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The calculation of volumes for irregular bodies holds significant relevance across various production processes. This spans tasks such as evaluating the growth status of crops and fruits, conducting morphological analyses of spatial objects based on volume parameters, and estimating quantities for earthwork and excavation. While methods like drainage, surface reconstruction, and triangulation suffice for smaller irregular bodies, larger ones introduce heightened complexity. Technological advancements, such as UAV photogrammetry and LiDAR, have introduced efficient point cloud data acquisition methods, bolstering precision and efficiency in calculating volumes for substantial irregular bodies. Notably, open-pit mines, characterized by their dynamic surface alterations, exemplify the challenges posed by large irregular bodies. Ensuring accurate excavation quantity calculations in such mines is pivotal, impacting operational considerations, acceptance, as well as production cost management and project oversight. Thus, this study employs UAV-acquired point cloud data from open-pit mines as a case study. In practice, calculating volumes for substantial irregular bodies often relies on the point cloud slicing method. However, this approach grapples with distinguishing multi-contour boundaries, leading to inaccuracies. To surmount this hurdle, this paper introduces an enhanced point cloud slicing method. The methodology involves segmenting point cloud data at fixed intervals, followed by the segmentation of slice contours using the Euclidean clustering method. Subsequently, the concave hull algorithm extracts the contour polygons of each slice. The final volume calculation involves multiplying the area of each polygon by the spacing and aggregating these products. To validate the efficacy of our approach, we employ model-derived volumes as benchmarks, comparing errors arising from both the traditional slicing method and our proposed technique. Experimental outcomes underscore the superiority of our point cloud volume calculation method, manifesting in an average relative error of 1.17%, outperforming the conventional point cloud slicing method in terms of accuracy.

Trucking is an important production link in most open-pit mines, and its transportation cost accounts for more than 50% of the total production cost of open-pit mines. The quality of the driver’s driving behavior plays a crucial role in the fine control of the production cost of transportation. Different from the previous evaluation studies of drivers’ driving behavior in open-pit mines, which mainly took safety driving behavior index as a factor variable, this paper puts forward a comprehensive evaluation method of driving behavior of mining truck drivers, which takes both safety driving and transportation cost as factor variables. Taking the mining truck as the research object, firstly, a scientific and reasonable data collection scheme is established, and the data information characterizing the transport state of the mining truck is obtained through data collection and analysis. Secondly, the RKNN algorithm of time series prediction and the wavelet analysis method are used to achieve noise reduction and missing processing of the original data so as to obtain accurate sample data. Then, taking the principal component analysis method as the entry point, through constructing the principal component analysis theory model, the key index system representing safe driving behavior and transportation cost is established to realize the comprehensive evaluation of the driving behavior of mining truck drivers, and the evaluation system of “standard driving”, “prudent driving” and “aggressive driving” of mining truck drivers is formulated. The results show that after noise reduction, the accuracy of mining car operation data can be improved by 7~12%, and the transportation cost can be reduced by about 5% after the driver’s operation behavior is standardized.

The extensive vegetation destruction in opencast mining regions has led to various environmental problems, including the loss of biodiversity. However, our understanding of biodiversity’s response to survival, as well as its interactions with soil characteristics and climate change, remains limited. To address this gap, we analyzed data from a long-term monitoring site in an opencast coal mine reclamation region, focusing on the effects of species diversity, soil properties, and climate factors on the survival of four key restored species at 17, 22, and 27 years after planting. Our findings indicate that increased plot diversity is associated with decreased overall survival, and significant variations in diversity levels were observed among different plots. We also found that soil properties influenced species’ survival response to diversity, and these responses varied with stand age. In the early stages of succession, soil and diversity primarily affect species survival, with diversity playing a more dominant role as stand age increases. Overall, our findings suggest that the interaction between species diversity and soil composition significantly influences the survival of species. Continuous monitoring is necessary to validate these conclusions, particularly considering the diverse planting patterns in mine reclamation areas that can result in varying feedbacks of biodiversity on species survival.

As the key technology of high-step stripping and blasting engineering, throwing blasting will be the development trend of the production optimization and benefit maximization of the open-pit mine in the future. In order to break with the research idea of optimizing the cast blasting effect by improving the effective throwing rate for a long period of time, maximizing the economic benefit of the subsequent dragline stripping technology and stabilizing the engineering connection, this paper takes the Heidaigou open-pit mine as the research object. Through data acquisition, analysis, and data fusion of the heaped-up bulk characteristics, the heaped-up bulk profile can be obtained to characterize the cast blasting effect. Secondly, the key factors influencing the cast blasting effect are determined based on the gray relational degree theory. Then, the black box principle of the system control theory is adopted as the guiding principle of the blasting optimization. Based on the production data of field cast blasting, the dynamic change law between the controllable variables of system input and the observable variables of system feedback in the black box system are studied and explored without consideration of the internal structure or the energy transformation relationship of the cast blasting system. Finally, the optimal blasting parameter combination under different working conditions is obtained. If the research results are successfully applied, it is expected that the dragline stripping technology cost of the Heidaigou open-pit mine can be reduced by 5~10%, and the results can also provide new ideas and new ways of optimizing the design of cast blasting.

The mining of mineral resources has caused serious damage to the ecosystems of mining areas, resulting in the degradation of large areas of vegetation. In the Loess Plateau in particular, the ecological environment is fragile, and soil erosion is serious. It is urgent to restore vegetation and to improve the quality of the damaged environment. In the process of restoring the vegetation in the Pingshuo opencast mining area, this paper investigates the growth rates of species and the factors that affect these rates. The results showed that the maximum growth rate of Robinia pseudoacacia was 0.25 m/year in Mingled stand and 0.23 m/year in pure stand. The growth rate of R. pseudoacacia in Mingled stand was higher than that in pure stand, and the diversity indicators in the Mingled stand plots were higher than those in the pure stand plots. The stepwise regression analysis of the species diversity index, soil, and climate with the growth rate of the two plots showed that Margalef’s richness index had a significant effect on the growth rate of R. pseudoacacia in Mingled stands. This indicates that the R. pseudoacacia in our study area grows faster in mingled stand and that the Ulmus pumila and Ailanthus altissima that belong to the broad-leaved forest will grow together with R. pseudoacacia. The configuration pattern of broad-leaved pure stand is more singular than that of broad-leaved mingled stand, so the pure stand is not more suitable for vegetation restoration in the mining area.

A landslide of the north open-pit (323N) and the stability and design optimization of the south open-pit (323S) slope in the 323 belts of the Tanjianshan Gold Mine were studied. On 14 September 2020, a large landslide occurred on the east side of 323N, which posed a severe threat to the safety production of the mine. To avoid a similar slide on the south open-pit in the 323S, the limit equilibrium method was used to estimate the stability of the final slope of the designed initially open-pit in the 323N. The results show that the location and scale of the landslide are in good agreement with the three-dimensional laser scanning data. The effectiveness of the limit equilibrium method in slope stability analysis of the Tanjianshan Gold Mine was validated. The stability of the final slope of the initial design of 323S was analyzed. The sensitivity of the safety factor of homogeneous slope and heterogeneous rock slope to the bench face angle (BFA) and the difference of landslide type were compared and studied. When the spatial geometric relationship of rock masses with different lithology is complex, the engineering analogy method is inapplicable to calculation of parameters such as the BFA of heterogeneous rock slope and overall slope angle of the open-pit. The slope safety factor should be checked, and the slope step parameters are warranted to be optimized. The safety and economic benefits of the slope can be improved.

Dagushan Iron Mine is a large-scale open-pit mine. In this mine, the belt conveyors residing in the rock slope are employed for ore haulage. However, after the − 210 m bench was excavated, many fractures occurred in one of the roadways placing the belt conveyors. In this paper, this engineering case was introduced in detail and the fracturing mechanism was investigated numerically. A numerical model containing complex stratigraphy and geological conditions was built for fracturing mechanism analysis. The strain-softening constitutive model was adopted to describe the post-failure behavior of rock mass. The model was validated with field monitoring data and spot observations, and then used to analyze the interactions between the roadway and rock slope induced by bench excavation. The deformation and stress evolutions in the rock slope and the fracturing process of concrete lining were further clarified for this roadway-landslide system. The numerical results show that the − 210 m bench excavation activated the F14 and F15 faults (with activity initiating low and extending upwards) and generated large shear bands, forming an isolated potential sliding strip. The large displacement of the potential sliding strip acting on the roadway led to the fracturing of the concrete lining. The rock masses around the roadway have also been damaged severely. The control measures of slope cutting were suggested for future production and evaluated using the numerical model. It was found that the suggested control measures could manage the convergent deformation of the roadway to within the appropriate limit and ensure that the belt conveyor can be used for ore haulage until nearly the end of production. The suggested control measures are feasible and practical, and provide a reference for addressing similar engineering problems. Highlights: This paper reports an engineering case of the Dagushan open-pit mine in detail, which is about the fracturing of the concrete lining of the belt conveyor roadway induced by slope excavation. To investigate the fracturing mechanism, a numerical model containing complex stratigraphy and geological conditions was built and basically verified by the field monitoring data and spot observations. The numerical studies show that the -210m bench excavation activated faults from down to up to form an isolated possibly-sliding strip and the large displacement of the possibly-sliding strip acting on the roadway leading to the fracturing of the roadway concrete lining. Based on the requirement of the normal operation of the belt conveyors, control measures of slope cutting were suggested for future production and evaluated using the numerical model. The suggested control measures can ensure the belt conveyor serves the ore haulage until the whole production ends. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The truck–shovel system is the most common material transportation system in open-pit mines. The configuration of trucks and shovels directly affects the efficiency and cost of transportation in open-pit mines. Under the condition that the types and quantities of trucks and shovels are known, in order to obtain the optimal configuration scheme in the open-pit mine transportation system this paper presents a method to determine the optimal scheme by conducting experiments based on the simulation truck–shovel system model in Flexsim software. We test candidate configuration schemes that are solved by the mathematical model with daily minimum production and expected profit constraints in the simulation model, and finally obtain the optimal truck–shovel configuration scheme that meets the ore output requirements of each loading point. Through simulation experiments, the daily production of the optimal truck–shovel configuration scheme is 3.75% higher than that of the original mine scheme and the profit is increased by 3.85%. The results show that the open-pit truck–shovel system constructed by Flexsim has great research potential and value for the optimization of truck–shovel configuration schemes. [ABSTRACT FROM AUTHOR]

Contemporary off-grid mining operations rely on diesel fuel for the provision of their total energy including electricity, heat, and haulage. Given the high cost of diesel and its imposed greenhouse gas emissions, mining companies are looking for more affordable and cleaner sources of energy for their operations. Although renewable energy systems, such as solar photovoltaic and wind provide efficient solutions to address this challenge, full decarbonization has shown to be very challenging, mainly due to the high cost of battery storage along with the inability to meet total site energy demand. Integrating hydrogen and thermal storage with battery banks can facilitate a full transitioning off diesel. In this sense, the present study intends to offer an innovative decarbonized solution by integrating wind turbines with a multi-storage system (battery, hydrogen, and thermal storage) to supply the total energy (electricity, heat, and haulage) for remote open-pit mines. Among the different proposed fully decarbonized configurations in this study, it is shown that a renewable system with a hydrogen-powered fleet and hybridized battery/hydrogen storage configuration can present the most economically viable case for open-pit mines with a considerably less life-of-mine cost. [ABSTRACT FROM AUTHOR]

This study determines the safety-stability factors of the waste dump benches at different heights and analyses the deformation law, stress variation, and crack propagation characteristics of typical slope models. The meso-mechanical parameters obtained by discrete element numerical simulation are modified through slope radar monitoring data. The results show that the critical height of the dumping benches of the studied open-pit mine is 60 ~ 70 m, and the amount of bench settlement is positively correlated with the height of the benches. After the critical height is exceeded, the bench forms a three-wedge failure due to uneven settlement. [ABSTRACT FROM AUTHOR]

According to the remote sensing monitoring method of the ground deformation before mine landslide, the discrimination basis of the reliability of different orbit SAR data sets was proposed, and the inducing factors of landslide were analyzed. Taking the slope of the Anqian Yabaling open-pit mine in Anshan city as an example, using 44 Sentinel-1 radar images(two groups of ascending orbits and one group of descending orbit), the time series InSAR method was used to analyze the surface movement characteristics of the slope 6 months before the landslide occurred on November 25, 2019. The results show that the monitoring results obtained by different orbit data sets in the same studied area are different. The position of the top and rear edge of the landslide area showed an unusually strong acceleration within a period of time(approximately 45 days) before the landslide. The research results can provide new ideas for early identification of landslide hazard in mining areas using InSAR technology in the future. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The influence of different parameters on the offset tracking calculation results was analyzed. Then, the offset tracking method based on texture features was added to the offset tracking tool of SNAP8.0. Two offset tracking methods were combined to process the Sentinel-1 ascending and descending data. Two-dimensional deformation of the open-pit mine were calculated according to the geometry of ascending and descending observation. The results show that there are 6 large gradient deformation areas in waste dump, mining area, and stripping area. Vertical and east-west deformation ranges from -42.41 m to 40.71 m and -50.41 m to 42.80 m, respectively. In stripping area, vertical and east-west deformation reaches the maximum, which is -42.41 m and -50.41 m, respectively. The identified large gradient deformation is mainly located in the areas with frequent mining and dumping operations, Therefore, SAR offset tracking technology can effectively monitor the deformation in operation area of open-pit mine, so as to ensure the safe production and life in mining area.

With the advancement of the information revolution, the promotion of resource development and environmental protection concepts in recent years, deep-hole bench blasting technology in domestic open-pit mines is developing rapidly under the guidance of intelligent and green blasting mining concepts. In terms of blasting equipment, a large number of electronic detonators were widely used; In terms of blasting systems, the intelligent blasting technology integrating intelligent drilling rig system, intelligent design system, explosive on-site mixing, and other technologies had taken shape. In terms of blasting technology, blasting vibration prediction theory and control, dust control, and shock wave and noise prevention, etc. have effectively controlled of the harmful effects of blasting, and gradually achieved the requirements of green blasting. Lastly, the problems in blasting equipment and blasting technology were sorted out, and the future development and research directions of green intelligent blasting in open-pit mines were pointed out.

Landslides seriously threaten the safety of human life and property. In order to predict the on-set of potential landslides, this paper first characterizes the physical and mechanical parameters of rock mass on the basis of core rock quality designation identification, the geostatistics interpolation method, and the Hoek-Brown criterion. Then, the rock-mass physical and mechanical parameters characterization model was transformed to the slope numerical models, and the characteristics of potential landslides were predicted combined with the monitoring data and numerical simulation. Finally, on the basis of pairing between potential- and historical landslide cases, an early-warning indicator of a potential landslide was set as a posterior indicator of a historical landslide with the highest similarity. The results show that the potential landslide mode of the west and the southwest slope of the Wushan open-pit mine, the case study considered here, was a single-step wedge landslide and an integral-incline landslide. These two types of landslides were found to be most similar to those in the Anjialing open-pit mine and the Fushun West open-pit mine. Based on the posterior-warning indicator of the most similar landslide cases, the warning indicators of the west and southwest slope are set as 12.7 mm/d and 135.2 mm/d. The proposed method here provides a reference for the establishment of early-warning indicators for landslides in open-pit mines.

Automatic change detection based on remote sensing is playing an increasingly important role in the national economy construction. To address the problem of limited change detection accuracy in existing single-level difference networks, this study proposes the Multi-level Difference Network (MDNet) for automatic change detection of ground targets from very high-resolution (VHR) remote sensing images. An early-difference network and a late-difference network are combined by MDNet to extract multi-level change features. The early-difference network can focus on change information throughout to reduce the spurious changes in the change detection results, and the late-difference network can provide deep features of a single image for reducing rough boundaries and scattered holes in the change detection results, thus improving the accuracy. However, not all high-level features extracted by MDNet contribute to the recognition of image differences, and the multi-level change features suffer from cross-channel heterogeneity. Stacking them directly on channels does not make effective use of change information, thus limiting the performance of MDNet. Therefore, the Multi-level Change Features Fusion Module (MCFFM) is proposed in this study for the effective fusion of multi-level change features. In the experiments, the publicly available open-pit mine change detection (OMCD) dataset was used first to achieve a change detection of open-pit mines over a large area, with an F1-score of 89.2%, increasing by 1.3% to 5.9% compared to the benchmark methods. Then, a self-made OMCD dataset was used to achieve an F1-score of 92.8% for the localized and fine-scale change detection in open-pit mines, which is an improvement of 0.7% to 5.4% compared to the benchmark methods. Finally, the Season-varying Change Detection Dataset is used to verify that the MDNet proposed can detect changes in other scenarios very well. The experimental results show that the proposed MDNet has significantly improved the performance of change detection on the three datasets compared with six advanced deep learning models, which will contribute to the development of change detection with VHR remote sensing images.

To tackle the challenges posed by dense small objects and fuzzy boundaries on unstructured roads in the mining scenario, we proposed an end-to-end small object detection and drivable area segmentation framework for open-pit mining. We employed a convolutional network backbone as a feature extractor for both two tasks, as multi-task learning yielded promising results in autonomous driving perception. To address small object detection, we introduced a lightweight attention module that allowed our network to focus more on the spatial and channel dimensions of small objects without impeding inference time. We also used a convolutional block attention module in the drivable area segmentation subnetwork, which assigned more weight to road boundaries to improve feature mapping capabilities. Furthermore, to improve our network perception accuracy of both tasks, we used weighted summation when designing the loss function. We validated the effectiveness of our approach by testing it on pre-collected mining data which were called Minescape. Our detection results on the Minescape dataset showed 87.8% mAP index, which was 9.3% higher than state-of-the-art algorithms. Our segmentation results surpassed the comparison algorithm by 1 percent in MIoU index. Our experimental results demonstrated that our approach achieves competitive performance.

Automatic extraction of land use and land cover changes in mining areas is crucial for the supervision of mineral resources. This study proposes an automatic open-pit mine (OM) change detection method via a novel deep learning model, DA-UNet++ (Deformable-Attention-UNet++), and an object-based approach from high resolution remote sensing images. First, by embedding a deformable convolution module and attention mechanism module into UNet++ network, and constructing a skip sampling strategy, DA-UNet++ is proposed to combat the high heterogeneity of shape and scale of ground objects in OM environment and improve the change detection accuracy. Second, an object-based post-processing (OBPP) approach is presented for enhancing raw change detection results of DA-UNet++, which includes object-based expectation maximisation optimisation and morphological close operation. In the experiments, Season-varying Change Detection Dataset is first employed to evaluate the effectiveness of the proposed DA-UNet++ by comparing with other benchmark models. Then, self-made Ordos OM Change Detection Dataset including 38 OMs is utilised to verify the efficacy of the proposed method, and comprehensive metric F 1 − s c o r e of 85.6% is achieved. Evaluation results prove that the proposed method provides superior change detection performance compared with several benchmark methods, and has practical significance for OM management and monitoring. [ABSTRACT FROM AUTHOR]

5G communication network is vital to the intelligent and unmanned technology of open-pit mine, but the high cost of 5G base station deployment will bring huge cost increases to mining enterprises. Thus, this article proposes an improved sparrow search algorithm (SSA) using random walk strategy (RWSSA) to optimization the distribution and signal coverage of 5G base stations in open-pit mine. In order to verify the performance of the algorithm, the SSA, the modified ant lion optimizer, the particle swarm optimization, and the RWSSA were used to compare and analyze the accuracy and speed of the algorithm in solving high dimensionality benchmark functions, respectively. The dimensions used in the test are 30, 100, and 500 dimensions. After that, four algorithms were applied to a real example to optimize the deployment of 5G base stations, including macrobase stations and microbase stations. RWSSA has very good performance in terms of performance and practical application. Therefore, RWSSA is more suitable for the application of 5G base station distribution optimization in open-pit mines. [ABSTRACT FROM AUTHOR]

Cast blasting–dragline stripping technology is the most advanced mining technology used in open-pit mines. For a long time, however, its precision has been hindered. In this paper, we aim to improve the precision of cast blasting–dragline stripping technology and promote its intelligent design. We present a method to determine cast blasting stockpile forms. First, the 3D point cloud data for the Heidaigou open-pit mine from recent years were collected and counted, and a 3D mathematical model of overcasting stripping steps was constructed. Then, data classification and multivariate statistical analysis were used to establish a cast blasting stockpile characteristic parameter database. Next, locally weighted linear regression was used as the fitting method to achieve shape fitting under different cast blasting step heights. Finally, interval estimation was used as the fitting result test method to verify the morphology of the acquired cast blasting stockpile form. The research results show that the cast blasting stockpile form obtained by fitting can truly reflect the cast blasting effect of the Heidaigou open-pit mine and ensure the reliability and accuracy of the subsequent design of cast blasting–dragline stripping technology. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Mining Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nonferrous Metals (Mining Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A large amount of fog is generated during the shovel loading operation point in open-pit mine in winter, which blocks the driver􀆳s view, reduces mining and loading efficiency. Considering the actual situation and comparative analysis, the compressed air jet was proposed to disperse the fog. An open-pit mine was taken as the research object, a compressed air jet fog dispersal model of the shovel loading operation point in open-pit mine was established, using ANSYS Fluent to simulate the influence of outlet wind speed, fan installation number and installation angle on fog dispersal effect of compressed air jet. The results show that two compressed air jets with outlet wind speed of 39.7 m/ s can drive fog more effectively, and when the two compressed air jets are installed at an internal angle of 15°, the fog dispersal effect is well. The scheme was applied in the open-pit mine, the fog dispersal effect is obvious and the shovel driver's line of sight is improved. It can provide technical support for fog dispersal in winter at shovel loading operation point in open-pit mine in winter. [ABSTRACT FROM AUTHOR]

• The fixation of Cu in the mixture of composted sludge and soil will go through three stages. • Fulvic acid can induce Cu fixation on Albite by forming Chrysocolla. • More Cu can be fixed on the small particle size Albite. Fulvic acid (FA), typical organic matter derived from humification process in composted sludge, possesses the potential to remediate mine soils contaminated by heavy metals. To understand the cooper (Cu) immobilizing process in open-pit mine soil induced by FA, changes of Cu speciation in mixture of open-pit mine soil and composted sludge was tracked over 180 days. It was observed that the organic-bound and residual fraction of Cu increased dramatically with the corresponding decrease of Fe/Mn oxide-bound Cu in the first 60 days, then the organic-bound fraction decreased to about its initial proportion during 60-120 days, while residual fraction still increased, and the proportion of residual Cu accounted for over 85% and became stable after 120 days. To reveal the mechanism of FA inducing Cu fixation on Albite which is the main phase of soil primary ore, two groups of Cu adsorption experiments with and without FA were designed. With the addition of FA, the adsorption capacity of Cu by Albite increased by 1.55 times and the content of residual Cu in Albite increased by 7.7 times. It was found that the Cu absorbed in smaller Albite particle induced by FA formed a secondary mineral——Chrysocolla, causing increase of residual fraction of Cu. These results revealed the mechanism: FA was absorbed on the surface of Albite after complexing with Cu ions in the solution, and then it induced Cu into the interlayer and pore channels of Albite. The Cu in the Albite was immobilized by forming Chrysocolla finally. [Display omitted] [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Open-pit mine step height increase has positive significance for the enterprise, but the material of the dump is heterogeneous and discrete, and the mechanical properties of the lower materials are different with the increase of the height, so, it is necessary to refine the evaluation of the safety and stability of the slope while improving the height of the soil dumping step, and to optimize the height of the step from the perspective of safety. In this paper, the mechanical properties of the material under different consolidation pressures are obtained through laboratory test and numerical simulation of the material obtained from the dumping site of the open-pit mine in Tianchi Energy South Open-pit Mine, Xinjiang. By means of DEM numerical simulation, the change rule of the safety and stability coefficient of the dump steps in different areas and at different heights was obtained. The results show that with the increase of consolidation pressure, the degree of internal cementation and the mechanical strength of the sample increase. The instability of the inner dump slope will lead to circular arc landslide, which is characterized by uneven settlement at the top of the slope in the initial stage, and a large amount of slope particles rolling down in the later stage. When the strength reduction exceeds the safety stability factor, the velocity of the particles on the slope will change abruptly. The safety and stability coefficient and the step height change as a logarithmic function. The stability of the bottom dump step is better than that of the common dump step, and the bottom dump step cannot maintain stability when the height is 75 m.

During the production of open pit coal mine, coal seams with different natural index values of coal quality are often mined at the same time. In view of this phenomenon, the market competitiveness of enterprises can be improved through the balance of coal quality, so as to obtain greater economic benefits. Through the analysis of the natural index of coal quality, aiming at the ore whose coal sales purpose is determined or not determined, combined with the actual sales plan, the weight of each natural index of coal quality is determined by the method of subjectivity and objectivity, and the influence degree of the natural index of coal quality on the coal quality is accurately obtained. Through the improved VIKOR algorithm, the evaluation model of coal production use selection is established, and the optimal coal production use of open pit mine with undetermined coal sales purpose is obtained. The coal quality natural index and the production index of the open pit mine were prioritized, and the constraint equation and objective function were established to obtain the optimal mining range within a certain period of time, so as to ensure the realization of the goal of coal quality balance under the guidance of normal production.

Due to the complexity of road in open-pit mine, the existing truck travel time prediction methods are difficult in the actual deployment. This leads to the truck optimal scheduling system only realizing scheduling instead of optimization. A combined prediction model of truck multi-section travel time in open pit mine based on velocity field is proposed. The open-pit mine road is divided into multiple road sections. the random forest algorithm is used to construct the unit prediction model to predict the travel time of the truck in each section. Then the predicted values of the unit prediction models are accumulated to obtain the travel time predicted value of the truck on in the composite road section. In order to improve the prediction precision, the average velocity of the truck is taken as an influence factor of the travel time. The velocity field is constructed according to the collected velocity information of the truck. The average value of the truck velocity at all points on a road section is calculated, which is approximate to the average velocity of the truck on the road section, and the average velocity is input into the unit prediction model. Based on the data of truck schedule information in truck dispatching system of Yimin Open-pit Mine, the combined prediction model is trained, and the prediction precision and real-time performance of the model are tested. The results show that the combined prediction model of truck travel time in multiple sections of open-pit mine based on velocity field has high prediction precision for truck travel time in composite road sections. The average absolute error percentage is 4.81%, which is more than 2% lower than the single prediction model based on random forest algorithm. The operation time of the combined prediction model is less than 1 s, which can realize the real-time prediction of truck travel time.

During the production of open-pit mines, the stability of slopes can be affected by various factors such as structural surfaces, production blasting vibrations, and mining areas. In this study, the researchers focused on the slope of the open-pit mine at Yinshan and employed UAV mapping technology to conduct an on-site geological engineering investigation. Information on the yield, trace length, spacing, and density of the structural surface of the south slope was obtained. The researchers also carried out vibration blasting tests in combination with the production blasting activities in the mine to determine the blasting vibration attenuation law and whether the blasting vibration speed met safety specifications. Additionally, numerical simulation methods were used to examine the influence of the mining area on the stability of the current slope and the designed excavation slope. The slope stability was evaluated using the limit equilibrium method, and the researchers separately discussed the influence of self-weight load and self-weight load plus blasting vibration force on the stability of the high slope of the open pit. The results showed the following: (1) The rock mass structural plane in the south slope of the mining area was mainly dominated by a medium-large dip structural plane, and three faults and joint fissures in the investigation area combined to form cutting and sliding surfaces in the rock mass that were prone to collapse and sliding. (2) The maximum blasting vibration speed met safety requirements. (3) There was no large range of plastic zone damage in the entire slope, and the overall stability of the slope was good. (4) The present slope was relatively stable when considering only self-weight stress and the blasting vibration force. However, there was a certain risk of instability in the design of the excavation slope.

To address the problem of dust pollution caused by open limestone mining, a highly effective microbial dust suppression agent (MDS/PVAc) was successfully prepared using Bacillus megaterium and polyvinyl acetate (PVAc) as raw materials. The results showed that when 0.7 mol·L−1 cementing solution and 4% PVAc were added, and the bacterial concentration was 20% and the surface tension and contact angle of MDS/PVAc solution were 33.8 mN /m and 10.75°, respectively, which could effectively wet the dust and enhance its surface hardness up to 83 HA. Compared to water, the MDS/PVAc-treated dust showed stronger wind erosion and water resistance. In addition, the pores between the dust particles and those between adjacent particles were filled with calcite crystals produced by microbial mineralization, showing high thermal stability. The results show that Bacillus megaterium and polyvinyl acetate can improve the wettability and microbially mediated dust suppression, which is of great significance for mine dust treatment technology. [Display omitted] • Microbial dust-fixing suppressant was prepared for the of limestone open pit mine. • Microbial dust-fixing suppressant can consolidate limestone dust. • Dust suppression performance analysis and microscopic analysis; [ABSTRACT FROM AUTHOR]

The change of physical and mechanical properties of slope rock mass in open-pit mines in seasonally frozen area under the action of freeze–thaw cycles is one of the main reasons for slope instability. In this paper, taking the mechanical parameters of coal seam and sandstone layer in the Beitashan Pasture Open-Pit Mine in Xinjiang as the research object, considering the combined effect of the frost-heave tensile stress in the crack perpendicular to the crack surface and the three-dimensional confining pressure in the crack, the criterion for cracking of fractured rock mass under freeze-thaw condition is determined by applying the principle of stress superposition and the theory of strain energy density factor, and the theoretical frost-heave stress required for cracking is deduced. On this basis, the sensitivity analysis of the fixed factors and variable factors to the theoretical frost-heave stress was performed, respectively. Finite element analysis was utilized to analyze the slope stability under the attenuation of five groups of different rock mass mechanical properties and to determine the slope angle required for the slope stability. Seven different slope angles of sidewall mining ranging from 36° to 51° are analyzed. The results of finite element analysis show that considering the timeliness difference of rock mass parameters with time, the safety factor of slope is reduced from the original 1.70 to 1.18, and 91,500 tons of coal resources can be recovered every year, with remarkable economic benefits. [ABSTRACT FROM AUTHOR]

Ecological restoration of open‐pit mine wasteland is critical to the sustainable development of the mining industry. Using high‐throughput sequencing, we analyzed soil properties and nematode community structure and function to evaluate the impact of ecological package restoration on the quality of underground ecosystem reclamation in desert steppe open‐pit mine wasteland. After 7 years of ecological package restoration at an open‐pit quarry, two management methods (annual removal of dominant plant genera and annual reseeding of missing plants) achieved the expected outcomes of the restoration project (return to the conditions of the pre‐disturbed ecosystem). Based on LEfSe multi‐level discriminant analysis and shared genera analysis, we suggest that Oxydirus, Dorylaimus, Trichotylenchus, Plectus, Scutylenchus, Paratylenchus, Tylencholaimus, and Cephalobus may be the key soil nematode genera in the damaged open‐pit quarry ecosystem. We also evaluated the soil health status of different ecological package restoration time periods (2 and 5 years) at an abandoned desert steppe open‐pit iron mine by analysis of the soil properties and nematode communities. We suggest that ecological package restoration for 5 years achieved the expected restoration outcomes in the open‐pit iron mine wasteland. Based on LEfSe analysis and shared genera analysis, we suggest that Acrobeles, Microdorylaimus, Cehalobus, Tripylina, and Ecumenicus may be the key soil nematode genera in the damaged open‐pit iron mine ecosystem. Our findings provide a reference for evaluating the reclamation effect of ecological package restoration in open‐pit mine areas. [ABSTRACT FROM AUTHOR]

In this paper, the atmospheric flow field characteristics in a deep open-pit mine are investigated numerically and theoretically. A theoretical model on the recirculation length based on the energy equation is used, and a total variation diminishing (TVD) difference scheme with second-order accuracy is used to solve the NS equations with a standard two-equation k-ε turbulence model. The effects of elevated inner dump on the flow field characteristics of the open-pit mine are analyzed detailedly with the same inflow parameters. The results show that a recirculation zone exists in the open-pit mine due to the reflux from the high-pressure zone to the low-pressure zone. As the height of the inner dump increases, the flow becomes more complicated, and the low-pressure zone and the recirculation zone become bigger. The elevated inner dump makes it difficult for the internal fluid to flow to the outside, which results in the increase of the dust concentration. At last, the influences of key parameters on flow filed are conducted by normalizing the depth of the lowest direct current flow on the windward slope. The sensitivity analysis is done by study each influencing factor. This paper offers an effective way to study the flow field characteristics in an open-pit coal mine, which is essential to the dust pollution control of open-pit mine. [ABSTRACT FROM AUTHOR]

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In the process of open-pit coal mine production, mining and transport loss of excavator accessories, iron and other large ferromagnetic objects with the coal into the crusher, will result in crusher jammed, broken tooth damage and even motor burn down and other serious production accidents, based on the principle of low frequency eddy current detection can effectively detect ferromagnetic objects, the characteristics of the ferromagnetic objects open-pit mine secondary crushing plant movement monitoring research. Taking SANDVIK's CR610/14—35 double-tooth roller sieve crusher as the experimental object, the mechanism of the detection system was analytically modeled according to the principle of electromagnetic mutual induction. The results of modeling and experiments show that the eddy current generated by ferromagnetic objects is weak due to the existence of strong background noise. The signal to noise ratio(SNR)can be improved by optimizing the parameters of the detector and planning the path of the detector. According to the characteristics of the experimental object, the maximum SNR was obtained when the ratio of the radius of the metal to the detection distance was 0.048, and the ratio of the coil radius to the detection distance was 0.044 5. In the 1~35 kHz segment, the SNR is higher in the low frequency band than the high frequency band. The initial value and response time of the path entering the detection area perpendicular to the detection axis have obvious advantages over the path entering the detection area parallel to the axis.

In order to clarify the influence of the location of the external dumping on the stability of the open-pit slope, a two-dimensional theoretical model of composite slope is established, and the formula for calculating the safety factor of end-slope stability under the action of the dumping site is derived, and the mechanism of the influence of the distance between the external dumping and the end-slope on the safety factor of the slope is expounded. In addition, a three-dimensional numerical analysis model is established by using FLAC3D software, and the slope stability of the composite slope of the external dumping and the side slope of a mine in China is analyzed. The failure mechanism and characteristics of composite slope in open pit coal mine are expounded. By studying working conditions under the distance of 50 m, 70 m, 90 m, and 110 m between the dump and the side of the mine, it is found that the safety factor of the slope increases with the increase of the distance. The safety factors of the models with distances of 50 m and 70 m are relatively low. The safety factors have been improved obviously after the distance exceeds 90 m. At the same time, according to the calculated safety factors and displacement data of the simulated monitoring points, the safe distance between the dumping site and the side wall of the mine is 110 m.

In this paper, it is pointed out that there are several main problems in the construction of intelligent open-pit mines in China at this stage, such as independent systems, mainly relying on manual control, passive implementation of disaster monitoring and lack of intelligent analysis. Moreover, this paper explores the connotation of intelligent open-pit mines and defines the intelligent open-pit mines as a large intelligent driven system consisting of Internet of everything and platform integration. The underlying platform of intelligent open-pit mines based on industrial Internet of things cloud operating system is proposed. Real-time data is obtained by advanced programmable remote utility server via Modbus/OPC/PPI/MPI and other industrial protocols. Off-line data can be entered manually according to the needs of field work. These data can be connected to the existing ERP or manufacturing execution system of open pit mining enterprises to realize the seamless connection of external data. Based on the industrial Internet of Things cloud operating system MixIOT as the platform, raster database, offline database, statistical database, report database, etc. are established according to different data sources to realize routing, exchange and storage of all kinds of data in open pit mines. At the same time, industrial data analysis service system is used to analyze the operation of open-pit mine production equipment. The three key technologies of the underlying platform of intelligent open-pit mines are data acquisition technology, data analysis service technology and application display technology.

In an open-pit mine in Xinjiang, part of the stripped area is covered by burnt rock. Due to the low strength and fragility of burnt rock, dust is more easily generated during blasting. Taking the mining area as the research background, the mechanical property parameters of burnt rock were tested, and the blasting parameter design of on-site operation was understood. The blasting numerical simulation of burnt rock step was carried out by using a numerical simulation software (LS-DYNA). From the angle of stress on rock, the stress cloud and stress curve of numerical simulation are analyzed, and it is concluded that the fundamental reason for the large dust production in blasting operation is that the burnt rock is crushed excessively after the action of explosion wave, and the explosive energy is too large, which is converted into kinetic energy to drive the dust to escape. In order to improve the utilization rate of explosives and reduce the output of blasting dust, the original blasting parameters were optimized as 8-m hole spacing, 6.5-m row spacing, 0.21-kg/m³ unit explosive consumption, 1-m interval charge, and 55-ms short-delay blasting through numerical simulation and orthogonal experiment. In the mining area, the measures of dustproof and dust reduction by blasting protection blanket and dust absorption cotton are adopted. Combined with the optimized blasting parameters, the field test proves that the dust removal efficiency is up to 82.4%.

Blast fragmentation size distribution is one of the most critical factors in evaluating the blasting results and affecting the downstream mining and processing operations in open-pit mines. Image-based methods are widely applied to address the problem but require heavy user interaction and experience. This study deployed a deep learning model Mask R-CNN to develop an automatic measurement method of blast fragmentation. The model was trained using images captured from real blasting sites in Nui Phao open-pit mine in Vietnam. The trained model reported high average precision scores (Intersection over Union, IoU = 0.5) 92% and 83% for bounding box and segmentation masks, respectively. The results lay a solid technical basis for the automated measurement of blast fragmentation in open-pit mines. [ABSTRACT FROM AUTHOR]

An innovative scheme of induced caving by blasting was adopted in the depillaring continuous miner panel CM1 of Jhanjra Colliery of Eastern Coalfields Limited, a subsidiary of Coal India Limited. Initially, the blasting pattern was designed with respect to underground workings and later with respect to the surface, vertically above the panel, to facilitate effective caving. The natural caving was delayed due to the presence of three hard-rock beds of more than 5000 cavability index in the immediate roof of the R-VI seam in addition to the oversized left-out standing pillars kept during coal extraction in the panel, which provided extra supports to the hanging roof-rock in the goaf. To mitigate the situation, the design parameters were meticulously planned and implemented for successful blasting operations, which led to effective caving in the goaf and enabled successful extraction of the coal from the panel maintaining the required level of safety and productivity. [ABSTRACT FROM AUTHOR]

This paper analyzes the slope stability of inner dump covering end-slope after the end-slope mining of a domestic open-pit coal mine by means of theoretical analysis and numerical simulation. Firstly, the theoretical model of inner dump covering end-slope is established from two-dimensional view point. At the same time, the calculation formula of slope safety factor after inner dump covering end-slope is given, and the mechanism of slope safety improvement in this process is expounded. Then the numerical analysis software FLAC3D is used to analyze the stability of the end-slope without inner dump after the end-slope mining, and the process of inner dump covering end-slope is divided into three stages. According to the simulation results, the follow-up of the inner dump obviously reduces the shear strain increment of end-slope rock, and the deformation range and amount of rock also obviously reduce. Therefore, the inner dump can effectively improve the slope safety. Especially, in the early stage of the inner discharge work, the effect of increasing the stability of the end-slope is the best.