The lower Ku’erbin River gold deposit, presently in the explorationphase, represents a newly identified epithermal gold deposit within the northern Lesser Khingan Range. The gold orebodies, or mineralization, are predominantly hosted within the Lower Cretaceous Ganhe Formation andesites, marking the inaugural discovery of gold mineralization in this region. To systematically investigate the relationship between the host rocks and gold mineralization, comprehensive field geological surveys, petrological analyses, zircon U-Pb geochronology, and petrogeochemical studies were undertaken. LA-ICP-MS zircon U-Pb dating indicates that the andesites hosting the ore were formed at (106.4±1.0)Ma(MSWD=1.8) during the late Early Cretaceous. Petrogeochemical and zircon Hf isotopic analyses reveal that the Ganhe Formation andesites in the lower Ku’erbin River gold district are characterized as magnesian andesites of the low-iron calc-alkaline series. These andesites exhibit high MgO contents(2.55%~4.72%), elevated Mg^# values(48~64), and low TFeO/MgO ratios(1.01~1.95), indicating formation in an active continental margin tectonic setting. Their genesis is attributed to stagnant slab melting, primarily influenced by subducted sediment melts with additional contributions from subduction-related fluids. The magma experienced interactions within the shallow mantle and crust-mantle mixing during its ascent, exemplifying the synergistic coupling of multi-stage geological processes. Zircon Ce-U-Ti oxybarometry analysis indicates that the volcanic rocks of the Ganhe Formation in the mining area exhibit ΔFMQ values ranging from 0.13 to 2.85, with an average of 0.94, suggesting moderately high oxygen fugacity. Furthermore, the zircon Ti temperatures are relatively elevated, averaging 820 ℃, which is likely associated with the prolonged replenishment of the magmatic system. A comprehensive analysis suggests that the Ganhe Formation volcanic rocks possess significant gold mineralization potential, providing a crucial scientific foundation for future regional exploration efforts.

The Matigou-Miaogou gold deposit, situated in Fengxian, Shaanxi Province, within the West Qinling region of China, is positioned at the southern margin of the western Shangdan fault zone, centrally located in the Qinling orogenic belt. This deposit represents a quintessential example within Shaanxi Province’s recent strategic initiatives aimed at advancing ore prospecting breakthroughs. The geological strata in this region span from the Paleoproterozoic to the Quaternary periods. Owing to multiple episodes of rifting, contraction, and amalgamation since the Proterozoic era, the exposed strata have experienced varying degrees of deformation, resulting in the formation of near east-west trending complex folds and faults. During the Triassic period, the region experienced intense magmatic activity, characterized by frequent magma intrusions that were often accompanied by multi-stage mineralization. Consequently, this area constitutes a significant structural zone for gold and nonferrous polymetallic mineralization. Notably, the diorite-porphyrite distribution within the mine area is extensive, with evident mineralization and alteration phenomena observable in certain sections, which are spatially closely associated with the ore bodies. This study conducts a preliminary investigation into the metallogenic epoch and mechanisms of the Miaogou gold deposit through a comprehensive analysis of the regional metallogenic background, geological characteristics, rare earth and trace element compositions of rocks (ores), H-O-S isotopic data, and zircon U-Pb dating of diorite-porphyrite veins in the Miaogou gold mine area. In this region, the diorite porphyrite exhibits total rare earth element (ΣREE) concent rations ranging from 99.45×10⁻⁶ to 121.44×10⁻⁶, with light rare earth element (LREE) concent rations between 90.60×10⁻⁶ and 112.26×10⁻⁶, and heavy rare earth element (HREE) concent rations from 8.85×10⁻⁶ to 10.12×10⁻⁶. The europium anomaly (δEu) values range from 0.91×10⁻⁶ to 0.99×10⁻⁶, while the cerium anomaly (δCe) values range from 0.93×10⁻⁶ to 0.94×10⁻⁶. For the ore samples, ΣREE content varies between 46.88×10⁻⁶ and 121.44×10⁻⁶, LREE content ranges from 41.60×10⁻⁶ to 184.34×10⁻⁶, and HREE content spans from 5.28×10⁻⁶ to 21.17×10⁻⁶. The δEu values for the ores range from 0.57×10⁻⁶ to 1.49×10⁻⁶, and δCe value s range from 0.85×10⁻⁶ to 0.98×10⁻⁶. Additionally, the δD_V-SMOW values range from -96‰ to -59‰, and the δ ¹⁸ Ofluid values range from 7.3‰ to 10.3‰, and the value of δ ³⁴S is from 4.15‰ to 11.88‰. The zircon U-Pb concordant age of the diorite porphyrite is determined to be (220.7±1.0)Ma, with a weighted average age of (219.8±2.1)Ma. The findings indicate that the majority of the metallogenic materials at the Miaogou gold mine are derived from magmatic sources, with a minor contribution from the surrounding rock strata. The metallogenic fluids are of multiple origins, predominantly consisting of magmatic water. It is posited that the Miaogou gold mine was formed during the Late Triassic period. During this epoch, significant brittle-ductile shear deformation and magmatic activity were intimately associated with gold mineralization and alteration processes. These geological phenomena likely provided the necessary thermal energy and mineral sources, facilitating the activation, migration, and enrichment of siliceous materials and minerals within the early Paleozoic Luohansi rock group. These materials subsequently concentrated within the multi-fissures oriented in the west-north-east-south direction, associated with brittle-ductile shear deformation. The tectonic deformation, magmatic activity, and ore-forming enrichment events of the Late Indosinian period hold substantial significance. The Miaogou gold deposit is thus interpreted as a product of extensive and intense deformation, metamorphic-magmatic activity, and fluid interactions governed by the brittle-ductile shear zones during the Late Triassic.

The Saibagou region is situated in the eastern segment of the tectonic belt along the northern margin of the Qaidam Basin. Within this area, a series of gold deposits have developed along the NNW-oriented ductile shear belt and its subsidiary faults. This study conducted in situ sulfur isotope and trace element analyses of pyrite from the primary ore-forming stages of the Gashun, Tuoxingou, and Wudarehu gold deposits, building upon comprehensive field geological investigations and mineralogical studies. The findings reveal that the sulfur isotopes of the gold deposits in the Saibagou area exhibit a relatively concentrated tower-type distribution, with an average range of -1.55‰ to 3.93‰. This distribution suggests characteristics indicative of both mantle-derived and granite-derived sulfur, aligning closely with the sulfur isotope composition typical of orogenic gold deposits located along the northern margin of the Qaidam Basin. The overall composition is enriched with arsenic （As）, cobalt （Co）, nickel （Ni）, and selenium （Se）, while the relative concent rations of gold （Au）, silver （Ag）, copper （Cu）, lead （Pb）, zinc （Zn）, and bismuth （Bi） are notably high. A significant correlation is observed between Au and As. Gold predominantly occurs within the pyrite lattice as a solid solution, whereas copper primarily associates with pyrite as independent elements rather than substituting for iron （Fe）. The ore-forming fluid is characterized by a relatively reductive environment. Through a comprehensive analysis encompassing ore-controlling structures, alteration types, mineral associations, host rock characteristics, trace element geochemistry, and sulfur isotope data, the gold deposit in the Saibagou area is classified as an orogenic gold deposit.

The Qibaoshan deposit, situated within the Qin-Hang metallogenic belt in eastern China, exemplifies a typical cobalt-bearing polymetallic deposit. Currently, its metallogenic mechanism remains inadequately elucidated, primarily due to the absence of systematic investigations into the mineralogical characteristics of pyrite, the primary cobalt-hosting mineral. This deficiency has significantly impeded a comprehensive understanding of the deposit’s genesis and ore-forming processes. In this study, we employ integrated petrographic, mineralogical, and geochemical analyses to delineate the ore-forming stages, systematically characterize the trace-element composition of pyrite, and subsequently discuss the metallogenic mechanism of the deposit. Microscopic examination of the ore reveals that pyrite in the Qibaoshan deposit can be categorized into two episodes and five stages: PyⅠ formed during the sedimentation-diagenesis stage of the first episode, manifesting in fractures of gangue minerals as diagenetic pyrite, while PyⅡ to PyV are products of the second episode of magmatic hydrothermal activity. PyⅡ is predominantly associated with arsenopyrite, while PyⅢ is linked to an abundance of cobalt-nickel minerals. PyⅣ serves as a primary mineral component in sulfide veins, and PyⅤ is found within carbonate veins. The δ ³⁴S values of pyrite range from 1.24‰ to 2.10‰. Integrating these findings with prior research, it is inferred that the ore-forming materials predominantly originated from magmatic sources and seawater sulfate. The major and trace element characteristics of pyrite provide a comprehensive record of the diagenetic-hydrothermal evolution process. Specifically, PyⅠ and PyⅡ display sedimentary origins（Co/Ni<1）, whereas the subsequent PyⅢ and PyⅣ exhibit hydrothermal characteristics（Co/Ni>1，S/Se<1×10⁵）. The concent rations of arsenic and selenium progressively increase from stageⅡ to stageⅣ, indicating a transition in the ore-forming fluid temperature from an initial high temperature to a medium-low temperature. The high nickel content（average 159×10^-6） in pyrite, along with the presence of lamprophyres and diabase in the region and the sulfur isotope data of pyrite, suggests that the ore-forming materials may have been derived from basic rocks. A thorough analysis reveals that the deposit experienced sedimentation and diagenesis, during the Late Paleozoic era, followed by alteration due to magmatic hydrothermal fluids, and several phases of mineral enrichment. The spatial emplacement of the deposit was influenced byregional unconformities and fault systems. The findings of this study enhance the understanding of the metallogenic processes associated with hydrothermal cobalt deposits and offer a scientific foundation for cobalt resource exploration within the Qin-Hang metallogenic belt.

The Huangjindong gold field, situated in the northeastern region of Hunan Province within the Jiangnan Orogen, represents a major gold production site，boasting cumulative proven resources of approximately 80 tonnes with an average grade of 5 g/t.The ore bodies are predominantly hosted within interlayer shear fractures that have developed along the limbs of overturned folds trending from northwest-west to east-west.Despite its economic significance，a comprehensive understanding of the ore-controlling structural architecture has been lacking.Historically, the absence of a systematic analysis of the structural framework and deformation styles has impeded both a profound understanding of metallogenic regularity and the scientific planning of exploration initiatives in this field.To address this deficiency，this study conducts a detailed structural analysis grounded in extensive, fine-scale route mapping and field-based structural observations.The primary objectives were to （1） delineate the fold architecture and characterize the deformation patterns that govern mineralization, （2） elucidate the formation mechanisms of the predominant structures, and （3） explore the implications for future gold exploration endeavors. Our findings reveal a structural framework characterized by two primary elements: a system of NWW- to E-W-oriented folds and a series of NE-oriented faults. A notable structural divergence is evident across the regional Niwan Fault.To the west of this fault, the fold system consists of overturned anticline-syncline pairs with NWW-trending hinges and axial planes consistently dipping towards the NNE. Conversely, the eastern block exhibits folds with E-W-oriented hinges and north-dipping axial planes, suggesting a significant counterclockwise deflection of structural trends in the footwall compared to the hanging wall. We propose that the initial development of this fold system was governed by a critical layer-parallel décollement horizon located between the Xiaomuping and Huanghudong formations.Under a regional NNE-SSW compressional tectonic regime, this décollement facilitated detachment and slip, resulting in the formation of fault-propagation folds at its leading edge. We hypothesize that the observed deflection across the Niwan Fault was induced by subsequent northward thrusting along a concealed, approximately E-W-striking reverse fault. The fault in question likely originates from the Caledonian orogeny, and its movement has resulted in the differential rotation of the footwall block. The structural model developed in this study has significant implications for exploration.Future research should focus on: （1） systematically investigating the ore-hosting potential of interlayer shear fractures that have developed along the limbs of the identified folds, as these serve as primary fluid conduits and sites of mineral deposition; （2） considering the vertical segmentation and enrichment characteristics of ore shoots within these structures; （3） revising traditional exploration strategies that assumed a straightforward correlation of ore veins across the Niwan Fault; and （4） improving the targeting of intersections between the northeast-trending fault system and the northwest-west to east-west interlayer shear fractures, as these junctions likely functioned as high-permeability zones conducive to fluid concentration and enhanced gold deposition. This refined structural framework offers a robust foundation for future evidence-based exploration in the Huangjindong gold field and similar structurally controlled regions.

The Wengkongba copper deposit，situated in Jinggu County, Pu’er City, Yunnan Province, is part of the northern segment of the South Lancangjiang volcanic arc metallogenic belt. It is categorized as a continental volcanic sedimentary-reformed deposit characterized by complex mineralization processes, which pose chal-lenges to conventional prospecting methods. In recent years, advancements in tectonogeochemical exploration technology have positioned it as a pivotal approach for the prediction of concealed orebodies. This study employs tectonogeochemical anomaly analysis to integrate the characteristics of tectonogeochemical element associations, anomaly distribution patterns, and their indicative significance. The primary findings are as follows：Surface factor analysis of the deposit area distinctly reveals the coexistence of two significant mineralization processes, namely volcanic sedimentary mineralization and tectonic reworking mineralization. Among the extracted factors, factor F5 suggests the potential superimposition of alkali-rich acidic magmatic hydrothermal fluids, which may have played a significant role in the later stages of mineralization. Factor F1 indicates distinct lithofacies zonation within the intermediate-basic volcanic rock series, providing valuable insights into the geological context of mineralization. Notably, the volcanic lithofacies in the northern part of factor F6 and the undivided T₂ strata, located in the western part of the deposit area, exhibit a pronounced tendency towards copper enrichment and mineralization during the volcanic sedimentary-diagenetic minera-lization stage, thereby emerging as potential key zones for mineralization. Furthermore, the tectonic influence on mineralization in the Wengkongba copper deposit is particularly prominent, with anomalies in ore-forming element associations displaying a distinct belt-like distribution along the north-south axis. This distribution pattern clearly demonstrates that the SN-trending faults, lithological unconformity interfaces, and lithological boundaries in the region function as significant ore-conducting structures, facilitating the migration of ore-forming fluids. Concurrently, the spatial arrangement of these element association anomalies along the near-EW （east-west） direction strongly suggests that the deposit is predominantly influenced by EW-trending faults. These EW-trending faults have been identified as the primary ore-controlling structures that dictate the ultimate emplacement of orebodies. Furthermore, multi-element association anomaly analysis reveals that the factor scores of various ore-forming elements frequently intersect and overlap at specific locations where lithological unconformities, lithological boundaries, and faults converge. The intersection and overlapping zones, along with their adjacent regions, have been identified as primary targets for exploration in this study, as they are highly probable locations for ore body accumulation. Based on the a forementioned research findings, five prospecting targets were delineated within the Wengkongba copper deposit area. Subsequent drilling validation in these target areas yielded significant results, uncovering multiple layers of concealed copper-lead mineralized ore bodies of considerable thickness and extent. These findings not only confirm the efficacy of tectono-geochemical exploration techniques in this deposit but also suggest that the Wengkongba copper deposit possesses substantial resource potential, thereby establishing a solid foundation for the further development and utilization of mineral resources in the region.

The Xijiele research area is situated in the southern region of Qinghe County, within Altay Prefecture, Xinjiang. This area exhibits a complex geological structure, characterized by the presence of basic volcanic and clastic rock formations within the Late Paleozoic island arc zone. This study utilizes 1∶10 000 soil geochemical measurement data to evaluate the relative merits and drawbacks of conventional anomaly delineation techniques versus lithological zoning anomaly lower limit lining methods. The findings reveal that traditional approaches, which apply a uniform lower limit for anomalies across the entire region, are vulnerable to interference from areas with high background levels, resulting in the potential oversight of false or weak anomalies. In contrast, the lithological zoning anomaly lower limit lining method enhances the precision of anomaly identification by categorizing sedimentary, volcanic, and intrusive rocks into three distinct sub-zones, calculating lining values, and normalizing them accordingly. The validation of established gold （Au） and copper （Cu） mineral deposits within the region indicates that the anomalies identified through the lithological zoning method not only demonstrate a higher degree of concordance with the spatial distribution of the mineral deposits but also exhibit more distinct concentration zoning characteristics. Furthermore, their spatial distribution patterns show improved correlation with the regional geological background of mineralization. This method effectively enhances the contrast between anomalies and background by mitigating the influence of lithological background variations, thereby offering a novel technical approach for the identification of geochemical anomalies in areas with complex lithological distributions. It holds significant practical value for guiding mineral exploration efforts in regions with analogous geological backgrounds.

The Jinshan gold mining area is located in the central-southern segment of the Qixia-Penglai metallogenic belt within the Jiaodong region and is characterized as a medium-sized altered rock-type gold deposit. As surface prospecting efforts have reached a bottleneck, there is an increasing urgency to pursue deep-side prospecting to identify additional resources. To expand the prospecting domain and achieve breakthroughs in deep and edge exploration, geophysical techniques such as high-precision surface magnetic surveys and controlled source audio magnetotelluric （CSAMT） soundings are employed to assess and evaluate gold resources in the eastern part of the Jinshan mining area. By processing inversion data from high-precision ground magnetic surveys and CSAMT soundings, and integrating these with previous geological research, a comprehensive geological interpretation was performed on the magnetic anomaly correlation imaging inversion results and the CSAMT inversion outcomes. This study elucidated the magnetic properties, geoelectrical characteristics, and spatial distribution of deep geological formations and fault structures in the eastern segment of the Jinshan gold mining area. It also delineated the development location, extension, and variations in the deep attitude of the regional ore-controlling structure, specifically the Xiaozhuang-Dazhuangtou ductile shear zone, within the eastern Jinshan gold mining area. Furthermore, the research identified that the minimum magnetic anomaly jump points, low-value anomaly zones in magnetic anomaly correlation imaging coefficients, and low-resistivity anomaly zones in apparent resistivity serve as geophysical indicators of the Xiaozhuang-Dazhuangtou ductile shear zone. Based on these insights, potential areas for mineralization were inferred. Subsequent drilling operations led to the discovery of one concealed gold ore body and five gold mineralization bodies within the two inferred favorable mineralization areas, thereby validating the reliability of the inversion interpretation results derived from the high-precision magnetic survey and controlled source audio magnetotelluric sounding. A comprehensive analysis indicates that the integration of high-precision magnetic surveys with CSAMT surveys enables precise detection of the spatial distribution and extension of deep geological formations and fault structures in the eastern sector of the Jinshan gold mining area. The ore-controlling structure, identified as the Xiaozhuang-Dazhuangtou ductile shear zone, is characterized by geophysical signatures of“low magnetism and low resistivity.” In the eastern region of the Jinshan mining area, this shear zone exhibits an approximately east-west orientation, with its dip angle decreasing progressively from nearly vertical to 45°~60° southward. Drilling validation results suggest that the eastern section of the Jinshan gold mining area possesses substantial prospecting potential, justifying further exploration in both deep and peripheral zones. The integrated geophysical methodology, combining high-precision magnetic surveys with CSAMT surveys, is demonstrated to be an effective strategy for deep and peripheral prospecting, highlighting its promising application potential.

The Bailincheng Zn-polymetallic deposit is situated within the northern section of the Mesozoic tectono-magmatic-metallogenic belt of the Taihang Mountains, specifically in the eastern region of the Dahenan granitoid pluton. This study employs electron probe microanalysis(EPMA) to determine the major elements compositions of Pyrite and sphalerite, laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS) for trace elements, and in-situ sulfur isotope analysis to elucidate the ore-forming environment, genetic type of the deposit, and the source of ore-forming materials. The orebodies of the Bailincheng Zn-polymetallic deposit occur in subtabular to lenticular forms, aligned with the structural belt, and are hosted within limestone. The findings reveal that Pyrite is characterized by an average sulfur content of 53.51% and iron content of 46.96%, indicating a slight enrichment in Fe and depletion in S compared to theoretical values(S=53.45%, Fe=46.55%), which suggests a Fe-rich, S-deficient nature. Additionally, δFe/δS-As and As-Co-Ni discrimination diagrams suggest a magmatic–hydrothermal origin. The Fe/(S+As) ratio in Pyrite exhibits a strong correlation with the mineralization position(r=0.878). In the Bailincheng deposit, Pyrite displays Fe/(S+As) values ranging from 0.857 to 0.902, with an average value of 0.877, suggesting formation in a shallow environment. The Co/Ni ratios in Pyrite range from 2.9 to 277.2, with Py-1(associated with early-formed oxide minerals) averaging 30.7 and Py-2(associated with late-stage sphalerite) averaging 131.5. Both Py-1 and Py-2 exhibit Co/Ni ratios greater than 1, indicative of hydrothermal Pyrite. Sphalerite displays Zn/Fe ratios ranging from 76.69 to 84.97 (average 80.46) and Zn/Cd ratios from 320 to 419 (average 377.16), which are characteristic of a medium-temperature hydrothermal deposit. Furthermore, the ln(Ga)/ln(In) ratios in sphalerite suggest affinities with skarn-type deposits. The δ ³⁴S values of Pyrite range from 5.47‰ to 8.88‰, with an average of 6.7‰. Compared to surrounding deposits, Pyrite from Bailincheng exhibits more positive δ ³⁴S values, indicating that the sulfur in the ore-forming fluids was primarily derived from magmatic-hydrothermal sources, with minor contributions from strata-derived sulfur. Pyrite is identified as the principal gold-bearing phase, with arsenic and gold showing a positive correlation, suggesting that gold primarily occurs as lattice-bound ionic gold within the Pyrite. In summary, the Bailincheng Zn-polymetallic deposit in the northern Taihang Mountains is characterized by skarn-type mineralization, and represents a medium-temperature magmatic-hydrothermal deposit formed in a shallow environment.

Energy consumption in comminution processes, which include blasting, crushing, and grinding, constitutes a significant portion of operational costs in hard-rock mining. Traditional optimization approaches often treat blasting and crushing as separate systems, leading to inefficient energy distribution and underutilization of chemical energy （explosives） to alleviate the burden on downstream mechanical comminution.This study addresses this gap by developing a quantitative energy coupling model that connects blasting energy input, rock fragmentation distribution, and subsequent crushing energy consumption. To quantify these relationships, a comprehensive experimental program was conducted on two representative rock types：granodiorite porphyry and skarn.The methodology integrates dynamic impact tests using a Split Hopkinson Pressure Bar （SHPB） with static-impact crushing tests employing a drop-weight apparatus.The SHPB tests, conducted under varying impact air pressures, simulated the rock fracturing process under explosive loading.The results indicate a clear linear dependency, wherein the three-dimensional mean particle size of the blasted rock decreases proportionally with increasing incident energy. Subsequent to the primary stage, drop-weight tests were conducted on oversized fragments to establish an exponential growth model for crushing energy consumption as a function of input particle size. This model underscores the substantial energy costs associated with processing coarse blast fragmentation.By mathematically integrating both stages, the study developed a comprehensive model of total energy consumption. The analysis reveals that the total system energy exhibits a characteristic “U-shaped” trend （decreasing then increasing） within the constraints of the process.Specifically, an increase in blasting energy initially leads to a significant reduction in mechanical crushing load. However, beyond a certain point, further increases in blasting energy result in diminishing returns.The model identifies precise optimal operating points, with minimum total energy consumption recorded at 176.66 J for porphyry and 91.54 J for skarn.These minima correspond to an optimal fragment size range of 37~42 mm.By targeting this specific fragmentation range, overall system energy consumption can be reduced by up to 42.8% compared to conventional operational parameters.These findings reveal a fundamental conflict between the nonlinear characteristics of crushing dissipation and the gradient distribution of blasting energy. The results indicate that relying exclusively on mechanical crushing for size reduction is energetically inefficient for hard rocks. Instead, increasing the proportion of rock breakage achieved through chemical energy or implementing multi-stage crushing strategies can substantially improve system performance.This study, for the first time, develops a closed-loop quantitative coupling model of blasting energy, fragment size, and crushing energy. It elucidates the nonlinear principles governing inter-process energy transfer and provides both a theoretical foundation and parameterized guidance for optimizing energy use throughout the entire process. This research offers significant engineering value for cost-effective and sustainable energy-efficient hard-rock mining.

In order to advance the engineering applicability of basalt fiber reinforced polymer （BFRP） anchors in complex geological settings,this study undertook field pull-out tests on a railway slope and conducted a systematic analysis of the bonding performance and load transfer characteristics of BFRP anchors under in-situ stress conditions. The investigation focused on axial force, shear stress, load-displacement curves, and macroscopic failure phenomena under varying pull-out loads to elucidate the influence of anchorage length on the mechanical response. The findings demonstrate that when the anchorage length is less than 3.0 meters, the axial force distribution remains relatively uniform. However, lengths exceeding 3.0 meters result in discrete distributions with a tendency to shift towards greater depths. The shear stress along the anchorage depth follows a biphasic pattern characterized by rapid attenuation followed by gradual attenuation. While increasing the anchorage length significantly enhances the load-bearing capacity, it does not alter the overall distribution trend of shear stress. The load-displacement curves of long anchors exhibit cumulative failure characteristics, which can be categorized into elastic, elastoplastic, and sliding failure stages. Post-test analyses indicate that the spatial distribution of cracks within the grout is influenced by a tensile stress field, which mirrors the deformation sequence and stress disparities between the two interfaces. These findings elucidate the load transfer mechanism and failure modes of BFRP anchoring systems, offering both theoretical support and empirical evidence for parameter design and practical engineering applications.

To investigate the mechanical properties of early-age cemented tailings backfill under multi-stage cyclic loading, a series of multi-stage cyclic loading-unloading uniaxial compression tests were conducted using a WHY-600 press. The tests considered curing age, loading time, and loading gradient as variables to analyze the uniaxial compressive strength and fracture morphology of the backfill. Additionally, the evolution of wave velocity was examined through ultrasonic wave velocity testing. The findings indicate that the uniaxial compressive strength of the backfill increases with extended loading time. Notably, the strength variation from 150 s to 300 s is more pronounced than that from 300 s to 450 s. Furthermore, as the loading gradient increases, the uniaxial compressive strength initially rises and subsequently declines, suggesting that moderate static load damage enhances the compressive performance of the backfill. At an early stage, the failure mode of the backfill body under the influence of multi-stage cyclic loading and unloading transitions from X shear failure to a mixed shear failure primarily characterized by X conjugate shear failure, and subsequently to a mixed shear failure predominantly governed by Y shear. The loading duration and loading gradient exhibit a significant synergistic effect on the variation in wave velocity of the backfill. Specifically, when the loading duration exceeds 300 seconds and the loading gradient surpasses σ _0.5, the wave velocity initially decreases with increasing loading cycles and subsequently recovers to some extent. Utilizing a long short-term memory neural network in conjunction with a genetic algorithm, a predictive model for the uniaxial compressive strength of early tailings consolidated backfill, subjected to multi-stage cyclic loading and unloading, has been developed. Upon validation, the model demonstrates correlation coefficients of 0.9814 and 0.9466, respectively, with a calculation error range of 3.21% to 12.47%, thereby indicating its high applicability and reliability.

To elucidate the impact of the cutting tooth intrution angle on the rock-breaking mechanism of rotating drums in gravity-type vertical shaft tunneling machines, a comprehensive investigation was undertaken. This study employed both numerical simulation and similarity testing to examine rock-breaking characteristics across varying intrution angles. A numerical model of rolling cutting tooth rock-breaking was developed using the finite-discrete element method （FDEM）. The study analyzed the effects of different cutting tooth intrution angles on the rock-breaking mechanism and efficiency by examining factors such as rock joint evolution, failure modes, fragmentation volume, cutting tooth forces, and specific energy consumption. Additionally, rock-breaking tests with analogous materials were conducted to compare the rock-breaking processes at different intrution angles, thereby validating the accuracy and reliability of the numerical simulation results. The findings reveal that with an increase in the cutting tooth intrution angle, the rock failure mode transitions from primarily shear failure to predominantly tensile failure, accompanied by shear failure, resulting in more extensive fracture propagation. The volume of rock fragmentation exhibits a gradual increase with the intrution angle, whereas the force required for rock-breaking by the cutting teeth decreases significantly. Consequently, the specific energy consumption per unit volume of fragmented rock diminishes progressively, leading to a marked improvement in the rock-breaking efficiency of the cutting teeth. The results from numerical simulations are consistent with the patterns observed in similarity tests, thereby validating the efficacy of the established model. These findings provide a theoretical foundation for optimizing the structural parameters of the drum and designing the cutting tooth layout in gravity-type vertical shaft tunneling machines. They offer substantial engineering reference value for enhancing the efficiency of mechanized vertical shaft tunneling and reducing energy consumption.

To elucidate the mechanical response mechanisms and the deformation and failure characteristics of layered cemented backfill under the influence of complex interlayer parameters, this study investigates the stage subsequent filling method employed in an iron mine. The research systematically examines the effects of stratification angle, cement-sand ratio, and intermediate layer height on the mechanical properties and damage evolution of backfill through comprehensive uniaxial compression tests. The findings indicate that both the uniaxial compressive strength and the elastic modulus of the backfill decrease with an increase in stratification angle, a decrease in cement-sand ratio, and an increase in intermediate layer height. The sensitivity of these factors to strength is ranked as follows: cement-sand ratio>intermediate layer height>stratification angle. Further analysis reveals that the relationship between these three factors and compressive strength adheres to a logarithmic function. The multivariate nonlinear regression prediction model developed in this study demonstrates high accuracy and serves as a quantitative tool for predicting strength. Analysis of the stress-strain curve indicates that the layered structure results in the characteristic four-stage deformation behavior of the filling body. As the layer angle increases, the cement-sand ratio decreases, or the height of the middle layer increases, the post-peak ductile deformation capacity of the filling body diminishes, rendering the failure process more brittle. This study elucidates the mechanical weakening mechanism of the layered filling body. The findings provide theoretical guidance for optimizing the design parameters of interlayers in the filling body, predicting its macroscopic mechanical behavior, and managing the stability of the stope.

As the centralized repository for waste materials produced during mining operations, the stability of waste dump slopes is crucial for ensuring mine safety. These slopes are influenced by the combined effects of various factors. In the assessment process, it is imperative to consider not only the inherent randomness of each evaluation indicator but also the uncertainties stemming from incomplete information or ambiguous judgments. This study introduces an evaluation method, grounded in game theory and an improved cloud model, that accurately quantifies the hazard levels of waste dumps. In constructing the evaluation indicator system, a comprehensive analysis of factors affecting slope instability in waste dumps, is conducted. Key parameters, such as slope angle(α), slope height(H), unit weight(γ), cohesion(c), internal friction angle(φ), and moisture content(MC), are selected to develop a multidimensional and comprehensive evaluation indicator system. Data from 50 sets of slope sample trials are utilized. The entropy weight method and the G1 method are utilized to determine the objective and subjective weights of each indicator, respectively. Subsequently, game theory is applied to integrate and optimize these subjective and objective weights, thereby mitigating the subjectivity and limitations inherent in single weighting approaches. To overcome the challenges posed by traditional cloud models in managing data within fuzzy boundary intervals, semi-ascending and semi-descending cloud models are employed to represent uncertainties at these intervals, leading to the development of an improved cloud model. By combining the subjective and objective weights with the cloud model’s capability to handle uncertainty, an accurate quantification of the hazard levels of waste dump slopes is achieved. The membership degrees of various hazard levels are calculated to ascertain the hazard levels of the sample waste dumps, which are then compared with the evaluation outcomes derived from individual subjective or objective weighting methods, as well as the actual hazard levels. In conclusion, the capability of the Game-Improved CM to classify hazards is thoroughly examined. To enhance the verification of the model’s accuracy and reliability, it is employed to evaluate and analyze ten sets of test sample data. The findings of this study reveal that the hazard level assessments of waste dumps conducted using the Game-Improved CM align closely with actual conditions. Furthermore, when compared to existing methodologies, the evaluation approach utilizing the Game-Improved CM exhibits enhanced practicality and reliability.

A refractory zinc ore, distinguished by its high magnesium content and low grade, was found to contain valuable elements, primarily zinc and cadmium, with concentrations of 1.60% and 50.60 g/t, respectively, predominantly hosted within marmatite. The principal impurities in the ore were identified as SiO₂ and MgO, with concentrations of 37.66% and 34.47%, respectively. The gangue minerals were primarily composed of serpentine, pyroxene, amphibole, and chlorite, with marmatite exhibiting a complex paragenetic relationship with these magnesium-bearing gangue minerals. To effectively mitigate the adverse effects of high serpentine content on zinc flotation performance, a series of systematic single-factor flotation condition tests were conducted. The interaction mechanism between a combined reagent of C₆H₈O₇+(NaPO₃)₆ and serpentine was analyzed using infrared spectroscopy. Additionally, changes in the elemental composition and morphological characteristics on the surface of marmatite, both before and after treatment with C₆H₈O₇+(NaPO₃)₆, were meticulously examined using scanning electron microscopy and energy dispersive spectroscopy(SEM-EDS). The optimal technical parameters for the roughing flotation stage were ascertained through experimental investigations. These parameters comprised a grinding fineness of 75.23% passing 0.075 mm, a C₆H₈O₇ dosage of 600 g/t, a (NaPO₃)₆ dosage of 800 g/t, a CuSO₄ dosage of 500 g/t, a butyl xanthate dosage of 120 g/t, and a No.2 oil dosage of 24 g/t. Utilizing a closed-circuit flotation flowsheet characterized by “one roughing, two scavenging, and two cleaning stages, with middlings sequentially returned to the preceding stage”, a final zinc concentrate was effectively produced. This concentrate exhibited an assay of 48.52% Zn, 1 400×10^-6 Cd, and 1.92% MgO, with respective recoveries of 89.47% for zinc, 84.20% for cadmium, and 0.16% for magnesium oxide. Infrared spectroscopy analysis indicated that the interaction with the C₆H₈O₇+(NaPO₃)₆ reagent system resulted in the emergence of two new distinct absorption peaks on the serpentine surface. The observed spectroscopic features were identified as the C=O and P=O stretching vibration peaks. Simultaneously, the Mg-O out-of-plane vibration peak exhibited a shift from its initial position at 567 cm^-1 to 546 cm^-1. These spectroscopic alterations suggest that the reagent combination likely adsorbs onto the serpentine surface through complexation. Further corroboration was provided by SEM-EDS analysis, which revealed that post-treatment with C₆H₈O₇+(NaPO₃)₆, elements such as O, Mg, and Si were no longer detectable on the marmatite surface. Notably, the marmatite surface was predominantly devoid of adhering serpentine particles. This compelling evidence indicates that the application of C₆H₈O₇+(NaPO₃)₆ effectively mitigates hetero-coagulation between serpentine and marmatite, thereby significantly enhancing the selectivity of the flotation process.

The spiral concentrator is a type of gravity-based beneficiation equipment extensively utilized in the processing of hematite, specular iron ore, chromite, and ilmenite, owing to its advantages of minimal environmental impact, low production costs, and straightforward configuration. In industrial applications, surface instabilities, known as roll waves, are frequently observed in spiral concentrators due to fluctuations in the free surface, with flow resistance being a primary factor influencing flow stability. This study focuses on three key factors affecting flow resistance: wall roughness, fluid viscosity, and trough surface grooving.Utilizing computational fluid dynamics (CFD) technology, we investigated the influence patterns of these parameters on the stability of separation flows in spiral concentrators. Analysis based on the liquid film evolution equation reveals that the inertial forces within the spiral sorting stream are unstable and contribute to destabilizing the flow. In contrast, surface tension mitigates the development of minor disturbances, thereby enhancing flow stability. A CFD model of a spiral concentrator was employed to simulate the flow field under varying flow resistance conditions. The simulation results indicate that an increase in wall roughness, fluid viscosity, or the number of grooves on the surface results in a gradual increase in flow resistance, subsequently reducing the maximum achievable Reynolds number of the spiral separation flow. Furthermore, the increase in flow resistance led to a decrease in both the Froude number and the Weber number, with reductions of 4.8% and 14.0% observed when the roughness was increased from 0.1 mm to 0.5 mm and 1.0 mm, respectively. Similarly, when the viscosity was elevated from 0.010 Pa·s to 0.020 Pa·s and 0.025 Pa·s, the Froude number decreased by 8.9% and 20.7% respectively. Additionally, increasing the number of engraved grooves on the surface from 0 to 10 and 19 resulted in a reduction of the Froude number by 13.6% and 16.7%, respectively. These findings demonstrate that increased flow resistance contributes to enhanced flow stability.

Pyrrhotite is a prevalent gangue mineral found in non-ferrous sulfide ores, including those of copper, lead, and zinc. Its non-stoichiometric crystal structure, characterized by variable iron-to-sulfur(Fe/S) ratios, leads to complex crystal-chemical behavior. Additionally, the unstable bonding state at its surface makes it highly susceptible to oxidation when exposed to oxygen in the flotation pulp. These characteristics often impede the selective flotation separation of valuable minerals, presenting a significant challenge in the efficient recovery of non-ferrous metals. During the oxidation process, iron ions migrate from the bulk to the mineral surface, where they coordinate with O₂, OH⁻, and H₂O to form an outer layer of iron oxyhydroxide(FeOOH), while leaving behind an iron-depleted, sulfur-enriched sublayer. This process is influenced by the pulp’s pH and oxidation-reduction potential(Eh), leading to the progressive oxidation of monosulfide species within the sublayer to disulfides and polysulfides, thereby continuously altering the surface chemistry of pyrrhotite. Under mild oxidation conditions, surface metal-hydroxyl complexes are formed, which modify the surface charge and result in a positive zeta potential. In contrast, xanthate collectors are present in solution as negatively charged anions, which facilitates their electrostatic adsorption onto pyrrhotite. This interaction undermines the efficiency of depression and complicates the separation of pyrrhotite from target minerals. Under conditions of intensified oxidation, Fe(OH)₃ precipitates form on the mineral surface. The pronounced hydrophilic nature of Fe(OH)₃ results in the formation of a dense hydrophilic film, which markedly diminishes mineral floatability and significantly impedes the flotation of pyrrhotite. It is important to note that pyrrhotite primarily exists in two crystalline forms: non-magnetic hexagonal pyrrhotite and magnetic monoclinic pyrrhotite. The inherent crystallochemical differences between these forms result in distinct surface oxidation kinetics, surface electrical properties, and adsorption affinities for flotation reagents. Consequently, the two polymorphs exhibit differing flotation behaviors within the same flotation system, thereby substantially complicating the separation of valuable non-ferrous sulfide minerals. The detrimental impact of pyrrhotite on flotation separation is primarily exhibited through two mechanisms: (1)its oxidation process depletes dissolved oxygen(DO) in the pulp, which is crucial for the surface oxidation activation of target sulfide minerals during flotation;(2) galvanic interactions occur when pyrrhotite is in contact with other sulfides in the pulp, thereby modifying the surface chemistry of the associated minerals. In industrial applications, synergistic strategies can be implemented to selectively depress or activate pyrrhotite flotation. These strategies include controlling its oxidation rate by adjusting pH levels or adding antioxidants, regulating pulp DO through staged aeration or the use of redox modifiers, and modulating the electrochemical interactions between pyrrhotite and target sulfide minerals.