The Xiaohengjiang gold deposit, situated in northeastern Hunan Province, represents a significant recent discovery within the Guanzhuang gold deposit comprehensive exploration area in Liling City, Hunan Province. This deposit encompasses the Tieshijian and Taohua ore sections and is hosted within the Huanghudong Formation of the Lengjiaxi Group, part of the Neoproterozoic Qingbaikou Formation. Its formation and spatial distribution are predominantly influenced by nearly north-south-oriented fault structures. The primary ore types present include fractured-altered slate and sulfide quartz vein gold ores. Currently, the deposit is classified as having a medium resource scale, with substantial potential for further exploration and resource expansion. Despite its geological importance, there has been limited research investigating the relationship between acidic magmatic rocks and gold mineralization in this region. To address this research gap, the present study concentrates on the geochronology, petrogenesis, and tectonic implications of the granodiorite veins exposed within the mining area. Utilizing zircon LA-ICP-MS U-Pb dating techniques, the emplacement age of the granodiorite veins was determined to be in the Early Paleozoic［（437.2±8.0）Ma］. This result suggests that the gold mineralization events in the region are temporally linked to Caledonian magmatic activities, indicating an association with regional tectonomagmatic processes. The granodiorite veins exhibit high silicon content, moderate aluminum levels, and are enriched in alkali elements, while displaying low concentrations of iron, magnesium, manganese, and phosphorus, characteristics typical of S-type granites. The rare earth element（REE） distribution patterns demonstrate a rightward decline, accompanied by a weak negative Eu anomaly and significant enrichment in large-ion lithophile elements（LILEs） such as Rb, Th, U, and La. In contrast, high-field-strength elements（HFSEs）, including Nb, Sr, P, and Ti, show notable depletion. These geochemical attributes suggest that the granodiorite veins originated from crustal sedimentary sources through partial melting and underwent substantial fractional crystallization during their formation.Furthermore, the granodiorite veins are postulated to have formed within a tectonic environment transitioning from a syn-collisional to a post-collisional extensional regime. This transitional setting facilitated the interaction between tectonic and magmatic processes, thereby contributing to gold mineralization. A comprehensive analysis confirms a spatial and temporal correlation between Caledonian magmatic activities and gold mineralization events. Based on these findings, it is recommended that future exploration efforts concentrate on areas surrounding Caledonian intrusive rocks. These areas may possess untapped mineralization potential, offering opportunities for the discovery of new gold resources. This approach not only enhances the understanding of mineralization processes but also provides practical guidance for regional gold exploration and resource development strategies.
The manganese deposits in China are predominantly of sedimentary type, having formed from the Middle Proterozoic to the Neoproterozoic, the Late Paleozoic, and the early Mesozoic eras. These deposits are chiefly located in South China, with the “Datangpo-type” manganese deposit serving as the most representative example. In recent years, notable advancements have been achieved in the study of marine sedimentary carbonate-type manganese deposits within the Carboniferous sedimentary rock series in western China. Several medium to large manganese deposits, including the Aoertuokanashi, Muhu, and Maerkantu deposits, have been discovered in succession. The Xiaoerbulake manganese deposit, which is the focus of this study, is a newly identified deposit, situated in the Aketao area of Xinjiang Province. This deposit formed at the margin of a continental rift basin, exemplified by Qiaerlong, and is found within the stratified gray-black manganese-mineralized, pyrite-bearing argillaceous limestone of the Lower Carboniferous Talong Group. The deposit is primarily characterized by the presence of three manganese-rich minerals: rhodochrosite, manganocalcite, and kutnohorite. To comprehensively examine the sources of ore-forming materials and the formation environment of the Xiaoerbulake manganese deposit, a series of petrographic, mineralogical, and lithogeochemical analyses were undertaken. The lithogeochemical data reveal that in comparison to the surrounding rocks, the manganese ore is characterized by titanium depletion and low SiO2/Al2O3 ratios, indicative of high-iron, medium-phosphorus, low-grade manganese ore. Trace elements such as Rb, Ta, and Hf are relatively deficient, whereas Th, Sm, and Y are enriched. The distribution of rare earth elements（REE） shows a pattern of light REE depletion and high REE enrichment, marked by a weakly negative Ce anomaly, a positive Eu anomaly, and a positive Y anomaly, suggesting that the manganese deposit originated from submarine hydrothermal venting. Environmental discrimination analysis indicates that the Y/Ho ratio of the manganese ore aligns with values typical of Phanerozoic limestone; additionally, the Sr-Ba ratio, the weakly negative Ce anomaly, and the positive Y anomaly imply that manganese mineralization occurred in a brackish to hypersaline, relatively oxidized depositional environment. The mechanism of mineralization can be described as follows: during the late Paleozoic era, Fe-Mn-enriched polymetallic submarine hydrothermal fluids interacted with seawater. This interaction led to the preferential accumulation of Mn²⁺ and Fe²⁺ ions as mixed （Mn, Fe）-（oxy）hydroxide complexes within redox transition zones characterized by relatively oxygen-deficient, reducing, and mildly alkaline to acidic conditions. These complexes subsequently underwent diagenetic transformation through reactions with carbonate ions, resulting in the formation of manganese carbonate assemblages predominantly composed of rhodochrosite. These assemblages were then transported to favorable sedimentary depressions, where they co-precipitated with carbonate sediments, ultimately leading to the formation of the Xiaorbulak manganese deposit.
In recent years, substantial advancements have been achieved in the exploration of gold deposits within the Back-Longmenshan tectonic belt, which boasts a resource of approximately 50 tons. The Xinjiazui gold deposit, a newly identified site within this belt, exhibits medium to large prospecting potential. The gold deposits are predominantly located within the northeast-trending Yanzibian-Huashigou brittle-ductile shear zone, with the formation of ore bodies and mineralized bodies being stringently governed by these shear zones. The host rock primarily comprises iron bearing magnesite spotted phyllite and carbonaceous silica slate. The predominant ore type is quartz vein, and the mineralization alterations closely associated with gold include silicification, pyritization, and minor arsenopyritization.While previous researchers have made certain advancements in the study of this ore deposit, there remains a relative paucity of research focused on its mineralogical aspects. This study, grounded in comprehensive field investigations, concentrates on the gold-bearing minerals pyrite and arsenopyrite. Utilizing methodologies such as microscopic observation, back-scattered electron(BSE) imaging, and electron probe micro-analysis(EPMA), the research aims to elucidate the mineralogical characteristics of these gold-bearing minerals, investigate the occurrence state of gold, and determine the physical and chemical conditions of mineralization, as well as the genesis of mineral deposits. The findings indicate that the hydrothermal mineralization process can be categorized into three distinct stages: Stage Ⅰ, characterized by quartz-pyrite formation; Stage Ⅱ, defined by quartz-calcite-natural gold polymetallic sulfide, development; and Stage Ⅲ, marked by quartz-carbonate, formation, with Stage II being identified as the principal mineralization phase. Pyrite is classified into three generations:the sedimentary diagenesis stage(Py0), the early mineralization stage(Py1), and the main mineralization stage(Py2), during which arsenopyrite coexists with the main stage pyrite. Gold is present in two forms: visible gold and invisible gold. Visible gold appears in the main mineralization stage of pyrite as encapsulated and fractured gold. The occurrence of invisible gold exhibits distinct variations. During the sedimentation and early mineralization stages, gold within pyrite is present as nano gold(Au0). In contrast, during the main mineralization stage, pyrite contains both nano gold(Au0) and lattice gold(Au+). In arsenopyrite, all gold exists exclusively as lattice gold(Au+). The Xinjiazui gold deposit was formed under medium-high temperature conditions at a moderate to considerable depth, with f(S2) values ranging from -8.5 to -4.5. When compared to typical ductile shear zone-type gold deposits in the Longmen shan orogenic belt, and considering the geological and geochemical characteristics, it is inferred that the Xinjiazui gold deposit is an orogenic gold deposit influenced by brittle-ductile shear zones.
The Daju area is situated in Angren County, Xigaze City, Tibet, approximately 30 km southwest of the Zhunuo super large porphyry copper deposit. The Daju granite hosts a substantial development of tourmaline veins, which vary in width and can reach up to 1 meter at their widest point. Comprehensive analyses, including electron probe microanalysis and laser ablation inductively coupled plasma mass spectrometry （LA-ICP-MS）, have been conducted to elucidate the genesis, geochemical characteristics, and prospecting implications of these tourmaline veins. Based on microscopic examination and morphological characteristics, tourmaline in the Daju area can be categorized into three distinct types：（1） Fan-shaped tourmaline （Tur-Ⅰ）, predominantly subhedral to euhedral, exhibiting yellowish-brown to greenish-blue pleochroism, and possessing the largest particle size; （2） Cylindrical tourmaline （Tur-Ⅱ）, also subhedral to euhedral, primarily short columnar with cross-sections often triangular or polygonal, displaying yellow-green pleochroism and medium particle size; （3） Fine granular tourmaline （Tur-Ⅲ）, mostly anhedral and granular, generally amorphous, with yellowish-orange to green pleochroism, and characterized by the smallest particle size. All types of tourmalines have moderate Mg/（Mg+Fe） ratio, high Na/（Na+Ca） ratio, and low X□/（X□+Na+K） ratio, belonging to the alkali group dravite tourmaline-black tourmaline solid solution series, and the main replacement mechanism of elements is Fe3+Al-1 and （NaMg）（X□Al）-1. The elevated magnesium content （1.18~1.74 apfu）, strontium content （589×10-6~1 943×10-6）, vanadium content （154×10-6~371×10-6）, and the absence of aluminum cation at the Y position in the three types of tourmalines suggest a hydrothermal origin. In the graphical projection for Sr/Pb-Zn/Cu-Ga deposit type discrimination, tourmaline from the Daju area predominantly falls within the transition zone from metamorphic tourmaline to porphyry copper deposits. This suggests a potential genetic link between the formation of tourmaline in the Daju area and porphyry copper deposits. Trace element analysis reveals that Daju tourmaline exhibits a high Sr/Y ratio, elevated levels of Ba, Rb, and Ni, and a low Li content. These geochemical characteristics align with those observed in the Zhunuo porphyry copper deposit but differ from tourmalines associated with lithium and beryllium mineralization in the leucogranites of the Gyirong and Cuona regions in southern Tibet. This indicates that the Daju area holds significant potential for the formation of porphyry copper deposits, warranting further exploration efforts.
The Xilin area in Guangxi is geologically positioned within the Xilin-Baise fault-fold belt of the Northwest Guangxi Depression on the Yangtze Plate, representing a vital segment of the Au-Sb polymetallic metallogenic belt in the western Guangxi-southwestern Guizhou-southeastern Yunnan region, also known as the Youjiang Basin. To explore the distribution characteristics of ore-forming elements and mineralized bodies, and to achieve advancements in mineral exploration, this study implemented a 1∶10 000 scale soil geochemical survey and prospecting prediction. Through a systematic analysis of geochemical parameters, correlation coefficients, spatial distribution patterns, and single-element/composite anomalies using indicator elements (Au, Ag, As, Sb), three key anomalous zones (GXB-1, GXB-2, GXB-3) were identified for prioritized exploration. The key findings indicate that Au and Sb exhibit high concentration and variation coefficients, suggesting a strong metallogenic potential. Significant correlations have been identified among Au, Sb, and As, indicating their potential as indicator element associations. The skewed distribution patterns of Au and Sb suggest the presence of secondary enrichment processes. An integrated analysis of metallogenic characteristics and geochemical anomalies has led to the identification of five single-element anomalies and two composite anomalies. Trenching verification has revealed three auriferous mineralized zones. The gold mineralization predominantly occurs in silicified clastic rocks of the Baifeng Formation, specifically at structural contacts between NW-trending cross-layer fractures and interlayer fracture zones. These structural features have been established as key indicators for prospecting in future exploration endeavors.
To investigate the influence of blasting disturbances on the surrounding rock of stopes in deep environments, this study developed a numerical model of a deep stope featuring staged longhole drilling, utilizing the discrete element method platform (PFC3D) and based on the engineering conditions of a hard rock mine in southern China. A five-row fan-shaped blast hole configuration was designed, and numerical simulations of millisecond-delayed blasting were conducted. The findings indicate that distinct dynamic response characteristics are observed in various zones of the surrounding rock under multi-row blasting conditions. Notably, the particle vibration amplitudes in the goaf sidewalls initially increase and subsequently decrease as the blast hole row spacing increases. Additionally, the vibration of the roof shows a marked reduction when the spacing exceeds 1.5 meters, whereas the row spacing between 1.0 and 1.5 meters has a relatively minor effect. Significant vibration accumulation is anticipated on the bench face and free surface. Cumulative deformation damage is primarily observed in the left abutment, bench face, and roof of the goaf under blasting loads, while the right abutment exhibits minimal damage. A distinct strip-shaped damage zone is evident on the left abutment, and large-scale rock collapse is likely on the bench face. Field validation corroborates substantial collapse risks in the roof strata and localized damage zones in the left abutment, aligning with numerical predictions. This study offers practical guidance for optimizing blasting design and mitigating disaster risks in deep hard rock mining operations.
To address the technical challenges associated with the design and construction of large-section single tunnels in water-rich basalt with tuff strata, such as the determination of construction methods and support parameters, a comprehensive study was conducted. This study was based on a new high-speed railway tunnel project in Yunnan Province and employed engineering investigation, field monitoring, and numerical simulation to examine the deformation and control technology of the surrounding rock. The results indicate the following：（1）Implementing initial support immediately after excavating the upper bench using the two-bench method significantly reduces the crown settlement rate, achieving a final settlement of approximately 38.5 mm, thereby effectively limiting further deformation of the arch base.（2）During excavation, horizontal deformation is concentrated at the arch foot and waist. After excavation, the maximum horizontal displacement shifts downward to the arch wall, with the affected area expanding outward in a butterfly-like pattern. In the two-bench method, the monitoring points at the upper and middle benches exhibit greater clearance convergence values and rates compared to the three-bench method, whereas the lower bench shows smaller values. Additionally, the rapid closure of the invert in the two-bench method results in superior deformation control.（3）Tunneling through strata with high water content creates a dewatering funnel, where groundwater seeps out along the tunnel face and benches. The two-bench method reduces the initial support closure time, leading to decreased dewatering. However, it results in the formation of a high-pressure zone above the crown.（4）The installation of additional drainage pipes can mitigate the load on the lining structure. Furthermore, the integration of mechanized construction techniques with the two-bench method has approximately doubled the average monthly construction progress.
As mining activities continue to intensify, underground roadways encounter unprecedented stability challenges due to increasingly complex stress environments, dynamic geological variations, and anthropogenic disturbances. Accurate prediction of roadway deformation is essential for ensuring mining safety and optimizing operational layouts. However, conventional single neural network models often struggle to effectively capture both abrupt local features and long-term evolutionary trends in nonlinear displacement time series. To address these limitations, this study introduces an innovative hybrid model combining a Temporal Convolutional Network and Long Short-Term Memory（TCN-LSTM-AddAttn） architecture, enhanced with an additive attention mechanism, to achieve high-precision predictions of roadway deformation. The proposed architecture employs a parallel framework to leverage the strengths of both TCN and LSTM. An additive attention mechanism is incorporated to dynamically prioritize critical patterns from both networks. The model employs learnable parameters to calculate feature similarity and utilizes the Softmax function to generate normalized weights, facilitating the adaptive fusion of multi-scale representations. Validation of the model is conducted using displacement data from four monitoring points(W1430-10, W1430-11, W1480-7, W1530-11) across various roadways in the Yunnan Zizou iron mine. Data preprocessing involves the removal of outliers using a Hampel filter, interpolation of missing values via cubic spline, and min-max normalization to standardize input scales. The processed data are divided into training, validation, and test sets in an 8∶1∶1 ratio. Hyperparameters, including TCN channels (32), LSTM hidden dimensions (64), batch size (32), and learning rate (0.001), are optimized through grid search to ensuring generalization across diverse mining scenarios. Experimental results indicate that the TCN-LSTM-AddAttn model outperforms standalone TCN, LSTM, and the TCN-LSTM hybrid models. In the case of W1430-10, the TCN-LSTM-AddAttn model demonstrates a Mean Absolute Error (MAE) of 0.0292 mm, representing a 47.95% reduction compared to the TCN-LSTM model. Additionally, it achieves a Root Mean Square Error (RMSE) of 0.0396 mm, marking a 37.34% reduction, and a Symmetric Mean Absolute Percentage Error (SMAPE) of 0.0337, indicating a 47.91% reduction. The Adjusted R² (R adj) value of 0.9861 suggests near-perfect prediction accuracy. For W1430-11, the model records an MAE of 0.0282 mm (28.79% reduction), an RMSE of 0.0366 mm (27.52% reduction), a SMAPE of 0.0738 (28.70% reduction), and an R adj of 0.9799. Comparable improvements are noted for W1480-7 and W1530-11, with prediction errors consistently remaining below 0.1 mm. By incorporating multi-scale feature decoupling and dynamic weighting, the proposed model offers robust technical support for assessing mine roadway stability, identifying risk zones, and providing early safety warnings.
In the field of rock mass engineering, the precise simulation of the post-peak mechanical behavior of rocks is essential for ensuring engineering safety and for the prevention and management of disasters. To overcome the limitations associated with fixed parameter approaches in conventional Mohr-Coulomb models for simulating post-peak failure stages, this study introduces an innovative experimental data-driven multi-parameter dynamic collaborative correction method. Initially, by integrating Python with the FLAC3D platform, we developed a real-time backpropagation algorithm alongside a three-dimensional constitutive field dynamic iteration model. This framework facilitates the multi-threaded collaborative optimization of parameters, including cohesion, internal friction angle, and dilatancy angle, via embedded interfaces. Subsequently, utilizing strain gradient adaptive theory, we devised a real-time data assimilation engine capable of dynamically adjusting constitutive parameters through cyclic correction mechanisms. This approach effectively addresses the modeling challenges posed by the nonlinear coupling effects inherent in traditional static segmentation methods, which exhibit errors exceeding 15%.During the validation process, a numerical model for uniaxial compression, with dimensions of 50 mm×50 mm×100 mm and comprising 2 541 mesh elements, was utilized. A Python script was employed to dynamically invoke the s.stress()[2][2] function in FLAC3D, allowing for the extraction of stress fields. This process initiated multi-parameter collaborative corrections whenever the experimental data surpassed a deviation threshold of Δσ=0.01 MPa. The experimental findings demonstrate that the dynamically corrected model effectively captured the post-peak strain-softening behavior of the rock. The stress levels predicted by the original model consistently exceeded the actual values, whereas the stress simulations from the corrected model aligned closely with the experimental values, thereby completely mitigating the trend of overestimation. This study offers novel insights into optimizing the accuracy of rock parameter estimation and provides a scientific basis and guidance for geotechnical engineering design.
High-quality and stable backfill is a crucial technical requirement for ensuring safe and efficient mining operations. This study addresses the issue of unstable backfill quality in a gold mine, which adversely impacts stope safety and production efficiency, by exploring the feasibility and optimization of paste backfill utilizing fine-grained tailings. Through comprehensive testing of the tailings’ fundamental physical and chemical properties, flocculation settling behavior, slurry flow characteristics, and numerical simulation of pipeline transportation, optimal backfill process parameters were identified. The test results indicate that the tailings possess a specific gravity of 2.651 g/cm³, a natural bulk density of 0.967 g/cm³, with particles smaller than 74 μm comprising 71.33%, categorizing them as typical fine-grained tailings. Flocculation settling tests reveal that a feed concentration of 12% and a flocculant dosage of 30 g/t yield optimal settling performance, achieving a bottom flow concentration of 53.38%. The incorporation of a rake mechanism further enhances the bottom flow concentration to 61.35%. Rheological assessments reveal that the fine-grained composite tailings slurry behaves as a non-Newtonian fluid characterized by yield stress, aptly described by the Bingham model. The findings indicate that the slurry’s mass concentration substantially influences its flowability, with increased concentration correlating with decreased flowability, whereas the ash-to-sand ratio exerts a comparatively minor influence. Furthermore, numerical simulations of pipeline transport demonstrate that when the slurry concentration surpasses 65%, the slurry maintains uniform flow within the pipeline, devoid of stratification or segregation. The velocity profile displays typical fluid dynamic characteristics, exhibiting higher velocities at the pipe center and lower velocities near the pipe wall. Mass concentration, inlet flow rate, and pipe diameter significantly impact resistance loss, while the ash-to-sand ratio has a lesser effect. Specifically, reducing the mass concentration, enhancing the inlet flow rate, or decreasing the pipe diameter results in increased resistance loss within the pipeline. These research outcomes furnish a theoretical foundation and practical guidance for optimizing fine-grained tailings paste backfill processes and pipeline system design, improving backfill quality and system stability, and supporting safe and efficient mine production.
To investigate the influence of cellulose ether on the fluidity and compressive strength of classified tailings cemented backfill （CTCB）, hydroxypropyl methyl cellulose （in concentrations ranging from 0.1% to 0.3%） was utilized as a cellulose ether admixture. The variations in fluidity and strength of CTCB, both with and without cellulose ethers, were quantitatively assessed through rheological, expansion, bleeding, and unconfined compressive strength tests. Furthermore, the differences in microstructures of CTCB and the mechanism underlying cellulose ether-modified CTCB were investigated using chemical bonding water tests, scanning electron microscopy（SEM）, and mercury intrusion porosimetry（MIP）. The findings indicate that, compared to CTCB slurry without cellulose ether, at a concentration of 72%, an ash-to-sand ratio of 1∶4, and a cellulose ether content of 0.3%, the yield stress and plastic viscosity of the slurry increased by factors of 62.66 and 8.55, respectively, while the bleeding rate was completely eliminated.The addition of cellulose ethers to CTCB slurry results in increased yield stress and plastic viscosity, while simultaneously reducing the bleeding rate and enhancing the stability of the slurry.The effects become more pronounced with higher dosages of cellulose ethers. Notably, the expansion of the CTCB slurry decreases by 49.18%, indicating a negative correlation between cellulose ether dosage and slurry expansion, which suggests an adverse impact on the fluidity of the CTCB slurry.Furthermore, cellulose ethers exhibit an inhibitory effect on both the early （3 day） and long-term （28 day） compressive strength of CTCB. Specifically, when the cellulose ether content is increased from 0 to 0.3%, the 3-day compressive strength decreases by 49.44%, and the 28-day compressive strength decreases by 41.17%. The reduction in compressive strength becomes more significant with higher dosages of cellulose ethers. Scanning electron microscopy （SEM） analysis indicates that the incorporation of cellulose ethers does not alter the type of hydration products formed by the cementitious powders. The findings from the chemical binding water test suggest that incorporating cellulose ethers leads to a reduction in the content of hydration products. Observations utilizing mercury intrusion porosimetry （MIP） demonstrate that cellulose ethers introduce air, which subsequently increases the macropore content and overall porosity of the backfill. This results in suboptimal densification of CTCB. These research outcomes offer a valuable reference for the application of cellulose ethers in the modification of CTCB.
The aim of this study is to determine the optimal width of mine pillars that ensure stability under room-and-pillar mining conditions. A phosphorus mine in Guizhou serves as a case study for this investigation. The research integrates theoretical analysis, numerical simulation, and on-site monitoring to examine the load-bearing mechanisms of mine pillars and their appropriate widths within the context of room-and-pillar mining. Additionally, the study explores the impact of pillar width on quarry stability and validates the proposed optimization plan for pillar dimensions through simulation tests and practical engineering applications. The findings indicate that, following the initial excavation of the quarry, the maximum vertical displacement of the quarry’s roof plate varies at each stage. The displacement distribution is predominantly symmetrical along the quarry’s center line and decreases progressively towards the sides of the center line. As the excavation of the mining pillar advances through each phase of the quarrying process, a positive correlation is discerned between the displacement changes within the quarry and the exposed quarry area. Simultaneously, the displacement of the peripheral rock overlying the quarry demonstrates a gradual reduction along the left and right sides of the quarry’s center line. The displacement and settlement values of the surrounding overlying rock progressively decrease along these sides, culminating in a final displacement pattern that resembles an ‘arch’ shape. Following the excavation of each stage of the ore body, a high-stress region emerges within each stage of the mine pillar and the mining airspace. The quarry’s mine pillar enters a yield state, with the vertical stress on the quarry’s roof plate being significantly lower than that on the mine pillar. Tensile stress predominantly occurs around the mining airspace. The maximum vertical displacement and settlement value, as well as the maximum vertical stress value of the quarry, are recorded at 41.5 mm and 76.17 MPa, respectively. Notably, there is no significant plastic damage to the mine pillar, with damage being confined to localized areas. Empirical evidence from field engineering practice indicates that the theoretical analysis supporting an 8-meter pillar width is justified. Throughout the various phases of the ore body re-mining process, the displacement and settlement of the mine pillar remain minimal, with a recorded maximum displacement of 13.37 mm and a peak stress of 3.45 MPa, the reby confirming the pillar’s stability. These findings offer valuable theoretical insights and technical support for the safe and efficient extraction of phosphorus mines under analogous conditions.
Tailings dams, which are primarily utilized for the storage of tailings or industrial waste produced by mining activities, represent significant sources of high potential energy and pose considerable risks.A failure of such a dam could result in immeasurable losses.Consequently, online monitoring of tailings dams is essential for real-time analysis and risk mitigation.This monitoring is critical for promptly assessing the safety status of tailings dams, preventing dam failures, and safeguarding human lives and property. Therefore, anomaly detec-tion in time series data derived from tailings dam monitoring systems is of paramount importance. In response to the frequent occurrence of anomalies within multi-sensor monitoring systems for tailings dams, which severely affect safety assessments, this paper proposes an enhanced TCN-Transformer hybrid anomaly detection model.This model incorporates a temporal convolutional network （TCN） component into the traditional Transformer model, replacing the absolute position encoding mechanism.This approach effectively captures complex long-term dependencies in time series data, thoroughly integrates global temporal information, and enhances the model’s accuracy in anomaly detection.Moreover, the model’s self-attention mechanism has been optimized through the implementation of a branching structure design and the integration of maximum and minimum strategies.This enhancement enables the extraction of spatial features from tailings dam time series data, allowing reconstruction errors and correlation differences to reinforce each other during detection. Consequently, the model’s anomaly detection performance is improved. By employing a self-supervised training paradigm, the model reduces its dependence on large-scale supervised datasets, thereby enhancing its practicality and generalization capabilities.Experimental results demonstrate that the proposed TCN-Trans-former anomaly detection model achieves an average F1 score of 0.9486, marking a significant improvement in detection accuracy and performance over traditional models.This model holds substantial importance for anomaly detection and safety management in the context of tailings dam time series data.
Carbon-containing refractory gold ores present a significant technical challenge in the fields of mineral processing and metallurgy, primarily due to the impact of carbonaceous materials on gold leaching behavior. This paper provides a comprehensive review of the resource distribution, mineral structural characteristics, and adsorption mechanisms associated with carbonaceous materials in these ores. It emphasizes the exploration of the physical and chemical properties of carbonaceous materials and their interaction mechanisms with gold. The study reveals that factors such as specific surface area, pore structure, functional group composition, and degree of graphitization of carbonaceous materials have a substantial influence on the preg-robbing effect. The adsorption of elemental carbon is predominantly driven by physical adsorption, whereas humic substances interfere with gold leaching through chemical adsorption and complexation. In contrast, the impact of hydrocarbons on gold adsorption is found to be negligible. Furthermore, this paper examines the analytical capabilities of multi-scale characterization techniques in assessing the microscopic morphology, crystalline structure, and molecular composition of carbonaceous materials. It highlights the limitations inherent in single characterization techniques and underscores the necessity for the integration of multiple techniques to thoroughly analyze the structural characteristics of carbonaceous materials. This research offers significant theoretical foundations and serves as a reference for the efficient processing of carbon-containing refractory gold ores and the precise characterization of carbonaceous materials.
To establish a foundation for assessing the feasibility of comprehensive utilization of mineral resources in a lead-zinc ore, an extensive investigation into process mineralogy and beneficiation testing was conducted. This study employs a range of analytical techniques, including chemical analysis, X-ray diffraction analysis, optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy micro-area composition analysis, and mineral liberation analysis (MLA), to examine the chemical composition, mineral composition, and occurrence state of the primary minerals—lead, zinc, and silver—within the ore. The research focuses on identifying the key mineralogical factors influencing mineral processing efficacy. Subsequently, the beneficiation process and achievable separation indices of the ore were determined through beneficiation testing. The findings indicate that the mineral composition of the ore is relatively complex, with the predominant metal minerals being galena, sphalerite, and pyrite, while argentite is the sole silver mineral present. The gangue minerals predominantly comprise feldspar (including both potassium feldspar and plagioclase feldspar), quartz, and chlorite, with subordinate amounts of sericite, biotite, rhodochrosite, and fluorite. The principal recoverable elements in the ore, through beneficiation, are lead (Pb), zinc (Zn), and silver (Ag), with concentrations of 2.72%, 2.28%, and 65.00×10-6, respectively. Lead is primarily present as lead sulfide, constituting 89.34%, followed by lead sulfate at 7.72%. Zinc predominantly occurs as zinc sulfide (sphalerite), accounting for 95.61% of its presence. Silver is mainly found as silver sulfide (argentite), comprising 65.68% of its occurrence. This ore is characterized as a silver-bearing primary lead-zinc sulfide ore with a typical disseminated structure.The primary mineralogical factors influencing the beneficiation outcomes are as follows: Firstly, the complex and irregular output forms of galena and sphalerite within the ore, along with their intricate intergrowth, significantly impact the quality and recovery rates of lead and zinc concentrates. Secondly, the close association between argentite and galena, followed by sphalerite, dictates the pathway for silver enrichment. Based on the ore’s characteristics and preliminary exploratory tests, beneficiation research was conducted utilizing a priority flotation process, specifically prioritizing lead flotation followed by zinc activation. This approach yielded stable test indices. The closed-circuit flotation test achieved a lead concentrate with a grade of 65.08% Pb and a recovery rate of 91.32%, and a zinc concentrate with a grade of 41.70% Zn and a recovery rate of 85.96%. Additionally, the valuable metal silver was significantly enriched in the lead concentrate, with a content of 1 323.80×10-6 and a recovery rate of 79.28%. The outcomes of the beneficiation tests exhibit a high degree of consistency and alignment with the predictions made by process mineralogical studies.
Utilizing the global refined copper trade volume data spanning from 2004 to 2023, we employ complex network analysis to construct both random and weighted networks, thereby examining the global refined copper trade patterns from three perspectives: the overall trade structure, trade associations, and the roles of major trading nations. Additionally, we apply an enhanced gravitational model to assess the potential of China’s refined copper trade with its top 10 trading partners. The findings reveal that: (1)The global refined copper trade exhibits characteristics of a small-world network, characterized by a multi-core trade association structure, evolving from an initial dominance by European and American countries to later incorporating nations from Asia, Africa, and the Middle East. (2)China and the United States emerge as principal importers of refined copper, while Chile, Peru, Japan, and Australia serve as major exporters. The United States and India function as pivotal intermediaries in the refined copper trade, with Germany and Italy acting as central hubs. (3)Among the top 10 trading partners, Chile and Australia present potential, for restructuring, whereas South Korea, the United States, and Zambia, exhibit significant potential. Additionally, Japan, the Philippines, Kazakhstan, Peru and Poland are potential pioneering. The study provides some policy recommendations for the development of international refined copper trade and China’s import of refined copper.
In the context of the “dual carbon” objective, the vertical integration of the energy metal industry chain has emerged as a crucial strategy for facilitating energy transformation. This study adopts a configurational perspective, employing the “Technology-Organization-Environment”(TOE) theoretical framework, alongside necessary condition analysis (NCA) and fuzzy set qualitative comparative analysis(fsQCA) methods, to systematically investigate the driving mechanisms behind vertical integration within the energy metal industry chain. The research findings indicate that: (1)Vertical integration results from the synergistic interaction of multiple factors, with technical, organizational, and environmental factors not being individually necessary conditions; (2)The backward integration of new energy enterprises follows two configuration paths: a single core-driven supply chain stability and a dual core-driven revenue supply chain stability; (3)The forward integration of non-ferrous metal enterprises is characterized by two modes: technology supply chain synergy-driven and technology-revenue-environment comprehensive driven approaches.The study reveals the distinct driving mechanisms of vertical integration employed by enterprises at various stages of the industry chain, offering both a theoretical foundation and practical insights for optimizing the configuration of the energy metal industry chain. The research indicates that enterprises should select an integration strategy aligned with their specific resource endowments, while governmental bodies should develop tailored industrial policies to facilitate the coordinated development of the industry chain.
In the context of fostering sustainable and healthy development within the rare earth industry, it is imperative that enterprises adhere to environmentally compliant operations. Nonetheless, the industry is currently confronted with significant challenges, including environmental regulatory rent-seeking, inadequate oversight, and insufficient supervision. These issues not only jeopardize the industry’s sustainable development but also pose potential risks to ecological environments. This study introduces an innovative tripartite evolutionary game model that incorporates rare earth enterprises, local ecological-environmental bureaus, and the Ministry of Ecology and Environment （MEE）. An in-depth analysis was conducted to investigate the evolutionary strategies of each stakeholder under various scenarios, and the stability of system equilibrium points was thoroughly examined. Additionally, numerical simulations were utilized to systematically assess the impact of key parameter adjustments on strategy selection, thereby providing quantitative scientific evidence to inform the optimization of regulatory policies. The findings indicate that： （1） The implementation of a robust reward-punishment mechanism by the Ministry of Ecology and Environment （MEE） is crucial. This mechanism not only effectively mitigates rent-seeking behavior between rare earth enterprises and local environmental authorities but also steers all stakeholders towards environmentally compliant strategies by dynamically adjusting the intensity of incentives. （2） Excessively high reward levels may have detrimental effects, potentially reducing the central government’s motivation for stringent oversight. Consequently, a scientifically designed reward-punishment mechanism must ensure that “the aggregate of rewards/penalties for enterprises and the credit losses incurred under rigorous supervision surpass their rent-seeking benefits, or that the total rewards/penalties for local environmental bureaus exceed their collusion gains.” This is vital for ensuring the sustainable development of the industry. （3） The study underscores the limitations of singular governance approaches. The results demonstrate that relying solely on cost-benefit adjustments or traditional reward-punishment measures is inadequate for effective governance. It is recommended that the Ministry of Ecology and Environment （MEE） implement a collaborative governance strategy that capitalizes on the synergistic integration of reward-punishment and credit constraint mechanisms. By intensifying penalty severity and credit losses, alongside augmenting incentives and diminishing corporate environmental costs, the standardization of enterprise compliance can be more effectively realized.
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