In response to the long-standing narrow perception of metal mine safety that is confined to two dimensions (mining safety technology and safety management),and the common failure to incorporate corporate operational safety and en vironmental and social responsibility into the scope of safety,as well as the deep-seated problems of functional separation,infor mation silos,and fragmented objectives among the various dimensions of mine safety governance,this paper introduces the con cept of holistic safety and proposes a new collaborative safety model for metal mines led by the ESG framework.Subsequently, the functional characteristics and inter reactions of the four safety dimensions in metal mines are systematically analyzed,and the suitability of the ESG framework system for coordinating these four safety dimensions is elaborated.On this basis,supported by system safety science and resilience theory,a new collaborative safety model for metal mines is constructed,covering three layers:strategic decision-making,collaborative information,and execution.The model operates through mechanisms of informa tion integration,risk transmission perception,collaborative decision optimization,and emergency coordination command.Fur thermore,a holistic safety panoramic collaborative platform for metal mines is proposed,based on multi-agent systems,digital twins,and other cluster technologies,to achieve deep integration of multi-source heterogeneous data and intelligent coordination of safety governance.Finally,comprehensive countermeasures and recommendations are provided in terms of institutional de sign,organizational restructuring,and capacity building.The research results offer an integrated theoretical framework and im plementation pathway for the collaborative development of metal mines toward systematic and holistic safety,and provide lead ing insights for the transformation of future metal mine safety governance systems.

Through the collaborative optimization of mining sequence by three-dimensional geological modeling and dy namic programming algorithm,a multi-level space design decision model for open-pit block mining is constructed.Based on the spatial heterogeneity of ore bodies,a three-level zoning framework of ′gion-block-strip′ atively proposed:the mining units are divided according to the geological structure at the regional level,the operation units are subdivided according to the minerali zation continuity at the block level,and the advancing direction and size are optimized at the strip level.The model takes the maximization of net present value as the objective function,and uses heuristic algorithm to solve the global optimal solution.An empirical study of an open-pit mine in Inner Mongolia through the 3DMine platform shows that compared with the traditional o verall mining,the partition timing optimization scheme significantly improves the net present value by 7.0%,and the amount of waste rock stripping is reduced by 22.5%.The core mechanism is to isolate the influence of ore body variation by spatial parti tion,and to realize the synergistic gain of priority mining in high-grade rare earth enrichment area and development delay in deep high-cost area by time series optimization.The ′region-block-strip′ three-level partition architecture net present value maximization optimization model provides a ′pace-economy-time′ three-dimensional collaborative optimization paradigm for green intelligent mining of open-pit mines.

Under the background of global economic integration,the nickel supply chain is constrained by multiple risks and presents a problem of insufficient resilience,which seriously restricts the stable development of the industry and down stream related fields.Taking the resilience of nickel supply chain as the research object,the DEMATEL-ISM-MICMAC integra tion method was used to construct an index system of influencing factors covering 10 factors in four dimensions of supply chain resistance,recovery,re-organization and renewal,and the action rules,hierarchical structure and attribute characteristics of each factor were systematically analyzed.The research shows that the macroeconomic and policy environment is the core driving force for the improvement of nickel supply chain resilience,which can leverage the resilience construction of each link of the industry through hierarchical transmission.Industrial synergy and circular development are important related factors,which form a strong linkage effect with multi-dimensional influencing factors.The influencing factors of the resilience of the nickel supply chain show distinct hierarchical characteristics,and can be divided into three categories : leading,undertaking and assisting accord ing to the driving-dependence attribute.All kinds of factors play their own roles and work together in the resilience system. Based on this,the promotion strategy is proposed from the perspective of government-enterprise coordination : the government sets up special funds,formulates targeted policies,establishes market risk prevention and control mechanisms,and strengthens macro-level driving and guidance.Enterprises consolidate the industrial foundation,increase investment in innovation and R & D,deepen the upstream and downstream coordination of the industrial chain,and implement micro-level resilience improvement measures.The government and enterprises jointly build a pilot project to improve the resilience of the supply chain,forming a promotion mechanism of the whole chain linkage.This study improves the theory and method of strategic mineral supply chain resilience research,and provides a scientific decision-making basis for ensuring the safety and stability of nickel industry chain supply chain and promoting the sustainable development of the industry.

In this study,the acoustic emission (AE) system was used to monitor the rockburst process,and the acoustic optical-mechanical multiphysics characterization method was creatively used to explore the failure mode,strength deformation and acoustic emission evolution characteristics of the fractured rock under grouting conditions,and the effects of fracture pres sure relief and grouting on the rockburst process and its prevention and control effect were analyzed.The results show that the peak stress of high-energy storage granite after fracture is only about 65% of that of the intact rock sample.Grouting can im prove the compressive strength of the cut rock.The stress concentration is transferred from the cave wall to the depth of the sur rounding rock through the fracture,which induces macroscopic crack propagation,but may cause local instability,thus posing a threat to safety.Therefore,the filling technology is used to prevent and control rockbursts by coordinating the joint cutting and pressure relief method.The strength and cohesiveness of grouting materials have a significant impact on the failure mode of rockbursts,and grouting can alleviate the stress concentration problem generated by the crevice tip,and reduce the strength and failure degree of rockburst to a certain extent.In this study,a true triaxial-single-plane air test system that is closer to the stress characteristics of deep tunnels is constructed,and an experimental method for collaborative explosion control between joints and grouting is proposed,which systematically reveals the coupling mechanism of slitting-induced stress migration,grouting inhibi tion of crack tip stress concentration and the coupling mechanism of the two on the prevention and control of rockbursts,which provides a new experimental basis and method reference for the prevention and control of disasters in underground projects.

Aiming at the problems of strong noise interference and significant non-stationarity of sound signals in the process of coal-rock cutting,and the shortcomings of traditional methods in feature extraction and recognition accuracy,a coal rock recognition method combining variational mode decomposition (VMD ) and attention mechanism convolutional long-term and short-term memory network (CNN-LSTM-AM ) is proposed.First,VMD combined with a Shannon entropy-based mode se lection criterion is employed to adaptively decompose and reconstruct raw AE signals,effectively suppressing mechanical,elec trical,and external noise while preserving key acoustic features,thereby achieving denoising and feature enhancement under complex conditions.Second,a CNN-LSTM-AM recognition model is constructed,where convolutional and LSTM layers are uti lized for deep spatial feature extraction and temporal dependency modeling,and an attention mechanism is introduced to strengthen the association between global and local information,enhancing the model′s ability to identify mixed coal-rock media.Finally,a coal-rock cutting AE experimental platform was established to collect sample data under six typical cutting conditions for validation.The experimental results indicate that,for six-class classification,the proposed method attains an ac curacy and precision of 98.33%,along with a recall of 98.37% and an F1-score of 98.33%,markedly surpassing comparative models such as CNN,LSTM,and CNN-LSTM.These findings verify the effectiveness,robustness,and engineering applicability of the proposed method under complex underground conditions.

Aiming at the problem of mining-induced stress superposition interference and grade fluctuation caused by concurrent mining of multiple ore bodies in deep high-stress environment,a set of coordinated mining control methods for deep mines with multi-constrained linear programming and space-time optimization of mining-induced stress field are proposed.First ly,a dynamic optimization model integrating three-level constraints of mining section,middle section and stope is constructed, and the model construction principle and solution strategy of nonlinear target linear transformation,two-way constraint decompo sition and dynamic calibration of working conditions are clarified.Then,taking the non-pillar sublevel caving stope in the -570 m middle section of an iron mine as the engineering background,the engineering application steps of the model and the entropy weight-TOPSIS multi-criteria decision analysis method are clarified,and the quantitative optimization of the mining scheme is completed.Finally,through numerical simulation,the evolution law of ground pressure and the mechanism of stress field recon struction under different mining sequences are revealed,and the safety control effect of the model optimization scheme is demonstrated.The results show that the model reduces the comprehensive grade control error of the whole mine to ±0.02%.At the same time,the optimized balanced propulsion and staggered peak mining strategy suppresses the mining stress concentration, reduces the maximum deformation of the surrounding rock of the stope from 0.258 1 m to 0.200 3 m,and guides the roof de formation energy to be released gently.The research results have formed a control system of mathematical programming optimi zation and mechanical simulation verification,which provides theoretical support and decision-making basis for the efficient and safe mining of deep complex multi-ore bodies.

As the key technical means of surrounding rock stress control,the layout of advanced pilot tunnel is of great significance to ensure the stability of the project.In order to further reveal its mechanism of action,the finite difference method and particle flow numerical simulation software were used to systematically study the macroscopic mechanical response and mi croscopic failure mechanism of rock during the excavation of the advanced pilot tunnel of deep buried tunnel.The results show that the stress state of surrounding rock changes from three-way compression to two-way compression during the excavation of the advanced pilot tunnel of deep buried tunnel.As the dip angle of the pilot tunnel increases,the rock strength decreases first and then increases.The optimal pressure relief effect can be achieved by using the 45° dip angle pilot tunnel arrangement.Un der biaxial compression,the rock with holes is dominated by tensile cracks,and the proportion of tensile cracks under the load ing-unloading path is higher than that under the pure loading path.The influence of intermediate principal stress on rock me chanical properties under pure loading path is significantly higher than that under loading-unloading path,and there is a stron ger positive correlation between octahedral shear stress and average stress.The research results can provide theoretical basis and technical support for the stability control of surrounding rock in deep tunnel engineering.

In the stability analysis of the surrounding rock after the excavation of a circular cavern,the mechanical mech anism of how to simultaneously consider the postpeak shear expansion effect of the surrounding rock and the damage evolution and their coupled influence is not clear.Based on the Mohr-Coulomb criterion,an elastic-plastic analytical model coupling shear expansion and damage is constructed,and the relationship between the shear expansion angle and plastic strain is estab lished through the plastic potential function,and then the damage evolution equation characterized by plastic volumetric strain is derived,so as to organically link the post-peak strain softening characteristics of the surrounding rock and the volumetric ex pansion induced by shear expansion and the damage development.In order to solve the nonlinear problem of the controlling e quations in the plastic zone,the finite difference method is adopted for the hierarchical solution,and a semi-numerical and semi-analytical iterative stress-strain-damage computation process is proposed,which can be solved to obtain the distributions of the stress,strain and damage variables of the surrounding rock.The results show that: the established coupling model has been verified by cases,and compared with the traditional linear softening method with strength parameters,this model describes the post-peak softening behavior based on the physical mechanism (volume expansion leads to damage),which is more general and reasonable;the increase of damage parameter β and shear expansion angle ψ will exacerbate the damage of the cave wall and lead to a significant increase in the range of the plastic zone and the loosening circle,but neither of them affects the maximum peripheral However,neither of them affects the maximum circumferential stress value of the surrounding rock;the damage pa rameter β has a significant effect on the rate of recovery of radial stress to the original rock stress level,and the larger β is,the slower the recovery is,and the effect of the shear expansion angle ψ on the recovery rate is negligible.The above quantitative and qualitative conclusions can provide important references for the assessment and control of underground engineering rock stability.

Under the influence of complex geological structure and strong engineering disturbance,the surrounding rock of roadway shows significant nonlinear large deformation characteristics,and the problems such as serious floor heave and fail ure of support system are increasingly prominent.Taking the track downhill roadway in the fifth mining area of Leji barite mine as the research object,the floor stress distribution characteristics and floor failure depth under complex stress environment are analyzed through the floor heave mechanical model.The numerical model is established to calculate the stress and strain state of the floor.The failure depth of the floor is highly consistent between the theoretical analysis and the numerical calculation re sults.For the differential rock stratum structure of the cross-layer roadway,according to the different lithology of the floor,targe ted control measures are formulated and applied to the engineering site.Practice has proved that the classification support strat egy can effectively limit the deformation of surrounding rock.The monitoring results show that the maximum damage of floor heave is 35.6 mm,which is within a reasonable range.The effective control of floor heave shows that the proposed classification support scheme is reasonable,which provides scientific guarantee for guiding safe and efficient mining on site.

In order to study the mechanical properties and damage mechanism of rock under high temperature,the uniaxi al compression simulation of sandstone under real-time high temperature was carried out by particle flow software PFC3D.The stress-strain characteristics and crack development process of sandstone at different temperatures are clarified,and the variation law of peak stress,peak strain and crack development of sandstone with temperature is clarified.Based on the mechanical prop erties,the thermal damage mechanism of sandstone is clarified,and the damage statistical constitutive model of sandstone under high temperature is established.The results show that the peak stress and peak strain of sandstone decrease with the increase of temperature in the temperature range of 0~25 ℃.In the temperature range of 25~150 ℃,the peak stress and peak strain have the same change trend,which increases first and then decreases.In addition,the toughness index is introduced to reflect the an ti-failure ability of sandstone,and its change rule is the same as the evolution trend of peak stress.As the temperature increa ses,the thermal stress will promote the propagation of the original crack and generate new cracks,and the expansion of the in ternal particles will further accelerate the crack development and eventually form the overall damage.Finally,the damage statis tical constitutive model of sandstone under high temperature is constructed,and the rationality of the model is verified by the simulation results.This study can provide theoretical support for the analysis of mechanical properties of sandstone under high temperature environment.

To address the issues of overgrinding and low yield of qualified size fractions during the grinding of carbonate containing iron ore,this study investigated the effect of grinding media shape on grinding characteristics using a high-silicon, high-carbonate iron ore from the Anshan area as the research object.Grinding tests were conducted with spherical,short cylin drical,and short frustum conical media on both narrow size fractions and full size fraction feed.The grinding performance was systematically evaluated using particle size distribution,the Rosin-Rammler particle size characteristic equation,grinding kinet ics models,overgrinding index (content of -0.01 mm),and qualified size fraction content (0.1~0.01 mm).Based on these evaluations,media size combination was optimized following the linear superposition principle.The results indicate that spheri cal media exhibit the highest grinding efficiency but also the highest overgrinding index and poorer product uniformity.Short cy lindrical media yield the best product uniformity and the lowest overgrinding index,albeit with lower grinding efficiency.The short frustum conical media show intermediate performance.The optimized media combination scheme—“spherical (ϕ40 mm) + short cylindrical (ϕ25×30 mm) + short cylindrical (ϕ15×10 mm)” with a mass ratio of 2∶1∶1—achieves a balance be tween high grinding efficiency and reduced overgrinding,while increasing the qualified size fraction content.This synergistic optimization provides a more favorable feed size distribution for the subsequent beneficiation of carbonate-containing iron ore.

As the primary gold-bearing mineral in refractory gold ores,the oxidation efficiency and lattice destruction de gree of pyrite directly constrain the gold leaching rate.To clarify the phase transformation patterns and structural reconstruction mechanisms of pyrite in different wet oxidation systems,this paper systematically reviews the research progress in three major systems:pressure oxidation,bio-oxidation,and chemical oxidation.In the pressure oxidation system,pyrite is mainly converted to ferric sulfate under acidic conditions and subsequently hydrolyzed to hematite,while under alkaline conditions,it transforms via iron oxide intermediates to hematite.In the bio-oxidation system,pyrite is oxidized to soluble sulfates through direct,indi rect,or combined microbial actions.In the chemical oxidation system,pyrite is decomposed to ferric sulfate by strong oxidants under acidic conditions,whereas under alkaline conditions,iron hydroxide and goethite are the primary products,with sulfur be ing ultimately converted to sulfate through multi-step oxidation.Through a systematic summary of the oxidation mechanisms and phase transformation pathways in each system,the regulatory effects of key process parameters on the directional transformation of pyrite are clarified,and the formation mechanisms of passivation layers along with their inhibition strategies are revealed,pro viding a theoretical reference for the wet oxidation treatment of pyritic refractory gold ores.

Aiming at the difficulty in effectively removing strongly magnetic pyrrhotite (accounting for 57.15% of the to tal sulfur) from a high-sulfur magnetic iron concentrate in Inner Mongolia by magnetic and gravity separation methods,which adversely affects the quality of the iron concentrate,this study proposes a direct flotation process for deep desulfurization and synchronous sulfur recovery without further grinding.Based on process mineralogy studies,a closed-circuit flotation flowsheet consisting of one roughing,four cleaning,two scavenging,and middlings recirculation was adopted.Under the feed conditions of 64.82% TFe and 1.30% S,a high-quality iron concentrate with 65.27% TFe,0.16% S,and TFe recovery of 97.85% was ob tained,along with a sulfur concentrate grading 40.44% S with a sulfur recovery of 87.36%.This process achieves deep desul furization of iron concentrate and efficient recovery of sulfur resources without grinding,offering a new technical route for the ef ficient and clean utilization of similar high-sulfur iron concentrates.

To achieve the comprehensive utilization of associated cobalt resources in a sedimentary-hydrothermal re formed iron deposit,a systematic process mineralogy study was conducted on the sulfur-copper mixed concentrate from the ben eficiation process.Multiple techniques,including chemical analysis,X-ray fluorescence (XRF),scanning electron microscopy (SEM),electron probe microanalysis (EPMA),and optical microscopy,were employed.The results reveal that cobalt is prima rily hosted in pyrite (0.149% Co) and chalcopyrite (0.045% Co) via isomorphism,with a combined distribution rate of 87.07%.The independent cobalt mineral,cobaltite,is present in very low abundance (0.06%).Flotation exploratory tests confirmed that cobalt reports to the sulfur concentrate during copper-sulfur separation,with a grade ranging from 0.14% to 0.16%.The harmful element arsenic is also concurrently enriched in the sulfur concentrate (0.59% As),which is difficult to remove effectively and severely impacts the concentrate quality.Attempts to further concentrate cobalt from the sulfur concen trate showed that while cobalt could be enriched to 0.30% in the tailings,the arsenic content simultaneously increased to 2. 20%.This study concludes that separate recovery of cobalt from this material is not feasible due to its dispersed occurrence and the difficulty of arsenic separation.It is,therefore,recommended that cobalt be recovered as a associated component of the sul fur concentrate.

To address the challenges of high additive cost,substantial impurity dissolution,significant environmental pol lution,and high energy consumption in existing vanadium extraction processes from vanadium-bearing steel slag,this study pro posed a clean vanadium extraction process based on blank roasting followed by ammonium bicarbonate leaching.Using a vana dium-bearing steel slag with a V2 O5 content of 0.95% as the raw material,the effects of key roasting and leaching parameters on vanadium leaching efficiency were systematically investigated,and the phase evolution and selective leaching mechanism were elucidated by means of XRD and SEM-EDS.The results showed that under the optimal conditions of blank roasting at 950 ℃ for 3 h,ammonium bicarbonate concentration of 140 g/L,leaching temperature of 80 ℃,leaching time of 2 h,and liquid-to solid ratio of 10∶1 mL/g,the vanadium leaching efficiency reached 43.96%.After concentration,the vanadium concentration in the leachate reached 9.21 g/L,while the contents of impurities such as Ca,Fe,Mg,Al,and Mn were all below 0.01 g/L,dem onstrating the excellent selective leaching capability of this system for vanadium.Mechanistic studies revealed that vanadium was primarily hosted in silicate matrices and calcium-aluminum-iron composite oxide phases.During the leaching process, CaCO3 was newly formed,accompanied by the transformation of some silicate phases,while spinel and aluminate structures such as Ca2 Fe2 O5 ,MgFe2 O4 ,and Ca12 Al14 O33 remained stable,revealing from the phase perspective the mechanism of efficient impurity suppression and selective vanadium release.This process requires no roasting additives,operates under mild condi tions,and yields a leachate with low impurity content that can serve as a high-quality feed for subsequent vanadium precipitati on.This study provides a promising technological pathway for the green utilization of low-grade vanadium-bearing steel slag.

In copper-zinc sulfide ores containing pyrrhotite,the floatability of pyrrhotite differs little from that of activated sphalerite in conventional xanthate collector systems,making pyrrhotite a major gangue impurity in zinc concentrate.This often leads to low zinc separation efficiency,substandard concentrate grade,and poor resource recovery.To address these challenges, this study takes a copper-zinc sulfide ore containing pyrrhotite as the research object.Based on systematic process mineralogy studies,beneficiation process exploration was conducted,and the optimal process flow of “preferential copper flotation,magnetic separation to remove pyrrhotite and zinc flotation” was determined.Subsequently,condition tests for copper flotation,magnetic separation,and zinc flotation were carried out to optimize the key parameters of each operation,followed by full-process closed circuit tests.The test results show that the full-process closed-circuit test yields a copper concentrate with a copper grade of 25.080% and a copper recovery of 76.56%,and a zinc concentrate with a zinc grade of 50.82% and a zinc recovery of 93.23%.This process effectively eliminates the interference of pyrrhotite in copper-zinc separation and achieves efficient sepa ration and recovery of copper and zinc resources,providing a reliable technical reference for the industrial beneficiation of simi lar complex refractory copper-zinc sulfide ores.

To address the challenges in separating copper-lead sulfide minerals and the high toxicity and severe pollution associated with traditional dichromate inhibitors,a novel eco-friendly organic depressant(ZJ201) for galena was developed through molecular design.The separation performance of ZJ201 was systematically evaluated through flotation tests on pure minerals,artificially mixed minerals,and closed-circuit tests on real ore.The mechanism of action was elucidated using contact angle measurement,Zeta potential analysis,Fourier transform infrared spectroscopy (FTIR),and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS).The results indicated that within the pH range of 4 to 7,ZJ201 could selec tively and strongly depress galena while minimally affecting the floatability of chalcopyrite.At pH=6 with a ZJ201 dosage of 2 mg/L,the recovery of galena was reduced to below 2.5%,while the recovery of chalcopyrite remained above 90%.Closed-cir cuit tests on real ore yielded a copper concentrate with a Cu grade of 32.34%,Pb content of 1.66%,and Cu recovery of 98.56%,as well as a lead concentrate with a Pb grade of 67.14%,Cu content of 0.049%,and Pb recovery of 99.74%,dem onstrating excellent separation efficiency.Mechanism studies revealed that ZJ201 preferentially and chemically adsorbs onto the galena surface via its phosphate and hydroxyl functional groups,significantly enhancing its hydrophilicity,thereby achieving ef ficient and selective separation of chalcopyrite from galena.

The efficient flotation separation of chalcopyrite from pyrite is crucial for utilizing copper sulfide resources. However,the unavoidable copper ions in the pulp activate pyrite,severely hindering separation efficiency.To reveal the under lying mechanism and guide collector selection,this study systematically investigated the impact of copper ion activation on the adsorption behavior and selectivity of different collectors on both minerals by integrating density functional theory (DFT) cal culations,molecular dynamics (MD) simulations,and flotation tests.The results indicate that Cu2+ preferentially adsorbs at the sulfur-top site on the pyrite (100) surface with an adsorption energy of -102.89 kJ/mol,significantly enhancing its surface re activity through charge transfer.Theoretical calculations suggest a negative correlation between a collector′s adsorption strength on chalcopyrite and its separation selectivity.Flotation tests verified that among the studied collectors,the order of collecting a bility for chalcopyrite from strong to weak is isobutyl xanthate,diammonium dibutyl dithiophosphate (DDA),diethyl dithiocar bamate (DDTC);Whereas the order of selectivity for Cu-S separation from strong to weak is DDA,DDTC,isobutyl xanthate. MD simulations further elucidated that copper ion activation non-selectively enhances collector adsorption on pyrite,substantial ly reducing the adsorption difference between pyrite and chalcopyrite,thereby deteriorating flotation selectivity.In conclusion, for pulp systems containing unavoidable copper ions,collectors with inherent high selectivity for chalcopyrite,such as DDA, should be prioritized to mitigate the activation effect and ensure separation performance.

A high-carbon lead-zinc ore in Ganluo,Sichuan,contains Pb of 2.45% and Zn of 4.65%,with an oxidation rate ranging from 10% to 30%,belonging to mixed lead-zinc ore.The ore has a high organic carbon content,which tends to cause non-selective adsorption of flotation reagents,resulting in high reagent consumption and severe Pb-Zn mutual content in the existing flotation process.To improve the separation performance,a decarburization stage was introduced prior to lead flota tion,using a mixture of kerosene and diesel (mass ratio 1∶1) as the decarburization collector,followed by optimization of the reagent regime through conditional tests.Based on the original closed-circuit flotation process of "one roughing,four cleaning, four scavenging with middlings return" for lead and "one roughing,four cleaning,five scavenging with middlings return" for zinc,the decarburization stage significantly reduced the mutual content of lead and zinc in the concentrates.The lead concen trate with a Pb grade of 51.22% and Pb recovery of 88.85%,and the zinc concentrate with a Zn grade of 51.17% and Zn re covery of 71.22% were obtained.Compared with the process without decarburization,the mutual content of lead and zinc in the concentrates was significantly reduced,and the separation indexes were notably improved.

To address the challenges associated with lime application in the high alkali sulfur suppression lead flotation process for high-sulfur,high-carbon,and finely disseminated lead-zinc ores—such as pipeline scaling,low precious metal recov ery,and high wastewater treatment costs—this study focuses on a high-sulfur,high-carbon lead-zinc ore from Inner Mongolia. Based on process mineralogy research,a highly efficient depressant XKY-02 for pyrrhotite and a highly selective collector XK 201 for galena were developed for low-alkalinity conditions.Laboratory-scale closed-circuit tests were conducted using a "lead preferential flotation" process consisting of one stage of roughing,two stages of scavenging,and four stages of cleaning after re grinding of the rough concentrate.Under the optimal low-alkalinity reagent regime,a lead concentrate with a lead grade of 56.44%,silver grade of 260.55 g/t,lead recovery of 76.58%,and silver recovery of 45.29% was obtained.Compared with the conventional high-alkalinity reagent regime,the lead recovery increased by 5.39 percentage points and the silver recovery in creased by 7.61 percentage points.The low-alkalinity process significantly improved the pulp environment,notably enhanced the zinc concentrate index,and effectively reduced the consumption of lime and lead collector,demonstrating significant eco nomic and environmental benefits.This low-alkalinity process provides a new technical approach for the efficient utilization of refractory high-sulfur,high-carbon lead-zinc ores.

　Bayan Obo rare earth tailings are rich in various strategic resources such as thorium and rare earth elements. Hydrothermal leaching with hydrochloric acid is an important technical approach to realize resource recovery and environment friendly disposal.To systematically explore the leaching effect and intrinsic mechanism of the tailings in the hydrochloric acid hydrothermal system,and clarify the influence of different leaching times on the leaching behavior of valuable elements (espe cially thorium),a variety of characterization methods including Inductively Coupled Plasma Emission Spectroscopy (ICP),X ray Diffraction (XRD),Fourier Transform Infrared Spectroscopy (FT-IR),Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS),Thermogravimetry-Differential Scanning Calorimetry (TG-DSC) and Zeta potential analysis were a dopted in this study to systematically investigate the phase changes,element leaching rules and surface property evolution of the tailings during the hydrothermal leaching process.The experimental results show that under the conditions of liquid-solid ratio of 6∶1 mL/g,temperature of 90 ℃ and leaching time of 4 h,the leaching rates of Th,Ca,Fe,Pb,Mg,Mn,Al and PO3 4 reach 20.08%,39.63%,36.81%,52.75%,69.25%,59.94%,58.69% and 73.64%,respectively.Among them,the leaching rates of major rare earth elements with important industrial value such as Y,Pr and Nd all exceed 30%.After leaching,the total weight loss of the tailings decreases significantly from the initial 9.14% to 1.98%,the absolute value of the surface Zeta poten tial changes from -4.93±0.70 mV to -9.70±0.68 mV,the hydrophilicity is significantly enhanced,and the thermal stability and chemical stability are obviously improved.The study confirms that hydrochloric acid can selectively leach the easily soluble mineral phases on the surface of the tailings through the synergistic effects of interfacial corrosion,acidolysis reaction,ion ex change and preferential dissolution of defects,promoting the enrichment of high-stability components such as silica,fluorite and monazite in the solid phase.This study not only provides a theoretical basis and technical reference for the efficient recovery of valuable elements (especially thorium and rare earth elements) from Bayan Obo rare earth tailings,but also offers a feasible path for the environment-friendly storage of such tailings,which is of great significance for promoting the resource utilization of rare earth tailings and the construction of green mines.

In order to explore a new technology of environmental protection and efficient rock breaking,a composite blas ting method is formed by combining the rapidity of explosive heat release with the phase change of dry ice.Through the model blasting test,the rock breaking capacity of explosive-dry ice composite blasting is systematically studied,and the block distribu tion and fracture field evolution law are emphatically analyzed.The test results show that the dry ice sublimates rapidly after the detonation of the explosive,and the degree of rock fragmentation increases significantly with the synergistic effect of the explo sive.With the increase of the amount of dry ice,the fractal dimension of rock mass fragmentation shows an upward trend,indi cating that the explosive-dry ice composite blasting can effectively enhance the uniformity of rock mass fragmentation.The in corporation of dry ice increases the production of explosive gas,drives the development of fractures,and significantly expands the scope of effective crushing zone.The explosive-dry ice composite blasting realizes the cascade release and effective utiliza tion of energy through the synergistic effect of chemical energy release and physical phase change expansion of explosion,and has the technical advantages of efficient rock breaking and environmental friendliness.This study provides practical reference for the new development in the field of mine blasting.

Slotted cartridge blasting improves the quality of roadway excavation and the stability of surrounding rock by directional control of blasting energy release path.Aiming at the problems of stress dispersion and surrounding rock damage in conventional blasting in the corner area of rectangular rock roadway excavation,based on the existing symmetrical slotted car tridge structure,a right-angle slotted cartridge structure suitable for blasting control in the corner area is proposed.Based on the LS-DYNA numerical simulation method,the energy propagation characteristics,surrounding rock damage evolution law and crack propagation form of the structure under single-hole and multi-hole blasting conditions are systematically analyzed.By comparing with the simulation results of different charging structures,the energy directional release and damage control effect are evaluated,and the field application verification is carried out in combination with the engineering practice.The results show that the right-angle slotted cartridge can realize the aggregation and synergistic release of blasting energy in the vertical orthogo nal two-way direction.The energy regulation mechanism is that the stress concentration effect in the slit direction is enhanced, and the stress response of the surrounding rock in the non-slit area is significantly weakened,so as to guide the stable expan sion of the crack along the preset path and inhibit the crushing failure of the non-slit area.The crack propagation influence in dex Ks and the crushing zone damage influence index Kc proposed in the study can effectively reflect the spatial distribution of blasting energy and the regulation ability of surrounding rock damage morphology by the slit structure,and provide a unified in dex for the quantitative evaluation of different slit charge structures.The engineering practice results further show that the ener gy directional release law of the right-angle slotted cartridge has good applicability in the actual rectangular and complex cross section rock roadway excavation,which can significantly improve the section forming quality and reduce the degree of over-ex cavation and surrounding rock loosening.The research results provide a theoretical basis and technical reference for the structural optimizationdesignof slottedcartridgeblastingandthedamagecontrol of complexsectionroadway.

Mine monitoring images suffer from low signal-to-noise ratio and high dynamic range noise due to low illumi nation, non-uniform artificial lighting, and dust or fog interference,which limits the accuracy of safety monitoring results.To enhance image clarity in mine monitoring,a novel image denoising algorithm combining gamma transformation with Local Inter pretable Model-agnostic Explanation (LIME) algorithm is proposed.Firstly,the LIME algorithm is applied to enhance illumi nation in raw mine images,while adaptively adjusting the gamma parameter based on the image mean to achieve pixel-wise brightness correction,thereby improving overall brightness and balancing light distribution,and preliminarily restoring details in dark regions.Next,an image decomposition technique based on the atmospheric scattering model separates the image into scene radiance,transmission,and global atmospheric light components.A spatially adaptive exposure adjustment is then implemented by constructing an exposure matrix for the transmission component using a camera response model,followed by linearly weigh ted fusion of the transmission component to remove dust and fog noise.Finally,the denoised and enhanced image is reconstruc ted using the Koschmieder model.The proposed method is compared experimentally with several state-of-the-art algorithms,in cluding improved Enlighten-GAN,multi-weight fused Retinex,three-stream three-channel color-balanced defogging,and Z DCE-DNet.Results show that the proposed method achieves a Gradient Magnitude Similarity Deviation (GMSD) of 0.359,an information entropy-weighted Structural Similarity Index (SSIM) of 0.947,and a multi-scale structural similarity index of 0.971,demonstrating significant performance advantages.This algorithm provides an effective solution for improving both effi ciency and quality in mine monitoring image processing and offers valuable reference for advancing intelligent image processing applications in underground mining environments.

In recent years,mine inspection robots have gradually replaced humans to perform inspection tasks in danger ous and harsh mining environments.However,the existing inspection robots have problems such as low efficiency and long paths in path planning and task allocation.It is necessary to develop more efficient methods for path planning and task alloca tion.By combining Genetic Algorithm (GA) with A-star algorithm,a new path planning method for mine inspection robots was proposed.By integrating the search strategies of four-neighborhood and eight-neighborhood in the A-star algorithm;introducing weights into the evaluation function to optimize the search process;and improving the crossover and mutation processes of the genetic algorithm by introducing heuristic crossover and cloning mutation methods,the time and length of the robot′s task exe cution were reduced.The experimental results show:① The path planning scheme using the improved A-star algorithm has fe wer path bends,does not collide with obstacles,and has a shorter path length.The path planning time and length of this algo rithm are only 7.2 s and 29.8 m respectively.② When the inspection task is 18,the average moving distance of the improved genetic algorithm is only 109.4 m.The research reflects that the proposed improved path planning and task allocation method effectively optimizes the path planning quality and task execution efficiency of mine inspection robots in complex mining envi ronments,and has certain practical application value.

The underground environment is harsh,with dim lighting and high levels of dust and moisture,resulting in poor image quality for safety monitoring.To improve the clarity of underground safety monitoring images,an image enhancement al gorithm based on a multi-branch attention convolutional neural network is proposed.The algorithm consists of an attention sub network,noise subnetwork,enhancement subnetwork,and reinforcement subnetwork.Model compression is achieved through pruning and quantization,while adaptive adjustment of algorithm parameters is enabled by brightness and noise monitoring modules.Additionally,multimodal fusion techniques are employed to optimize algorithm performance.Results show that the pro posed algorithm has an average running time of 0.056 seconds,with an average Peak Signal to Noise Ratio (PSNR) of 32.56 dB,an average Structural Similarity Index (SSIM) of 0.91,and an average Mean Absolute Error (MAE) of 0.043.In image enhancement tasks for suspected gas leakage areas,equipment failure zones,and human facial regions,the proposed algorithm significantly outperforms both the Multi-Scale Retinex with Color Restoration (MSRCR) algorithm and traditional Convolutional Neural Network Image Enhancement (CNN-IE) algorithms in terms of fPSNR ,fSSIM ,and fMAE .In practical applications,the algo rithm achieves PSNR values above 33 dB across various scenarios,fSSIM ranging from 0.92 to 0.96,and fMAE below 0.025.The study demonstrates that this algorithm effectively enhances image quality,meets real-time requirements,provides robust techni cal support for mine safety monitoring,and contributes to improving the safety level of mining operations.

Rock point load test is a test method to quickly obtain the mechanical properties of rock.However,there are some problems in the existing point load equipment,such as inconvenient carrying and difficult constant loading rate.There fore,a new point load tester is developed through the following ideas:the deceleration motor is used to improve the loading pump oil circuit,and the ability of stable loading and adjustable rate under controllable weight and volume is realized.The em bedded data acquisition unit is integrated to synchronously record the point load value and displacement,and eliminate the manual recording error.In order to verify the improvement effect,the green sandstone is selected to carry out the indoor test, and the test results are compared with the traditional point load equipment.The results show that the discrete coefficient of the rock point load strength index measured by the hydraulic servo point load tester is reduced by 35%,and the failure mode of the sample is more stable.The linear fitting analysis of the measured point load strength and uniaxial compressive strength shows that the relationship between the two is highly positively correlated,which verifies the reliability and superiority of the perform ance of the new hydraulic servo point load tester.

There are many residual coal and serious air leakage in the goaf of inclined coal seam,which provides a favor able environment for coal spontaneous combustion disaster.In order to explore the distribution law of coal spontaneous combus tion dangerous area in inclined coal seam goaf,taking 72 76 working face of Yuandian No.2 Coal Mine as the research object, the physical model of inclined coal seam goaf was constructed.Through the combination of field measurement,experimental re search and numerical simulation,combined with the qualitative and quantitative analysis of air leakage flow field in goaf,the distribution characteristics of coal spontaneous combustion dangerous area and high temperature point under different air supply volume were studied.The results show that the air leakage volume of the working face is basically consistent with the field measurement results,and the main air leakage area is concentrated in the range of 0~30 m along the inclined angle of the working face.With the increase of air supply volume,the width of coal spontaneous combustion danger zone increases gradual ly,and the coal spontaneous combustion danger zone on the intake side migrates to the deep part of the goaf.The maximum width of the oxidation zone increases by 1.3 m,but the coal spontaneous combustion danger zone on the return side gradually approaches the working face,and the maximum width increases by 4.1 m.The high-temperature point shifts to the deep part of the inlet side with the increase of air supply.The analysis results provide a theoretical basis for the prevention and control of coal spontaneous combustion in inclined coal seam goaf.

　When the mine skip shaft is used as a return air shaft,the return air carrying moisture and pollutants is easy to corrode the wellhead steel structure and reduce the visibility of the operation,which seriously threatens the safety production. Aiming at the core problems of return air overflow,equipment corrosion and environmental deterioration in skip shaft,a new scheme of full section isolation and intelligent control of pressure difference of jet gas curtain is proposed.The return air inter ception and partition device for skip well in metal mine was developed,and the field industrial test was completed.Based on the principle of air curtain jet dynamics,the device uses a flat cross jet to form a full-section air curtain barrier.Combined with re al-time pressure monitoring and PLC remote frequency conversion control,it realizes accurate control of air flow interception and dynamic matching of wind pressure.It has the characteristics of simple structure,flexible regulation and strong adaptabili ty.The actual measurement shows that the device can significantly improve the wellhead operation environment,the air flow iso lation rate exceeds 90%,effectively eliminate the corrosion hidden danger of the return air to the lifting equipment,and improve the operation safety.The research results provide reliable technical solutions for mine safety production and ventilation system optimization,fill the technical gaps in related fields,and have important engineering application value and promotion prospects.

In order to explore the influence of freeze-thaw cycles on the mechanical properties and shear band evolution mechanism of copper tail fine sand in Tibet,triaxial shear tests under different freeze-thaw cycles and confining pressures were carried out,and digital image measurement technology was used to measure the strain of the whole surface.The study reveals the variation law of stress-strain characteristics,strength characteristics,elastic modulus and shear strength index of saturated fine tailings.The decay law of cohesion and internal friction angle is described by Logistic model.The influence of freeze-thaw action on the initiation time and initiation strain of shear band is quantitatively characterized,and its evolution path is ana lyzed.The results show that the confining pressure and freeze-thaw cycles have a significant antagonistic effect on the mechani cal behavior of tailings fine sand.The confining pressure increases the failure strength,promotes the plastic deformation and in hibits the attenuation of elastic modulus by enhancing the lateral constraint.The freeze-thaw cycle leads to the decrease of strength and elastic modulus by repeated frost heave and thaw settlement,which aggravates the tendency of brittle failure.With the increase of freeze-thaw cycles,the cohesion and internal friction angle are significantly attenuated due to the destruction of cementation structure and the grinding of particle edges and corners,which provides a prediction tool for the anti-freeze-thaw design of tailings pond engineering.The micro-mechanism analysis shows that the micro-cracks and weak surfaces induced by freeze-thaw action will develop preferentially,resulting in the early initiation time of the shear band and the decrease of the crit ical strain.The morphology also gradually develops from the initial concentrated distribution to the dispersed multi-band sys tem,showing the cumulative evolution path of the internal damage of the fine sand during the freeze-thaw process.

To efficiently remediate combined heavy metal-contaminated soil with high concentrations in mining areas,this study explored the simultaneous passivation effects of organo-modified bentonite on Cd,Pb and Zn in composite contaminated soil using various organic modifiers.Sodium dodecyl sulfate (SDS) and tetraethylenepentamine (TEPA) were selected as opti mal modifiers through initial screening.Under optimal modification conditions,the reduction rates of available Cd,Pb and Zn in soil increased from 10.23%,11.50% and 12.80% for unmodified bentonite to 31.53%,41.64% and 37.72% for SDS-modi fied bentonite,and to 21.62%,32.56% and 37.35% for TEPA-modified bentonite,respectively.Characterization using FTIR, XRD and SEM-EDS confirmed successful loading of organic modifiers onto bentonite.TEPA enhanced heavy metal immobiliza tion through complexation by amino groups,while SDS facilitated immobilization via electrostatic attraction and ion exchange by sulfonic groups.Additionally,organic intercalation reconstructed the pore network of bentonite,forming an intercalation-exfoliat ion coexistent structure and increasing the average pore diameter,thereby optimizing mass transfer pathways.Organo-modified bentonite significantly improved the remediation efficiency of heavy metal composite contaminated soil through a dual mecha nism of "pore structure optimization combined with functional group binding".

The rapid development of digital photogrammetry and LiDAR technologies has made underground three-dimen sional data acquisition more convenient and efficient.The foundation for obtaining complete 3D real-world maps of mine tunnels lies in the high-precision registration of sequential point clouds,with the core being the estimation of spatial transformation pa rameters between point clouds to achieve unified spatial coordinates across multiple stations.However,the dusty and noisy envi ronment in underground excavation areas,along with deteriorating roadway structures,makes it difficult for existing point cloud registration methods to establish stable corresponding features,resulting in low registration accuracy and poor quality of 3D tun nel modeling.To improve the robustness and precision of point cloud registration in excavated roadways,a node association based algorithm (Robust-Fast Global Registration,R-FGR) is proposed.This algorithm first extracts point cloud features using Fast Point Feature Histograms (FPFH) descriptors,then employs a k-nearest neighbors matching strategy to obtain initial cor respondences among multi-station point clouds.It subsequently calculates the association degrees between matched points and extracts reliable candidate inliers based on these degrees.Finally,a robust loss function is constructed using progressive non convex optimization,and the global optimal registration result is determined iteratively by minimizing the objective function.A case study was conducted at the Dongshan Coal Mine in Heilongjiang,where various registration algorithms were compared.Re sults show that the proposed method achieves the highest robustness and registration accuracy,enabling automatic alignment of multi-temporal point clouds and effectively supporting 3D roadway mapping and dynamic updating tasks.

To develop low-carbon cementitious materials suitable for marine engineering,this study investigated the effects of simulated seawater mixing on the properties and hydration process of supersulfated cement (SSC).The setting time and compressive strength were tested,and the microstructural evolution and hydration-hardening mechanisms of SSC mixed with simulated seawater were systematically analyzed using X-ray diffraction,mercury intrusion porosimetry,thermogravimetric anal ysis,hydration heat measurement,and other methods.The results indicated that simulated seawater shortened the initial and fi nal setting times of SSC by 20 min and 25 min,respectively,and increased the compressive strength at 1 d,3 d,and 28 d by 15.8%,4.5%,and 4.0%,respectively.The performance improvement is mainly attributed to the simulated seawater (particu larly NaCl therein) promoting the dissolution and hydration of slag,thereby altering the composition and distribution of hydra tion products.The early-formed Friedel′s salt and C-(A)-S-H gel jointly filled the gaps between ettringite (AFt) crystals,re fined the pore size of the hardened paste,and significantly reduced the porosity of harmful capillary pores larger than 20 nm. This study provides a theoretical basis for the application of seawater-mixed SSC in marine engineering.

To address the environmental issues caused by the accumulation of blast furnace slag,this study systematically investigated the effects of alumina silica ratio,Na2 O content,and CaO content on the phase evolution,microstructure,and prop erties of blast furnace slag-based foam ceramics using Pansteel blast furnace slag as the main raw material.The regulation mechanisms of each component on the ceramic properties were analyzed through X-ray diffraction (XRD),scanning electron microscopy (SEM),combined with mechanical property,porosity,and thermal conductivity tests.The results show that increas ing the alumina silica ratio drives the phase transformation from quartz and sphene to alumina and perovskite,significantly en hancing the density,strength,and thermal conductivity of the material.When the Na2 O content reaches 1.75%,the ceramic ex hibits a uniform pore structure,while excessive Na2 O leads to the formation of albite (NaAlSi3 O8 ).Although CaO promotes sintering,excessively high CaO content inhibits the crystallization of anorthite,resulting in deteriorated properties.Under the optimized formulation (mass ratio of blast furnace slag and boric acid of 50∶10,alumina silica ratio of 0.5,Na2 O content of 1.75%),the prepared foam insulation ceramic achieves a flexural strength of 4 MPa,thermal conductivity of 0. 079 5 W/(m·K),bulk density of 2.22 g/cm3,and water absorption of 3.7%,all of which meet the requirements of the standard "Foam Ceramic Insulation Panel for Building" (JG/T 511—2017).

To address the demand for special building materials with high early strength and rapid setting and hardening in emergency repair projects,and to explore high-value utilization pathways for bulk industrial solid waste in building materi als,this study proposes the preparation of a high-volume iron tailings sand mortar using alkali activation technology.The study utilizes fly ash (FA) and ground granulated blast furnace slag (GGBFS) as precursors,with iron tailings sand fully replacing natural sand as the fine aggregate.Through orthogonal experimental design,the effects of four key factors,namely the mass ratio of FA to GGBFS,NaOH solution concentration,water-binder ratio,and mortar-binder ratio,on the workability of fresh mortar and the mechanical properties of hardened mortar were systematically investigated.The results show that the primary and sec ondary influence order of each factor on the 24-hour compressive strength of mortar is the mass ratio of FA to GGBFS,the con centration of NaOH solution,the water-binder ratio and the cement-sand ratio.The GGBFS content is the decisive factor deter mining early strength,mainly because GGBFS can provide a rich calcium source for the system,promoting the formation of a large amount of dense C-(A)-S-H gel.Under the optimal mix ratio,the 24-hour compressive strength of mortar reaches 33.69 MPa,exhibiting excellent rapid hardening and early strength characteristics.Meanwhile,the iron tailings sand content reaches 66.7%,achieving efficient resource utilization of solid waste.This study provides scientific basis and technical support for the development of emergency repair materials with both excellent mechanical properties and environmental benefits.

Aiming at the demand for green,low-carbon and high-performance materials in deep mine grouting engineer ing,an all-solid waste grouting material system with carbide slag (CS) and red mud (RM) as synergistic activators and blast furnace slag (GGBS) and fly ash (FA) as precursors was developed.The properties of fluidity,setting time and compressive strength were systematically tested,and the types of hydration products,pore structure characteristics and microstructure evolu tion of the materials were revealed by means of X-ray diffraction (XRD),Fourier transform infrared spectroscopy (FTIR), mercury intrusion porosimetry (MIP) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) .The re sults show that under the condition of CS-RM synergistic excitation,the constructed all-solid waste grouting material system has good construction workability and mechanical properties under normal temperature curing conditions,and the 28 d compressive strength can reach 13.90 MPa.The microscopic analysis shows that the system forms a cementation structure dominated by C (A) -S-H gel,with a concentrated pore size distribution and a dense microstructure.The mechanism analysis shows that the rapid release of alkaline components from carbide slag can form a synergistic excitation effect with the active components in red mud,promote the dissolution and recombination of active Si and Al in the precursor,and then generate continuously distributed cementitious products,thereby constructing a dense and stable structural system.The research reveals the internal mechanism of preparing high-performance grouting materials by multi-source solid waste synergistic excitation,which can provide theoreti cal basis and technical reference for green grouting and solid waste resource utilization in deep mine engineering.