CHINA MINE ENGINEERING

Abstract:In order to study the stability of a surface building (structure) under the influence of the old mined-out area and the disturbance of the second-stage mining project, this paper firstly uses the 3Dmine-rhinoceros-Griddle-FLAC3D coupling modelling technology to establish a three-dimensional numerical calculation model of the mine. Then, according to the design of the second-stage mining project of the mine, the mine production process is simulated according to the order of 'mining from top to bottom in the middle section of the ore body and mining from bottom to top in the middle section'. Finally, the stability of the surface building (structure) under the old goaf and mining disturbance is analysed, The results show that after the mining and filling of the ore body is completed, the maximum horizontal displacement of the surrounding rock of the 2^# shaft, 3^# shaft and 1# blind air shaft of the mine is 4mm, and the maximum horizontal deformation of the surrounding rock of the shaft wall is 38223×10^-2mm/m, the maximum tilt value of the surface building (structure) is -60958×10^-2mm/m, the maximum curvature is -96682×10^-7 /m, and the maximum horizontal deformation is 18821×10^-2mm/m, which all meet the protection requirements of the first-class building (structure). That is to say, the existing old goaf conditions and the adjacent shaft and surface buildings (structures) under the second-stage mining disturbance can maintain a stable state and meet the requirements of safe production. The research results can provide reference for similar projects.

Abstract:Under the background of rapid development of engineering construction, blasting technology is widely used in infrastructure projects, and its potential impact on the stability of adjacent key water conservancy facilities (such as reservoir dams) cannot be ignored. In this study, a lead-zinc mine adjacent to a dam in Tibet was taken as the background. Combined with field investigation and numerical simulation methods, the influence of excavation blasting in different underground sections on the stability of the dam was systematically explored. A fine three-dimensional numerical model of underground blasting and dam is established, and the influence of mining blasting on dam stability under three typical blasting conditions is simulated by using dynamic software ANSYS/LS-DYNA. The propagation characteristics of blasting vibration wave, shear stress distribution characteristics, particle vibration velocity (PPV) and acceleration of dam body are analyzed. The results show that with the propagation of blasting vibration wave, the stress of dam crest increases gradually, and the stress of rock mass at dam abutment and dam heel is significantly higher than that in other areas. The maximum shear stress of the unit at the top, abutment and heel of the dam is 073MPa. The PPV values of each measuring point in X , Y and Z directions were all less than 06cm/s. The comprehensive analysis shows that the blasting operations in the 3230m, 3300m and 3350m sections of the lead-zinc mine do not pose a significant threat to the stability of the adjacent dam body. The research results provide theoretical reference and technical support for the safe construction of underground engineering blasting, and provide new ideas and methods for the stability evaluation and risk management of reservoir dams.

Abstract:This study proposes a mining slope monitoring network optimization method that integrates numerical simulation and clustering analysis algorithms to address the problems of sparse monitoring networks and insufficient spatial representativeness caused by equipment costs and terrain limitations in mining slope monitoring. This method first explores the stability evolution law of slopes under normal and rainfall conditions based on the strength reduction method, and divides the slope risk areas; On this basis, particle swarm optimization algorithm is introduced to determine the clustering centers of each partition, and redundant monitoring points are eliminated by combining spatial correlation coefficient, ultimately achieving the optimization of the mining slope monitoring network. This article takes the Chongqing Huaxin limestone dolomite mine as a case study to verify the effectiveness of the monitoring network optimization method. The results showed that after optimization, the number of monitoring points decreased from 35 to 18, and the overlapping information entropy decreased by 293%. While ensuring monitoring coverage, the monitoring cost was significantly reduced, providing a theoretical basis for the economic monitoring of mine slopes.

Abstract:Drilling-and-blasting remains the predominant method for metal mining in China, and blast simulation is the key to optimizing blast design. For years, the Chinese blasting-simulation community has relied heavily on foreign codes such as ANSYS/Autodyn and LS-DYNA, creating an urgent need for domestic alternatives. Based on single-hole blasting-crater tests in concrete, this paper presents the first systematic comparison between GalaxyEDS—a Chinese explicit-dynamics software—and the international commercial code Autodyn. The comparison evaluates their ability to reproduce the physical phenomena numerically and assesses the domestic software’s accuracy and suitability for mining applications. The results show that GalaxyEDS closely matches both experimental data and Autodyn predictions in crater morphology, bulging motion, and blasting action index, providing quantitative support for the engineering deployment of the domestic code.

Abstract:In order to study the local resistance characteristics of the damper roadway and the accurate calculation method of air volume, taking the underground damper roadway of a mine in Hengyang, Hunan as the research object, the method of combining field test and numerical simulation was used to study the air flow field and local resistance characteristics of different damper angles. Combined with the area of air flow passing through the area, the calculation formula of air volume in the damper roadway with the size of the damper and the maximum wind speed at the damper as independent variables was deduced. The results show that the ventilation resistance and resistance coefficient in the field test show a trend of “slow growth-rapid growth” with the increase of the damper angle; in the numerical simulation test, the wind speed gradually shows an uneven distribution with the increase of the damper angle. Comparing the results of the field test and the numerical simulation, it is found that the CFD simulation method can accurately predict the change law of the local resistance when the damper angle is below 60°; the air volume calculation formula constructed by the combination of CFD simulation and numerical analysis can accurately calculate the air volume of the damper roadway, which can provide accurate data for the monitoring of the mine ventilation system and the intelligent regulation of the air volume.

Abstract:Aiming at the actual conditions of No.2-1^# and No.2-2^# ore bodies in a certain mine, based on the backfill mining method currently used in the mine, three stope structure parameter schemes were studied. The research was carried out by combining Midas modeling with FLAC numerical simulation to analyze the vertical displacement and principal stress distribution characteristics of each scheme, and a technical and economic comparison was conducted. The results show that Scheme 3 with large stope and small pillar (stope 50m, barrier pillar 10m, low-strength backfill) has obvious advantages over other schemes in controlling surrounding rock deformation, reducing backfill costs (5332 million yuan per standard ore block), and improving mining efficiency. Its maximum displacement value, maximum principal stress value, and minimum principal stress value all meet the stability requirements for safe mining. The research results provide technical parameter references for the safe production of the mine.

Abstract:Moisture content is a key factor affecting the mechanical properties and failure modes of granite. In order to explore the influence of different moisture contents on the mechanical properties and failure modes of granite, three groups of uniaxial compression and acoustic emission tests of granite with different moisture contents (dry, natural and saturated) were carried out. The influence of moisture content on granite was discussed from the mechanical behavior, fracture mode and acoustic emission parameter characteristics of samples. The results show that with the increase of water content, the peak stress and elastic modulus of granite decrease gradually. Compared with dry samples, the peak stress of saturated samples decreases by about 5152%, and the elastic modulus decreases by about 2277%. The peak strain decreases first and then increases. The peak strain of granite in natural state is the lowest, about 0694%. Poissons ratio increased linearly from 021 to 025. The higher the water content, the more obvious the stress drop phenomenon in the stress-strain curve of the granite sample. With the increase of water content, the number of tensile cracks on the surface of granite samples decreases, and the volume of rock collapse increases. The failure mode of rock changes from splitting failure to tensile-shear mixed failure, and finally to X-type conjugate shear failure. With the increase of water content, the hydration reaction weakens the cohesion between particles, and the rock is more prone to micro cracks.

Abstract:Rock burst is a common geological disaster in the process of deep mining. The occurrence of rock burst is sudden, instantaneous and destructive. In order to predict the occurrence of rockburst, this paper calculates the elastic strain energy based on the uniaxial compressive strength test results, and identifies the rockburst tendency according to the maximum storage elastic strain energy index and the improved brittleness index. The results show that the rock burst tendency of core samples is either no rock burst tendency or no rock burst tendency. This method provides a scientific theoretical basis for predicting rockburst tendency from the perspective of energy index.

Abstract:The article takes the Panjiatian Iron Mine area as the research subject and conducts rock mass quality evaluation using the RMR method based on the investigation of engineering geological characteristics. First, modern three-dimensional laser scanning technology is used to investigate the structural planes of the rock mass in the mining area, obtaining characteristics such as the strike, spacing, and persistence of the rock mass structural planes. Furthermore, statistical work on the rock quality RQD values of the engineering geological boreholes DH01 and DH02 is carried out, and representative rock samples are selected for uniaxial compression tests to obtain various parameters for the RMR rock mass quality evaluation system. The RMR rock mass quality evaluation results indicate that the quality of the lower plate rock mass in Panjiatian Iron Mine is moderate; the quality of the industrial ore rock mass is moderate; the quality of the low-grade ore rock mass is moderate; the quality of the upper plate rock mass (east) is good; and the quality of the upper plate rock mass (west) is moderate. This rock mass quality evaluation has certain guiding significance for the selection of subsequent engineering design parameters.

Abstract:Using technologies such as the Automatic Mineralogy Quantitative Analysis System (MLA 650), Scanning Electron Microscope (SEM) combined with Energy Dispersive Spectroscopy (EDS), and Inductively Coupled Plasma Mass Spectrometry (ICP-MS), a systematic process mineralogy study was conducted on a complex titanium-iron placer in Australia. The results show that due to solid solution separation and oxidative alteration of iron-titanium minerals, complex associations such as ilmenite, altered ilmenite, iron-rich ilmenite, maghemite, and titanium-rich hematite are formed. Gangue minerals are mainly quartz and feldspar, while rutile and zircon are distributed in fine grains. The main valuable elements in the ore are Ti (average grade of TiO2 is 272%) and Fe (474%), with Zr (0109%) recoverable as a by-product. The particle size of ilmenite and magnetic iron minerals is concentrated in the range of 002-032mm, while zircon (002-016mm) and rutile (001-016mms) are embedded in fine grains. The liberation degree exceeds 96% when the ore is finely ground to 0075mm. The magnetic properties of titanium-iron minerals overlap (130-550mT), requiring magnetic separation via reduction roasting modification. The research results provide a mineralogical theoretical support for the development of efficient separation processes for such complex placer deposits.

Abstract:Through a comparison of the pre-separation dephosphorization processes of copper and molybdenum in a large domestic copper-molybdenum beneficiation plant, and a comprehensive technical and economic comparison of the dephosphorization schemes, based on the results of the scheme comparison and combined with the production experience of similar domestic beneficiation plants, the “stirring+thickener dewatering+grinding and scrubbing with sodium sulfide” dephosphorization scheme is recommended.

Abstract:In response to the problem of controlling the stability of the perimeter rock along the air-retained roadway in the lower coal seams of the close group of coal seams, taking the open channel along the 201 working face of the 0213 working face of the Huangbaizi coal mine as the engineering background, the theoretical analysis, numerical simulation and industrial validation methods were used to analyze the structural characteristics of the overlying rocks along the open channel of the near coal seam, to obtain the minimum resistance required for the support body along the open channel, and to simulate the distribution characteristics of stress and plasticity zones of perimeter rock under the situation of the coal pillars with or without the coal columns left behind from the overlying mine airspace area. The simulation analyzed the distribution characteristics of the surrounding rock stress and plastic zone in the case of overlying coal pillars with or without overburdened mine openings. The research results show that: ① the roadside support body mainly bear the roadside support body outside the exposed rock layer, the upper and lower coal seam collapse zone rock self-weight, the roadside need to provide support resistance can not be less than 75254kN. ② obtained two cases of the roadside support body width technical parameters, from the eye of the opening 0-260m along the open space to stay along the road, the choice of 12m width of the roadside support, from the eye of the opening 260-1250m along the empty space to stay, the choice of 10m width, the choice of 10m width, the choice of 10m width, the choice of 10m width, the choice of 10m width, the choice of 10m width. Along the empty lane from 0-260m from the open cutting eye, 12m width roadside support body is selected, and 260-1250m from the open cutting eye, 10m width roadside support body is selected, which can meet the support demand. ③Propose the method and parameter of perimeter rock stability control along the empty stay lane, and carry out industrial verification of the proposed program, the entire service period of the lane did not occur during the phenomenon of roofing, collapsing gangs, anchor rods and cables support failure, etc., the effect of the lane perimeter rock control is good, the amount of deformation of the perimeter rock has always been less than 250mm, to ensure that the working face of the safe and efficient mining, the program has certain practical significance for solving the problem of perimeter rock stability control of the stay lane along the empty stay lane in the conditions of the same kind of project. This program has certain practical significance for solving the problem of stability control of perimeter rock in similar projects.

Abstract:Open-pit coal mines typically maximize slope excavation angles to improve economic efficiency, but this also significantly increases the risk of slope instability. Unmanned aerial vehicle (UAV) oblique photogrammetry, as an emerging technology, can acquire high-spatial resolution images, providing rapid and accurate data for slope stability analysis. The image data acquired through UAV aerial surveys is processed to generate a digital elevation model (DEM). Slope instability parameters such as slope and aspect, as well as relevant geological information, are extracted and used as input for an artificial neural network (ANN). ANNs have the ability to learn and generalize from unknown data. This study used a random sampling method to select open-pit coal mines from different regions as training samples. A feedforward backpropagation algorithm was used to conduct a slope sensitivity analysis, categorizing the study area into four disaster susceptibility levels. Four input parameters, slope, aspect, drainage density, and geological structure, were used in model training. Each factor was ranked according to its importance in inducing slope instability. Twenty percent of the samples were used for testing and 20% for validation. The resulting hazard risk assessment zoning map provides a scientific reference for future open-pit coal mine slope instability risk warning and mitigation planning.

Abstract:On the basis of summarizing the history and characteristics of the formulation of flood control standards for tailings pond in China, the flood control standards for reservoirs and dams in domestic water conservancy industry and tailings pond in foreign metallurgical mining industry are compared and analyzed. Through the reliability analysis of the flood control standard for the specific service life of the tailings pond, the quantitative values of the engineering reliability of the tailings pond when different flood control standards are selected under different service life conditions are obtained, and how to analyze and evaluate the applicability of the selected flood control standards according to the specific service life of the tailings pond is clarified. Finally, the verification is illustrated with an engineering example. The research results can provide a quantitative reference for the technical personnel of the tailings pond industry in selecting flood control standards and evaluating the flood control reliability of the tailings pond.

Abstract:To clarify the research hotspots and development trends in the field of intelligent open-pit mining planning, this paper takes the relevant literature on intelligent open-pit mining from 2010 to 2024 in the China National Knowledge Infrastructure (CNKI) database as the data source and uses CiteSpace 631 (64 bit) software for knowledge mapping visualization analysis. Through the analysis of keyword co-occurrence, emergence, and clustering, the research hotspots and core themes in this field are sorted out. The results show that the high-frequency keywords in the research on intelligent open-pit mining planning are mainly concentrated in “open-pit mine”, “drone”, “truck dispatching”, “driverless”, “slope monitoring”, etc., forming research clusters centered on the application of intelligent mining technology, production scheduling optimization, and safety monitoring and control. The keyword emergence map indicates that “intelligent mine”, “driverless”, “big data”, etc. are the research frontiers in recent years, reflecting the trend of the field towards intelligence and digitalization. Cluster analysis further reveals that subfields such as numerical simulation, boundary optimization, and intelligent equipment have formed stable research directions, and each direction shows the characteristics of technology integration. The research can provide references for academic research and engineering practice in the field of intelligent open-pit mining planning.