X-ray diffraction analysis and TOF-SIMS element surface scanning analysis were conducted to assess the processing and availability of clay-type potassium-lithium ore in the Salt Lake of Balunmahai Basin in Qaidam.Additionally，a dissolution test was performed to further investigate the potential utilization of this resource.The findings indicate that the predominant mineral types present in clay-type potassium-lithium deposits within salt lakes include rock-forming mineral fragments，salt minerals，substances adsorbed on mineral surfaces，and layered mineral structural surfaces.The primary chemical components consist of K，Na，O，Cl.The content of salt mineral components such as Cl^-，SO{}_{\mathrm{4}}^{\mathrm{2}}^-，K，Ca，Na，Mg，and B₂O₃ is notably high，while the concentrations of rare elements Li，Rb，Cs，and Sr are evident.Water-soluble substances found in the clay layer include stone salt，carnallite，and hydrochloromagnesite，with Li and K being capable of dissolution and utilization through water solutions.The analysis indicates that the predominant occurrence types of potassium （K） are soluble salt minerals，feldspar，and clay minerals.Lithium，on the other hand，is primarily found in the forms of adsorbed lithium and structural lithium.Adsorbed lithium includes water-soluble lithium and acid-leached lithium，while residual lithium is classified as structural lithium.The estimated potential resource of lithium chloride （LiCl） is 1.1441 million tons，whereas potassium chloride （KCl） is estimated at 13.9522 million tons.Dissolution tests conducted on the ore from Balunmahai Salt Lake indicate that the potassium content meets industrial standards for solid ore，while the lithium content meets criteria for liquid ore，affirming its extractability，value，processability，and accessibility.It is recommended that the comprehensive utilization grade of clay-type lithium ore exceed or equal 32.25×10^-6.

The primary host rocks of the Sanshandao gold deposit in the Jiaodong region are the Mesozoic Linglong granite and Guojialing granite.Through the application of petrographic analysis，geochemical assays，and zircon U-Pb geochronology，the geochemical classifications，formation ages，magma source regions，and petrogenesis of the granite were investigated.Additionally，the relationship between diagenesis and mineralization was examined.The geochemical characteristics of the rocks reveal a relatively high content of SiO₂，Al₂O₃，and total alkali （Na₂O+K₂O）.The aluminum saturation index （A/CNK） is 1.34，classifying these rocks within the Peraluminous-Calcium alkaline series.The concentration of rare earth elements （REE） is relatively low，with a relative enrichment of light rare earth elements （LREE） and a deficiency in heavy rare earth elements （HREE）.The rocks are enriched in large-ion lithophile elements （LILE） such as Rb，Sr，and Ba，while high field strength elements （HSFE） such as Ta，Nb，P，and Ti are notably deficient.The geochemical characteristics of the Sanshandao giant porphyritic granite are comparable to those of sodium-rich granites and young tonalite-trondhjemite-granodiorite （TTG） complexes （younger than 3 Ga）.The zircon U-Pb weighted average age of the giant porphyritic granite is determined to be（127.05±0.41）Ma，corresponding to the early Cretaceous Guojialing period granite.The gold concentration in the giant porphyritic granite is markedly lower compared to that in early Precambrian metamorphic rocks.Integrating these findings with prior research，it is inferred that the giant porphyritic granite predominantly comprises lower crustal acidic magma，with a minor contribution from mantle-derived basic magma，formed through magmatic mixing.The formation of the rock occurred within an extensional tectonic environment characterized by the subduction of the Pacific Plate and the destruction of the North China Craton.The presence of large feldspar crystals within the rock can be attributed to post-magmatic potassium mineralization.Additionally，Early Precambrian metamorphic rocks，which exhibit relatively high background values of gold abundance，undergo partial melting.During this process，geochemical elements are redistributed，leading to the activation and migration of gold，which results in the formation of a gold-rich fluid reservoir and the subsequent production of gold-poor granite.The rapid intrusion of granite，coupled with the detachment fault system induced by significant crustal uplift and potassium mineralization，collectively contributed to the initial expansion and subsequent rupture of rock volume.This process created an optimal physical trap space conducive to the accumulation and enrichment of ore-forming fluids.

The debate surrounding the source，properties and evolution of ore-forming fluids and the genesis of gold deposits in the Wangu area are still remains unresolved.To address this issue，the present study focuses on the Jiangdong gold deposit within the Wangu area，conducting a comprehensive analysis of quartz samples from different stages of the deposit.This analysis includes SEM-CL observation，microtemperature measurement of fluid inclusions，laser Raman spectroscopy，and H-O isotopic compositional analysis.Through examination of the relationship between the veins and the symbiotic combination between the minerals，four distinct mineralization stages have been identified.The mineralization stages at the study site are prioritized as follows： （1）quartz-scheelite stage，（2）quartz-pyrite stage，（3）quartz-pyrite-arsenopyrite-polymetallic sulfide stage，and （4）quartz-calcite stage，and the main mineralization stages are the second and third stages.Fluid inclusions within the quartz at each stage were categorized into three types，namely aqueous inclusions （TypeⅠ），aqueous and CO₂ three-phase inclusions （TypeⅡ），and pure CO₂ inclusions （TypeⅢ）.The homogeneous temperatures of the four phases of fluid inclusions range from 264 ℃ to 347 ℃，255 ℃ to 329 ℃，194 ℃ to 271℃，and 157 ℃to 235 ℃ respectively，aand the salinities range from 2.82% to 8.56% NaCl_eqv，from 1.84% to 9.04% NaCleqv，from 2.24% to 11.23% NaCl_eqv，and from 1.87% to 8.71% NaCl_eqv.The H-O isotope analysis indicates that the ore-forming fluids in the Jiangdong gold deposit are predominantly sourced from magmatic fluids，likely associated with magmatic activities during the Yanshanian period.Fluid-rock interactions may have resulted in the early ore-forming fluids being influenced by partially metamorphic fluids.Over the course of mineralization from early to late stages，the composition of the ore-forming fluid transitioned from a medium-temperature and medium-low salinity H₂O-NaCl-CO₂ system to a medium-low temperature and medium-low salinity H₂O-NaCl system.Gold is primarily transported in the form of Au（HS）{}_{\mathrm{2}}^{-} within ore-forming fluids，with fluid immiscibility and fluids-rock reaction likely serving as the primary mechanisms for gold precipitation.When considering the geological characteristics of the Jiangdong gold deposit，along with fluid inclusion studies and H-O isotope data，it can be classified as a magmatic hydrothermal deposit associated with magmatic activity.

The Jiaodong Peninsula represents the largest gold orefield in China and ranks as the third largest globally，with orebodies predominantly controlled by fault structures.The mineralization of gold deposits within the Sanshandao fault zone exhibits variability attributable to alterations in the controlling fault structures，leading to disparities in ore body continuity and ambiguous exploration indicators.This study systematically cataloged and sampled multiple drill holes and underground tunnels along exploration line 30 in the Beibuhaiyu and Sanshandao gold deposits.Based on the paragenetic associations of minerals and the cross-cutting relationships among ore veins，the gold deposits in the northern sea area can be categorized into four distinct metallogenic stages：quartz-pyrite-potassium feldspar（stage Ⅰ），quartz-pyrite-chalcopyrite-native gold（stage Ⅱ），quartz-pyrite-galena-sphalerite-native gold（stage Ⅲ），and barren siderite-calcite（stage Ⅳ）.Notably，stage Ⅱ and stage Ⅲ represent the primary metallogenic phases for native gold.The analysis of ore-bearing and barren sections of controlling faults through shortwave infrared spectroscopy has demonstrated substantial differences in alteration mineral composition，Al-OH absorption peak positions，and crystallinity index （IC）.Notably，elevated Pos2200 and IC values exhibit a strong positive correlation with gold mineralization.Furthermore，statistical evaluation of grade data from multiple drill holes，augmented by machine learning algorithms，underscores the significant influence of IC values.The analysis of trace elements in pyrite revealed substantial positive correlations among elements including arsenic（As），lead（Pb），bismuth（Bi），tellurium（Te），antimony（Sb），and，gold（Au）.Consequently，this study has established a novel exploration indicator grounded in variations in fault attitude，shortwave infrared spectroscopy markers，and pyrite elemental，commposition.This indicator holds considerable significance for informing practical prospecting efforts.

The cohesion（c） and internal friction angle（φ） of rock are critical parameters in the design and stability assessment of rock engineering projects.Direct measurement of these parameters necessitates condu-cting numerous rock triaxial or shear tests，which are both time-intensive and expensive.This study proposes the development of intelligent models to predict the values of c and φ based on four readily obtainable parameters：P-wave velocity（V_P），density（ρ），uniaxial compressive strength（UCS），and Brazilian tensile strength（BTS）.A total of 199 datasets containing various rock types were collected and randomly partitioned into a training set（80%） and a test set（2%）.The distribution characteristics and correlations among the data were analyzed using scatter plots for data distribution and correlation plots for variables.To address discrepancies in characteristic attributes，such as magnitude and order of magnitude across different input variables，a normalization function was applied.Subsequently，five ensemble trees were utilized to develop predictive models for rock shear strength parameters.Bayesian optimization was employed to optimize the hyperparameters of the models.Concurrently，five-fold cross-validation was implemented during model training.To evaluate the performance of the models，four widely recognized regression metrics were utilized：The coefficient of determination （R2），root mean square error （RMSE），mean absolute error （MAE），and variance accounted for （VAF）.Additionally，a ranking system was introduced to provide a comprehensive assessment of the five models.The model evaluation demonstrated that the constructed models exhibited robust predictive performance，with the extremely randomized tree model outperforming others.Specifically，for predicting the value of c，the R² was 0.993，the RMSE was 0.45，the MAE was 0.309，and the VAF was 99.306%.For predicting the value of φ，the R² was 0.97，the RMSE was 0.823，the MAE was 0.612，and the VAF was 97.058%.Furthermore，the application of the SHAP interpretation method for sensitivity analysis indicated that V_P，UCS，and BTS significantly influenced on the prediction of c，whereas ρ had a substantial impact on the prediction of φ.Finally，rock blocks were collected and processed into samples for physical-mechanical testing to determine the V_P，ρ，UCS，BTS，c，and φ values of rocks at various locations within the Jinchuan Ⅱ and Ⅳ mining areas in China.The model was effectively utilized to predict the c and φ values for rocks in the Jinchuan mining area，thereby validating its practicability.Furthermore，a graphical user interface was developed to facilitate ease of use for engineers and technicians in the field.

In shallow overburden area，acquiring geological prospecting information via geological outcrops presents significant challenges.Consequently，there is an urgent requirement for the implementation of geophysical technologies to enhance the optimization of prospecting target areas and the strategic placement of boreholes.Typically，epithermal gold deposits do not directly produce geophysical anomalies.The geophysical properties of gold ore bodies，alteration zones，and their surrounding lithologies remain insufficiently understood.The Alinghe mining area，located within the forested region of northeast China，is characterized by shallow soil cover.The scarcity of rock outcrops has rendered traditional geological and mineral mapping techniques largely ineffective，underscoring the necessity for an increased reliance on geophysical prospecting methods in gold exploration.In response，we conducted high-resolution 1∶5 000 magnetic surveys over areas exhibiting soil gold anomalies，alongside 1∶5 000 induced polarization （IP） measurements using gradient arrays in selected hydrothermal alteration zones.Through the integrated analysis of resistivity and polarizability anomalies，we identified areas with favorable gold mineralization potential.Subsequently，electrical resistivity tomography （ERT） was employed to delineate vertical geological characteristics.In conclusion，verification of drilling and logging activities was conducted.The aforementioned geophysical exploration study yielded the following findings：（1） A series of parallel magnetic anomaly stripes were identified within the andesite distribution area.The observed low magnetic anomalies are attributed to the demagnetization effect resulting from hydrothermal alteration.Hydrothermal activity can reduce the magnetic susceptibility of andesite by up to 1 000 nT.（2） Induced polarization （IP） measurements revealed that the distribution of low apparent resistivity aligns closely with the regions of low magnetic anomalies.The apparent resistivity in the hydrothermally altered area is 100 Ω·m lower than that of the surrounding regions，indicating a water-rich shallow hydrothermal alteration zone.The anomaly of high apparent polarizability suggests a relatively pyrite-rich area associated with epithermal gold ore bodies.（3） Occam’s inversion of electrical resistivity tomography （ERT） data effectively delineates vertical geological features，including surrounding rock，hydrothermal channels，and pyritization zones，which are closely associated with gold mineralization.（4） The geological and alteration assumptions derived from the aforementioned geophysical data were validated by borehole ZK01 along the ERT line，resulting in the identification of two gold-bearing horizons and six gold mineralized bodies within a depth of 100 meters.Through the analysis of curves and crossplots of various logging parameters，the geophysical characteristics of the six gold mineralized bodies were categorized into channel type and terminal type.These two types of gold deposits are distributed on both the upper and lower sides of the high polarizability anomaly，suggesting that a high polarizability anomaly alone is not a direct indicator of a gold ore body，although it holds significant implications for prospecting.In this study，the epithermal gold deposit was systematically targeted for detection.A range of surface geophysical exploration methods was employed to progressively and effectively refine the exploration target area.Subsequent borehole verification confirmed the presence of several gold mineralized bodies，thereby validating the efficacy of the employed methods.The two distinct types of gold-mineralized bodies，categorized based on the combination of geophysical parameters and spatial distribution differences，indicate a terminal position within the mineralization system and suggest minimal erosion post-mineralization.This distinction holds significant implications for the interpretation of geophysical data and has practical relevance for prospecting and exploration efforts.

The Luobuzhen gold and silver epithermal deposit is located in the southwestern part of the Zhunuo ore concentration area，within the western segment of the Gangdese metallogenic belt in Tibet.This deposit，containing approximately eight tons of gold resources and associated with silver（Ag），lead（Pb），and zinc（Zn），is hosted within the continental volcanic rocks of the Pana Formation，part of the Linzizong Group.Its occurrence is controlled by a fault fracture zone exhibiting a near east-west trending.The Luobuzhen region exhibits silicification，sericitization，clay alteration，and propylitization，with ore bodies predominantly located within the intensely silicified alteration zone at the contact interface between dacite and granodiorite.The mineralization process can be divided into three distinct stages：The quartz-pyrite stage（Stage Ⅰ），the quartz-polymetallic sulfide stage（Stage Ⅱ），and the quartz-carbonate vein stage（Stage Ⅲ）.Notably，Stage Ⅱ represents the primary ore-forming phase.The formation temperatures for stages Ⅰ and Ⅱ were determined to be（366±4）℃ and （263.5±80.5）℃，respectively，using arsenopyrite thermometry.Electron probe micro-analysis（EPMA） data indicates that silver in the Luobuzhen deposit predominantly occurs in tellurite as visible silver，in silver-bearing tetrahedrite as invisible silver，and to a lesser extent in sphalerite，chalcopyrite，and pyrite.Silver is present as an isomorphic component within silver-bearing tetrahedrite，sphalerite，chalcopyrite，and pyrite，while in galena，it occurs as micro-inclusion silver.Gold predominantly exists as “invisible gold” within particulate（<50 μm） pyrite.In stage Ⅰ，gold primarily manifests as solid solution gold or lattice gold，whereas in stage Ⅱ，it is mainly found as nanoscale micro-particulate gold.The activation and concentration of metal elements in the Luobuzhen deposit are attributed to the synergistic effects of various factors，including sulfur fugacity，pH value and temperature within the fluid system.The primary mechanisms responsible for the precipitation of gold and silver are sulfuration.

To examine the distribution characteristics of trace elements within the primary sulfides of the Qibaoshan Pb-Zn polymetallic deposit in Wulian，and to constrain the genetic types of the deposit，this study conducted a detailed analysis of the mineralogy and LA-ICP-MS trace element composition of sphalerite and galena formed during different mineralization stages，building upon the geological investigation of the deposit.Based on comprehensive field investigations and laboratory mineralogical studies，the metallogenic processes of the Qibaoshan Pb-Zn polymetallic deposit can be delineated into three distinct stages：The polymetallic sulfide + cataclastic rock stage （Stage Ⅰ），the polymetallic sulfide + quartz + dolomite stage （Stage Ⅱ），and the quartz + dolomite stage （Stage Ⅲ）.LA-ICP-MS analysis indicates that sphalerite is enriched in Fe，Co，Mn，and Cd，but depleted in Ge，Se，Te，Re，and Tl，whereas galena exhibits significant enrichment in Ag and Cd.The elements Cu，Cd，Fe，Mn，Co，and In in sphalerite are primarily present in the form of isomorphous substitutions，while microinclusions within galena are occasionally observed.Silver （Ag） in galena is present in an isomorphic form，whereas copper （Cu），zinc （Zn），and arsenic （As） are found as microinclusions within the carbonated ore galena.An investigation into the metallogenetic temperatures of trace elements in sphalerite indicates that the cataclastic brecciated ore，formed during stageⅠ，predominantly crystallized at medium temperatures.In contrast，the carbonate ore，formed during stage Ⅱ，primarily crystallized at low temperatures.Based on the geological attributes and trace element distribution of the deposit，the Qibaoshan Pb-Zn polymetallic deposit is classified as a middle- to low-temperature hydrothermal vein-type deposit associated with magmatic hydrothermal processes.

The Dadiangou gold deposit，located in the Longnan region of Gansu Province，represents a typical orogenic gold deposit that has been discovered in recent years.The occurrence statusof gold significantly influences the development and utilization of these deposits，as well as the choice of metallurgical techniques for gold ore processing.To enhance the understanding of the gold occurrence within the Dadiangou deposit，this study utilizes a comprehensive array of investigative methodologies，including field surveys，reflective microscopy，and electron probe microanalysis.The findings suggest that the gold ore types at the Dadiangou gold deposit can be categorized into two primary types：Quartz vein typeand altered rock type.The gold within these ores predominantly exists as independent minerals，with the primary gold-bearing minerals being pyrite，chalcopyrite，galena，and quartz.The principal gold mineral is gold mineral，with minor occurrences of electrum and sylvanite.Gold particles within the ore manifest in four distinct forms：Fissure-filling，intergranular，inclusion，and interlocking.However，Fissure-filling has been identified as the predominant type.The particle size of gold is primarily extra micro-particulate（0.0050~0.0002 mm，42.03%） and micro-particulate（0.010~0.005 mm，28.26%）.Although micro-medium to fine grains are less，abundant，they contribute significantly to the overall resource grade due to their higher area content，accounting for 76.53%.The fineness of gold is predominantly above 900，which may be attributed to the combined influence of ore-forming fluids with a high gold-to-silver ratio and ore-forming temperatures that are medium to low.

Jiaodong is recognized as the third largest concentration of gold deposits globally.Recent advancements have been achieved in the exploration of gold deposits and the associated metallogenic theories.However，significant gaps remain in the understanding of the genesis of these deposits and the sources of mineralizing materials.A critical question that persists is how to scientifically and coherently elucidate the enrichment of gold （Au） in deposits that exceed the concentrations found in the surrounding rocks.In this study，we systematically collected and analyzed samples of Late Mesozoic granite and Early Cambrian metamorphic rocks from Jiaodong that have not undergone mineralized alteration to determine their gold（Au） content.The average Au content of 97 granite samples was found to be 0.31×10^-9.Specifically，the average Au contents for Linglong-type，Guojialing-type，and Weideshan-type granites were 0.25×10^-9，0.28×10^-9，and 0.35×10^-9，respectively.Additionally，the average Au content of 397 samples of Early Precambrian metamorphic rocks was determined to be 1.05×10^-9.The abundance of gold in all geological units in Jiaodong is comparable to or lower than that in the Earth’s crust and the average gold content in the North China Plate.However，the gold content in early Precambrian metamorphic rocks is 3.39 times higher than in late Mesozoic granite.Based on previous studies，it is inferred that there is no source area or ore-source rock（layer） with anomalous gold enrichment in Jiaodong.Instead，the substantial gold mineralization is attributed to the partial melting of the ancient metamorphic basement during the Late Mesozoic.During the formation of granitic magma via partial melting of basement metamorphic rocks in the lower crust，over 70% of the gold（Au） precipitates in a comparable “melting” process with in the ultra-high temperature environment，resulting in the production of Au-poor granites.The fluids associated with the magmatic activity of pre-mineralization Linglong and Guojialing-type granites facilitated the migration and enrichment of Au.The substantial alterations in the geochemical com-position of Weideshan and Laoshan-type granites during and subsequent to the mineralization period disrupted the chemical equilibrium of the fluids，thereby creating favorable conditions for the precipitation of gold（Au）.

Bauxite serves as a crucial raw material for the production of aluminum.However，China’s domestic bauxite resources have long been insufficient to satisfy the country’s demand.Consequently，it has beome imperative to import substantial quantities of high-quality bauxite from international sources to fulfill domestic requirements.The international trade dynamics of bauxite are continually evolving，influenced by economic policies and various other factors.Drawing upon the global bauxite trade volumes from 2012 to 2022，this paper employs complex network analysis to construct boths to chastic and weighted networks of bauxite trade.It examines the evolution of the global bauxite trade patterns，the changing status of major trading nations，and the specific characteristics of China’s bauxite trade network.The findings indicate that the scale of the global bauxite trade network demonstrates robustness.However，the network’s structure is asymmetrical，with trade connections between countries being relatively dispersed.The global bauxite trade exhibits significant frag-mentation.Among the nations engaged in bauxite trading，Australia and China，demonstrate the highest levels of import and export activity.However，their intermediary control capabilities require enhancement.Conversely，India possesses relatively robust intermediary control capabilities，effectively functioning as a “bridge” within the trade network.China stands as the world’s largest importer of bauxite，with an increasing prominence in export trade volume and a relatively concentrated market structure for both imports and exports.In the future，China is poised to broaden its bauxite import market framework，with a diverse array of potential sources.On one hand，China can augment its import share from established trading partners，including Australia，Indonesia，Brazil，and Guyana.On the other hand，China can leverage its geographical advantages to procure bauxite from Turkey，India，and other nations along the “Belt and Road Initiative”.

To investigate the correlation between the particle size distribution of tailings and the rheological properties and strength of cemented tailings backfill（CTB），five different types of CTBs were artificially prepared using full tailings，cyclone overflow，and underflow tailings.Rheological and strength tests were conducted on the CTBs，and changes in the internal pore structure of the tailings backfill were analyzed using mercury intrusion methods（MIP）.The impact of the particle size distribution of tailings on the rheological properties，strength，and microstructural characteristics of CTBs were assessed.The findings indicate that an increase in fine tailings content by -38 μm results in higher rheological parameters（yield stress and plastic viscosity） of fresh CTBs，with a greater increase observed at higher fine tailings content levels.The variation in particle size distribution of tailings leads to noticeable differences in the thickness of water film of solid particles in the backfilling slurry.Specifically，an initial increase followed by a subsequent decrease in water film thickness is observed with increasing fine tailings content.The initial yield stress and plastic viscosity of backfilling slurry are influenced by the water film thickness and specific surface area of solid particles.An exponential relationship is observed between the initial yield stress and plastic viscosity of CTB when the fine tailings content exceeds 44.37%.The strength of CTB initially increases and then decreases as the fine tailings content increases.The fine tailings content of 44.37% represents the optimal particle size distribution of tailings.In this condition，the compactness of the skeleton structure of the CTB formed by the accumulation of tailings is at its maximum，resulting in the lowest values for total porosity，average pore size，and the percentage of harmful pores larger than 0.2 μm.

The peak particle velocity（PPV） resulting from blasting vibration serves as a crucial metric in assessing the efficacy of blasting and mining design parameters.To enhance the accuracy of PPV predictions，a novel parameter self-optimizing PSO-XGBoost prediction model is introduced，leveraging the Particle Swarm Optimization （PSO） algorithm in conjunction with optimized Extreme Gradient Boosting （XGBoost）.The research focuses on the LK open-pit copper-cobalt mine and examines five influencing factors，namely the maximum single explosive charge，total explosive charge，measured distance to blast center，average depth of blastholes，and elevation difference，as study parameters.A total of 187 sets of measured data from on-site blasting operations are gathered for further investigation into predicting PPV using the PSO-XGBoost model.The findings indicate that the PSO-XGBoost prediction model produces superior prediction evaluation metrics （R²=0.921，RMSE=0.0752，MAE=0.0717，MBE=0.0683）， compared to alternative models，including the traditional XGBoost model，the SSA-XGBoost hybrid optimization model，and the Sariakaliski empirical formula.The sensitivity analysis reveals that the total explosive charge，significantly influences PPV prediction outcomes，underscoring the importance of using an appropriate amount of explosives to avoid energy inefficiency in blasting activities. Furthermore，the research demonstrates that the PSO-XGBoost prediction model，is capable of effectively addressing the nonlinear attributes of various factors，as well as integrating nonlinear and discrete data to develop a dependable，straightforward，and efficient PPV prediction model.This study offers valuable insights for promptly predicting blasting vibration in open-pit mining and assessing the impacts of blasting activities.

The Jiaodong Peninsula is the largest gold-producing region in China，however，the sources of its substantial gold reserves remains uncertain.Analyzing the trace elements in pre-mineralization Late Jurassic Linglong-type plutons （Linglong，Kunyushan），Early Cretaceous Guojialing-type plutons （Guojialing，Congjia），syn- to post-mineralization Early Cretaceous Weideshan-type plutons，and the mafic dioritic enclaves within the latter two plutons reveals that these formations generally exhibit lower concentrations of elements such as Cu，Au，Ag，Sb，and As compared to the average values of the continental crust.Specifically，the gold content is typically below 0.5×10^-9，aligning with prior test results and suggesting a depletion process of elements such as gold during magmatic evolution.Furthermore，a significant positive correlation is observed between the Cu/Ag ratio and Cu content in both Linglong-type and Weideshan-type samples.In Guojialing-type plutons and their enclaves，a positive correlation between the Cu/Ag ratio and Au content has been observed.This relationship suggests that during magma evolution，monosulfide solid solution continuously separates from the magma.Consequently，Mesozoic magmatic rocks exhibit lower Cu/Ag ratios and reduced metal content.The accumulation of these sulfides in the middle to lower crust forms an enriched source layer of gold and other elements，thereby providing ore-forming materials essential for gold mineralization in the Jiaodong region.The study also suggests that the separation of monosulfide solid solutions during magma evolution may be a common process，which could also explain why the continental crust is depleted in copper and other elements compared to the mantle.

The block caving method is known to result in a specific range of surface subsidence，which is a major safety risk in mining operations.UAV aerial survey technology offers numerous advantages，including enhanced safety，simple operation process and high precision in monitoring large and complex surface areas. Therefore，this study concentrates on the largest block caving mine in China，employing UAV aerial survey techniques to remotely monitor surface subsidence caused by block caving mining methods.The development of UAV aerial survey technology has led to the proposal of a 3D modeling method for surface subsidence based on UAV aerial survey.An accuracy analysis method for the 3D modeling process was also presented.By cons-tructing 3D models，analyzing the extent of surface subsidence affected areas，examining profile data of subsidence affected areas，and conducting theoretical analysis，this study investigates changes in the subsidence area of the mine from March 2022 to March 2023. Based on an analysis of the subsidence range and orebody profile within the vein，as well as predictions of surface subsidence using the probability integral method （PIM），it can be inferred that the extent of active subsidence is influenced by the distribution of active drawpoints. Furthermore，by utilizing PIM to forecast subsidence values，a comparison between the calculated and actual subsidence amounts at the Pulang copper mine，the maximum error is less than 0.18 m. The prediction of surface subsidence patterns in this mine can be achieved through the application of the probability integral method，which is grounded in the principles of stochastic medium theory. Utilizing the PIM allows for the anticipation of surface subsidence regularity，thereby facilitating effective surface treatment and mitigation of debris flow within the mine. By integrating 3D modeling with surface subsidence patterns，various recommendations can be formulated for the management of subsidence pits and the development of a drawing plan for the mine.

This study investigates the shear strength characteristics of loess under varying water content，with a specific focus on loess from Gansu Province.Through direct shear experiments and nuclear magnetic resonance tests，the research reveals the impact of water content on the shear strength of loess and its underlying microscopic mechanisms.The experimental findings indicate that increasing water content results in elevated internal porosity，an initial increase followed by a decrease in cohesion force，a reduction in the internal friction angle，and enhanced ductility of the soil samples.The mechanism underlying this change involves the alteration in water binding mode，matrix suction，and the degree of cementation between particles due to increased water content.When the initial water content of the soil sample is low，an increase in water content leads to the thickening of the strongly bound water film between particles，thereby enhancing the cementation effect and generating matrix suction，which in turn increases cohesion force.Concurrently，the lubrication of particles by water results in a reduction of the internal friction angle.When the optimal water content is surpassed，the soil sample exhibits a progressive expansion of cracks，an increase in the free water between particles，and a subsequent weakening of the cementation between particles and the matrix suction.This leads to a reduction in cohesion force and an increase in the internal friction angle due to the expansion of soil particles.Finally，when the water content approaches the liquid limit of the soil sample，the soil particles become obstructed by free water，leading to a reduction in the water film force between particles and rendering the cementation effect ineffective.Consequently，the matric suction is reduced to zero，resulting in cohesion approaching zero.Additionally，the occluding force between particles diminishes，causing a further decrease in the internal friction angle.This study also employed nuclear magnetic resonance （NMR） testing to further analyze the microstructural changes and internal water distribution within the loess.The experimental results indicated that an increase in water content led to a significant rise in the main peak of the NMR transverse relaxation time （T₂） spectral distribution.Additionally，the second wave peak exhibited a pronounced rightward shift，suggesting that water infiltrated the smaller pores.Furthermore，the small-sized pores within the soil appeared to expand and merge into medium-sized pores.The proportion of various pore types in soil samples under different water content conditions was also quantified through calculations.The findings indicate that an increase in water content leads to a reduction in the proportion of micropores within the soil，while the proportion of macropores increases，thereby enhancing the overall porosity of the loess soil sample.This phenomenon also contributes to the further diminution of the shear strength of the loess samples.

To address the challenges associated with the probability distribution and weight allocation processes of evaluation indicators for the stability of artificial pillars （backfill） using the segmented empty-field subsequent filling method，an evaluation indicator system was developed.This system considers the influences of five categories of information sources：Engineering geological environment，rock mass quality，mechanical response indicators，acoustic emission parameter characteristics，and geometric shapes.The resulting evaluation framework encompasses 17 factors that influence stability.Based on this analysis，the recognition framework and evaluation index grading standards for the stability of artificial pillars （backfill） were established utilizing Dempster-Shafer （D-S） evidence theory.By incorporating the normal membership function and an enhanced Kullback-Leibler （K-L） distance，the probability distribution and weight allocation of indicator factors were optimized.Consequently，an improved multi-source information fusion model，grounded in D-S evidence theory，was developed for the assessment of artificial pillar （backfill） stability.The applicability of the model was verified through five typical artificial pillar（backfill） in a mine with segmented open stoping subsequent filling mining.The results indicate that the stability evaluation levels for multi-source information fusion were ranked as follows：AP-2=AP-3=AP-5（Level Ⅱ）>AP-4（Level Ⅲ）>AP-1（Level Ⅳ）.These stability evaluation out-comes are largely consistent with previous assessments based on displacement，acoustic emission on-site monitoring，and numerical simulation analysis.This congruence validates the scientific efficacy of the evaluation model in practical applications.Consequently，this model offers a more comprehensive approach for analyzing the stability of artificial pillars （backfill）.

The Knelson concentrator，a commonly utilized centrifugal gravity separation device in gold ore processing，is esteemed for its superior recovery efficacy with respect to fine gold.The separation performance of the Knelson concentrator is intricately linked to both material characteristics and operational parameters，with heavy mineral concentration mechanisms varying depending on specific conditions.Consequently，investigating the impact of heavy mineral concentration mechanisms on separation efficiency can be instrumental in enhancing the effectiveness of gold ore separation processes.This study utilized a quartz vein gold ore from Gansu Province as the primary material to investigate the correlation between the concentration criterion （X） of individual enrichment rings of the MD3 Knelson concentrator and the mechanisms of concentration and separation.The findings indicate that heavy minerals were predominantly enriched through plating on the concentrate bed surface when X exceeded 9.In cases where X ranged from 5 to 9，heavy minerals were enriched through the continuous replacement of gangue minerals.Correspondingly，when X was less than 5，heavy minerals were enriched through elutriation.At a rotational speed of 1 465 r/min and a water flow rate of 3.0 L/min，coarse and medium-grained gold were concentrated in the lower rings through substitution，while micro and fine-grained gold were accumulated in the upper rings through surface plating and percolation or migration.The resulting concentrate grade was 124.4×10^-6 with a gold recovery rate of 70.36%，indicating optimal beneficiation effectiveness.Excessive X values led to material bed compaction and premature onset of overload phenomena.If the X value is insufficiently large，the high water flow results in the depletion of micro and fine gold particles，which are detrimental to the gold recovery process and should be minimized in industrial applications.

As the issue of elevated temperatures in deep mining operations becomes increasingly significant，the implementation of cooling technologies has become widespread.Among these，water source heat pump cooling technology，which utilizes low-temperature subterranean water as a cooling source，offers distinct advantages over traditional ice cooling and air conditioning systems.Specifically，it is characterized by superior energy efficiency，environmental sustainability，and operational effectiveness.The west wing excavation tunnel of the Linglong gold mine at the -750 m section is influenced by factors such as inlet air temperature，ground temperature，and equipment heat dissipation，leading to a working face temperature of up to 37 ℃.Efforts to mitigate this by increasing the inlet air volume and altering the ventilation method，have proven ineffective in significantly reducing the working face temperature.To address this issue，this study leverages the presence of substantial low-temperature groundwater， conducts an analysis of cooling and heat transfer mechanisms，and proposes a localized cooling technology scheme based on water source heat pump technology.Utilizing theoretical calculations and simulation methodologies，the variations in the temperature field of the tunnel under different supply air temperature and volume conditions were simulated.This analysis facilitated the determination of optimal cooling parameters and cooling capacity.Additionally，the selection of equipment and the practical application of the cooling system were conducted.The findings indicate that a localized cooling scheme，which involves positioning the refrigeration unit at the working face，offers a simpler structure，and is more economical and practical.The optimal cooling temperature for long-distance excavation in the -750 m section is determined to be 10 ℃，with a supply air volume of 5.0 m3/s and a cooling capacity of 300.36 kW，serving as a reference for equipment selection.During the on-site application，the establishment of a water storage tank and the implementation of spray cooling measures effectively addressed the issues of insufficient water supply in the refrigeration system and significant cooling loss along the air supply route.Consequently，the temperature at the excavation working face decreased from 37.0 ℃ to 26.2 ℃，a reduction of 10.8 ℃.The average temperature reduction within a 50- meter radius of the working face and the transportation roadway was 8.9 ℃ and 2.9 ℃，respectively.This indicates a significant improvement in the high-temperature conditions of the excavation tunnel.The implementation of this localized cooling technology provides a valuable technical reference for addressing deep heat issues in similar mining environments.

In recent years，the northeastern margin of the Jiaolai Basin has emerged as a significant gold concentration zone within the Jiaodong region.This development follows the discovery of several gold deposits，such as Pengjiakuang，Liaoshang，and Xilaokou，prompting numerous geological prospecting units and scientific research institutions to intensify efforts towards achieving breakthroughs in deep-level prospecting.The Controlled Source Audio Magnetotelluric Method（CSAMT）has been prominently utilized due to its capacity to overcome the limitations of natural field source signals，offering substantial exploration depths，high resolution，and efficient observationsal capabilities.The study concurrently advances research in subsurface sounding and profiling，with recent extensive applications in mineral exploration recently.In this investigation，CSAMT was deployed in the Qianchuiliu mining area.By integrating geological data with the inversion of rock resistivity properties，we analyzed electrical characteristics and spatial features of structural alterations in the shallow subsurface at a depth of -1 000 meters.This analysis builds upon previously identified deep-seated，concealed ore-controlling structural alteration electricity features. A comprehensive analysis of the metallogenic characteristics and prospecting principles associated with the electrical structure was conducted.The findings revealed a thick，near-east-west tectonic fracture zone in the mine’s deep section of the mine.The electrical structure of the geological formation predominantly displays a three-layer configuration characterized by high-low-high resistivity from shallow to deep levels.Additionally， the top interface of the Queshan rock body demonstrates a shallow-deep-shallow trend when observed from south to north.The deep，extensive thick low-resistance fracture zone and the shallow trap low-resistance electrical body exhibit considerable potential for exploration and should be prioritized primary targets in forthcoming drilling initiatives.Controlled Source Audio-frequency Magnetotellurics （CSAMT） offers outstanding vertical resolution，facilitating accurate assessment of the structural fracture zone’s thickness，fracture development sites，and deep extensions. Furthermore，it effectively delineates the spatial distribution characteristics of the structural fracture zone and rock mass in this mining area，aligning with drilling results.The study effectively validates the “three-layer structure exploration model”and confirms the existence of the “near east-west tectonic ore-controlling model” in the Qianchuiliu mining area.CSAMT is demonstrated to be a highly effective method for gold exploration along the northeast margin of the Jiaolai Basin.

During the development of high-temperature true triaxial testing， the imposition of high-temperature environments， cyclic loading and unloading， cyclic thermal shocks， and other complex loading conditions necessitates stringent requirements for the thermal insulation performance of the test system. In oder to scientifically and rationally select appropriate thermal insulation materials for the high-temperature true triaxial test machines under such complex conditions， three kinds of high-temperature engineering thermal insulation materials （GX）， glass fiber， and high-temperature resistant resin composite thermal insulation material （BX） and high temperature barrier composite mica material （YM）were prepared. A series of laboratory tests， including cyclic thermal shock， high-temperature exposure， and cyclic loading and unloading， were conducted to simulate the mechanical and thermal conditions representative of operational environments. These tests aimed to evaluate the thermal conductivity， elastic modulus， compressive strength， and microstructural evolution characteristics of the materials under complex working conditions. The results indicate that the thermal conductivity of the three insulation materials initially increases and subsequently decreases with rising temperature under high-temperature conditions， while the elastic modulus exhibits a certain degree of reduction. During cyclic thermal shock experiments， the thermal conductivity of the YM material demonstrated a consistent decline with an increasing number of heating and cooling cycles. In contrast， the thermal conductivity values of the other two materials initially increased and then decreased.The variation in the elastic modulus exhibited a pattern analogous to that observed under high-temperature conditions. Under cyclic loading and unloading conditions， the thermal conductivity of the insulation material initially increases and subsequently decreases as the number of cycles progresses. Notably， the first cycle of loading and unloading exerts the most significant influence on the thermal insulation and physical properties of the material. Scanning Electron Microscopy （SEM） results indicate that the pores within the laminated structure of the YM material remained small following thermal shock， with no significant crack formation observed after high-temperature treatment. The structure was both complete and stable. A comprehensive evaluation of the thermo-mechanical properties revealed that， after exposure to high-temperature environments and cyclic thermal shock， the structural integrity of the YM material was exceptionally stable. Consequently， YM material is deemed the optimal choice for insulation in rock true triaxial testing machines. This study establishes a foundational framework for the selection of thermal insulation materials in true triaxial test equipment and offers significant guidance for both the research and application of thermal insulation material sheets in true triaxial test machines.

Reconstructing the industrial value chain is a strategic decision for China to overcome the challenges posed by the western rare earth supply chain restruction and the capture of low-end value from the perspective of “dual circulation” strategy.By examining the structural changes in both internal and external value chains，this paper analyzed the logical differences in the development of rare earth industry under the “external circulation” and “dual circulation” patterns. Furthermore， the study utilized the export technical complexity and DEA-Malmquist index to assess the global value chain position and domestic development level of China’s rare earth industry. Ultimately， the research delves into the potential strategies for the reconstruction of the internal value chain within this industry.The findings indicate that China’s rare earth industry is vulnerable to risks such as external “decoupling”，constraints associated with “low-end locking”，and challenges stemming from internal competition among homogeneous enterprises under the prevailing influence of “external circulation”.In accordance with the “double cycle” model， China’s rare earth industry is anticipated to transition from a strategy of consolidation to one of integration，thereby bolstering the resilience and risk mitigation capabilities of the rare earth supply chain. Additionally，China’s prominent position within the global rare earth value chain has consistently remained strong，with overall improvements in the efficiency of domestic industry operations.However，further optimization of the scale structure within downstream segments is deemed necessary. In order to address the significant shifts in the global rare earth supply chain，it is imperative for China to develop its domestic rare earth industry value chain through advancements across the entire industry value chain and facilitate regional and industrial advancements.This can be achieved by implementing a dual strategy that involves leveraging expertise from the upper echelons of the value chain and market insights from the lower end to establish dominance in the regional rare earth industry value chain.Ultimately，the integration of these two chains will contribute to the reconfiguration of the global rare earth industry landscape.

The Zhaoping fault zone represents one of the three principal gold ore belts，each containing substantial reserves exceeding one thousand tons，within the Jiaodong region.Exploration efforts in the Jiaogezhuang-Xiadian area have reached depths of up to 2 kilometers，indicating significant potential for further exploration in both the deeper sections and the surrounding periphery of this zone.Nonetheless，several challenges hinder mineral exploration in these deeper peripheral areas，including a lack of clarity regarding metallogenic patterns，inadequate signal reception from conventional geophysical methods under，substantial overburden，and the complexities associated with managing extensive datasets generated from deep mining operations.Through the analysis of geological maps，exploration line profiles，and exploration data，alongside the implementation of three-dimensional physical inversion techniques for gravity，magnetic，and electrical properties，a comprehensive understanding of the exploration prospects in the area has been attained.This research provides a foundational basis for advancing exploration strategies in forthcoming initiatives.The three-dimensional geological model was developed by using human-computer interaction modeling technology，it extending from the surface to a depth of -4 000 meters.Spatial analysis of the three-dimensional geological model reveals a pattern of ore-controlling faults with varying angles from the shallow to the deeper sections.It is found that the gold mineralisation is highly enriched in the section of steep and slow dip faults and in the section of slow dip faults，and the gold ore body follows the law of lateral volatility and equidistant distribution to the NE.This study introduces a prospecting methodology informed by the principles of “fault ore control law”combined with a detailed three-dimensional geological model.It identifies regions with anomalous structural morphology as favorable zones for mineralization，thereby addressing the challenge of detecting abnormal ore deposits beneath deep cover.Furthermore，a comprehensive exploration prediction model has been developed for the central segment of the Zhaoping fault zone through the extraction of five characteristic variables，such as tectonic strike reversal section，tectonic dip reversal section，tectonic surface change rate，orebody dip isotropy and orebody flanking.As a result，twelve target areas for deep mineral exploration have been identified.The integration of these characteristic variables has projected a potential gold mineral resource of 416 tons，thereby guiding the direction for subsequent deep exploration.Preliminary drilling of the target area has revealed an industrial orebody，representing a new breakthrough in the search for ore in the Zhaoping fault zone.

The Lidonggou gold deposit represents the first newly identified endogenous gold deposit in recent years within the basement cap rock of the Beiba area in Hanzhong area，Shaanxi Province.Over 20 gold ore bodies have been delineated，with lengths ranging from 70 to 1 400 meters， and an average thickness between 0.31 and 9.8 meters.The gold grade varies from 0.83×10^-6 to 21.21×10^-6， classifying it as a medium-sized deposit.The gold deposit is predominantly hosted within the marble and sericite quartz schist of the Mawozi Formation，and is controlled by north-northeast trending fault structures.The ore types predominantly consist of breccia and quartz vein，formations，characteristic of a tectonically altered rock and quartz vein-type gold deposit.The principal metallic minerals identified include native gold，pyrite，molybdenite，and chalcopyrite.Mineralization processes are primarily characterized by limonitization，pyrite mineralization，and magnetite mineralization，with sporadic occurrences of malachite and azurite mineralization.Silicification，tourmalinization，and gold mineralization exhibit a close interrelationship.Preliminary analyses suggest that the formation of the Lidonggou gold deposit has undergone four distinct stages：The formation of ore layers encompasses several processes，including early-stage gold formation，ore enrichment and mineralization，as well as supergene weathering and erosion.The mineralization process is categorized into three distinct stages：The post-magmatic hydrothermal mineralization phase occurring during the Jinning epoch，the post-magmatic hydrothermal superimposed transformation mineralization phase during the Chengjiang epoch，and the supergene oxidation phase.The “stage of quartz，native gold，and polymetallic sulfides” constitutes the principal mineralization phase in this region.The mineral assemblage during this stage includes quartz，native gold，pyrite，molybdenite，chalcopyrite，and sphalerite，which collectively signify the primary phase of gold re-enrichment in the area.Drilling verification reveals that the orebody trends southwestward at greater depths.While the deep extension of quartz vein-type gold orebodies within quartz sericite schist is constrained，the deep extension of interlayer fractured zones in marble exhibits relative stability，with a large number and significant scale of controlled gold orebodies，presenting good prospecting potential.The proposed strategy emphasizes the deployment of shallow work control，particularly targeting quartz vein-type gold ore bodies within quartz sericite schist.Additionally，the focus will be on the exploration and assessment of breccia-type and quartz vein-type gold ore bodies influenced by marble interlayer fracture zones in the mid-depth regions.The primary exploration objectives and directions include the implementation of medium-depth engineering verification， boundary expansion exploration，and the identification of concealed orebodies.This understanding can serve as a foundational basis for the exploration and expansion of the mining area，while also offering critical guidance for the identification of similar gold deposits within the region.

The Jiaodong region represents the most significant gold ore cluster in China，with the temporal and spatial distribution of gold deposits being closely associated with Late Mesozoic granites.The emplacement timing of the Early Cretaceous Weideshan granite aligns with the epoch of large-scale gold mineralization，marking it as a crucial geological body for ore formation.The Zhouguan rock mass，a constituent of the Weideshan granite，exhibits a strong spatial and temporal correlation with gold mineralization.Based on comprehensive studies encompassing systematic petrology，zircon U-Pb isotope dating，and whole rock major and trace element geochemistry，the Zhouguan rock mass was emplaced during the late Early Cretaceous period，specifically between （119.4±1.1）Ma and （118±1）Ma.This emplacement coincided temporally with gold mineralization events.The rock mass is characterized by low silicon （Si），high magnesium （Mg），and rich sodium （Na） content，along with relatively elevated concentrations of chromium （Cr），nickel （Ni），cobalt （Co），and scandium （Sc），as well as a high Sr/Y ratio and significantly depleted zirconium （Zr） content.These rocks are classified within the high-potassium calc-alkaline series and are identified as high-Mg diorite.The magma is derived from the partial melting of the enriched lithospheric mantle and incorporates some crustal materials.The emplacement of magma in the Zhouguan rock mass and Weideshan granite induced significant uplift of the shallow crust，leading to the formation of a series of extensional structures.These structures facilitated the migration of ore-forming fluids and created favorable conditions for fluid enrichment and orebody formation.

In the extraction of overlying orebodies in complex environments，it is imperative to prioritize safety and efficiency while preserving the stability of rock strata to prevent surface collapse and safeguard structures.To accomplish these objectives，it is essential to develop effective strategies for managing rock strata movement by comprehensively assessing the impact of underground backfill mining.An initial study was conducted on the impact of various mining field structural parameters，including roof thickness，original rock stress，and backfill ratio，on overlying rock movement at the Panlong lead-zinc mine.This analysis utilized a nonlinear elastic foundation beam mechanical model.Subsequent numerical simulations were performed to determine overlying rock movement values under varying backfill ratios.The results were compared to those obtained from the mechanical model，revealing differences ranging from 3% to 9%，thus validating the reliability of the mechanical model’s results.A ground mine backfill mining technology for controlling settlement of overlying rock was proposed and implemented in industrial experiments.Research findings suggest that the primary factors influencing overlying rock movement，in order of significance，are the backfill ratio，structural parameters of the mining field，roof thickness，and original rock stress.Increasing the backfill ratio is crucial for managing overlying rock displacement，while adjusting anchor support spacing and backfill ratio according to the mining field structure are effective methods for controlling overlying rock displacement.

In order to examine the influence of hydration conditions on the mechanical properties of skarn，a Split Hopkinson Pressure Bar（SHPB） system was utilized to apply both axial and confining pressure.Cylindrical samples measuring 50 mm×50 mm were subjected to a combined static-dynamic loading method under natural and water-saturated conditions.The axial pressure applied was 3 MPa，with a confining pressure of 1 MPa.Impact tests were carried out at air pressures of 0.8，0.9，1.0，1.1，1.2 MPa，with three replicates con-ducted for each pressure level.The research examined the dynamic compressive strength，energy transfer characteristics，and fracture morphology of rock samples subjected to axial and confining pressures in different states.A comparison was made between the dynamic mechanical properties and fracture patterns of skarn samples in their natural and water-saturated states，with an analysis of the softening effect of water on the rock.Furthermore，the study investigated the dynamic mechanical properties，energy dissipation，and fracture morphology of skarn samples with varying water content.The findings suggest that the dynamic compressive strength of water-saturated skarn samples was，typically lower than that of samples in their natural state，with a reduction ranging from 10.47% to 16.32%.Nevertheless，the impact of water on the dynamic mechanical strength of skarn was found to decrease as the strain rate increased.Additionally，water was observed to decrease the energy absorption rate of skarn samples，although when the energy absorption density reached a certain threshold，the presence of water did not affect the dynamic compressive strength of the skarn.The impact fracture morphology of water-saturated and natural state samples exhibited differences in the strain rate effect due to hydration.Specifically，skarn in the natural state displayed more pronounced characteristics at lower strain rates.

Excavation disturbances induce high stress concentrations and stress redistribution within the mine rock body.Additionally，hydraulic factors diminish the rock body’s strength.Mines situated in the southern region of China are particularly susceptible to disasters during the rainy season due to the influence of rainfall.Therefore，investigating the combined effects of these factors on the mechanical properties of mine rock is of significant importance for ensuring the long-term stability of mine side slopes.The study utilized a slope rock body from the Yinshan Mine in Jiangxi Province as a sample and conducted a graded loading creep test based on a triaxial compression test to investigate the mechanical properties of millimeter-scale rock under the combined effects of excavation unloading and pore water pressure.The results indicate that，with increasing excavation unloading and pore water pressure，the short-term peak strength and elastic modulus of the saturated millimeter-scale rock progressively decrease.Under identical excavation unloading conditions，an increase in pore water pressure leads to a reduction in the strength of saturated millimeters due to the influence of the pore water pressure.This results in an increase in transient strain，a decrease in the transient elasticity modulus，and a reduction in resistance to deformation.Additionally，both creep strain and steady-state creep plasticity exhibit exponential growth with the increase in axial stress up to a certain threshold.Under identical pore water pressure conditions，the instantaneous strain and instantaneous elastic modulus of the excavation-disturbed specimen are lower than those of the undisturbed specimen.Additionally，the creep strain and creep rate escalate with the increasing degree of unloading due to excavation.This observation suggests that excavation-induced disturbances diminish the rock strength，rendering the rock body more susceptible to deformation.The findings indicate that the rock strength of phyllite is diminished due to excavation disturbances，rendering the rock mass more susceptible to creep damage.The study further reveals that the combined effects of excavation unloading and pore water pressure exacerbate this reduction in strength.Consequently，the rock mass becomes increasingly prone to creep damage，thereby compromising the stability of slopes.

The Gaosongshan gold deposit represents one of the most significant epithermal gold deposits identified in the northern Lesser Khingan Range region of northeast China.The gold orebodies are predominantly hosted within the intensely altered volcanic rocks of the Lower Cretaceous Banzifang and Ningyuancun Formations，manifesting primarily as veinlets and veins.Despite the deposit’s significance，research on the ore-bearing wall rocks remains relatively underdeveloped.To elucidate the genesis and formation ages of these rocks，comprehensive isotopic dating and elemental geochemical analyses have been undertaken.The dacite of Banzifang Formation obtained ²⁰⁶Pb/²³⁸U surface ages ranging from 112.1 to 115.9 Ma，as deter-mined by zircon laser ablation inductively coupled plasma mass spectrometry（LA-ICP-MS） U-Pb dating.Addi-tionally，⁴⁰Ar-³⁹Ar dating was conducted using multiple collector noble gas mass spectrometry with the Helix MC on plagioclase and feldspar samples collected from the andesite of the Banzifang Formation and the rhyolite of the Ningyuancun Formation within the Gaosongshan deposit，resulting in plateau ages of （111.2±0.9） Ma and （103.9±1.0） Ma，respectively.The dates，obtained through two independent geochronological methods，suggest that the wall rocks of the Gaosongshan deposit were formed during the late period of Early Cretaceous，rather than the Early Cretaceous as previously believed.Major and trace element analyses reveal that the vol-canic rocks of the Banzifang and Ningyuancun Formations exhibit similar geochemical characteristics.Both formations are characterized by high silicon content（SiO₂=62.26%~71.07%），enriched alkali（Alk=7.28~9.28），elevated aluminum levels（A/CNK=1.15~1.80），and low calcium content（CaO=0.09%~2.03%） and depeled magnesium （MgO=0.47%~3.95%） belonging to shoshonite series.The rocks exhibit an enrichment in light rare earth elements （LREE） and large ion lithophile elements，while showing a depletion in heavy rare earth elements （HREE） and high field strength elements such as Nb，Ta，and Ti，characteristics that are akin to those of arc volcanic rocks.Integrating these findings with data from previous studies，we propose that the magmatic activity closely linked to the epithermal mineralization occurred in the late period of Early Cretaceous within an extensional tectonic setting.This setting was likely initiated by the slab rollback associated with the subduction of the Paleo-Pacific oceanic plate.

The Hetai goldfield，situated in Guangdong Province represents the largest gold mining district in South China.The confinement of the Au orebodies to mylonite zones has led to the classification of this goldfield as a prototypical example of gold mineralization associated with ductile-shear deformation.Comprehensive mineralogical analyses were performed on ore thin sections utilizing optical microscopy and scanning electron microscopy（SEM），followed by electron probe microanalysis（EPMA） to determine the mineral geochemistry.In the Hetai goldfield，a significant discovery was made，identifying the presence of Cu-Zn intermetallic compounds and native Ni minerals.The Cu-Zn intermetallics exhibit a copper mass fraction ranging from 58.63% to 62.14%，with an average of 60.41%，and a zinc mass fraction ranging from 35.55% to 38.48%，with an average of 36.63%.Additionally，trace amounts of Fe，Au，and Pb were detected in the Cu-Zn intermetallic compounds.The calculated molecular formula is Cu_0.61Zn_0.37Fe_0.02，which is approximately Cu₂Zn.The native nickel（Ni） minerals exhibit a Ni mass fraction ranging from 86.33% to 87.74%，with an average of 87.26%，and an iron（Fe） content ranging from 4.56% to 5.02%，with an average of 4.72%.Additionally，these minerals contain trace amounts of sulfur（S），copper（Cu），and tellurium（Te）.The derived molecular formula，Ni_0.93Fe_0.05S_0.02，suggests the presence of iron-bearing native nickel.The genesis of copper-zinc（Cu-Zn） intermetallic compounds and native nickel within the Hetai goldfield is likely associated with deep mantle fluids and is postulated to have occurred during the initial phase of hydrothermal mineralization.This phenomenon specifically，transpired within a high-temperature environment characterized by localized deficiencies in sulfur and oxygen during the quartz-sulfide stage.These findings corroborate prior results obtained from He-Ar isotope analyses，thereby affirming the participation of a minor proportion of mantle-derived fluid in the process of gold mineralization.

With the rapid development of China’s economy，the traditional model of crude economic growth has exacerbated resource shortages，and intensified environmental pressure.Consequently，the vigorous development of a green，circular economy and the improvement of resource utilization rates are imperative.Gold tailings，a form of solid waste，are produced as a byproduct of the extraction and processing of gold mineral resources.Gold production predominantly utilizes the cyanide extraction method，necessitating the addition of cyanide during the process.Consequently，residual cyanide remains in the tailings，contributing to environmental pollution and posing risks to human health.Furthermore，as the scale of gold production expands，the accumulation of gold tailings increases annually，leading to significant land occupation.In China，the comprehensive utilization rate of metal tailings averages less than 10 percent，which is markedly lower compared to other bulk solid wastes.Gold tailings are rich in both heavy metal elements and valuable minerals，improper management not only results in the wastage of natural resources，but also poses significant safety risks.Bibliometrics，the application of mathematical and statistical techniques to quantitatively analyze information within the literature of a specific field，can elucidate the characteristics of research activities and identify emerging trends in that domain.Employing bibliometric methods and VOS viewer software，this study aimed to elucidate the research dynamics pertaining to the treatment and comprehensive utilization of gold tailings，both domestically and internationally.The findings indicate a growing trend in research on gold tailings treatment and comprehensive utilization，with close inter-country research linkages and a steadily improving comprehensive utilization rate of gold tailings in China.The research in this field predominantly focuses on three directions，namely flotation of gold tailings，comprehensive utilization of gold tailings，and ecological restoration of gold tailings.Innovations in separation and purification technologies for various components in gold tailings， have the potential to enhance the comprehensive utilization of these tailings，thereby increasing their added value.Such advancements can facilitate the quantitative reduction，resource utilization，and high-value application of gold tailings.Currently，the overall comprehensive utilization of gold tailings，both domestically and interna-tionally，is increasing.However，challenges remain in the resource utilization of gold tailings，necessitating further in-depth research.It looks forward to the future development direction of harmless treatment and high value utilization of gold tailings.The comprehensive utilization of gold tailings can turn waste into treasure，turn harm into benefit，and alleviate the prominent contradiction between China’s economic development and ecological environment destruction and resource shortage.

The northeastern region of Hunan Province，situated within the central Jiangnan Orogenic Belt，is distinguished by the presence of numerous gold deposits，notably including the Wangu and Huangjindong.To systematically investigate the genetic relationships between various fluid-rock interactions and the mechanisms of gold precipitation in this area，comprehensive field geological investigations，petrographic analyses，and thermodynamic simulation have been undertaken.Geological field investigations have identified silty slate as the primary ore-bearing wall rock in northeast Hunan.This rock is notably characterized by extensive bleaching alteration，with ore bodies predominantly situated within the bleached zones.In contrast，certain ore bodies are found within carbonaceous slate，which retains its black coloration and exhibits no visible color change despite undergoing hydrothermal alteration.Petrographic analysis reveals that the bleached zones contain numerous siderite spots，which are intersected by pyrite and arsenopyrite.Conversely，in the carbonaceous slate，sulfide minerals are intimately associated with carbonaceous matter（CM）.The thermodynamic simulation indicates that siderite present in the bleached zone can interact with the fluid，leading to gold precipitation through sulfidation.Similarly，chlorite within slate can also engage with the fluid to initiate sulfidation.However，the dissolution rate of carbonate exceeds that of chlorite，suggesting that carbonate exhibits higher chemical reactivity，which is more conducive to gold mineralization.The carbonaceous matter（CM） in the carbonaceous slate can enhance gold deposition by reducing the fO₂ in the fluid through fluid-rock interactions，facilitating fluid boiling，and providing sites for fluid transport and precipitation.Consequently，the silty slates and carbonaceous slates in northeast Hunan are capable of promoting gold mineralization through distinct mechanisms and are thus favorable wall rocks for gold mineralization.

Mining operations and engineering projects frequently produce numerous unstable artificial waste slopes，which pose significant hindrances to human activities.Consequently，the implementation of effective slope morphology optimization is essential for ensuring engineering safety and maximizing landfill capacity.The development of an efficient，accurate，and scientifically robust method for slope morphology optimization holds substantial theoretical and practical importance for the management of unstable artificial slope projects.Consequently，we propose an advanced slope morphology optimization method，termed LM-LSO，which integrates the levenberg-marquardt （LM） algorithm with the light spectrum optimizer （LSO）.Initially，stability coefficients for various slope configurations were computed utilizing the limit equilibrium method，with cut and fill volumes estimated based on the differences in two-dimensional profiles，thereby generating the sample data.Subsequently，cross-product terms among variables were incorporated to capture nonlinear relationships，and the LM algorithm was applied for the nonlinear fitting of the sample data.In conclusion，an infeasible solution rejection method was employed to address stability coefficient constraints，optimizing the solution using the LSO algorithm and benchmarking it against four other algorithms.This approach was implemented to optimize the terrace height，width，and slope angle of a gypsum stack slope in Sichuan Province.The objective was to minimize the excavation volume while ensuring adherence to stability regulations.The final optimized design parameters include terrace heights（h） of 6.38 m，step widths（l） of 4 m，step inclinations（α） of 25.11°，and a minimal excavation volume（V_min） of 298.92 m2.The method comprehensively considers the economic feasibility and stability of slope optimization，ensuring both landfill capacity and safety.

Autonomous driving technology plays a crucial role in the development of smart mines，with its primary challenge being the safe navigation of vehicles within the intricate and dynamic environments of open-pit mines.Mining roads are frequently characterized by a high density of diverse obstacles，including rockslides，water pits，and ruts，which present in various forms and are widely dispersed.These conditions pose substantial safety risks to the autonomous operation of mining vehicles.At present，although numerous road obstacle detection algorithms have been proposed，their detection accuracy is frequently constrained by the distinctive conditions present in open-pit mines，thereby hindering their ability to satisfy practical application requirements.This study presents a road obstacle detection algorithm for open-pit mines based on RT-DETR.The algorithm integrates the RepViT network within the encoder phase to augment the model’s feature extraction capabilities，thereby facilitating a more precise capture of the characteristic information of road obstacles.In the decoder section，the algorithm employs channel compression pruning techniques，which significantly decrease the model’s computational complexity and enhance detection speed.Furthermore，it incorporates the RepAttC3 module，augmented with an attention mechanism，thereby enhancing the model’s capability to detect multi-scale and small target obstacles.To evaluate the algorithm’s efficacy，a dataset comprising road obstacle images from various mines，seasons，and scenarios was assembled，specifically focusing on open-pit mine road obstacles.The experimental findings indicate that the algorithm exhibits superior performance in identifying road obstacles within open-pit mines，achieving an average detection accuracy of 92.7%，a comprehensive detection accuracy of 96.6%，and a detection speed of 12.3 milliseconds.In comparison to existing road obstacle detection algorithms，the proposed algorithm demonstrates distinct advantages in detecting multi-scale and small target obstacles，thereby offering more precise and efficient obstacle detection for vehicles operating in open-pit mining environments.It offers robust technical support for the development of autonomous driving technology in open-pit mines，further advancing the progress of smart mine construction.

Following the instability incident in the upper middle section of the filling stope at the West No.2 mining area of Longshou mine in Jinchuan，the original downward-layered consolidated filling method was replaced with the non-pillar sublevel caving method.To investigate critical technical challenges，such as cover layer formation and stope stability associated with the practical application of this method，numerical simulation techniques were employed for the research.The research findings suggest that as the sublevel stope area within a caving stope expands，the composite roof experiences a sequence of progressive failure stages.These stages include the initiation of failure cracks，dispersed bulk caving，arch batch caving，and plunger integral caving.By the conclusion of the first sublevel mining，the height of the roof collapse is expected to exceed 30 meters，thereby forming a sufficiently thick cover layer for the caving method stope.Concurrently，during the mining process，plastic zones are generated on the surface of the roof along the mining approach.The support structure serves a critical function in anchoring and stabilizing the majority of the plastic zones，thereby contributing to the overall stability of the mining approach.Despite the minimal displacement observed in the access roof，there is a pronounced stress concentration within 5 meters behind the working face，necessitating continued attention.An industrial experiment was subsequently conducted on-site，employing the non-pillar sublevel caving method and utilizing induced caving technology to establish a cover layer.To mitigate the risk of large-scale collapse of the composite roof，a technical strategy involving“stepped mining and uniform expansion of goaf combined with total ore extraction control”was implemented on-site.Microseismic monitoring and on-site tracking data revealed that during the initial sublevel mining phase，the actual caving height of the roof in the mining area surpassed 20 meters，resulting in the formation of a thick cover layer approximately 30 meters thick，inclusive of the reserved ore layer.Throughout the entire mining process，the stope remained in a stable condition.To address the issue of significant damage to the access road in the fractured ore and rock zone，a comprehensive technical scheme incorporating multiple support structures was proposed.For the problem of medium and deep hole damage，a systematic approach involving hole inspection，hole dredging，and hole filling was established.Additionally，relevant equipment was promptly introduced to mitigate operational intensity and enhance the applicability of the non-pillar sublevel caving method under the soft，fractured ore and rock conditions prevalent in the Jinchuan mining area.

The shallow orebody located at a depth of 1 500 meters within the Dayingezhuang gold mine in Jiaodong has been extensively delineated.Consequently，exploring the depth range of 1 500 to 3 000 meters is not only essential for providing supplementary resources to support further mine development but also possesses considerable demonstrative value for achieving new breakthroughs in ore exploration.To this end，a 4-kilometer-long multi-polarization electromagnetic sounding profile was conducted at the periphery of the Houtuan area of the Dayingezhuang gold mine.During this study，natural field electromagnetic signals ranging from 1 Hz to 100 kHz were collected.Inversion calculations produced resistivity and magnetization profiles extending to a depth of 3 000 meters.Based on the existing geological prospecting model and the electromagnetic characteristics of Neoproterozoic TTG and Jiaodong Group metamorphic rocks，which exhibit low resistivity and high magnetization，as well as Late Jurassic granite bodies，characterized by high resistivity and low magnetization，the transition zone from low resistance and high magnetization to high resistance and low magnetization is identified as the ore-controlling Zhaoping fault zone，and the expanding space where the dip angle of the fault zone from low-resistivity and high-magnetization to high-resistivity and low-magnetization is interpreted as the ore-controlling Zhaoping fault zone.Additionally，the region where the dip angle of the fault zone becomes more horizontal is inferred to be a favorable site for mineralization.This interpretation is supported by data from drill hole 80ZK2101，which identified a pyrite-silicified alteration zone between depths of 2 943.18 m and 3 108.41 m，with a gold ore body located at depths of 3 100.06 m to 3 101.06 m.The drilling results corroborate the interpretations derived from multi-polarization electromagnetic sounding data.

The Shanghai gold domestic board，gold international board，and Shanghai crude oil futures market play significant roles in emerging financial markets. However，the hedging capability of the gold domestic board and international board in relation to domestic and foreign crude oil markets are not clearly defined. It is crucial for regulators to assess the differences in hedging capability between the two gold markets in domestic and foreign crude oil markets，and to explore the underlying reasons. It is also crucial for regulators to have a comprehensive understanding of the evolution of gold markets in order to effectively implement risk management strategies.This study focuses on the gold domestic board，gold international board，Shanghai crude oil futures，and WTI crude oil futures as the research objects，analyzing the variations in risk hedging from the gold international board to Shanghai crude oil and WTI crude oil from an international perspective，as well as from the gold domestic board and international board to Shanghai crude oil from a domestic perspective. The study utilized the DCC-MGARCH model to analyze the dynamic correlation of yield among the gold domestic board，gold international board，Shanghai crude oil，and WTI crude oil. Additionally，the hedging capabilities of gold on crude oil was evaluated from the perspectives of extreme risk and falling prices. Lastly，an examination of volatility spillover and price discovery function provided insights into the varying hedging abilities of Shanghai and WTI crude oil on the gold domestic and international boards. The findings indicate that the correlation coefficients between gold domestic and international boards，Shanghai crude oil，and WTI crude oil exhibit dynamic characteristics. Additionally，the hedging capability of gold international board on Shanghai crude oil is weaker than that of WTI crude oil. This is attributed to Shanghai crude oil’s susceptibility to risks associated with WTI crude oil，as well as its lack of significant correlation with gold international board compared to WTI crude oil. Thirdly，the hedging capability of the gold international board for Shanghai crude oil is weaker than that of the gold domestic board. This disparity can be attributed to the inadequate market liquidity of the gold international board and its lagging price discovery function compared to the gold domestic board.

The sulfide minerals present in the tailings of metal mines substantially influence the strength of backfill materials.This study aims to comprehensively investigate the mechanical properties of backfill composed of sulfur-containing and desulfurized tailings.For this purpose，sulfur-containing tailings sourced from a mine and desulfurized tailings processed through industrial trials were utilized as the aggregate in the backfill.Cement served as the binding agent in the preparation of backfill specimens.To evaluate the mechanical performance，uniaxial compression and Brazilian splitting tests were conducted，facilitating a comparative analysis of the desulfurized and sulfur-containing backfill specimens.The research examines the impact of varying cement-sand ratios，solid content concentrations，and curing age on the compressive strength of two types of backfill materials.Furthermore，quantitative relationships among these variables were derived by fitting the experimental data，and the sensitivity of each factor was assessed.The findings reveal that：（1）The com-pressive strength of desulfurized tailings backfill consistently exceeds that of sulfur-containing tailings backfill.The uniaxial compressive strength of desulfurized tailings exhibits an average increase ranging from 2.02% to 14.12% compared to sulfur-containing tailings，while the tensile strength demonstrates an enhan-cement between 7.64% and 58.45%.（2）At a curing age of 28 days and a cement-sand ratio of 1∶8，the uniaxial compressive strength of sulfur-containing tailings remains relatively unchanged with increasing mass concentration.In contrast，the strength of desulfurized tailings backfill displays a distinct upward trend.（3）At a cement-sand ratio of 1∶4，the compressive strength of both sulfur-containing and desulfurized backfill exhibits an increase with higher slurry concentrations after a 60-day curing age；however，this increase is less pronounced compared to the 28-day curing age.Conversely，when the cement-sand ratio is decreased to 1∶8，the strength enhancement of sulfur-containing and desulfurized backfill after 60 days surpasses that observed after 28 days.（4） The reduction in sulfide content enhances the chemical stability of desulfurized tailings，thereby improving the mechanical properties of the backfill.（5） The strength of the backfill is most significantly influenced by curing age，followed by the cement-to-sand ratio，with mass concentration having the least impact.（6） Under constant conditions，the strength of both sulfur-containing and desulfurized backfill exhibits an exponential growth trend with increasing curing age，achieving a goodness of fit value of 0.9 or higher.The study demonstrates a linear growth pattern in relation to the increase in mass concentration，evidenced by a multiple correlation coefficient of 0.94 or higher.This paper aims to offer a practical reference of significance for understanding the developmental behavior of the mechanical properties of sulfur-containing and desulfurization tailings backfill.