Mining, Metallurgy & Exploration最新文献

{"title":"Slope Stability Analysis of Opencast Mine Dump using the Limit Equilibrium Method—a Case Study","authors":"Syed Saarim Ahmad","doi":"10.1007/s42461-024-01081-4","DOIUrl":"https://doi.org/10.1007/s42461-024-01081-4","url":null,"abstract":"<p>Slope failures in mine overburden dumps are recurring incidents leading to the loss of life and property. Since slope stability depends on several factors that may vary over a period of time, such as slope parameters and material characteristics, regular slope stability studies performed periodically are necessary for assessing the risk of slope failure more effectively. This study aims to analyse the slope stability of opencast lignite mine overburden dump benches by determining the slope factor of safety via 2-D limit equilibrium software. On the basis of their factor of safety values, slopes are categorized as ‘highly stable’, ‘moderately stable’ and ‘unstable’. Among the three slopes analysed, two are moderately stable, and one is highly stable. Slopes with a factor of safety ≥ 1.3 are considered highly stable, and those with a factor of safety between 1 and 1.3 are considered moderately stable. Unstable slopes have a factor of safety of less than 1. Through a series of iterative procedures, the maximum permissible bench heights for high slope stability are determined. By comparing the results with the present bench heights, height reductions are recommended for each bench. The study found that the heights of benches with moderately stable slopes must be reduced by 10 to 15 m to achieve high slope stability. The heights of the upcoming benches are recommended not to exceed 50 m. This study not only analyses the present conditions of slope stability but also provides recommendations regarding bench heights for attaining high slope stability, thus providing an actionable conclusion that can be implemented in the current state of practice. Although the study has limitations in terms of applicability outside of opencast mines with soft strata, the methods described can prove to be valuable for determining how to approach and proceed with similar case studies on slope stability.</p>","PeriodicalId":18588,"journal":{"name":"Mining, Metallurgy & Exploration","volume":"11 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142249360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A New Model Test Method for Single-Fracture Oriented Roof-Cutting Technology","authors":"Shilin Hou, Yajun Wang, Jun Yang, Jun Zhang, Manchao He, Hongcai Li, Gang Yang, Gonghua Chen","doi":"10.1007/s42461-024-01079-y","DOIUrl":"https://doi.org/10.1007/s42461-024-01079-y","url":null,"abstract":"<p>Single-fracture Oriented Roof-cutting Technology (SORT) is a key technology in the pillarless self-formed roadway mining method, which is a popular and widely used new coal mining method in China. In previous model tests, SORT was usually replaced by chain saw cutting or pre-installed isolation boards. This resulted in its process and effect being not realistically simulated. To solve this problem, the process and rock-breaking mechanism of SORT were analyzed in detail in this paper. Meanwhile, some factors affecting the performance of SORT were discussed by using the sensitivity analysis method. Based on this, a new SORT model test method was proposed and verified by a series of experiments. The results show that the most critical factors affecting the technical effect of SORT are blasting energy and energy concentration coefficient. In the model tests, explosive materials with fast reaction speed and good detonation effect should be preferred. On the other hand, compared with flexible energy guiding devices, rigid devices can play a better role in energy focusing and guidance, thus maximizing the simulation of the technical effect of SORT. Based on this idea, a series of tests were carried out with Ningtiaota coal mine as the engineering background. According to the test data, the optimal explosive material was determined to be low-cost black powder composed of potassium nitrate, sulfur and other components. Pre-fabricated slit steel pipe was determined as the optimal energy guiding device. In addition, the optimal values of other parameters were determined, including slit energy agent dosage and simulation device spacing. Finally, the method and device proposed in this paper were applied in the model test. The results show that the model test results are in good agreement with the field monitoring data. This proves that the SORT model test method, device, and test parameters proposed in this paper are feasible. This provides a new reference idea for further research on the pillarless self-formed roadway mining method, as well as other research involving SORT.</p>","PeriodicalId":18588,"journal":{"name":"Mining, Metallurgy & Exploration","volume":"9 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142249364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial Clustering of Primary Geochemical Halos Using Unsupervised Machine Learning in Sari Gunay Gold Deposit, Iran","authors":"Mohammad Hossein Aghahadi, Golnaz Jozanikohan, Omid Asghari, Keyumars Anvari, Sajjad Talesh Hosseini","doi":"10.1007/s42461-024-01065-4","DOIUrl":"https://doi.org/10.1007/s42461-024-01065-4","url":null,"abstract":"<p>Identifying geochemical halos is critical in locating ore deposits and detecting deeper anomalies. This study presents an approach that combines unsupervised random forests and clustering large applications algorithms to identify intricate patterns in a borehole set of 29 elements data in a suspected gold mineralization area in Iran. The raw geochemical data goes through a log-ratio transformation, followed by staged factor analysis to identify ten main elements. The proposed methodology separated the ten main elements into three distinct halos. The clustering process was validated using various statistical parameters to substantiate the approach’s effectiveness in handling data outliers. The Sequential Indicator Simulation method was used as a geostatistical tool to perform conditional simulation of front, near-ore, and tail halos. Multivariate modeling revealed that the primary halos exhibit a specific spatial pattern encompassing the ore deposit, reinforcing the possibility of a more profound anomaly. The three-dimensional (3D) results obtained from this investigation were subsequently compared with existing geological reports and a comparative method (K-means). This comparison revealed the successful detection of the near-ore halo within the subsurface, extending from the Earth’s surface to a depth of 200 m. Existing geological reports and databases confirm that this halo is strongly associated with the oxide zone.</p>","PeriodicalId":18588,"journal":{"name":"Mining, Metallurgy & Exploration","volume":"11 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142249361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on Slope Instability Mechanism and Constant Resistance Large Deformation Anchor Cable Control Technology in Strongly Weathered Strata of Open-Pit Mine","authors":"Yang Xiaojie, Wang Jingxiang, Tao Zhigang, Liu Keyuan, Shen Fuxin","doi":"10.1007/s42461-024-01076-1","DOIUrl":"https://doi.org/10.1007/s42461-024-01076-1","url":null,"abstract":"<p>To investigate the failure mechanisms of slopes and develop an integrated approach for slope reinforcement, monitoring, and early warning, the Daye open-pit copper mine slope was selected as the case study. Initially, field investigations and analyses of engineering geological conditions were performed to elucidate the deformation instability mechanisms of the slope. Subsequently, a numerical model was established to evaluate the slope reinforcement efficacy of constant resistance large deformation (CRLD) anchor cables with different anchorage lengths. The results demonstrate that increasing the anchorage length of CRLD anchor cables leads to a reduction in total slope displacement and an enhancement in the slope safety factor. The axial force distribution within the slope was segmented into three distinct zones: concentration area, transition area, and stable area. The optimal safety factor was achieved at an anchorage length of 20 m. This study provides insights into the slope deformation mechanisms, the anchorage performance of CRLD anchor cables, and their optimal anchorage lengths. Based on the findings, an integrated scheme for slope reinforcement, monitoring, and early warning is proposed. The field application results indicate significant improvements in the stability of the Daye open-pit copper mine slope.</p>","PeriodicalId":18588,"journal":{"name":"Mining, Metallurgy & Exploration","volume":"6 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of U(-V) Deposits in the La Sal District, UT and CO and Their Relationship to Paradox Basin Fluid Flow","authors":"Eytan Bos Orent, Mark D. Barton, Isabel F. Barton","doi":"10.1007/s42461-024-01062-7","DOIUrl":"https://doi.org/10.1007/s42461-024-01062-7","url":null,"abstract":"<p>This paper synthesizes new and previous work on the tabular sandstone-hosted uranium and vanadium deposits of the La Sal district, one of the principal U-V districts of the Colorado Plateau. Deposits form a 1–3 km wide, E-W trending 30 km long trend spanning the Utah-Colorado border, approximately orthogonal to the Uravan belt. Ore is hosted in the uppermost fluvial subarkosic sandstones of the Salt Wash Member of the Jurassic Morrison Formation and typically forms channel-parallel, elongate orebodies up to 180 m long, 90 m wide, and 1 m thick. Sandstones are interbedded with silty, muddy, and calcareous units. Principal mineralogical changes include quartz overgrowths accompanied by destruction of early diagenetic hematite. Precipitation of compositionally distinct carbonate cements and clays followed. Bleaching was prior to and/or contemporaneous with mineralization, which is restricted to bleached rocks. Petrography shows that ore minerals (uraninite, coffinite, and montroseite) in part predate growth of authigenic quartz and calcite cements, followed by the formation of ferroan dolomites. Abundant V-rich phyllosilicates may reflect back-reaction of montroseite with quartz and other minerals. New U-Pb dating of ore-hosting calcite (~144 Ma) and K-Ar dating of V-clays (~42–36 Ma) parallel published results for elsewhere on the Plateau. Sedimentary structures (e.g., crossbedding), primary porosity, and the distribution of lithofacies in the local Salt Wash channel system control mineral growth. The thin section- to district-scale observations suggest that mineralization formed either by mixing of two fluids, or alternatively by reaction of oxidized fluids with a reductant earlier introduced during bleaching, as has been suggested in other Plateau deposits.</p>","PeriodicalId":18588,"journal":{"name":"Mining, Metallurgy & Exploration","volume":"11 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of In-Situ Creep Behavior of Coal Mine Waste Dumps Using GBInSAR for Landslide Failure Prediction","authors":"Anup Tiwari, Monika Tewari, Khanindra Pathak, Bibhuti Bhusan Mandal","doi":"10.1007/s42461-024-01077-0","DOIUrl":"https://doi.org/10.1007/s42461-024-01077-0","url":null,"abstract":"<p>Landslides pose significant geohazards in both mining and natural slopes, necessitating effective temporal prediction of failure for slope-scale mitigation. The conventional understanding of creep behavior, derived from controlled laboratory testing, often falls short in explaining the dynamic in-situ creep characteristics of heterogeneous soil slopes. This study presents in-situ creep assessments through continuous displacement monitoring of an inactive coal mine waste dump, employing Ground-Based Interferometric Synthetic Aperture Radar (GBInSAR). This study explores the applicability of the inverse velocity (IV) method for landslide failure prediction. Additionally, it evaluates the performance of two widely adopted filters, namely, moving average and exponential smoothing. In contrast to prior findings, the study reveals a distinct pattern in the IV vs. time curve, transitioning from an initial linear trend to a new steady-state. Notably, the research highlights instances of false predictions, underscoring the importance of considering potential stick–slip behavior, particularly in dump slopes. Furthermore, the findings on tension crack formation and propagation offer insights crucial for selecting an appropriate constitutive model tailored to the characteristics of the waste dump. The findings from this study contribute valuable knowledge to the field of slope stability assessment and aid in refining the methodologies for accurate landslide failure prediction in complex, real-world scenarios.</p>","PeriodicalId":18588,"journal":{"name":"Mining, Metallurgy & Exploration","volume":"8 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Assessment of Interventions to Improve Underground Coal Miners’ Ability to Self-Escape Using Human-Centered Design Methods","authors":"Eugene A. Gyawu, Danise A. Baker, Kwame Awuah-Offei","doi":"10.1007/s42461-024-01067-2","DOIUrl":"https://doi.org/10.1007/s42461-024-01067-2","url":null,"abstract":"<p>The literature lacks analysis of human systems integration approaches for self-escape in mining. This research aimed to gather feedback from miners to identify technological interventions that could support their ability to perform critical self-escape tasks. We solicited feedback on the usefulness of 21 proposed interventions to improve confidence in self-escape knowledge, skills, and abilities (KSAs) and evaluate relationships between the interventions and specific demographic parameters of miners. We also analyzed decisions by miners to shelter in place or escape in an underground coal mine fire emergency in relation to how miners’ decisions affect the perceived usefulness of the interventions. This research utilizes a novel scenario-based survey to collect feedback from 116 miners. The results show that the miners ranked interventions related to self-contained self-rescuers (SCSRs) and refuge alternatives (RAs) as the most useful. Surprisingly, the demographic variables we examined did not differentially affect the perceived usefulness of the 21 interventions. Interestingly, participants who reported they would shelter-in-place (~ 48%) also thought all 21 interventions were more useful, with 11 out of 21 being statistically significantly higher at a 0.05 significance level. Future research will directly apply the results of this study to a series of proof of concept and prototype studies aimed at improving self-escape interventions through human systems integration.</p>","PeriodicalId":18588,"journal":{"name":"Mining, Metallurgy & Exploration","volume":"23 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the Flame Propagation Characteristics of Multi-point Methane Explosions in Long and Narrow Confined Spaces","authors":"Wen Jiang, Yi Qin, Ning Lu, Shimei Dai, Zhihao Zhang","doi":"10.1007/s42461-024-01075-2","DOIUrl":"https://doi.org/10.1007/s42461-024-01075-2","url":null,"abstract":"<p>To investigate the injuries caused by multi-point gas deflagration accidents within the complex environment of a mine, this paper conducts a numerical study of the flame propagation of methane explosions in a ventilation door and supporting structures. The effects of ignition source position, number, and changes in the state of the ventilation door were analyzed based on explosion simulation with three different ignition source settings. The results show that the interplay between the increased number of ignition sources and the confining effect of the flame significantly affected the structural evolution of the flame. After crossing the ventilation doors, the flame structure transitions to forms such as umbrella flame, columnar flame, tip flame, or twisted flame. In the early stages of flame propagation, reflected pressure waves are the main cause of changes in flame propagation velocity. As the reaction proceeds, the cause changes to an interaction between the turbulent flame, the chemical reaction, and the reflected pressure wave. The speed of a single ignition source passing through the ventilation door was 172.5 m/s, while the speeds of two ignition sources at increasing distances were 146.6 m/s and 115 m/s, respectively. Therefore, the speed of the flame passing through the ventilation door is inversely proportional to the number of ignition sources and inversely proportional to the distance between the ignition sources. Additionally, with two-point fire sources, the more distorted the vortex distribution, the more twisted the flame propagation shape. This study addresses the lack of research on the flame propagation characteristics of methane explosions in long and narrow confined spaces, which is crucial for gas explosion risk prevention.</p>","PeriodicalId":18588,"journal":{"name":"Mining, Metallurgy & Exploration","volume":"54 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Challenges in the Battery Raw Materials Supply Chain: Achieving Decarbonisation from a Mineral Extraction Perspective","authors":"Landon Jackson, C. Meinke, R. Chandramohan","doi":"10.1007/s42461-024-01070-7","DOIUrl":"https://doi.org/10.1007/s42461-024-01070-7","url":null,"abstract":"<p>Understanding constraints within the raw battery material supply chain is essential for making informed decisions that will ensure the battery industry’s future success. The primary limiting factor for long-term mass production of batteries is mineral extraction constraints. These constraints are highlighted in a first-fill analysis which showed significant risks if lithium-ion batteries are utilised to fully support vehicle electrification and intermittent energy storage. Nickel, lithium, cobalt, and graphite reserves risk 100% depletion with significant consumption of known resources. Furthermore, over 700 new critical mineral mines will need to be developed to meet the required production rates for decarbonisation by 2050. Demand for critical minerals will out-pace mine development timelines even as improvements are made to battery energy density and compositions. Governments and the private sector need to align themselves on decarbonisation goals to establish cooperative agreements on the critical mineral supply chain by reducing the barriers to entry and increasing exploration efforts. Additional measures must also be taken to reduce the demand for critical minerals. Policy such as incentivising public transportation and biking infrastructure can be exploited to drastically reduce the mineral demand placed on the mining industry.</p>","PeriodicalId":18588,"journal":{"name":"Mining, Metallurgy & Exploration","volume":"33 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing Tunnel Excavation: Intelligent Algorithms for Accurate Overbreak Prediction","authors":"Hadi Fattahi, Hamid Reza Nejati, Hossein Ghaedi","doi":"10.1007/s42461-024-01074-3","DOIUrl":"https://doi.org/10.1007/s42461-024-01074-3","url":null,"abstract":"<p>Excavating tunnels has become a widespread practice in the modern world, driven by the need for efficient transportation, subterranean storage, and mineral supply. One challenge encountered during tunnel excavation is the overbreak (OB) phenomenon, particularly prominent when utilizing drilling and blasting techniques. OB poses a risk by increasing operational expenses and compromising workplace safety. Therefore, accurately predicting the occurrence of OB during tunnel excavation is crucial. While various methods exist to forecast OB, traditional approaches like experimental, analytical, numerical, and regression methods face limitations due to uncertainties in geological and geotechnical parameters. In this paper, the use of Teaching–Learning-Based Optimization (TLBO) and Firefly (FF) algorithms is proposed to predict OB, aiming to fully comprehend the physical and mechanical characteristics of the rock mass while considering uncertainties and optimizing project completion in terms of cost and time. The model was constructed using data from three case studies: an Indian mine; the Azad tunnel on the Tehran-North route in Alborz, Iran; and the underground coal mine Tarzareh, comprising 217 data points. Parameters affecting the OB phenomenon in this study include rock mass rating (RMR), specific drilling (SD), perimeter holes powder factor (PPF), and spacing to burden ratio of contour holes (S/B). The dataset was divided into two groups: 80% for training the model and 20% for testing the relationship. To evaluate the model, statistical indices such as squared correlation coefficient (<i>R</i>²), root mean square error (RMSE), and mean square error (MSE) were used. The validation results indicated that the TLBO and FF algorithms performed satisfactorily, demonstrating high accuracy and low error. This suggests that engineers, scientists, and practitioners can benefit from employing intelligent approaches in mining and rock mechanics-related operations, utilizing the accurate model generated by these algorithms.</p>","PeriodicalId":18588,"journal":{"name":"Mining, Metallurgy & Exploration","volume":"2 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142183278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}