The rehabilitation of coal mines is an up-to-date issue, heavily discussed not only by the industry but also by scientists and the adjacent communities since open cut coal mining has extensive impacts affecting all pa...The rehabilitation of coal mines is an up-to-date issue, heavily discussed not only by the industry but also by scientists and the adjacent communities since open cut coal mining has extensive impacts affecting all parties. Whereas, before and during the mining process not only nature but sometimes also the population of a whole region has to give way to a mine, the consequences of the operations remain long after mining closure. Typically a once intact and functioning ecosystem is replaced with a destroyed wideness evocative of a moon landscape. Fortunately, the awareness of the need to rehabilitate the destroyed nature is increasing steadily and all involved parties are making efforts to improve the situation, even if it is a major challenge to bring all parties to a consensus. Therefore, a legislative basis is required and the know-how of optimal rehabilitation solutions must be developed. In this article the rehabilitation of mined land in Australia and Germany are compared. More precisely the article will present an overview of the legislative regulations, certain applied methods of rehabilitation work and the problems that are likely to occur in respect to the influence of mining on nature.展开更多
Deep Underground Science and Engineering(DUSE)is pleased to present this special issue on Groundwater and Stability in Deep Mining.As mining operations progress to greater depths to meet the growing global demand for ...Deep Underground Science and Engineering(DUSE)is pleased to present this special issue on Groundwater and Stability in Deep Mining.As mining operations progress to greater depths to meet the growing global demand for mineral resources and energy,the challenges associated with groundwater control and rock mass stability have grown increasingly critical.These challenges are exacerbated by complex geological conditions,structural heterogeneity,and intense mining-induced disturbances.This special issue seeks to address these challenges by showcasing cutting-edge research and technological advancements in the field.展开更多
Development of deep underground mining projects is crucial for optimum extraction of mineral deposits.The main challenges at great depth are high rock stress levels,seismic events,large-scale deformation,sudden failur...Development of deep underground mining projects is crucial for optimum extraction of mineral deposits.The main challenges at great depth are high rock stress levels,seismic events,large-scale deformation,sudden failures and high temperatures that may cause abrupt and unpredictable instability and collapse over a large scale.In this paper,a ground control and management strategy was presented corresponding to the three stages of projects:strategic design,tactical design and operational design.Strategic design is results in preparing a broad plan and primary design for mining excavations.The tactical design is to provide detail design such as stabilisation methods.Operational design stage is related to monitoring and updating design parameters.The most effective ground control strategies in this stage are maintenance,rehabilitation,monitoring and contingency plan.Additionally,a new procedure for design of ground support systems for deep and hard rock was proposed.The main principles are:static and/or dynamic loading types,determination of loading sources,characterisation of geological conditions and the effects of orientation of major structures with openings,estimation of ground loading factor,identification of potential primary and secondary failures,utilisation of appropriate design analysis methods,estimation of depth failure,calculation of the static and/or dynamic demand ground support capacity,and selection of surface and reinforcement elements.Gravitational force is the dominant loading force in low-level stresses.In high stress level failure mechanism becomes more complex in rock mass structures.In this condition,a variety of factors such as release of stored energy due to seismic events,stress concentration,and major structures influence on ground behaviour and judgement are very complicated.The key rock engineering schemes to minimise the risk of failures in high-stress levels at great depth involve depressurisation and quality control of materials.Microseismic and blast monitoring throughout the mining operations are required to control sudden failures.Proper excavation sequences in underground stopes based on top-down,bottom-up,centre-out and abutment-centre were discussed.Also,the performance of a ground support system was examined by field observation monitoring systems for controlling and modifying ground support elements.The important outcome of the research is that the proposed procedure of selecting ground support systems for static and dynamic situations was applied in several deep underground mines in Western Australia.Ground behaviour modes and failure mechanism were identified and assessed.Ground demand for static and dynamic conditions was estimated and an appropriate ground support system was selected and evaluated in site-specific conditions according to proposed method for ground support design at great depth.The stability of rock masses was confirmed,and the reliability of the design methodology for great depth and hard rock conditions was also justified.展开更多
Rising demand for minerals and metals in high-tech and new energy industries has led to a great interest in exploration of seabed mineral resources.Such resources,including polymetallic nodule(PMN),polymetallic sulphi...Rising demand for minerals and metals in high-tech and new energy industries has led to a great interest in exploration of seabed mineral resources.Such resources,including polymetallic nodule(PMN),polymetallic sulphide(PMS),and cobalt-rich ferromanganese crust(CFC),are considered as an alternative source of metals to terrestrial deposits.Although a considerable number of sea trials of deep-sea mining have been carried out,the deep-sea mining does not achieve the commercial exploitation due to the complexity of deep-sea mining system and deep-sea mining environment.In fact,to achieve commercial deep-sea mining,the technology and equipment of deep-sea mining are the key points.Therefore,the present study presents the development of the technology and equipment of deep-sea mining.It commences with a requirement of technology and equipment for deep-sea mining,including environmental impact,reliability,energy cost,efficiency,etc.Then,a historical perspective and present-day effort related to deep-sea mining vehicles are given,which highlights the evolution of collection mechanism and walking mode of deep-sea mining vehicle.Subsequently,the present study discusses the operation of subsea lifting system and surface support system,shedding light on the crucial equipment and processes.The challenges and prospects in the deep-sea mining are presented in final,including environmental protection,self-propelled crawler,hydraulic pipeline lifting,and intelligent equipment,etc.展开更多
Shear strain energy is a pivotal physical quantity in the occurrence of earthquakes and rockbursts during deep mining operations.This research is focused on understanding the changes in shear strain energy in the cont...Shear strain energy is a pivotal physical quantity in the occurrence of earthquakes and rockbursts during deep mining operations.This research is focused on understanding the changes in shear strain energy in the context of retreating longwall mining,which is essential for the optimized design and mitigation of rockbursts and seismic events.Through the application of innovative analytical models,this study expands its analytical range to include the variations in shear strain energy caused by fault coseismic slip.An integrated methodology is utilized,taking into account the changes in coseismic and fault friction parameters as well as enhancements in mining-induced stress and existing background stresses.Our numerical investigation highlights the significance of mining location and fault characteristics as key determinants of shear strain energy modifications.The analysis demonstrates significant spatial variability in shear strain energy,especially noting that fault slip near the mining face greatly increases the likelihood of rockburst.This finding emphasizes the need to integrate fault coseismic slip dynamics into the triggering factors of rock(coal)bursts,thus broadening the theoretical foundation for addressing geological hazards in deep mining operations.The results are further corroborated by observational data from the vicinity of the F16 fault zone,introducing the concept of mining-induced fault coseismic slip as an essential element in the theoretical framework for understanding rockburst triggers.展开更多
An application programming interface (API) usage specifcation, which includes the conditions, calling sequences, and semantic relationships of the API, is important for verifying its correct usage, which is in turn cr...An application programming interface (API) usage specifcation, which includes the conditions, calling sequences, and semantic relationships of the API, is important for verifying its correct usage, which is in turn critical for ensur-ingthe security and availability of the target program. However, existing techniques either mine the co-occurring relationships of multiple APIs without considering their semantic relationships, or they use data fow and control fow information to extract semantic beliefs on API pairs but difcult to incorporate when mining specifcations for mul-tipleAPIs. Hence, we propose an API specifcation mining approach that efciently extracts a relatively complete list of the API combinations and semantic relationships between APIs. This approach analyzes a target program in two stages. The frst stage uses frequent API set mining based on frequent common API identifcation and fltra-tionto extract the maximal set of frequent context-sensitive API sequences. In the second stage, the API relationship graph is constructed using three semantic relationships extracted from the symbolic path information, and the speci-fcationscontaining semantic relationships for multiple APIs are mined. The experimental results on six popular open-source code bases of diferent scales show that the proposed two-stage approach not only yields better results than existing typical approaches, but also can efectively discover the specifcations along with the semantic rela-tionshipsfor multiple APIs. Instance analysis shows that the analysis of security-related API call violations can assist in the cause analysis and patch of software vulnerabilities.展开更多
Deep-sea mining has emerged as a critical solution to address global resource shortages;however,the mechanical interaction between tracked mining vehicles(TMVs)and soft seabed sediments presents fundamental engineerin...Deep-sea mining has emerged as a critical solution to address global resource shortages;however,the mechanical interaction between tracked mining vehicles(TMVs)and soft seabed sediments presents fundamental engineering challenges.This study establishes a multiscale modelling framework coupling the discrete element method(DEM)with multi-body dynamics(MBD)to investigate track-seabed dynamic interactions across three operational modes:flat terrain,slope climbing,and ditch surmounting.The simulation framework,validated against laboratory experiments,systematically evaluates the influence of grouser geometry(involute,triangular,and pin-type)and traveling speed(0.2–1.0 m/s)on traction performance,slip rate,and ground pressure distribution.Results reveal rate-dependent traction mechanisms governed by soil microstructural responses:higher speeds enhance peak traction but exacerbate slip instability on complex terrain.Critical operational thresholds are established—0.7 m/s for flat terrain,≤0.5 m/s for slopes and ditches—with distinct grouser optimization strategies:involute grousers achieve 35%–40%slip reduction on slopes through progressive soil engagement,while triangular grousers provide optimal impact resistance during ditch crossing with 30%–35%performance improvement.These findings provide quantitative design criteria and operational guidelines for optimizing TMV structural parameters and control strategies,offering a robust theoretical foundation for enhancing the performance,safety,and reliability of deep-sea mining equipment in complex submarine environments.展开更多
Using electric motors instead of diesel engines as the driving system for mining excavators can reduce the energy consumption and operating costs.However,pure electric-driven mining excavators are prone to unexpected ...Using electric motors instead of diesel engines as the driving system for mining excavators can reduce the energy consumption and operating costs.However,pure electric-driven mining excavators are prone to unexpected power outages in mines because of drastic changes in load power,leading to significant fluctuations in the power demand of the grid,which in turn affects production.To solve the above problem,a pure electric-driven mining hydraulic excavator based on electric-motor-driven swing platform and hydraulic pumps was used as the research object.Moreover,supercapacitors and DC/DC converter,as the energy storage system(ESS)adjust the output power of the grid and recover the braking kinetic energy of the swing platform.Subsequently,a novel integrated energy management strategy for a DC bus voltage predictive controller based on the power feedforward of fuzzy rules is proposed to run mining excavators efficiently and reliably.Specifically,the working modes of the ESS are determined by the DC bus voltage and state of charge(SOC)of the supercapacitor.Next,the output power of the supercapacitor and the DC bus voltage were controlled by adjusting the charging and discharging currents of the DC/DC converter using a predictive controller and fuzzy rules.In addition,a digital prototype of the excavator was verified using an original machine test.The performance of the different strategies and driven systems were analyzed using digital prototypes.The results showed that,compared with traditional excavators with diesel engines,the operational cost of the developed excavators was reduced by 54.02%.Compared to pure electric-driven excavators without an ESS,the peak power of the grid for the developed excavators was reduced by 10%.This study designed an integrated energy management strategy for a pure electric mining excavator that can regulate the power output of the grid and maintain the stability of the bus voltage and SOC of the ESS.展开更多
To address the critical gap in linking multi-compartmental transfer with risks of trace metals(Cd,Pb,As,Cr,Ni)in mining environments.This study systematically investigated the trans-media migration of Cd,Pb,As,Cr,and ...To address the critical gap in linking multi-compartmental transfer with risks of trace metals(Cd,Pb,As,Cr,Ni)in mining environments.This study systematically investigated the trans-media migration of Cd,Pb,As,Cr,and Ni in China’s Dexing copper mining district through paired sampling of water-amphibians,soil-earthworms,and air-lichens.Advanced methodologies were employed,including ICP-MS quantification for heavy metals,geochemical indices(Igeo,BCF,BAF)to assess bioavailability,NMDS for source apportionment,and HPLC to detect DNA methylation alterations.Aquatic systems exhibited severe Cd/Pb enrichment(16.25-24.42μg/L;11-15×WHO limits),while agricultural soils showed extreme Cd contamination(1.5 mg/kg;15×background).Biota displayed metal-specific accumulation:frogs achieved BCFs>1,000 for Pb/Cd,earthworms showed pH-modulated BAFs>2.5 for Cd/As,and lichens recorded 100-1,000×atmospheric Cr enrichment.NMDS resolved three contamination pathways:mining-derived Cd/Pb/As(MDS1=2.56),atmospheric Cr(PC2=1.84),and geogenic Ni.Cd dominated ecological risks(Eri=554.25;RI 300),while atmospheric Cr drove carcinogenic risks(TCR=4.11×10^(-5))exceeding safety thresholds.The source-media-biota-risk framework pioneers the integration of geochemical transport with epigenetic toxicity biomarkers,demonstrating that sub-lethal Cd/Pb exposure induces genome-wide DNA hypomethylation(2.4%-6.6%reduction;ρ=−0.71 to−0.91).This paradigm shift prioritizes bioavailability-informed regulations over concentration-based metrics,offering actionable strategies for sustainable development goals-aligned mining pollution control.展开更多
A deep-sea mining riser is a crucial component of the system used to lift seafloor mineral resources to the vessel.It is prone to damage and failure because of harsh environmental conditions and internal fluid erosion...A deep-sea mining riser is a crucial component of the system used to lift seafloor mineral resources to the vessel.It is prone to damage and failure because of harsh environmental conditions and internal fluid erosion.Furthermore,damage can impact the response characteristics of the riser,but varying environmental loadings easily mask it.Thus,distin-guishing between riser damage and environmental effects poses a considerable challenge.To address this issue,a cantilevered model is created for a deep-sea mining riser via the concentrated mass method,and a time-domain analytical strategy is developed.The vortex-induced vibration(VIV)response characteristics of the riser are initially examined,considering various damage conditions and flow velocities.The study results revealed four primary observations:(a)effective tension can serve as a reliable indicator for identifying damage at lower velocities;(b)there are noticeable differences in displacement between the healthy and damaged risers in the in-line direction rather than the cross-flow direction;(c)frequency characteristics can more effectively distinguish the damage conditions at high flow velocities,with the mean square frequency and frequency variance being more effective than the centroid frequency and root variance frequency;(d)displacement differences are more sensitive to damage occurring near the top and bottom of the riser,while both velocity variations and structural damage can influence displacements,especially in regions between modal nodes.The vibrational behavior and damage indicators are clarified for structural health monitoring of deep-sea mining risers during lifting operations.展开更多
1.Introduction Changes in land use are key factors promoting global climate change,and the side effects of mining activity that destroy the soil,vegetation,and biodiversity lead to imbalanced carbon cycling in terrest...1.Introduction Changes in land use are key factors promoting global climate change,and the side effects of mining activity that destroy the soil,vegetation,and biodiversity lead to imbalanced carbon cycling in terrestrial ecosystems.展开更多
Copper smelting is the main source of arsenic pollution in the environment,and China is the largest country for copper smelting.Taking 2022 as an example,this study analyzes the distribution and fate of arsenic across...Copper smelting is the main source of arsenic pollution in the environment,and China is the largest country for copper smelting.Taking 2022 as an example,this study analyzes the distribution and fate of arsenic across the copper mining,beneficiation,and smelting processes using a life-cycle approach,providing important insights for arsenic pollution prevention and the resource utilization of arsenic-bearing solid waste.The results show that the amount of As in waste rock,tailing and concentrate are 53483 t,86632 t,76162 t,respectively.After smelting treatment,the amount of arsenic in different types of solid waste,wastewater,waste gas and products are 76128 t,1 t,31 t and 2 t,respectively,and the proportion in arsenic sulfide slag is the highest(55%).The amount of emission to the environment is 32 t,accounting for only 0.04%of total amount.In the future,key considerations are to improve the resource utilization rate of arsenic-containing solid waste(tailing,smelting slag),especially arsenic sulfide slag,and to digest its environmental risk.展开更多
Aseptic osteonecrosis of the femoral head is defined as the death of bone cells in the femoral epiphysis due to an interruption of blood supply. Most cases are linked to trauma, but non-traumatic cases also occur and ...Aseptic osteonecrosis of the femoral head is defined as the death of bone cells in the femoral epiphysis due to an interruption of blood supply. Most cases are linked to trauma, but non-traumatic cases also occur and can be associated with several known risk factors. This study aims to describe these risk factors identified in the former Katanga province, a region with significant mining activity. Method and Patients: This is a descriptive cross-sectional study conducted over a seven-year period (2017-2024), including all cases of aseptic osteonecrosis of the femoral head diagnosed in the orthopedic department of Medpark Clinic in Lubumbashi. The investigation of risk factors was based on the analysis of sociodemographic, clinical, radiological, and biological data. Results: Our study included a total of 110 patients with a mean age of 47.5 years. Among them, there were 46 women (41.82%) and 64 men (58.18%). Twenty-five patients (27.5%) reported a family history of osteonecrosis, and 24% were diagnosed with sickle cell disease. Chronic alcoholism was noted in 14 patients (12.73%), while diabetes was present in 8 (7.2%). Four patients (3.64%) were obese, and three were HIV-positive (2.72%). The use of nonsteroidal anti-inflammatory drugs (NSAIDs) was common, and prolonged corticosteroid use was documented in 5 patients (4.5%). Abnormally high cholesterol levels were found in 26 patients (23.6%). One patient had gout, and two suffered from acute rheumatic fever (1.8%). Regarding inflammatory markers, C-reactive protein levels and erythrocyte sedimentation rates were within normal limits for almost all patients. Electrolyte levels and phosphocalcic profiles showed no abnormalities. Furthermore, 33 patients (30%) did not exhibit any of the previously mentioned risk factors. Most of these patients lived in the regions of Kolwezi, Likasi, and Lubumbashi. Among this group, 25 patients reported performing physically demanding labor, particularly in mining operations. Conclusion: Our study highlighted well-known risk factors for osteonecrosis of the femoral head (ONFH). However, it also identified a significant number of cases without any identifiable risk factors, classified as idiopathic. Among these cases, some patients engaged in intense physical labor, often linked to mining exposure.展开更多
We document,for the first time,Mesoproterozoic-aged,continental arc magmatism in the Tasmanides.Granitoid samples intruding the Proterozoic Cape River Metamorphics in northeast Queensland contain abundant∼1200 Ma ign...We document,for the first time,Mesoproterozoic-aged,continental arc magmatism in the Tasmanides.Granitoid samples intruding the Proterozoic Cape River Metamorphics in northeast Queensland contain abundant∼1200 Ma igneous zircons,with early-Paleozoic metamorphic rim overgrowths.Analytical mixing between the igneous and metamorphic zircons produces cryptic discordant analyses,but the origin of said discordance is resolved with zircon Th/U ratios.Samples of the Fat Hen Creek Complex are peraluminous,calc-alkaline,S-type granitoids,that record high-grade metamorphism and trace element mobilization.The P3 and P42 intrusions are metaluminous,calc-alkaline,I-type granodiorite,which intruded the Cape River Metamorphics,and contain trace element signatures consistent with a continental-arc setting.We propose that a Mesoproterozoic continental terrane,herein referred to as the Oakvale Province,exists as basement to the Thomson Orogen.We propose several models for the formation of the Oakvale Province,with potential links to the Tarim Block,and the Yangtze Craton,during the late-Mesoproterozoic.We propose that the Oakvale Province supplied the Tasmanides with late-Mesoproterozoic detritus,and that such detritus was not solely sourced from the Musgrave Province as previously interpreted.Finally,we interpret the oroclinal bending of Paleozoic deformation and plutonic fabrics to reflect the buried extent of the Oakvale Province,and to potentially map out the Neoproterozoic rift margin associated with Rodinia break-up.展开更多
In this article,we present a comprehensive overview of the regulatory landscape governing Chinese medicinal practices in Australia,in which we describe the regulations for Chinese medicine practitioners in Australia,a...In this article,we present a comprehensive overview of the regulatory landscape governing Chinese medicinal practices in Australia,in which we describe the regulations for Chinese medicine practitioners in Australia,as of 2024,focusing in particular on the Title Protection model under the Health Practitioner Regulation National Law.Central to this discussion are the core roles of the Chinese Medicine Board of Australia(the Board)and the Australian Health Practitioner Regulation Agency(Ahpra)in ensuring public safety by guaranteeing that practitioners are appropriately qualified and suitable for registration.We also examine the structure and demographics of the Chinese medicine workforce in Australia and present details of the required registration process for practitioners.In addition,the article outlines specific requirements for registration,including the standards set by the Board for initial and ongoing registration,which are administered with the support of Ahpra under the National Registration and Accreditation Scheme.Furthermore,we present details regarding the approved qualifications,the rigorous assessment process for overseas qualifications,and the important role of regulatory examinations designed to uphold the high standards expected of practitioners,thereby ensuring they have acquired the professional competencies required by the Australian healthcare system.This overview offers valuable insights for both current and prospective practitioners of Chinese medicine in Australia.展开更多
Rationale:Australia is the only inhabited continent,which is not endemic to leishmaniasis.There are some published articles reporting cutaneous leishmaniasis in travellers,immigrants and refugees.However,mucocutaneous...Rationale:Australia is the only inhabited continent,which is not endemic to leishmaniasis.There are some published articles reporting cutaneous leishmaniasis in travellers,immigrants and refugees.However,mucocutaneous leishmaniasis has not been reported previously from the continent.Patient concerns:Lesions were present over the nasal septum and the oropharynx of a 34-year-old healthy non-indigenous male.Diagnosis was delayed as it took multiple biopsies as well as extensive discussions in a multidisciplinary team.Diagnosis:Mucocutaneous leishmaniasis.Interventions:Liposomal Amphotericin for 20 days.Outcomes:The patient was symptomatically improved after 3 weeks’treatment.Lessons:With international travel resuming after the pandemic,it becomes imperative that physicians in Australia are aware of this imported disease and its various presentations.展开更多
Feng Zhenyuan is a merchant selling knives and scissors in Yangjiang City,Guangdong Province.After over a decade of experience in the industry,he operates his own production facilities and distributes through multiple...Feng Zhenyuan is a merchant selling knives and scissors in Yangjiang City,Guangdong Province.After over a decade of experience in the industry,he operates his own production facilities and distributes through multiple e-commerce platforms including Pinduoduo,a Chinese online retailer whose main appeal is its shockingly low prices.“Pinduoduo has been relentlessly seeking low prices,”said Feng.“Many products claiming to be Yangjiang knives are priced 20 to 30 percent lower than genuine ones,leaving local merchants grappling with‘Gresham’s law,’which is about bad products driving out the good.”Feng added that about 30 percent of the factories in the Yangjiang knife and scissors sector have closed down,causing significant harm to this major pillar supporting local traditional industries.展开更多
In the digital control centre of the Chambishi copper mine’s southeast deposit in Zambia,a massive screen displays the status of various mining activities in real time:extraction,digging,machine operation,and transpo...In the digital control centre of the Chambishi copper mine’s southeast deposit in Zambia,a massive screen displays the status of various mining activities in real time:extraction,digging,machine operation,and transport.Although machinery sounds can still be heard in the underground galleries,this“digital mine”relies more on an integrated computerised system than on traditional manual labour.“We can observe and understand underground activities in detail without going underground,”explained Dean Mwelwa,an executive at NFC Africa Mining(NFCA),pointing to the control screen.展开更多
The weather in Australia is significantly influenced by water vapor evaporated fromwarm ocean surfaces,which is closely associated with various extreme weather events in the region,such as floods,droughts,and bushfire...The weather in Australia is significantly influenced by water vapor evaporated fromwarm ocean surfaces,which is closely associated with various extreme weather events in the region,such as floods,droughts,and bushfires.This study utilizes Precipitable Water Vapor(PWV)data from 15 Global Navigation Satellite System(GNSS)stations spanning 2010 to 2019 to investigate the spatiotemporal distribution of atmospheric water vapor across Australia,aiming to improve the accuracy of forecasting hazardous weather events.The results indicate distinct regional features in the spatial distribution of PWV.PWV gradually decreases from coastal areas toward inland regions and increases from south to north.Temporally,the overall trend of PWV remains consistent.From an annual trend perspective,most areas exhibit a decline in PWV content,with the exception of the southwestern coastal region,which shows an increasing trend.Furthermore,the study explores the correlations between PWV content and elevation,latitude,and longitude.Among these,latitude demonstrates the strongest correlation with PWV,with a correlation coefficient as high as 0.88,highlighting the significant impact of latitude on water vapor distribution.展开更多
Enhancing the mining speed of a working face has become the primary approach to achieve high production and efficiency in coal mines,thereby further improving the production capacity.However,the problem of rock bursts...Enhancing the mining speed of a working face has become the primary approach to achieve high production and efficiency in coal mines,thereby further improving the production capacity.However,the problem of rock bursts resulting from this approach has become increasingly serious.Therefore,to implement coal mine safety and efficient extraction,the impact of deformation pressure caused by different mining speeds should be considered,and a reasonable mining speed of the working face should be determined.The influence of mining speed on overlying rock breaking in the stope is analyzed by establishing a key layer block rotation and subsidence model.Results show that with the increasing mining speed,the compression amount of gangue in the goaf decreases,and the rotation and subsidence amount of rock block B above goaf decreases,forcing the rotation and subsidence amount of rock block A above roadway to increase.Consequently,the contact mode between rock block A and rock block B changes from line contact to point contact,and the horizontal thrust and shear force between blocks increase.The increase in rotation and subsidence of rock block A intensifies the compression degree of coal and rock mass below the key layer,thereby increasing the stress concentration degree of coal and rock mass as well as the total energy accumulation.In addition,due to the insufficient compression of gangue in the goaf,the bending and subsidence space of the far-field key layer are limited,the length of the suspended roof increases,and the influence range of mining stress and the energy accumulation range expand.Numerical test results and underground microseismic monitoring results verify the correlation between mining speed and stope energy,and high-energy events generally appear 1-2 d after the change in mining speed.On this basis,the statistical principle confirms that the maximum mining speed of the working face at 6 m/d is reasonable.展开更多
文摘The rehabilitation of coal mines is an up-to-date issue, heavily discussed not only by the industry but also by scientists and the adjacent communities since open cut coal mining has extensive impacts affecting all parties. Whereas, before and during the mining process not only nature but sometimes also the population of a whole region has to give way to a mine, the consequences of the operations remain long after mining closure. Typically a once intact and functioning ecosystem is replaced with a destroyed wideness evocative of a moon landscape. Fortunately, the awareness of the need to rehabilitate the destroyed nature is increasing steadily and all involved parties are making efforts to improve the situation, even if it is a major challenge to bring all parties to a consensus. Therefore, a legislative basis is required and the know-how of optimal rehabilitation solutions must be developed. In this article the rehabilitation of mined land in Australia and Germany are compared. More precisely the article will present an overview of the legislative regulations, certain applied methods of rehabilitation work and the problems that are likely to occur in respect to the influence of mining on nature.
文摘Deep Underground Science and Engineering(DUSE)is pleased to present this special issue on Groundwater and Stability in Deep Mining.As mining operations progress to greater depths to meet the growing global demand for mineral resources and energy,the challenges associated with groundwater control and rock mass stability have grown increasingly critical.These challenges are exacerbated by complex geological conditions,structural heterogeneity,and intense mining-induced disturbances.This special issue seeks to address these challenges by showcasing cutting-edge research and technological advancements in the field.
基金supported by Curtin International Postgraduate Scholarship(CIPRS)/Department of Mining and Metallurgy Scholarshippartly supported by National Natural Science Foundation of China the 111 Project under grant Nos.51839003 and B17009.
文摘Development of deep underground mining projects is crucial for optimum extraction of mineral deposits.The main challenges at great depth are high rock stress levels,seismic events,large-scale deformation,sudden failures and high temperatures that may cause abrupt and unpredictable instability and collapse over a large scale.In this paper,a ground control and management strategy was presented corresponding to the three stages of projects:strategic design,tactical design and operational design.Strategic design is results in preparing a broad plan and primary design for mining excavations.The tactical design is to provide detail design such as stabilisation methods.Operational design stage is related to monitoring and updating design parameters.The most effective ground control strategies in this stage are maintenance,rehabilitation,monitoring and contingency plan.Additionally,a new procedure for design of ground support systems for deep and hard rock was proposed.The main principles are:static and/or dynamic loading types,determination of loading sources,characterisation of geological conditions and the effects of orientation of major structures with openings,estimation of ground loading factor,identification of potential primary and secondary failures,utilisation of appropriate design analysis methods,estimation of depth failure,calculation of the static and/or dynamic demand ground support capacity,and selection of surface and reinforcement elements.Gravitational force is the dominant loading force in low-level stresses.In high stress level failure mechanism becomes more complex in rock mass structures.In this condition,a variety of factors such as release of stored energy due to seismic events,stress concentration,and major structures influence on ground behaviour and judgement are very complicated.The key rock engineering schemes to minimise the risk of failures in high-stress levels at great depth involve depressurisation and quality control of materials.Microseismic and blast monitoring throughout the mining operations are required to control sudden failures.Proper excavation sequences in underground stopes based on top-down,bottom-up,centre-out and abutment-centre were discussed.Also,the performance of a ground support system was examined by field observation monitoring systems for controlling and modifying ground support elements.The important outcome of the research is that the proposed procedure of selecting ground support systems for static and dynamic situations was applied in several deep underground mines in Western Australia.Ground behaviour modes and failure mechanism were identified and assessed.Ground demand for static and dynamic conditions was estimated and an appropriate ground support system was selected and evaluated in site-specific conditions according to proposed method for ground support design at great depth.The stability of rock masses was confirmed,and the reliability of the design methodology for great depth and hard rock conditions was also justified.
基金the National Science Fund for Distinguished Young Scholars(Grant No.52225107)National Key Research and Development Program of China(Grant No.2021YFC2801503)for funding provided to this work.
文摘Rising demand for minerals and metals in high-tech and new energy industries has led to a great interest in exploration of seabed mineral resources.Such resources,including polymetallic nodule(PMN),polymetallic sulphide(PMS),and cobalt-rich ferromanganese crust(CFC),are considered as an alternative source of metals to terrestrial deposits.Although a considerable number of sea trials of deep-sea mining have been carried out,the deep-sea mining does not achieve the commercial exploitation due to the complexity of deep-sea mining system and deep-sea mining environment.In fact,to achieve commercial deep-sea mining,the technology and equipment of deep-sea mining are the key points.Therefore,the present study presents the development of the technology and equipment of deep-sea mining.It commences with a requirement of technology and equipment for deep-sea mining,including environmental impact,reliability,energy cost,efficiency,etc.Then,a historical perspective and present-day effort related to deep-sea mining vehicles are given,which highlights the evolution of collection mechanism and walking mode of deep-sea mining vehicle.Subsequently,the present study discusses the operation of subsea lifting system and surface support system,shedding light on the crucial equipment and processes.The challenges and prospects in the deep-sea mining are presented in final,including environmental protection,self-propelled crawler,hydraulic pipeline lifting,and intelligent equipment,etc.
文摘Shear strain energy is a pivotal physical quantity in the occurrence of earthquakes and rockbursts during deep mining operations.This research is focused on understanding the changes in shear strain energy in the context of retreating longwall mining,which is essential for the optimized design and mitigation of rockbursts and seismic events.Through the application of innovative analytical models,this study expands its analytical range to include the variations in shear strain energy caused by fault coseismic slip.An integrated methodology is utilized,taking into account the changes in coseismic and fault friction parameters as well as enhancements in mining-induced stress and existing background stresses.Our numerical investigation highlights the significance of mining location and fault characteristics as key determinants of shear strain energy modifications.The analysis demonstrates significant spatial variability in shear strain energy,especially noting that fault slip near the mining face greatly increases the likelihood of rockburst.This finding emphasizes the need to integrate fault coseismic slip dynamics into the triggering factors of rock(coal)bursts,thus broadening the theoretical foundation for addressing geological hazards in deep mining operations.The results are further corroborated by observational data from the vicinity of the F16 fault zone,introducing the concept of mining-induced fault coseismic slip as an essential element in the theoretical framework for understanding rockburst triggers.
文摘An application programming interface (API) usage specifcation, which includes the conditions, calling sequences, and semantic relationships of the API, is important for verifying its correct usage, which is in turn critical for ensur-ingthe security and availability of the target program. However, existing techniques either mine the co-occurring relationships of multiple APIs without considering their semantic relationships, or they use data fow and control fow information to extract semantic beliefs on API pairs but difcult to incorporate when mining specifcations for mul-tipleAPIs. Hence, we propose an API specifcation mining approach that efciently extracts a relatively complete list of the API combinations and semantic relationships between APIs. This approach analyzes a target program in two stages. The frst stage uses frequent API set mining based on frequent common API identifcation and fltra-tionto extract the maximal set of frequent context-sensitive API sequences. In the second stage, the API relationship graph is constructed using three semantic relationships extracted from the symbolic path information, and the speci-fcationscontaining semantic relationships for multiple APIs are mined. The experimental results on six popular open-source code bases of diferent scales show that the proposed two-stage approach not only yields better results than existing typical approaches, but also can efectively discover the specifcations along with the semantic rela-tionshipsfor multiple APIs. Instance analysis shows that the analysis of security-related API call violations can assist in the cause analysis and patch of software vulnerabilities.
基金financially supported by the National Key Research and Development Program of China-Young Scientist Project(No.2024YFC2815400)the National Natural Science Foundation of China(No.52588202).
文摘Deep-sea mining has emerged as a critical solution to address global resource shortages;however,the mechanical interaction between tracked mining vehicles(TMVs)and soft seabed sediments presents fundamental engineering challenges.This study establishes a multiscale modelling framework coupling the discrete element method(DEM)with multi-body dynamics(MBD)to investigate track-seabed dynamic interactions across three operational modes:flat terrain,slope climbing,and ditch surmounting.The simulation framework,validated against laboratory experiments,systematically evaluates the influence of grouser geometry(involute,triangular,and pin-type)and traveling speed(0.2–1.0 m/s)on traction performance,slip rate,and ground pressure distribution.Results reveal rate-dependent traction mechanisms governed by soil microstructural responses:higher speeds enhance peak traction but exacerbate slip instability on complex terrain.Critical operational thresholds are established—0.7 m/s for flat terrain,≤0.5 m/s for slopes and ditches—with distinct grouser optimization strategies:involute grousers achieve 35%–40%slip reduction on slopes through progressive soil engagement,while triangular grousers provide optimal impact resistance during ditch crossing with 30%–35%performance improvement.These findings provide quantitative design criteria and operational guidelines for optimizing TMV structural parameters and control strategies,offering a robust theoretical foundation for enhancing the performance,safety,and reliability of deep-sea mining equipment in complex submarine environments.
基金Supported by National Natural Science Foundation of ChinaShanxi Coalbased Low-Carbon Joint Fund(Grant No.U1910211)。
文摘Using electric motors instead of diesel engines as the driving system for mining excavators can reduce the energy consumption and operating costs.However,pure electric-driven mining excavators are prone to unexpected power outages in mines because of drastic changes in load power,leading to significant fluctuations in the power demand of the grid,which in turn affects production.To solve the above problem,a pure electric-driven mining hydraulic excavator based on electric-motor-driven swing platform and hydraulic pumps was used as the research object.Moreover,supercapacitors and DC/DC converter,as the energy storage system(ESS)adjust the output power of the grid and recover the braking kinetic energy of the swing platform.Subsequently,a novel integrated energy management strategy for a DC bus voltage predictive controller based on the power feedforward of fuzzy rules is proposed to run mining excavators efficiently and reliably.Specifically,the working modes of the ESS are determined by the DC bus voltage and state of charge(SOC)of the supercapacitor.Next,the output power of the supercapacitor and the DC bus voltage were controlled by adjusting the charging and discharging currents of the DC/DC converter using a predictive controller and fuzzy rules.In addition,a digital prototype of the excavator was verified using an original machine test.The performance of the different strategies and driven systems were analyzed using digital prototypes.The results showed that,compared with traditional excavators with diesel engines,the operational cost of the developed excavators was reduced by 54.02%.Compared to pure electric-driven excavators without an ESS,the peak power of the grid for the developed excavators was reduced by 10%.This study designed an integrated energy management strategy for a pure electric mining excavator that can regulate the power output of the grid and maintain the stability of the bus voltage and SOC of the ESS.
基金financially supported by the Fundation of Key Laboratory of Ministry of Natural Resources for Eco-geochemistry (ZSDHJJ202202)Geological Investigation and Evaluation of Shale Gas in Complex Structural Areas of the Middle Yangtze plate(DD20250200604) of China Geological Survey+1 种基金the Natural Science Foundation of Guangdong Province,China(2023A1515140061)the Dongguan Science and Technology of Social Development Program(20231800935842, 20231800940562).
文摘To address the critical gap in linking multi-compartmental transfer with risks of trace metals(Cd,Pb,As,Cr,Ni)in mining environments.This study systematically investigated the trans-media migration of Cd,Pb,As,Cr,and Ni in China’s Dexing copper mining district through paired sampling of water-amphibians,soil-earthworms,and air-lichens.Advanced methodologies were employed,including ICP-MS quantification for heavy metals,geochemical indices(Igeo,BCF,BAF)to assess bioavailability,NMDS for source apportionment,and HPLC to detect DNA methylation alterations.Aquatic systems exhibited severe Cd/Pb enrichment(16.25-24.42μg/L;11-15×WHO limits),while agricultural soils showed extreme Cd contamination(1.5 mg/kg;15×background).Biota displayed metal-specific accumulation:frogs achieved BCFs>1,000 for Pb/Cd,earthworms showed pH-modulated BAFs>2.5 for Cd/As,and lichens recorded 100-1,000×atmospheric Cr enrichment.NMDS resolved three contamination pathways:mining-derived Cd/Pb/As(MDS1=2.56),atmospheric Cr(PC2=1.84),and geogenic Ni.Cd dominated ecological risks(Eri=554.25;RI 300),while atmospheric Cr drove carcinogenic risks(TCR=4.11×10^(-5))exceeding safety thresholds.The source-media-biota-risk framework pioneers the integration of geochemical transport with epigenetic toxicity biomarkers,demonstrating that sub-lethal Cd/Pb exposure induces genome-wide DNA hypomethylation(2.4%-6.6%reduction;ρ=−0.71 to−0.91).This paradigm shift prioritizes bioavailability-informed regulations over concentration-based metrics,offering actionable strategies for sustainable development goals-aligned mining pollution control.
基金financially supported by the National Key Research and Development Program of China(Grant No.2023YFC2811600)the National Natural Science Foundation of China(Grant Nos.52301349 and 52088102)+1 种基金the Qingdao Post-Doctorate Science Fund(No.QDBSH20220202070)the Major Scientific and Technological Innovation Project of Shandong Province(Grant No.2019JZZY010820).
文摘A deep-sea mining riser is a crucial component of the system used to lift seafloor mineral resources to the vessel.It is prone to damage and failure because of harsh environmental conditions and internal fluid erosion.Furthermore,damage can impact the response characteristics of the riser,but varying environmental loadings easily mask it.Thus,distin-guishing between riser damage and environmental effects poses a considerable challenge.To address this issue,a cantilevered model is created for a deep-sea mining riser via the concentrated mass method,and a time-domain analytical strategy is developed.The vortex-induced vibration(VIV)response characteristics of the riser are initially examined,considering various damage conditions and flow velocities.The study results revealed four primary observations:(a)effective tension can serve as a reliable indicator for identifying damage at lower velocities;(b)there are noticeable differences in displacement between the healthy and damaged risers in the in-line direction rather than the cross-flow direction;(c)frequency characteristics can more effectively distinguish the damage conditions at high flow velocities,with the mean square frequency and frequency variance being more effective than the centroid frequency and root variance frequency;(d)displacement differences are more sensitive to damage occurring near the top and bottom of the riser,while both velocity variations and structural damage can influence displacements,especially in regions between modal nodes.The vibrational behavior and damage indicators are clarified for structural health monitoring of deep-sea mining risers during lifting operations.
基金supported by the National Natural Science Foun dation of China(52374170 and 51974313)the National Key Research and Development Plan Project(2022YFF1303300).
文摘1.Introduction Changes in land use are key factors promoting global climate change,and the side effects of mining activity that destroy the soil,vegetation,and biodiversity lead to imbalanced carbon cycling in terrestrial ecosystems.
文摘Copper smelting is the main source of arsenic pollution in the environment,and China is the largest country for copper smelting.Taking 2022 as an example,this study analyzes the distribution and fate of arsenic across the copper mining,beneficiation,and smelting processes using a life-cycle approach,providing important insights for arsenic pollution prevention and the resource utilization of arsenic-bearing solid waste.The results show that the amount of As in waste rock,tailing and concentrate are 53483 t,86632 t,76162 t,respectively.After smelting treatment,the amount of arsenic in different types of solid waste,wastewater,waste gas and products are 76128 t,1 t,31 t and 2 t,respectively,and the proportion in arsenic sulfide slag is the highest(55%).The amount of emission to the environment is 32 t,accounting for only 0.04%of total amount.In the future,key considerations are to improve the resource utilization rate of arsenic-containing solid waste(tailing,smelting slag),especially arsenic sulfide slag,and to digest its environmental risk.
文摘Aseptic osteonecrosis of the femoral head is defined as the death of bone cells in the femoral epiphysis due to an interruption of blood supply. Most cases are linked to trauma, but non-traumatic cases also occur and can be associated with several known risk factors. This study aims to describe these risk factors identified in the former Katanga province, a region with significant mining activity. Method and Patients: This is a descriptive cross-sectional study conducted over a seven-year period (2017-2024), including all cases of aseptic osteonecrosis of the femoral head diagnosed in the orthopedic department of Medpark Clinic in Lubumbashi. The investigation of risk factors was based on the analysis of sociodemographic, clinical, radiological, and biological data. Results: Our study included a total of 110 patients with a mean age of 47.5 years. Among them, there were 46 women (41.82%) and 64 men (58.18%). Twenty-five patients (27.5%) reported a family history of osteonecrosis, and 24% were diagnosed with sickle cell disease. Chronic alcoholism was noted in 14 patients (12.73%), while diabetes was present in 8 (7.2%). Four patients (3.64%) were obese, and three were HIV-positive (2.72%). The use of nonsteroidal anti-inflammatory drugs (NSAIDs) was common, and prolonged corticosteroid use was documented in 5 patients (4.5%). Abnormally high cholesterol levels were found in 26 patients (23.6%). One patient had gout, and two suffered from acute rheumatic fever (1.8%). Regarding inflammatory markers, C-reactive protein levels and erythrocyte sedimentation rates were within normal limits for almost all patients. Electrolyte levels and phosphocalcic profiles showed no abnormalities. Furthermore, 33 patients (30%) did not exhibit any of the previously mentioned risk factors. Most of these patients lived in the regions of Kolwezi, Likasi, and Lubumbashi. Among this group, 25 patients reported performing physically demanding labor, particularly in mining operations. Conclusion: Our study highlighted well-known risk factors for osteonecrosis of the femoral head (ONFH). However, it also identified a significant number of cases without any identifiable risk factors, classified as idiopathic. Among these cases, some patients engaged in intense physical labor, often linked to mining exposure.
文摘We document,for the first time,Mesoproterozoic-aged,continental arc magmatism in the Tasmanides.Granitoid samples intruding the Proterozoic Cape River Metamorphics in northeast Queensland contain abundant∼1200 Ma igneous zircons,with early-Paleozoic metamorphic rim overgrowths.Analytical mixing between the igneous and metamorphic zircons produces cryptic discordant analyses,but the origin of said discordance is resolved with zircon Th/U ratios.Samples of the Fat Hen Creek Complex are peraluminous,calc-alkaline,S-type granitoids,that record high-grade metamorphism and trace element mobilization.The P3 and P42 intrusions are metaluminous,calc-alkaline,I-type granodiorite,which intruded the Cape River Metamorphics,and contain trace element signatures consistent with a continental-arc setting.We propose that a Mesoproterozoic continental terrane,herein referred to as the Oakvale Province,exists as basement to the Thomson Orogen.We propose several models for the formation of the Oakvale Province,with potential links to the Tarim Block,and the Yangtze Craton,during the late-Mesoproterozoic.We propose that the Oakvale Province supplied the Tasmanides with late-Mesoproterozoic detritus,and that such detritus was not solely sourced from the Musgrave Province as previously interpreted.Finally,we interpret the oroclinal bending of Paleozoic deformation and plutonic fabrics to reflect the buried extent of the Oakvale Province,and to potentially map out the Neoproterozoic rift margin associated with Rodinia break-up.
文摘In this article,we present a comprehensive overview of the regulatory landscape governing Chinese medicinal practices in Australia,in which we describe the regulations for Chinese medicine practitioners in Australia,as of 2024,focusing in particular on the Title Protection model under the Health Practitioner Regulation National Law.Central to this discussion are the core roles of the Chinese Medicine Board of Australia(the Board)and the Australian Health Practitioner Regulation Agency(Ahpra)in ensuring public safety by guaranteeing that practitioners are appropriately qualified and suitable for registration.We also examine the structure and demographics of the Chinese medicine workforce in Australia and present details of the required registration process for practitioners.In addition,the article outlines specific requirements for registration,including the standards set by the Board for initial and ongoing registration,which are administered with the support of Ahpra under the National Registration and Accreditation Scheme.Furthermore,we present details regarding the approved qualifications,the rigorous assessment process for overseas qualifications,and the important role of regulatory examinations designed to uphold the high standards expected of practitioners,thereby ensuring they have acquired the professional competencies required by the Australian healthcare system.This overview offers valuable insights for both current and prospective practitioners of Chinese medicine in Australia.
文摘Rationale:Australia is the only inhabited continent,which is not endemic to leishmaniasis.There are some published articles reporting cutaneous leishmaniasis in travellers,immigrants and refugees.However,mucocutaneous leishmaniasis has not been reported previously from the continent.Patient concerns:Lesions were present over the nasal septum and the oropharynx of a 34-year-old healthy non-indigenous male.Diagnosis was delayed as it took multiple biopsies as well as extensive discussions in a multidisciplinary team.Diagnosis:Mucocutaneous leishmaniasis.Interventions:Liposomal Amphotericin for 20 days.Outcomes:The patient was symptomatically improved after 3 weeks’treatment.Lessons:With international travel resuming after the pandemic,it becomes imperative that physicians in Australia are aware of this imported disease and its various presentations.
文摘Feng Zhenyuan is a merchant selling knives and scissors in Yangjiang City,Guangdong Province.After over a decade of experience in the industry,he operates his own production facilities and distributes through multiple e-commerce platforms including Pinduoduo,a Chinese online retailer whose main appeal is its shockingly low prices.“Pinduoduo has been relentlessly seeking low prices,”said Feng.“Many products claiming to be Yangjiang knives are priced 20 to 30 percent lower than genuine ones,leaving local merchants grappling with‘Gresham’s law,’which is about bad products driving out the good.”Feng added that about 30 percent of the factories in the Yangjiang knife and scissors sector have closed down,causing significant harm to this major pillar supporting local traditional industries.
文摘In the digital control centre of the Chambishi copper mine’s southeast deposit in Zambia,a massive screen displays the status of various mining activities in real time:extraction,digging,machine operation,and transport.Although machinery sounds can still be heard in the underground galleries,this“digital mine”relies more on an integrated computerised system than on traditional manual labour.“We can observe and understand underground activities in detail without going underground,”explained Dean Mwelwa,an executive at NFC Africa Mining(NFCA),pointing to the control screen.
基金funded by Jiangsu Province Geological Engineering Environment Intelligent Monitoring Engineering Research Center Open Fund,grant number 2023-ZNJKJJ-08The National Natural Science Foundation of China,grant number 41674036.
文摘The weather in Australia is significantly influenced by water vapor evaporated fromwarm ocean surfaces,which is closely associated with various extreme weather events in the region,such as floods,droughts,and bushfires.This study utilizes Precipitable Water Vapor(PWV)data from 15 Global Navigation Satellite System(GNSS)stations spanning 2010 to 2019 to investigate the spatiotemporal distribution of atmospheric water vapor across Australia,aiming to improve the accuracy of forecasting hazardous weather events.The results indicate distinct regional features in the spatial distribution of PWV.PWV gradually decreases from coastal areas toward inland regions and increases from south to north.Temporally,the overall trend of PWV remains consistent.From an annual trend perspective,most areas exhibit a decline in PWV content,with the exception of the southwestern coastal region,which shows an increasing trend.Furthermore,the study explores the correlations between PWV content and elevation,latitude,and longitude.Among these,latitude demonstrates the strongest correlation with PWV,with a correlation coefficient as high as 0.88,highlighting the significant impact of latitude on water vapor distribution.
基金supported by Technology Innovation Fund of China Coal Research Institute(2022CX-I-04)Science and Technology Innovation Venture Capital Project of China Coal Technology Engineering Group(2020-2-TD-CXY005)。
文摘Enhancing the mining speed of a working face has become the primary approach to achieve high production and efficiency in coal mines,thereby further improving the production capacity.However,the problem of rock bursts resulting from this approach has become increasingly serious.Therefore,to implement coal mine safety and efficient extraction,the impact of deformation pressure caused by different mining speeds should be considered,and a reasonable mining speed of the working face should be determined.The influence of mining speed on overlying rock breaking in the stope is analyzed by establishing a key layer block rotation and subsidence model.Results show that with the increasing mining speed,the compression amount of gangue in the goaf decreases,and the rotation and subsidence amount of rock block B above goaf decreases,forcing the rotation and subsidence amount of rock block A above roadway to increase.Consequently,the contact mode between rock block A and rock block B changes from line contact to point contact,and the horizontal thrust and shear force between blocks increase.The increase in rotation and subsidence of rock block A intensifies the compression degree of coal and rock mass below the key layer,thereby increasing the stress concentration degree of coal and rock mass as well as the total energy accumulation.In addition,due to the insufficient compression of gangue in the goaf,the bending and subsidence space of the far-field key layer are limited,the length of the suspended roof increases,and the influence range of mining stress and the energy accumulation range expand.Numerical test results and underground microseismic monitoring results verify the correlation between mining speed and stope energy,and high-energy events generally appear 1-2 d after the change in mining speed.On this basis,the statistical principle confirms that the maximum mining speed of the working face at 6 m/d is reasonable.
