation of surrounding rock of mining roadway，taking 3-805 working face of Jingfang Mine as an example，3DEC soft⁃ ware is used to comprehensively analyze the activity law of surrounding rock of coal mine roadway. In this study，3DEC software is used to construct a 260 m × 200 m × 68 m numerical model. The horizontal dis⁃ placement constraint and 6.5 MPa uniform load were set，and the coal seam is excavated step by step ( ini⁃ tial step distance 10 m，later 5 m ). The displacement，stress and roadway deformation of overlying strata are monitored by measuring lines. The results show that the immediate roof collapses with mining，the first weighting step of the main roof is 30 m ( the peak stress )，and the roof is completely compacted when ad⁃ vancing is 40 m. The evolution law is that the immediate roof collapses，the main roof masonry beam and the overlying rock sink synchronously. The stress distribution changes in stages. When advancing is 10 m，a tri⁃ angular pressure relief zone is formed in the roof and floor，and then it turns into an inverted funnel shape， with a tendency stress concentration range of about 20 m. The surrounding rock deformation of the roadway is dominated by the roof activity of the goaf，and the stress of the coal pillar changes from double peak to sin⁃ gle peak，reaching a peak of 18.27 MPa at 20 m after the working face. The deformation is characterized by roof subsidence，floor heave and asymmetric movement of the two sides. The severe deformation occurs in the stage of roof collapse and compaction after the working face is pushed over. The conclusion reveals that the roof caving and compaction activities in the goaf are the core causes of surrounding rock deformation，it is necessary to take reasonable protection measures to improve the stability of roadway surrounding rock.

Since the tailings reservoir of Fengshan Copper Mine completes its closure，there is no place to discharge the generated fine-grained tailings，which restricts the production progress. In order to use unclassified tailings for backfilling，the original vertical sand silo is abandoned，instead，a deep cone thickener is adopted to thicken the unclassified tailings before backfilling the underground stopes. The parti⁃ cle size characteristics and sedimentation properties of unclassified tailings aggregates are among the key factors affecting unclassified tailings backfilling. To investigate the flocculation and sedimentation properties of the unclassified tailings from Fengshan Copper Mine，first，a laser particle size analyzer is used to con⁃ duct particle size analysis on the unclassified tailings. Second，through static thickening and sedimentation tests of the unclassified tailings，a selection test is carried out on 11 types of flocculants from 5 manufactur⁃ ers. The optimal feed concentration of the deep cone thickener and its consumption per unit is determined. The results show that the content of -20 μm ( -625 mesh ) ultrafine particles in the whole tailings sample of Fengshan Copper Mine is more than 35 %，with a median particle size d50 of 38.98 μm，so it belongs to fine�grained tailings. The optimal flocculant selected is Flocculant B1，with an optimal consumption per unit of 20 g/t，and the optimal feed concentration of the deep cone thickener is 15%~20%. These results can pro⁃ vide data support for the thickening of unclassified tailings in Fengshan Copper Mine.

During the mining period of the 30103 working face in Pingquan Coal Mine，gas exceeding the limit occurred multiple times in the upper corner，with the maximum gas exceeding the limit concentra⁃ tion reaching 2.1%，seriously threatening the safe and efficient mining of the working face. Through techni⁃ cal research，it has been determined that the main reasons for gas exceeding the limit in the upper corner in⁃ clude air leakage in the goaf，air pockets in the upper corner，and geological structural influences. Based on the current situation of gas control in the early stage of mining，the ventilation system of the working face was optimized by adopting a Y-shaped ventilation system and arranging "buried pipes in the goaf+high-lev⁃ el boreholes" for gas extraction. L - shaped air barriers and air flow ejectors were installed to reduce end air leakage and prevent tile accumulation in the upper corner，and the arrangement of boreholes along the groove was optimized. The actual application effect shows that after optimizing the ventilation system and ex⁃ traction process，the average gas concentration in the upper corner is 0.4%，the maximum gas concentration in the goaf is 1.2%，and the maximum gas concentration at the coal drop point is 0.6%. The gas concentra⁃ tion at each point is controlled within the allowable range，which solves the technical problem of corner air entrapment in traditional U-shaped ventilation systems and achieves significant application results.