Gently inclined ore bodies are recognized as one of the difficult-to-mine ore bodies. Under the condition that the mine production system is fixed, the conversion of mining for ore bodies with different occurrence conditions significantly affects the mine production efficiency and safety. When a mine converts from mining near-horizontal ore bodies to gently inclined-inclined ore bodies, the traditional method is faced with the problem that some stopes cannot utilize existing roadways for mining and cutting, and a large number of new mining preparation projects need to be developed. To address the above problems, a mining scheme of "arranging stopes perpendicular to the strike of the ore body, canceling cutting raise shafts, and using ore drawing drifts as the initial free surface and supplementary space" was proposed. This scheme can save some mining preparation projects such as trench roadways, medium-deep hole bottom pulling, ore drawing drifts and ore haulage roadways. The stability of this structure was demonstrated using FLAC3D software, and industrial tests were carried out on-site. The results show that the goaf model of stope 62-A has a relatively regular shape, basically no caving occurs and side walls, the ore loss rate is 2.3%, the dilution rate is about 8.5%, and the mining and cutting engineering quantity is reduced by about 14.8%. This scheme has advantages such as adapting to the change of ore body dip angle, simplifying stope structure and reducing engineering quantity, and provides a reference for the mining of similar ore bodies.

In view of the mining problems faced by Chalukou molybdenum-lead-zinc polymetallic mine in the Greater Khingan Mountains under deep (750-1 000 m), complex structure and volcanic rock geological conditions, the optimization of filling mining height based on rock mechanics and numerical simulation was carried out. Firstly, the mechanical parameters of the main rock mass in the mining area were obtained by rock mechanics tests, and a three-dimensional geomechanical model that accurately reflects the geological structure and topographic characteristics of the mining area was constructed using 3Dmine, ANSYS and Surfer software. Then, FLAC3D numerical simulation was used to systematically compare and analyze the influence of three mining heights of 60 m, 90 m and 120 m on the stability of stope and surface. The results show that the mining height of 60 m can effectively inhibit the expansion of plastic zone and control the displacement and stress concentration, which is the safe and economical optimal mining scheme. Although the mining height of 90 m can basically maintain the stability of the stope, there is a risk of local plastic zone penetration. The mining height of 120 m leads to the horizontal deformation, inclination and curvature of the surface far exceeding the safety limit. The research results clarify the safe mining height threshold of the complex deep orebody, revealing the internal mechanism of the increase of mining height leading to the penetration of plastic zone, which provide a theoretical reference for the optimization of deep filling mining scheme under similar complex geological conditions.

To address the challenges of complex preparation work and difficult roadway excavation within backfill bodies encountered in thick ore bodies using conventional open stoping with subsequent filling mining method, a new stoping technique combining remote-controlled LHD with flat-bottom structures for ore removal has been proposed. Based on the ore removal system utilizing LHD with flat-bottom structures, theoretical calculation formulas for the ore removal volume contribution coefficient of LHD were established under the working conditions of four different stope layout directions and stope structure parameters. An optimized method for determining the stope structure parameters was proposed for the improved traditional open stoping with subsequent filling mining method. Taking the Bangzhong Zinc-Copper Mine as the engineering background, an application research on the open stoping with subsequent filling mining method based on the LHD with flat-bottom structure mining system was carried out. The design method of the mining site structure parameters was also introduced. The results show that, the method can achieve a 21% reduction in stope preparation engineering quantity, an approximately 12% decrease in ore loss, and a 22% ore output ratio for remote-controlled LHD (the theoretical value is 19.6%). The preparation-cutting-extraction cycle of a single stope is comparable to that of the original mining method. The study results provide innovative solutions for the safe and efficient extraction of thick and large ore bodies.

To improve the stability of the surrounding rock in the stopes of lines 61-65 in the Makeng Iron Mine, the Mathews stability graph method and FLAC3D numerical simulation were comprehensively used. A stress-displacement analysis model was established, and the effects of stope structural parameters (length, width, height) on the stability of the surrounding rock were systematically studied. The results show that during the mining process, the roof is dominated by tensile stress concentration, while the side walls exhibit compressive stress concentration. The stope width plays a dominant role in the stress distribution of the roof. The stope length significantly affects the displacement and stress release of the side walls. Shortening the stope length significantly reduces the displacement of the side walls and the risk of caving, which enhances the stope stability. The parameter combination of 20 m×10 m×54 m (length×width×height) has the best effect in controlling the stress concentration of the roof and the deformation of the side walls. Reducing the mining height to 36 m inhibits the horizontal displacement to a certain extent. However, the risk of roof caving remains high in the fractured rock mass area, indicating that solely adjusting the mining height is difficult to solve the local stability problem. Based on the zoning design of rock mass quality, a slicing scheme was proposed. By optimizing the parameters of the fracture zone and shortening the stope length, this scheme effectively mitigates the problem of side wall caving in the 63-1R section. The research results provide a theoretical basis for the structural optimization and surrounding rock stability control of stopes in the Makeng Iron Mine.

To address the challenges such as potential large-scale surface subsidence caused by mining the hung-up orebody in the triangular ore belt of a certain silver-lead-zinc mine, two overall mining sequence plans were proposed based on the site engineering geological conditions. Plan I involves treating the goaf and hung-up ore zone prior to ore extraction, while Plan II involves extracting the ore first followed by treatment of the goaf and hung-up ore zone. A geological model was constructed by combining CAD, 3DMine, and MIDAS, and numerical simulation was subsequently employed to compare the distributions of the stress field, displacement field, and plastic zone at various mining stages for these two plans. The results indicate that Plan I is more favorable for controlling ground pressure and ensuring stability in both the stope and the hung-up ore zone during mining operations, while also reducing resource wastage. Based on the numerical simulation results and mining technical conditions, a coordinated mining scheme involving the initial construction of an artificial false roof (and floor) followed by extraction from the bottom was proposed, and the construction scheme for the artificial false roof (and floor) was determined. A prediction model for the settlement of the artificial false roof was developed using the random forest algorithm to continuously ensure the safety of hung-up ore extraction in the area. The results of the industrial-scale trial show that the extraction rate of the hung-up ore exceeds 80%, generating approximately 5 million yuan in profit.

According to the well-developed joints and fragmented orebody in certain middle sections of a gold mine, combined with the stability of the ore and surrounding rock, two mining schemes were proposed, including the upward drift cut-and-fill mining method and the sublevel cut-and-fill mining method. Through a comprehensive comparison of the technical and economic indicators, as well as the advantages and disadvantages of each method, the upward drift cut-and-fill mining method was ultimately selected. The Mathews stability graph method was then employed to design the stope dimensions (height × width × length) for the primary and secondary drifts, which were determined to be 3.3 m×8.0 m × 40 m and 3.3 m×7.0 m×40 m, respectively. Based on the pre-support mechanism of anchor cables, a support scheme was designed. Discrete element software was employed to simulate the crack development state in the fractured zone, and an indicator for the surrounding rock cracking zone was proposed to quantitatively characterize the cracking depth, thereby analyzing the stability of the stope. The results show that after anchor cable support, no significant rockfall occurs in the roof of the two-step drift, and no large-scale interconnected crack zones or widespread surrounding rock cracking zones are observed. Considering both support effectiveness and economic requirements, an anchor cable pattern of 3.3 m×4.0 m is identified as the optimal solution. Under this scheme, the roof displacement is approximately 84 mm, with a reduction of 26.96%, the total number of cracks decreases by 37.33%; and the equivalent depth of the cracking zone is 0.64 m, with a reduction of 36.63%, compared to the condition without support. The field industrial application shows that the maximum vertical displacement difference of the roof after support is 91 mm. This solution brings approximately 7.555 million yuan in economic benefits to the mine.

The production of open-pit mines is affected by geological fluctuations, and traditional methods are difficult to effectively coordinate multi-objective ore extraction strategies. Aiming at the uncertainty of ore grade and unit mining cost during the extraction process, a multi-objective uncertainty optimization model was constructed with the objectives of minimizing unit cost, maximizing total extraction amount, and minimizing the standard deviation of grade fluctuation. The Monte Carlo method was used to simulate the random variations of geological parameters. To improve the stability and diversity of the solution set, a dynamic reference point perturbation jumping mechanism and an adaptive scaling strategy for the objective space were designed and embedded into NSGA-Ⅲ, resulting in the DPRS-NSGA-Ⅲ algorithm. A case study was conducted on a large-scale molybdenum mine. The results show that the DPRS-NSGA-Ⅲ algorithm increases the total ore extraction amount by 2.03%, reduces the unit mining cost by 2.17%, and controls the grade deviation within 0.005 percentage points. The obtained Pareto solution set is uniformly distributed in the three-dimensional objective space, without abnormal clustering or collapse. The research results demonstrate good adaptability and practical application value in addressing uncertain factors in the ore extraction strategy of open-pit mines.

To mitigate the impact of variations in cementitious material dosage and slurry mass concentration in backfill batching system on the strength prediction of backfill in the stope, the shrinkage characteristics of unclassified-tailings backfill slurry, which were strongly correlated with two factors, were selected as the research subject. Static shrinkage tests and uniaxial compression tests were conducted with different cement-tailing ratios (1∶4, 1∶8, 1∶20) and mass concentrations (70%, 72%, 74%, 76%). The random forest algorithm was selected to calculate the feature importance scores of different factors, and a compressive strength prediction model was constructed based on the shrinkage ratio. The model was validated by combining in situ measured data from an upward horizontal slice mining stope in a lead-zinc mine. The results are concluded as follows. Firstly, when the cement-tailing ratio is constant, the shrinkage ratio of the backfill slurry decreases gradually with the increase of mass concentration. When the mass concentration is constant, the slurry shrinkage ratio also exhibits a decreasing trend with the increase of cement-tailing ratio. Backfill slurry with low mass concentration and a low cement-tailing ratio is more prone to bleeding and segregation, which leads to the deterioration of backfill quality. Secondly, by using a random forest model to calculate the feature importance scores of each factor, it is identified that the cement-tailing ratio has the greatest impact on the compressive strength of the backfill material (93%), and the shrinkage ratio (5.6%) has a greater impact on the compressive strength than the mass concentration (1.4%). Thirdly, the engineering application results show that compared with the prediction method based on mass concentration, the prediction results of the uniaxial compressive strength of the backfill based on shrinkage ratio have smaller errors in most cases and have a better engineering applicability.

The safety issues posed by blasting vibration to surrounding buildings urgently need to be addressed, while traditional vibration-reduction methods rely on empirical parameters and lack statistical support based on small sample sizes. By conducting blast vibration monitoring at a certain mine, the peak vibration frequency was extracted using the fast Fourier transformation (FFT). The characteristics of the peak vibration frequency were then analyzed using a comparative approach that incorporated the Bootstrap method, Bayesian analysis, and maximum likelihood estimation. Based on this, the inter-hole delay time was adjusted to half a cycle and verified through field tests to confirm the accuracy of this method. The results show that as the distance from the explosion source increases, the vibration velocity of the particle gradually decreases, and the attenuation characteristics of vibration velocity vary with direction. The Bootstrap method does not require the assumption that the population follows a specific distribution, instead drawing samples directly from the original sample. This approach better reflects the characteristics and distribution of the samples, resulting in statistical outcomes that are more representative of reality. An 8-ms half-cycle is determined to be the optimal inter-hole delay time. Field tests show that, compared to a 20-ms inter-hole delay time, an 8-ms inter-hole delay time reduces peak vibration velocity in the X, Y, and Z directions by 14.81%, 12.68%, and 36.51%, respectively, while the peak vibration velocity in the combined velocity direction decreases by 22.55%, demonstrating a significant vibration reduction effect. The research findings provide a basis for optimizing parameters in medium-deep holes underground blasting, effectively addressing safety issues caused by blasting vibrations.

Slopes containing steeply dipping weak interlayers often fail due to the development of sliding surfaces along the weak interlayer. To address the sensitivity analysis of factors affecting the stability of such slopes, a grey relational-orthogonal test composite algorithm was proposed. The algorithm combines orthogonal test design, range analysis and grey relational method, a slope in an open-pit mine in Yunnan Province was taken as an engineering case for study. The strength reduction method was used to calculate the slope safety factor. An orthogonal test L₁₆(4⁵) with four levels and five factors was designed to analyze the influence of interlayer thickness, interlayer dip angle, distance from interlayer to slope surface, interlayer internal friction angle and interlayer cohesion on the stability of the open-pit slope. The results show that the interlayer dip angle has the most significant influence on slope stability, with its range proportion reaching 51.89%, followed by the internal friction angle of the weak interlayer, with a range proportion of 24.51%, while the other factors have weaker influences. The analysis results of the composite algorithm show a consistent trend with the traditional range analysis results, but the sensitivity ranking is clearer, verifying the reliability of this method. The study suggests that in slope design, the slope angle should be controlled to be smaller than the interlayer dip angle, and the slope stability should be enhanced by increasing the internal friction angle of the weak interlayer. By quantifying the sensitivity weights of key factors, theoretical support is provided for disaster warning, support design and emergency response.

To achieve accurate prediction of roadway deformation, a parallel prediction model that combines a Temporal Convolutional Network (TCN) and a Transformer, optimized using the Alpha evolution (AE) algorithm was proposed. This model integrated TCN and Transformer architectures through a parallel framework. The TCN utilized dilated causal convolutions to extract local temporal features, while the Transformer employed a multi-head self-attention mechanism to enhance the capture of long-term temporal patterns. Finally, the model output results through a dynamic multi-model feature fusion mechanism guided by temporal attention. At the same time, the AE algorithm was introduced to optimize hyper parameters, leveraging adaptive evolutionary paths and a two-step mechanism to enhance the model's robustness as handling complex time-series data. Experimental validation was conducted using roadway displacement monitoring data from three different monitoring points in the middle levels of an iron ore in Yunnan. The results show that when the prediction step size ranges from 6 to 48, the AE-TCN-Transformer model maintains a root mean square error (RMSE) below 0.013 2 mm, a symmetric mean absolute percentage error (SMAPE) below 0.09%, and a coefficient of determination (R²) above 0.97. These performance metrics significantly outperform those of single models such as TCN, Transformer, LSTM, and other single-model approaches. This fully validates the accuracy and reliability of the AE-TCN-Transformer model in roadway deformation prediction and provides a new approach for precise prediction of roadway deformation.

To solve the problems of difficult management of the mudstone composite roof and poor roadway support effect in a coal mine in Shanxi Province, taking a typical working face of the coal mine as the engineering background, an in-depth study was conducted on the support scheme and support effect of the mining roadway with mudstone composite roof by means of field investigation, laboratory test, theoretical analysis and numerical simulation. First, the mudstone composite roof was classified according to the engineering geological conditions. Then, through physical and mechanical tests, the physical and mechanical parameters of each rock layer of the roof were obtained, which provides a reduction basis for the rock mass parameters in the numerical simulation. The corresponding roadway support schemes were formulated, and the support effect was evaluated using numerical simulation technology. The results show that based on the occurrence characteristics of the mudstone layer, the mudstone composite roof can be divided into five types. The main components of mudstone are clay minerals and quartz, with an internal friction angle of 30.78° and a cohesion of 75.362 kPa. A differentiated support scheme is proposed, that is, bolt-mesh-cable support is adopted for type Ⅰ, Ⅲ and Ⅳ roof roadways, bolt-mesh support is adopted for type Ⅱ roof roadway, and I-beam shed support is adopted for type Ⅴ roof roadway. The numerical simulation and field measurement results show that the designed support scheme can effectively control the deformation of the surrounding rock of the roadway and ensure the stability of the roadway with mudstone composite roof. The research results can provide a reference for roadway support design under similar geological conditions.

The open stoping method is mostly used in small and medium-sized iron mines with medium stability of ore and rock. In practical application, it is easy to induce large-scale caving of roof and surrounding rocks in goaf, which seriously threatens the safety production of mines. The complex and irregular goaf group left over by the open stoping method in Zhuba Iron Mine in Nanjiang city was taken as the research object. Through surface point cloud data obtained by high-precision UAV aerial photography, combined with the mine production plan maps, a refined three-dimensional numerical model of the ore and rock was constructed, and the dynamic evolution laws of the mechanical characteristics of the surrounding rock of the goaf groups were studied. The following conclusions are obtained. The height, volume, area, and quantity of the goaf at the 1 318 m middle section are all the maximum values, which are the key factors restricting the safe mining of the lower ore body. The residual ore body at the 1 318 m middle section and the residual horizontal pillar directly facing the goafs at the 1 258 m middle section are not suitable for mining. To ensure the safe mining of the lower ore body, a systematic protection scheme for the caving hazards and impact airwave hazard of the goaf group was proposed. The engineering practice results show that approximately 188 900 tons of ore were recovered from the 1 258 m middle section, and no large-scale caving occurred in the goafs of the 1 318 m middle section during the mining period; during the mining of the central orebody of the 1 208 m middle section, caving of varying degrees occurred in the goafs of the 1 318 m and 1 258 m middle sections, but the caving hazards did not affect the production area, verifying the safety and practicality of the proposed caving hazard protection scheme.

Taking Dahongshan Iron Mine as the engineering case, the study on the treatment of hidden goafs in open-pit slopes was carried out by combining theoretical analysis with numerical calculation. According to the relationship between goaf morphology and open-pit boundary, a treatment scheme of "blasting of goafs inside the boundary and filling of goafs outside the boundary" was proposed. The safety thickness of the goaf roof was determined, the progressive failure mode of the slope above the goaf was revealed, the treatment scope of goaf filling and the compressive strength threshold of the filling body were obtained, and the stability of the open-pit slope after goaf treatment was evaluated. The results indicate that the safety thicknesses of the goaf roofs inside and outside the open-pit boundary are 20-30 m and 20-25 m, respectively. The slope containing hidden goafs has successively experienced the failure processes of tensile cracking at the slope rear edge, progressive failure of goafs, local slope collapse, and large-scale slope instability. The filling treatment range for Layer Ⅱ and Layer Ⅲ goafs is 30 m from the slope side, and the compressive strength of the filling body should reach 20 MPa. After the filling treatment of goafs outside the open-pit boundary, the shear strain of the slope rock mass is reduced and transferred to the interior of the slope, and the safety factor of the slope can meet the stability requirements.

A newly built open-pit mine has power tower foundations of Yiquanyi Line and Jinzhong DC transmission lines distributed within about 300 m on both sides, and slope excavation of the mine may cause the power tower foundations to topple, sink, or be damaged by rockfall impact. Stereographic projection, limit equilibrium method and finite element numerical simulation methods were adopted, and the disturbance range caused by open-pit slope excavation, slope stability and the impact of rockfalls at the slope top on power tower foundations were analyzed from qualitative and quantitative perspectives. The results show that when the open-pit slope is excavated to the final boundary, the slope is in a stable state. The distances from the power tower foundations adjacent to both sides of the stope to the disturbance range are 69.2-192.9 m, and the tower foundations are outside the scope of potential slope sliding surfaces corresponding to the minimum safety factor. The rockfalls at the slope top of the mining area mostly roll into the surrounding depressions. The power tower foundations on both sides of the open-pit stope are located at a high position and there are no rockfalls nearby. The mining of the new open-pit mine will not cause impacts on the power tower foundations on both sides of the stope.

Due to the significant differences in the intensity characteristics of near-fault ground motion in different directions, taking typical near-fault seismic records as an example, three ground motion intensity parameters were selected to compare the variability of ground motion intensity in various directions. Based on OpenSees finite element software, the difference of seismic response of slopes under different directions of seismic was analyzed. Considering the strain softening characteristics of soil, the influence of directional effects of seismic motion on the seismic stability of slopes was explored. The results show that the PGA variability of peak acceleration in different directions reaches 62.5%. The displacement response of the slope top in the direction of the maximum PGA under seismic action increases by 20.5% and 86.5% respectively compared to the two components recorded in the measured horizontal seismic motion. The variation range of slope safety factor under different directions of seismic action is 0.93-1.15. Ignoring the seismic direction may overestimate the seismic capacity of the slope and increase the risk of seismic instability. The research results can provide reference for slope seismic design and disaster prevention.

To reveal the loading rate effect of roof fracture behavior, typical mine roof sandstone was taken as the research object. Brazilian splitting tests of five loading rate levels were carried out in the loading rate range of 0.001-10 kN/s. The mechanical behaviors such as tensile strength, fracture characteristics, initiation stress, acoustic emission characteristics and fracture microstructure were analyzed. Based on the distribution of acoustic emission sources, the evolution law of internal damage cracks in the samples under different loading rates was explored. The results show that the tensile strength increases by 0.64 MPa when the loading rate increases by one order of magnitude, but the ratio of crack initiation stress to tensile strength decreases. With the increase of loading rate, this ratio is 40.13%, 36.59%, 32.53%, 26.17% and 15.81% in sequence. When the loading rate increases by one order of magnitude, the average size of the fragments decreases by 0.229 mm, the degree of fragmentation increases, and the size distribution of the fragments develops towards homogenization. The acoustic emission source at low loading rate mainly appears along the macroscopic fracture surface, while at high loading rate, the distribution of acoustic emission source is more dispersed due to the initiation and propagation of cracks from multiple dispersed stress concentration areas. With the increase of loading rate, the transgranular phenomenon at the fracture surface becomes more and more significant, transitioning from a single crack and straight form at low loading rates to multiple cracks and complex forms at high loading rates.

To investigate the mechanical properties and energy evolution laws of fractured sandstone under water-bearing conditions, uniaxial compression tests were conducted using a microcomputer-controlled coal-rock rigid impact testing system on sandstone specimens collected from a mine in Ordos. The tests considered both natural and saturated states, as well as different fracture inclination angles (0°, 30°, 60°, 90°). The full stress-strain curves, physical and mechanical parameters, energy evolution laws, and crack propagation behavior of fractured sandstone were analyzed. The results show that compared with intact sandstone, the peak strength and elastic modulus of sandstone with pre-existing fractures are significantly reduced. The total energy absorbed by the specimens under natural states (196-317 kJ/m³) is approximately 1.85 times that under saturated states (102-176 kJ/m³), and the total energy increases as the fracture inclination angle increases. Regarding energy evolution, the proportion of elastic strain energy exceeds 92% during the stable damage stage, while it drops to below 61.5% during the accelerated damage stage, with the proportion of dissipated energy which shows the opposite trend. The failure mode of the specimens exhibits significant anisotropy, and the deterioration effect of water reduces the initiation stress by 13.43% to 18.18%, while also increasing the occurrence of rock spalling. Fracture inclination angle and water-bearing state are key factors controlling the mechanical properties, energy evolution, and failure mode of sandstone. The research findings can provide a theoretical basis for the stability control of water-rich fractured rock mass engineering.

To quantitatively analyze the dynamic response characteristics of prefabricated fractured rock mass under the coupled action of impact load and confining pressure, a SHPB numerical model was established using ANSYS/LS-DYNA based on one-dimensional stress wave theory and the HJC dynamic damage constitutive model. Dynamic impact simulations were carried out on prismatic marble specimens with different prefabricated fracture inclination angles and different initial confining pressures. The results show that under a given strain rate, the pre-peak segments of the stress-strain curves for various working conditions are basically coincident, and macroscopic cracking mainly occurs in the short duration near the peak stress. Confining pressure has a significant enhancement effect on the dynamic strength. The peak stress increases with the increase of confining pressure, and its increase with the variation of fracture inclination angle is more significant under high confining pressure. When the confining pressure is 0, 5 and 10 MPa, the increase of peak stress with the variation of fracture inclination angle is approximately 14%, 20% and 30%, respectively. The peak strain of the rock mass increases from about 0.004 to about 0.006 1. The crack morphology is generally dominated by "X"-type shear failure. Based on the crack propagation trajectory and the crack initiation mechanism, five typical crack types and one fragmentation characteristic can be summarized. As the confining pressure increases, the crack network inside the rock mass becomes more complex and the fragmentation degree of the specimen intensifies significantly. Energy evolution analysis shows that when the incident energy is kept consistent across all working conditions, as the confining pressure increases from 0 to 10 MPa, the average energy absorption rate of the specimen increases from 6.13% to 9.35%, the energy reflection rate decreases from 93.54% to 89.99%, and the energy transmission rate increases from 0.33% to 0.66%. The dissipated energy generally increases with the increase of confining pressure. As the fracture inclination angle increases, the dissipated energy shows a local low value near 45° and then increases rapidly. The research results can provide a reference for damage assessment and stability control of fractured rock mass under the coupled action of blasting vibration disturbance and in-situ stress in scenarios such as shallow slopes and deep roadways.

The strength prediction of grouting materials is of great significance to improve the reliability of material design for grouting. Aiming at the problems that the traditional empirical models are difficult to accurately capture the relationship between material composition and strength, and the insufficient generalization ability of models caused by small samples, a machine learning prediction framework combining physical mechanism and data enhancement was proposed. The material performance prediction results of four machine learning methods, Random Forest Regression (RFR), Artificial Neural Network (ANN), Support Vector Regression (SVR) and Linear Regression (LR), were compared and analyzed. The results show that the RFR model has the best predictive performance, and its determination coefficient (R²) is increased to 0.934, which is 21.8%, 10.4% and 1.6% higher than that of LR, SVR and ANN models, respectively. The mean square error MAE is reduced to 2.59, which is 14.5%, 13.4% and 9.1% lower than that of LR, SVR and ANN models, respectively. In the analysis of feature importance, the contribution of graphite ratio to compressive strength is 37.6%. The data enhancement technique based on physical constraints can significantly improve the robustness of small sample modeling. The MAE of RFR and ANN models increases by 39.8% and 18.3% respectively compared to those without data enhancement. The prediction error of the RFR model remains stable below 10% under various water-solid ratio conditions. The research results can provide reference for the proportion of grouting reinforcement materials in mines.

Grouting materials have significant applications in mining engineering, but their poor durability in deep and highly erosive environments severely restricts the long-term safe operation of mines. Modified grouting materials were prepared by replacing a portion of the cement with rice husk ash and slag. Using compressive strength, the strength erosion coefficient, and the mass loss rate as evaluation criteria, quantified assessments were conducted to evaluate the impact of different erosion environments on the durability of modified grouting materials in karst regions. Combining scanning electron microscopy and X-ray diffraction analysis, it revealed the erosion-resistant mechanism of the modified grouting material at the microscopic level. The results show that the rice husk ash-slag-cement grouting material exhibited the highest resistance to chloride-sulfate erosion, carbonate erosion and water leaching corrosion, with strength loss rates of 13.61%, 14.42%, and 4.79%, respectively, and mass loss rates of 3.30%, 2.38%, and 1.95%, respectively. It is more resistant to environmental erosion than pure cement grouting materials. At the microscopic level, it is observed that rice husk ash and slag form dense hydration products through hydration reactions, which can inhibit the degradation of the original hydration products caused by various corrosive environments. At the same time, the amorphous SiO₂ in rice husk ash reacts with Ca(OH)₂ through a pozzolanic reaction, and the secondary hydration of the slag generates more C-S-H gel, significantly enhancing the erosion resistance of the modified grouting material to chloride-sulfate, carbonate and water. The cost of grouting materials made from rice husk ash-slag-cement is 21% lower than that of pure cement, and they can extend the maintenance cycle of the project by approximately 51.41%.

Safety protection for hoist cars in ordinary inclined shafts primarily relies on passive safety devices installed within the shaft. To prevent catastrophic consequences resulting from an accelerated impact, a structure for an inclined shaft hoisting container was proposed, featuring mechanical braking, maintenance interlocks, and spring-loaded shock absorbers. By establishing a multi-body coupled impact dynamics model of the hoisting container-slope track system, the formation mechanism and key influencing factors of the rear wheel lift angle during braking impacts were revealed. Combining theoretical derivations, virtual prototyping simulations, and experimental validation, the effects of buffer spring stiffness, slope track angle, impact velocity, and various operational loads on the dynamic behavior of the hoisting container were systematically analyzed. The results show that the system impact force and rear wheel lift angle reach the minimum values when the spring stiffness is approximately 2 500 N/mm and 15 000 N/mm, respectively, representing reductions of 13.4% and 17.4% compared to the springless condition. The slope track angle is positively correlated with impact velocity and the rear wheel lift angle. The rear wheel lift angle under rated load conditions is 15% to 30% lower than that under no-load conditions. When the slope track angle increases from 10° to 30°, the derailment impact speed under rated load conditions decreases from 9.5 m/s to 7.3 m/s, and under no-load conditions, it decreases from 9.0 m/s to 5.2 m/s, resulting in a maximum safety margin of 28.8% for load-carrying capacity. The research findings provide a theoretical basis for improving container impact-resistant design and safe braking strategies.

Shotcrete support is widely used in roadway excavation support, with the advantages of low cost and high safety. The robot arm is the core part of the shotcrete robot. In order to improve the design theory, kinematics and trajectory planning analysis were carried out taking a six-degree-of-freedom robot arm as the research object. For the time-optimal trajectory planning of the robot arm, a trajectory planning method based on the improved whale optimization algorithm was proposed. By introducing the Circle chaos mapping, Cauchy perturbation strategy and the pheromone mechanism of the ant colony algorithm, the global search ability of the algorithm was enhanced, which effectively avoided being trapped in the local optimal solution, and significantly accelerated the convergence speed, while improving the efficiency and accuracy of the local search process. The improved whale optimization algorithm enables the robot arm to reach the target posture more quickly, successfully shortening the running time by 56.7%, thereby further verifying the feasibility of the algorithm.

To investigate the collision characteristics of grinding balls inside the cylinder of a vertical stirred mill during operation, a laboratory-scale vertical stirred mill was used as the research subject. Based on the Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD), a DEM-CFD simulation model was developed, taking grinding balls, slurry, and the agitator as the objects. The collision characteristics of grinding balls and their variation along the axial direction were systematically investigated based on five aspects, including the number of collisions, normal and tangential collision energies, and normal and tangential collision forces. The results show that collisions among grinding balls account for 90.5% of the total number of collisions, which is significantly higher than the number of collisions between grinding balls and the grinding cylinder. The tangential collision energy among grinding balls is approximately 1.4 times that of the normal collision energy, while the normal collision force is approximately 6.2 times that of the tangential collision force, indicating that the grinding effect of the grinding balls is more pronounced in the tangential direction. Grinding balls located between the bottom and the 3/8 mark of the cylinder exhibit collision characteristics marked by high collision frequency, high collision energy, and low collision force, which effectively refine the materials. The grinding effect in other areas is relatively small, suitable for rapid materials grading and allowing materials that meet the particle size conditions to overflow from the cylinder. This research achievement provides theoretical guidance for optimizing mill design and improving grinding efficiency.

To address the issue of insufficient surface feature recognition accuracy in traditional segmentation models caused by complex vegetation cover and blurred surface feature boundaries in mining remote sensing images, a dual-branch DB-TransUNet model was proposed. This model innovatively constructed a dual-branch encoding architecture and integrated features from both branches using an adaptive weighted fusion (AWF) module. By combining this with a channel adaptive enhancement (CA) module to optimize feature weight allocation during the decoding process, it achieved focused detection of features in key regions and effective suppression of background noise. The experimental results show that incorporating the AWF and CA modules improved the mIoU of the model by 4.16% and 78.63%, respectively. The full DB-TransUNet model achieves excellent segmentation results of mIoU=0.903 7 and mDice=0.948 8 in complex remote sensing scenarios. Compared to mainstream network segmentation architectures, the DB-TransUNet model demonstrates superior performance across all indicators, achieving higher accuracy and stronger generalization capabilities in the recognition and detailed segmentation of complex surface features in mining environments. The findings validates the effectiveness of a strategy combining complementary multi-source features with weighted fusion in mitigating vegetation-induced interference in the identification of mine surface features, thereby providing a reliable technical solution for high-precision intelligent monitoring in open-pit mining areas.

To address the challenge that existing denoising methods struggle to effectively extract microseismic signals from fractured rock masses in mines, a combined algorithm based on improved adaptive noise ensemble empirical mode decomposition (ICEEMDAN) and improved wavelet thresholding (IWT) was proposed. Firstly, the algorithm decomposed the noisy microseismic signal using ICEEMDAN to obtain the instrumental modal functions (IMF_s). Secondly, noise-containing components were filtered based on correlation coefficients, and the IWT algorithm was used for denoising. Finally, the denoised microseismic signal was obtained through wavelet transformation. At the same time, the accuracy of the algorithm was verified using both microseismic simulation data and real-world data. The denoising performance of the ICEEMDAN-IWT combined algorithm was quantitatively compared with that of other mainstream denoising algorithms, using the signal-to-noise ratio (SNR), normalized cross-correlation coefficient (NCC), and mean square error (MSE) as evaluation indicators. The results show that the ICEEMDAN-IWT combined algorithm achieves the best denoising performance, with an SNR of 28.06 dB, an NCC of 0.999 2, and an MSE of 0.014 45. After processing with the ICEEMDAN-IWT combined algorithm, the denoised waveform exhibits significantly improved characteristics while fully preserving the original phase information. However, there is still room for improvement in the denoising performance for waveform data with high amplitude ratios. Future research can further optimize the algorithm performance by incorporating intelligent methods such as deep learning.

To achieve efficient flotation of azurite, the influence of a new sulfurizing agent, GX2, on the sulfide flotation behavior of azurite was investigated through single-mineral flotation tests, with comparisons made to sulfurizing agents such as ammonium sulfate and sodium sulfide. Testing methods including Zeta potential measurement, contact angle tests, adsorption capacity tests, and X-ray photoelectron spectroscopy analysis were employed to explore the sulfidation mechanisms of different agents on azurite. The results indicate that GX2 exhibits superior sulfidation performance compared to the other two agents. Under conditions of pulp pH of 9, sulfidation time of 2 min, dibutyl dithiophosphate dosage of 120 mg/L, GX2 dosage of 20 mg/L, and collector oil dosage of 80 mg/L, the maximum flotation recovery rate of azurite can reach 94.37%. GX2 acts on the surface of azurite through chemical adsorption, enhancing its electronegativity and forming hydrophobic Cu—S components on the mineral surface, thereby increasing the adsorption capacity of collectors and improving the sulfidation effect on the mineral surface.

To effectively solve the dual technical problems of separation of fluorite, rare earth and minerals containing calcium, barium/strontium separation and separation of fluorite and rare earth in a fluorite-rare earth polymetallic ore in Henan Province, as well as the comprehensive utilization of low-grade molybdenum and lead, the beneficiation process was studied. The grade of CaF₂ and REO in the fluorite-rare earth polymetallic ore are 21.73% and 1.56%, respectively, accompanied by molybdenum and lead, and their grades are 0.055% and 0.54%, respectively. The content of calcite and barite in the gangue component is high, and it is closely related to fluorite and rare earth. The principle process of "first flotation enrichment of molybdenum and lead, then recovery of fluorite and rare earth" and the mineral processing scheme of "fluorite and rare earth mixed flotation" + "magnetic-gravity combined separation" were adopted. Modified fatty acid collectors CK-1 and CK-2 were used in combination, and calcium, barium/strontium gangue was strengthened and inhibited by acidified water glass. The whole process closed circuit test obtained lead concentrate with a Pb grade of 55.12% and a Pb recovery rate of 33.63%; molybdenum lead intermediate ore with a Mo grade of 3.28%, a Pb grade of 7.95%, a Mo recovery rate of 56.86%, and a Pb recovery rate of 13.03%; fluorite concentrate with a CaF₂ grade of 95.41% and a CaF₂ recovery rate of 79.32%; rare earth concentrate with a REO grade of 56.83% and a REO recovery rate of 45.10%. The process realizes the efficient recovery of fluorite and rare earth and the comprehensive utilization of molybdenum and lead, which provides technical support for the development and utilization of the complex polymetallic ore.

The Hami region of Xinjiang is rich in low-grade iron ore. A certain iron ore has a TFe grade ranging from 14% to 20%, with associated Ti, V, and P, and it is classified as an ultra-low-grade vanadium-titanium magnetite. To explore the potential for comprehensive recovery of its valuable components, process mineralogy studies including phase analysis and microscopic identification were carried out. The occurrence state, dissemination characteristics, and particle size of valuable minerals such as magnetite, ilmenite, and apatite were determined. On this basis, experimental studies on dry pre-concentration and the comprehensive recovery of iron (vanadium), titanium, and phosphorus were carried out. A full-process principle flowsheet was ultimately determined as dry pre-concentration-flotation for desulfurization-flotation for phosphorus recovery-low-intensity magnetic separation for iron-gravity separation for titanium recovery. An iron concentrate with a TFe grade of 57.15% and an operating recovery of 34.31%, a titanium concentrate with a TiO₂ grade of 46.40% and an operating recovery of 20.08%, as well as a phosphorus concentrate with a P₂O₅ grade of 28.25% and an operating recovery of 53.81% have been obtained. Rare earth element partitioning analysis was conducted on the various concentrate products obtained from the experiments, and the results show that rare earth elements exhibit the highest correlation with apatite, with a rare earth recovery of 60% in the phosphorus concentrate. The research findings can serve as a reference for the comprehensive utilization of such vanadium-titanium magnetite resources in the Xinjiang region.

In view of the situation that the graphite contained in graphite tailings is not fully recovered, experiments on graphite recovery were carried out on graphite tailings from a certain area in Heilongjiang with a fixed carbon content of 3.40%. The properties of graphite tailings were investigated by chemical multi-element analysis, XRD analysis and optical microscopy analysis methods. On this basis, roughing condition experiments and stage grinding-stage separation experiments of graphite tailings were carried out. The results indicate that graphite in the tailings mostly occurs in the form of inclusions or paragenesis adjacent to other minerals. Graphite particles vary in size and are mostly distributed in the +0.09 mm size fraction of the tailings. To fully liberate graphite from the tailings and avoid argillization, a multi-stage grinding and multi-stage separation flowsheet should be adopted. When the grinding fineness of the -200 mesh content is 29.52%, the flotation mass concentration is 20%, the kerosene dosage is 300 g/t, and the No.2 oil dosage is 50 g/t, graphite rough concentrate with a fixed carbon content of 15.62% and a recovery rate of 72.88% is obtained. A closed-circuit flotation test was carried out on the graphite tailings by adopting the process of four-stage grinding, one roughing, five cleaning, and combined middlings returning. Graphite concentrate with a fixed carbon content of 81.33% and a recovery rate of 61.51% is obtained.

The silver in a certain silver-polymetallic ore in Heilongjiang Province mainly occurs in sulfide minerals, the iron and manganese mainly occur in carbonate minerals, and a small amount of iron occurs in magnetite. In order to efficiently recover silver, iron and manganese from the ore, a combined flotation-magnetic separation process of silver flotation-iron low-intensity magnetic separation-manganese high-intensity magnetic separation was developed. The beneficiation indexes obtained from the closed-circuit test of the whole process are as follows: the silver grade of the silver concentrate is 3 287.35 g/t, and the recovery rate is 85.82%. The iron grade of the iron concentrate is 60.74%, and the recovery rate of magnetic iron is 79.85%. The manganese grade of the manganese concentrate is 15.03%, and the recovery rate is 76.65%. By optimizing reagent dosage and improving the process configuration in the pilot continuous separation tests, a silver concentrate with a silver grade of 4 120.36 g/t and a recovery rate of 88.75%, an iron concentrate with an iron grade of 62.38% and a magnetic iron recovery rate of 79.42%, and a manganese concentrate with a manganese grade of 15.06% and a recovery rate of 73.97% were obtained. The tailings water after flocculation and sedimentation with polyacrylamide is reused in the whole process, and the fluctuation of concentrate indices is less than 3.0%. The research results can provide a reference for the comprehensive utilization of similar complex mineral resources.

Under the background of the national "double carbon" strategy and the realization mechanism of ecological product value, in order to solve the dilemma of "two skins" of mine restoration and transformation of ecological product value in the Nanling Ethnic Corridor, 20 multi-mineral mine restoration cases in the region were taken as samples, and the grounded theory was used to carry out system coding analysis. Firstly, the four key problems of inefficient utilization of waste resources, prominent technical bottlenecks, weak funding sustainability and ineffective cross-departmental coordination were identified. Then, combined with the core attributes of regional multi-mineral composite, cross-domain governance and national dependence, the four-dimensional optimization path of waste recycling revitalization industry, breaking through technical bottlenecks, innovating financial mechanism and strengthening system governance was constructed. The results show that the path can be targeted to solve the unique restoration problems in the study area and make up for the theoretical defects in the realization of the mine restoration ecological product value in the Nanling Ethnic Corridor. It not only opens up the transformation channel from "lucid waters and lush mountains" to "gold and silver mountains" for cross-regional and multi-ethnic areas and provides a replicable "Nanling experience", but also provides a methodological reference for the study of the realization of ecological products value in similar regions.

To actively explore and establish a new path for green mining development with multiple objectives including the "green mine pattern", focusing on the standardization field of green mining development, guided by the macroscopic design idea of the standard system, adopting the theories of mineral resources discipline, and combining the practical work demands of green development in China's mining industry, exploratory research on the standardization path of high-quality green mining development of China's mining industry was carried out. Supported by the existing research achievements related to mineral resources, taking the green development concept as the administrative logic and the research on mineral resources standards as the technical logic, research work in the fields of basic general standards for green mining development, green geological exploration standardization, green mine standardization, and intensive and economical utilization standardization of mineral resources was carried out. Supported by the construction theories and models of the natural resources standard system, research on the green mining development standard system was carried out from three levels of basic standards, category generality and sub-category generality respectively, and the framework of the green mining development standard system was established. By analyzing the framework and contents of the green mining development standard system, the key research directions and implementation paths for the standardization of high-quality green mining development were put forward. The research findings have important guiding significance for supporting and promoting the high-quality green mining development.