Cemented backfill is a key load-bearing structure in backfill mining,playing an important role in supporting surrounding rock,controlling ground pressure,and ensuring stope stability.Its damage evolution behavior and constitutive mod els are directly related to the reliability of stability evaluation and structural design of deep stopes.With the increase in mining depth,cemented backfill is subjected to complex environments involving high in-situ stress,high temperature,seepage erosion, and blasting disturbance,and traditional evaluation methods based mainly on strength parameters can no longer meet engineer ing requirements.Based on the needs of safe and efficient deep metal mining and green backfill development,this paper sys tematically reviews the research progress on damage evolution and constitutive models of cemented backfill,focusing on damage characterization,damage evolution,and constitutive modeling.First,the definition methods of damage variables,including elas tic modulus degradation,statistical distribution theory,energy dissipation,acoustic emission parameters,and physical detection methods,are summarized.Then,the damage evolution laws under static loading are discussed from the perspectives of uniaxial compression,conventional triaxial compression,true triaxial compression,and special service environments involving tempera ture,seepage,and chemical corrosion,and the dynamic damage accumulation characteristics are analyzed in terms of strain rate effect,coupled static-dynamic loading,and cyclic impact.On this basis,the research status of static damage constitutive mod els,creep constitutive models,dynamic damage constitutive models,and backfill-rock composite constitutive models is re viewed.The results show that:① Damage variables of cemented backfill have gradually evolved from single macroscopic me chanical parameter characterization to multi-source damage characterization,but the quantitative relationships among different indicators still need to be improved;② Under static loading,the damage evolution of cemented backfill is jointly affected by stress path,material proportion,and service environment,showing obvious stage characteristics and path dependence;③ Under dynamic loading,the damage of cemented backfill is mainly manifested as strain rate effect,coupled static-dynamic response, and cyclic impact accumulation,but a gap remains between laboratory tests and field disturbance conditions;④ Existing consti tutive models can describe various mechanical behaviors,but the physical meaning of model parameters,applicability bounda ries,and engineering generalization still need to be strengthened.During the 15th Five-Year Plan period and beyond,future re search should focus on:① Establishing a quantitative correlation among multi-source damage indicators and a multi-scale dam age variable characterization framework;② Deepening the understanding of thermal-hydraulic-mechanical-chemical coupling damage mechanisms and developing generalized multi-field coupled constitutive models;③ Developing true triaxial coupled static-dynamic loading and cyclic impact test methods and establishing quantitative correspondences between laboratory test conditions and field disturbance conditions;④ Building a predictable parameter calibration framework for constitutive models to enhance the physical interpretability and engineering applicability of model parameters;⑤ Promoting the development of intel ligent damage identification and stability early warning technologies that integrate data-driven approaches with physical mecha nisms.

Blasthole sealing technology plays a key role in improving the energy utilization efficiency of rock blasting and ensuring engineering construction quality.In response to the demands of national energy security,green and low-carbon devel opment,and safe and precise blasting in underground engineering,this paper systematically reviews the development trajectory of blasthole sealing theory and technology by integrating typical technological achievements in rock blasting at home and abroad over the past two decades with the accumulated experience of the research team.The research progress of blasthole sealing the ory and technology in rock blasting is reviewed from four aspects:sealing mechanism,theoretical models and design methods of sealing length,performance characterization and evaluation of sealing materials,and development of sealing construction tech nology and equipment.The results show that:① Existing research has gradually evolved from empirical sealing practice to mechanism-oriented studies based on mechanical and energy analyses;② Studies on sealing length design have been continu ously deepened,but the adaptability of most theoretical models and experimental results under complex field conditions still re quires further verification;③ Research on sealing materials has made continuous progress,but the universality of material prop erties,targeted adaptability to specific working conditions,and establishment of a unified evaluation system still need to be im proved;④ Sealing technology is developing from traditional manual tamping toward mechanized and intelligent equipment,pro viding a technical basis for the refinement and standardization of blasting processes.Meanwhile,current research still faces sev eral challenges,including insufficient understanding of sealing mechanisms and inadequate adaptability of sealing length models to complex engineering conditions,limited applicability of material properties and lack of a unified evaluation system,insuffi cient digital-intelligent capability and online monitoring capacity of sealing construction equipment,and an underdeveloped col laborative transformation mechanism integrating theoretical research,material development,process equipment,and engineering application.Looking toward the 15th Five-Year Plan period and beyond,this field should focus on sealing length models cou pling sealing mechanisms with engineering conditions,new sealing materials and systematic evaluation frameworks,digital-intel ligent equipment integrating sealing construction and quality monitoring,and collaborative industry-university-research-applica tion transformation mechanisms,thereby promoting the development of blasthole sealing technology toward safer,more refined, greener,and more intelligent practices.

With the inevitable trend of metal mineral resource development shifting towards deeper deposits,the integrat ed mining,beneficiation,and backfilling process has emerged as a core direction for addressing complex geological conditions at depth and achieving intensive extraction.However,conventional integrated processes based on the drill-and-blast method com monly suffer from bottlenecks such as discontinuous production stages,uncontrolled fragmentation,low separation accuracy,and poor system coordination.This paper innovatively proposes a novel integrated process utilizing non-blast mechanized mining. Centered around continuous mechanized excavation,precise fragmentation control,efficient underground beneficiation,and in situ waste backfilling,this approach establishes a closed-loop "Mining-Beneficiation-Backfilling-Mining" operational model through fundamental process innovation and modular system integration.It aims to significantly enhance mining efficiency and resource recovery rates while simultaneously reducing energy consumption and environmental risks from the source.In order to provide theoretical and technical reference for the safe,green and efficient development of deep complex deposits,this paper systematically expounds the overall architecture,key technologies and personalized solutions adapted to different geological con ditions of ore bodies.

In the face of dynamic demand fluctuations in the commodity market,the existing static mining production plan is difficult to match the changing market demand,resulting in low resource allocation efficiency and high operational risk.A monthly plan adjustment and optimization method based on the "prediction-generation-evaluation" integrated framework is pro posed.Firstly,a hidden Markov model (HMM) is constructed to mine the time series characteristics of futures trading data and identify the hidden state (high/medium/low) of market demand.Secondly,a plan generation model coupled with dynamic de mand and risk preference is established.Different levels of Gaussian disturbance are introduced to simulate the risk preference of decision makers (aggressive/neutral/conservative),and a differentiated alternative plan set is generated in combination with mine process constraints.Finally,the DEA-AHP comprehensive evaluation system is constructed to quantify the objective pro duction efficiency and integrate the management strategy weights under different market conditions to achieve the optimal solu tion screening.The simulation test based on the actual mining production data of a mining enterprise shows that the comprehen sive utility score of the optimization plan generated by this method is better than the original plan in all 9 test scenarios,with an average increase of about 0.94%.It effectively solves the problem of disconnection between production decision and dynamic demand,and provides theoretical support for scientific decision-making in dynamic market environment.

Aiming at the problem of low-cost backfilling utilization for resource-oriented solid waste materials,this study takes multi-component solid wastes such as desulfurized gypsum,steel slag,and slag as the research objects,and conducts re search on the mix ratio optimization of component ratios of multi-component full-solid-waste-based cementitious materials. Based on the mixture design theory,16 groups of mix ratio schemes were designed to prepare multi-component solid-waste based cemented tailings backfill with 7-day and 28-day curing ages.Through dynamic and static mechanical tests,the mechani cal response laws and the optimal mix ratios meeting the dynamic and static strength requirements were explored.The results show that:① The dynamic and static compressive strengths of the backfill exhibit a significant positive correlation.Under the same mix ratio,the dynamic strength is higher than the static strength,and the dynamic and static strengths of the backfill at the 28-day curing age are generally higher than those at the 7-day curing age.② The strength prediction models constructed based on the response surface methodology have good accuracy.Combined with the factor analysis of multi-component solid wastes,it is found that within the material mix ratio range adopted in this experiment,slag content dominates the backfill strength under static load,while desulfurized gypsum content has the most significant impact on the strength under dynamic load.③ When the cement-sand ratio and slurry concentration are fixed,the backfill strength is determined by the synergistic effect of the multi-component solid wastes;the multi-component full-solid-waste-based cemented tailings backfill achieves high strength under the balanced mix ratio of low-to-medium content of desulfurized gypsum + moderate content of steel slag + high content of slag.The research results can provide theoretical guidance for the mix ratio design of solid waste-based cementitious materials.

Saw-tooth joints serve as a crucial idealized model in rock mechanics research,where precise prediction of shear strength holds significant engineering implications.This study integrates swarm intelligence optimization technology with interpretable data-driven methods.Based on 50 sets of direct shear test data,four key parameters were selected as inputs and shear strength as the output to construct four machine learning base models and two swarm intelligence optimization composite models.Model performance was quantitatively evaluated through six metrics,with TreeSHAP method applied to analyze input parameter feature importance.It is found that the prediction performance of the group intelligent optimization combination mod el is significantly better than that of the traditional machine learning model.CSA-XGBoost is the optimal model,which can a chieve accurate prediction.The normal stress and joint inclination at joint surfaces were identified as core influencing parame ters,contributing over 58% cumulative feature importance.This study provides an efficient technical approach for quantitative assessment of shear strength in sawtooth jointed rock masses,offering valuable insights for intelligent prediction of similar rock mechanics parameters.Future work could enhance model generalization capabilities through sample supplementation and engi neering validation.

Multi-physical field information fusion is a research hotspot of rock mass instability early warning.The charac teristics of acoustic emission and infrared temperature change in different stages of rock failure process were studied by using infrared temperature mutation ratio (ITMR) and acoustic emission mutation rate (AEMR) as quantitative indexes.The results show that the tangent modulus in loading process of the specimen presents the stage characteristics of “rapid rise-steady rise rapid decline”.The crack initiation strength determined by the maximum value of the steady rise and fall stage is 83.39 MPa, which is about 53% of the peak strength.With the increase of strain,the change rate of tangent modulus shows the stage char acteristics of “rapid decline-steady decline-rapid decline”.There is an obvious inflection point between steady decline and rap id decline.According to the inflection point,the damage strength is 139.67 MPa,which is about 89% of the peak strength. Taking the crack initiation strength and damage strength as the boundary,the deformation process of the specimen can be divid ed into compaction-elastic stage Ⅰ,crack initiation and stable propagation stage Ⅱ,and crack unstable propagation failure stage Ⅲ.There is a clear complementary relationship between AEMR and ITMR abnormalities.In stage Ⅰ,the changes of AE MR and ITMR are relatively stable,showing stable fluctuations in a small range.In stage Ⅱ,AEMR shows dramatic large-scale abnormal jumps frequently,which can be used as a precursor to rock failure,while ITMR changes smoothly.In stage Ⅲ,AEMR first has a large jump anomaly,and then reaches a quiet period,while ITMR large jump anomaly is more obvious,which can be used as a late precursor of rock instability.The research results are of great significance for the joint early warning of infrared andacousticemissiontopromotetheinstabilityof geotechnical engineering.

Deep coal mining has long been faced with high stress,strong corrosion and high ground temperature coupling environment,and the service performance of grouting anchor cable has been significantly attenuated.It is urgent to establish an analysis method that can characterize the deterioration process of its corrosion strength.Taking Zhaolou Coal Mine as the engi neering background,the influencing factors of grouting anchor cable corrosion were systematically analyzed by combining theo retical derivation with numerical simulation.The corrosion rate model considering chloride ion concentration and temperature effect was constructed,and the time-varying model of corrosion strength degradation of grouting anchor cable was further estab lished.The research shows that the corrosion strength degradation of grouting anchor cable is controlled by the diffusion of cor rosive medium,temperature change and material-interface synergistic degradation,which shows that the bearing capacity and interface bonding performance of anchor cable continue to decay with the service time.The corrosion degree of grouting anchor cable increases with the increase of service time.The corrosion rate reaches 12.83% and the loss rate of ultimate bearing ca pacity reaches 12.53% after 5 years of service.The numerical simulation results show that the deformation and stress redistri bution of roadway surrounding rock are more obvious under the condition of corrosion.The maximum difference of roof center point settlement is 5%,and the maximum difference of roof center line stress is 10.6%.The corrosion effect has a non-negli gible influence on the long-term stability of deep roadway support system. It is of great significance to study the deterioration mechanism and time-varying response of grouting anchor cable corrosion strength for improving the scientificity of deep roadway support design and ensuring the long-term safety of the project.

To investigate the influence of confining pressure on the creep behavior of rock,creep tests were carried out under various confining pressure conditions.By incorporating a hardening function and a damage variable,a hardening-damage coupled three-dimensional creep model for surrounding rock was established.On this basis,by introducing a yield function and a plastic potential function,the one-dimensional creep relation of sandstone was extended to a three-dimensional form,and the model parameters were identified and validated using experimental data.The results show that the predicted creep curves agree well with the experimental curves overall,with only local deviations in the accelerated creep stage,while the correlation coeffi cients are all greater than 0.90,indicating that the model can effectively describe the whole creep process of rock.Compared with the Nishihara model,the proposed hardening-damage coupled three-dimensional creep model for surrounding rock can not only characterize the coupled evolution of hardening and damage during creep,but also better capture the variation patterns in the decelerating creep,steady-state creep,and accelerated creep stages.The model can provide a theoretical reference for the long-term stability analysis of surrounding rock and geotechnical engineering design.

Under the influence of mining on the working face,the geological structure area is prone to induce rockburst, which poses significant safety hazards to mining operations.In response to the problem of intensified deformation and support failure of deep surrounding rock in a certain mine under high stress,high permeability and complex geological conditions,in or der to clarify the deformation and failure mechanism of deep surrounding rock and optimize the support scheme,triaxial cyclic loading and unloading tests were used to analyze the rock strength,deformation capacity and energy evolution characteristics under different confining pressure conditions.Conduct FLAC3D numerical simulation to reveal the propagation law of stress waves,stress concentration distribution,and rock failure mode under different dip angle joint conditions.Combining on-site stress monitoring to obtain stress changes and deformation responses of the surrounding rock of the roadway under mining dis turbance,and using them to verify numerical simulation results and determine support parameters.Research has shown that in deep high stress environments,the joint dip angle of surrounding rock significantly affects the propagation of stress waves and the form of rock failure.As the joint dip angle increases,the range of tensile failure of the rock mass expands,the area of shear failure gradually increases,and the stability of the surrounding rock significantly decreases.Under high stress conditions,the energy evolution characteristics of surrounding rock are characterized by a slight increase in the proportion of elastic energy at low stress states,while the proportion of dissipated energy significantly increases at high stress states,indicating that surrounding rock is more prone to plastic deformation and energy dissipation in high stress environments.On this basis,an anchor mesh spraying combined support scheme was proposed,which enhances the bonding between the anchor rod and the surrounding rock through resin anchoring,restrains the fractured surrounding rock with metal mesh,and forms a continuous closed protective structure through the spraying layer,thereby improving the overall integrity and self stability of the roadway surrounding rock. The research results indicate that this support scheme has lower material costs compared to traditional U-shaped steel arch sup port,and can effectively reduce bottom plate uplift,control roof crack development and convergence deformation of the two sides.The integrity of the roadway section and the stability of the surrounding rock are significantly improved,providing theoret ical basis and technical support for the prevention and control of rock deformation in deep mine roadways.

The development and utilization of vanadium-titanium magnetite resources in the Panzhihua-Xichang (Panxi) region face challenges in processing lowgrade,complexly intergrown ores.Based on a systematic review of existing technological innovations,this paper extracts the adaptation patterns between mineral occurrence characteristics and processing technologies, integrates technical contents from multiple aspects including separation optimization,equipment development,reagent creation, and associated element recovery,and establishes a wholeprocess technical analysis framework.The results show that in the iron separation stage,technologies such as highpressure grinding roll preconcentration (with tailings discarding rate increased by approximately 40% and energy consumption reduced by about 35%),stage grinding and separation,and magnetic separation flotation combined purification achieve iron concentrate quality improvement and energy consumption reduction.In the titanium separation stage,the combined process of gravity separationmagnetic separationflotation,together with novel collectors and intel ligent equipment,increases the recovery of -0.038 mm fine ilmenite from about 20% to about 35%,with titanium concentrate grade exceeding 46%.Associated elements are synergistically recovered through a flotationmetallurgy combined process:vanadi um is recovered during the smelting of iron concentrate,while chromium,cobalt and nickel are enriched from iron separation tailings.The sodium roastingdirect reduction coupling process provides a new approach for the recovery of vanadium,iron and titanium.This paper systematically summarizes the existing wholeprocess development technologies,clarifies the adaptation log ic among equipment,reagents and processes,as well as the matching patterns between mineral occurrence and processing tech nologies,providing a reference for future technological optimization.Future development should focus on intellectualization and greenization to promote efficient and clean resource utilization,thereby ensuring national strategic resource security.

As easily accessible gold ores are gradually depleted,the mining industry is increasingly compelled to address the processing of refractory gold ores.Among these,Double Refractory Gold Ores (DRGOs),characterized by both sulfide en capsulation and the carbonaceous "preg-robbing" effect,have emerged as a major bottleneck in current gold metallurgy.Al though traditional pretreatment methods such as roasting and pressure oxidation can effectively destroy sulfide structures and liberate the encapsulated gold,they suffer from high energy consumption,high costs,and severe pollution,making them incom patible with the contemporary demand for green and low-carbon development in the mining industry.Bio-oxidation,as an envi ronmentally friendly pretreatment technology,is progressively becoming a key development direction and research hotspot for the treatment of refractory gold ores,especially DRGOs.This review systematically summarizes the mechanisms and limiting factors of bio-oxidation pretreatment of gold ores,with emphasis on the direct-indirect synergistic mechanism of sulfide bio-oxi dation,degradation pathways of carbonaceous matter,formation patterns and elimination strategies of passivation layers,and the stress defense mechanisms of microorganisms under high-arsenic and high-acidity conditions.Furthermore,it discusses the ap plication of multi-omics technologies in deciphering the functional networks and metabolic regulation of microbial communities. By synthesizing the above research progress,this review elucidates the core mechanisms of Fe/S energy metabolism,arsenic re sistance regulation,and the synergistic metabolism of autotrophic-heterotrophic consortia in acidophilic microorganisms.It pro poses a combined processing route to synergistically address the dual challenges of "preg-robbing" and "passivation",andhighlights the future trend of multi-omics technologies transitioning from data description to functional prediction and precise regulation.This review aims to provide theoretical and technical support for the efficient and sustainable utilization of double re fractory gold ores.

To improve the comprehensive utilization rate of the polymetallic and nonmetallic mineral resources such as i ron,rare earths,and fluorite in Bayan Obo,a process mineralogy study was carried out on the mediumlow grade oxidized ores that had been stockpiled for many years at the Bayan Obo deposit with Xray diffraction (XRD) analysis,chemical composition analysis,scanning electron microscopy (SEM),and mineral liberation analyzer (MLA).The results show that the runofmine ore has a TFe grade of 28.74% and an REO grade of 5.45%.The main valuable minerals are magnetite/hematite,monazite, bastnaesite,and fluorite,while the main gangue minerals are amphibole and dolomite.Iron mainly occurs as hematite and mag netite.Iron is predominantly distributed in the coarser size fractions,whereas the rare earth elements are mainly concentrated in the finer fractions.The liberation degrees of the major minerals are relatively low,and the interlocking relationships among dif ferent minerals are very tight.Therefore,it is difficult to achieve efficient recovery of iron,rare earths,and fluorite by conven tional beneficiation processes.

In a high-arsenic tungsten-tin polymetallic ore from Inner Mongolia,the contents of Cu,Pb and Zn are 0.25%,0.31% and 1.10%,respectively,with As content as high as 1.54%.The arsenic-bearing mineral (arsenopyrite) is closely intergrown with metal sulfides,making the separation difficult.To avoid the negative impact of sulfide minerals on the subsequent tungsten-tin separation and to achieve comprehensive recovery of associated Cu,Pb and Zn,a flotation desulfuriza tion process was investigated based on process mineralogy.The results show that by adopting the process flowsheet of bulk flota tion of copper-lead-zinc-arsenic sulphide minerals under weakly acidic conditions,followed by separation of arsenic from the copper-lead-zinc bulk concentrate and then separation of copper from lead-zinc,and after reagent-removal treatment,the com bined depressant of lime + sodium humate + bleaching powder can effectively depress arsenopyrite at low alkalinity,achieving efficient separation of copper-lead-zinc from arsenic.After arsenic removal,the copper-lead-zinc bulk concentrate is treated with zinc sulfate + sodium sulfite + CMC to depress lead and zinc,thereby separating copper from lead-zinc.The closed-circuit test produced a copper concentrate with a Cu grade of 17.78% and Cu recovery of 63.51% (containing 0.77% As),a lead zinc bulk concentrate with Pb grade of 15.22% (Pb recovery 67.65%) and Zn grade of 41.04% (Zn recovery 71.94%,con taining 0.81% As),and an arsenic concentrate with As grade of 22.15% and As recovery of 91.11%.The desulphurization tailings (feed for subsequent tungsten-tin recovery) have their Cu,Pb,Zn,and As contents reduced to 0.03%,0.04%, 0.09%,and 0.14%,respectively,while the WO3 grade is 0.17% and Sn grade 0.21%,with WO3 recovery of 96.97% and Sn recovery of 85.67%,thus creating favourable conditions for the subsequent recovery of tungsten and tin.

To address the challenges of severe slime interference and inefficient recovery of fine-grained cassiterite from a highslime,finegrained tin ore in a concentrator,this study employed a centrifugal concentrator to pre-concentrate the fine cassit erite,effectively removing slime gangue and mitigating its adverse effects on subsequent flotation.The centrifugal concentrate was processed using a novel combined collector HC-51,primarily composed of dihydroxamic acid,through a flotation circuit consisting of one roughing,three cleaning,and three scavenging.A tin concentrate with a grade of 16.40% and a recovery of 75.73% was ultimately obtained,effectively resolving the processing difficulties associated with highslime,lowgrade fine tin slime products.This approach not only yields a relatively highgrade concentrate but also significantly reduces the slurry volume entering the flotation stage and substantially lowers flotation reagent costs,demonstrating distinct technical and economic advan tages.This study provides a feasible technical pathway for the efficient recovery of highslime,finegrained cassiterite and holds significant practical value and application prospects for the secondary utilization of lowgrade tin resources.

To comprehensively recover valuable metals such as Cu and Ag from a zinc kiln slag in Gansu Province,flota tion tests were carried out.In view of the high carbon content in the zinc kiln slag that deteriorates Cu-Ag flotation,decarburiza tion flotation condition tests were firstly conducted.Subsequently,the effects of activator,collector and frother dosages on Cu-Ag flotation were systematically investigated,and the optimal flotation conditions were determined.Finally,the flotation flowsheet of "pre-decarburization,one rougher,three cleaning and two scavenging" was established.The results show that the contents of Cu,Ag and C in the zinc kiln slag are 1.38%,107.09 g/t and 16.90%,respectively,indicating that Cu and Ag have high re covery value,while the excessively high carbon content severely interferes with Cu-Ag flotation.Under the conditions of grind ing fineness of -0.074 mm accounting for 80%,decarburization collector (kerosene) dosage of 2 000 g/t and frother (2# oil) dosage of 400 g/t,the carbon removal rate (C recovery) reaches 90.04%.The optimal Cu-Ag roughing conditions are:activa tor sodium sulfide dosage of 600 g/t,collector combination of ammonium dibutyl dithiophosphate + butyl xanthate of 200+100 g/t,and frother 2# oil dosage of 300 g/t.Under the optimized conditions,a copper-silver mixed concentrate with Cu and Ag grades of 13.36% and 1 162.70 g/t is obtained through closed-circuit flotation,with Cu and Ag recoveries reaching 66.62% and 75.58%,respectively,achieving efficient comprehensive recovery of copper and silver resources from the zinc kiln slag.

To address the challenge of inadequate oxidative degradation of sodium butyl xanthate (SBX) in mineral pro cessing wastewater,this study proposed the use of ultraviolet (UV)-enhanced ozone microbubble (O3 (MB)/UV) system for SBX oxidation,and systematically investigated its degradation performance and mechanism.Reactive oxygen species were iden tified via free radical quenching experiments,intermediates products were analyzed by gas chromatography-mass spectrometry (GC-MS),and reactive sites were predicted based on density functional theory (DFT) calculations,thereby elucidating the degradation pathway.The results showed that the O3 (MB)/UV system exhibited significantly superior SBX degradation effi ciency compared to ozone microbubbles or UV irradiation alone.Under the conditions of ozone dosage of 4 mg/min and UV light intensity of 25 W,the SBX removal efficiency reached over 99.9% within 4 min,with a COD conversion rate of 71%, which was notably higher than that of the H2 O2 /UV (25 W) system (42%).DFT calculations revealed that the highest occu pied molecular orbital (HOMO) of SBX is mainly distributed near the carbonyl (C􀰗O) and thiocarbonyl (C􀰗S) groups, among which the sulfur atom possesses a high Fukui function f- value,serving as the primary reactive site for electrophilic at tack.Mechanistic analysis indicated that the efficient oxidation of SBX relies on the strong oxidizing ability of ozone to initiate thiocarbonyl cleavage and subsequent radical chain reactions,while UV irradiation promotes the generation of hydroxyl radicals (·OH) and superoxide anions (·O 2 ) from ozone,synergistically facilitating the deep mineralization of SBX.This study clar ifies the degradation pathway and mechanism of SBX in the O3 (MB)/UV system,providing a novel,efficient,and secondary pollution-free approach for the treatment of complex mine wastewater.

In order to break through the application limitations of liquid oxygen open-pit mines,the field application re search of liquid oxygen phase change fracturing technology was carried out for the complex and limited working conditions of small section seepage shaft.The sludge compensation cracking scheme suitable for small section seepage shaft is explored,and the PVC sealed liquid oxygen cracking pipe and its supporting sealing test are designed to form the construction technology of seepage water drainage and pore formation in restricted space.The throwing characteristics of rock mass,the forming quality of borehole wall and the distribution law of block size after liquid oxygen phase change fracturing are systematically analyzed.At the same time,based on the ground vibration monitoring,the vibration characteristics and safety effects are studied.The results show that the optimized liquid oxygen fracturing process can effectively adapt to the small section seepage shaft environment. The spatial differentiation of wellbore wall is formed by the combined action of liquid oxygen blasting energy distribution,stress propagation path and rock mass structure characteristics.The continuous high-pressure gas promotes the expansion and penetra tion of the rock mass,and then forms the distribution characteristics of 10-20 cm rock fragments.The quasi-static effect of the phase change process makes the near-field of the ground show the significant characteristics of medium-low frequency and low vibration velocity.The research provides technical reference and theoretical basis for the efficient rock breaking of liquid oxygen phase change fracturing technology under complex working conditions.

Focusing on the hybrid energy storage system for wide-body truck composed by lithium battery and ultra-ca pacitor,a dedicated energy management strategy is required to significantly suppress the battery operating current,improve the cycling characteristics of the lithium-ion battery,thereby extending the service life of the energy system and reducing the oper ating cost of the wide-body truck.In this paper,an energy management strategy based on the Soft Actor-Critic (SAC) deep re inforcement learning algorithm is designed,and the physical characteristics of the hybrid energy storage system forms the foun dation of reward function design.The proposed strategy is validated using the well-established model,composed by the longitu dinal dynamics model of the pure electric wide-body truck,an equivalent circuit model of the hybrid energy storage system,and the associated models of other components.Simulation results show that,compared with a rule-based control strategy based on frequency separation,the proposed intelligent energy management strategy can effectively mitigate the impact of high current on the lithium-ion battery,reducing the battery peak current by 12.71%.In addition,the terminal voltage of the supercapacitor is effectively controlled,with a minimum voltage of 390 V,which always remains within the allowable operating range.The simula tion results confirmed the feasibility and efficacy of proposed deep reinforcement learning-based energy management strategy for the hybrid energy system of the wide-body mining truck.

Tailings ponds are special functional units with high risks and disturbances during the mining process,and their ecological environment quality shows significant differences at different life cycle stages.Existing studies mostly focus on the entire mining area,lacking systematic characterization of the long-term evolution laws of the ecological environment of tail ings ponds.Therefore,this study takes the Huangmailing phosphogypsum tailings pond in Hubei Province as an example,based on the long-term Landsat remote sensing images from 1994 to 2024,and selects the MSAVI and BSI indicators to replace the o riginal greenness (NDVI) and dryness (NDBSI) factors in combination with the environmental characteristics of the tailings pond.The improved remote sensing ecological index (TP_RSEI) is constructed by weighting the first and second principal components for quantitative evaluation.The research results show that:The average correlation degree of TP_RSEI is 0.70, which is better than that of a single indicator,and can effectively represent the ecological characteristics of the study area.In the temporal dimension,the mean value of TP_RSEI in the study area decreased from 0.64 to 0.52 over 30 years,with a de cline of 18.75%,showing a fluctuating evolution pattern of "first degradation and then improvement",which is highly coupled with the full life cycle stages of the tailings pond,namely "construction-operation-shutdown-restoration".In the spatial pattern, the ecological environment shows a significant feature of "degradation in the center and recovery at the edge".The high-inten sity storage during the operation period led to ecological degradation,while the closure and restoration projects promoted the gradual improvement of ecological quality.This study reveals the evolution laws of the ecological environment quality of tailings ponds from a full life cycle perspective.The proposed TP_RSEI method effectively enhances the applicability of the remote sensing ecological index in the complex scenarios of tailings ponds,providing scientific basis and technical support for the as sessment of ecological restoration effectiveness,regulatory decision-making,and the construction of green mines.

The stability evaluation of underground complex goaf group and its dynamic disaster prevention and control are the common problems faced by the safe mining of deep mineral resources.Aiming at the technical problem that it is difficult to accurately identify the instability risk of large-scale and irregular goaf group system,a collaborative evaluation scheme combi ning improved Mathews stability diagram method and FLAC3D numerical simulation is proposed.Firstly,based on the fine field investigation and rock mechanics parameters,the improved Mathews stability diagram method is used to classify the initial sta bility of the goaf.A three-dimensional numerical model reflecting the spatial correlation characteristics of goaf group is con structed to simulate and analyze the evolution law of stress-displacement field and the expansion and connection mechanism of plastic zone under the influence of mining.Through the mutual verification of the two methods,the spatial aggregation and non linear evolution characteristics of the cavity group instability are revealed,and the high-risk area of instability is delineated.Fi nally,based on the theory of impact wave dynamics,a coordinated disaster prevention and control scheme of "buffer layer ener gy dissipation + wave barrier isolation" is proposed,and the theoretical calculation model of key parameters is given.Taking the complex goaf group of III-IV ore body in Dahongshan Iron Mine as the engineering background,17 goaf areas are delineated as high risk areas of instability by using the proposed technical method,and the disaster prevention and control scheme of re serving waste rock cushion + building concrete wave wall is formulated.The technical system of "precise risk identification deep mechanism analysis-hierarchical targeted prevention and control" formed by this study provides a universal theoretical ba sis and technical path for the treatment of complex goaf groups in similar mines,and has important reference value for ensuring  thesafeminingofdeepresources.

In recent years,resource development and land use changes have significantly changed the surface structure and thermal environment of coal mining areas.Land surface temperature (LST),as an important parameter to characterize sur face energy balance and ecological environment change,has become an important index for ecological monitoring and restora tion evaluation in mining areas.Taking Shendong coal mine area as the research object,based on the LST inversion of Landsat 8 remote sensing image from 2014 to 2024,combined with BFAST algorithm,the temporal and spatial evolution characteristics and mutation process of surface temperature were analyzed.The results showed that the LST of the mining area showed a signif icant upward trend during the study period,and the area of the heating area was significantly larger than that of the cooling are a.The LST mutation events are mainly concentrated in 2019-2021,showing a transition from relatively stable to rapid warming. The LST time series has both stable periodic fluctuation and periodic warming characteristics.The change of LST is closely re lated to the change of land use.The expansion of construction land and sandy land,as well as the reduction of grassland,culti vated land and water area,weaken the transpiration cooling effect of vegetation and the thermal buffer function of water body, which are the main factors driving the surface temperature rise.In general,the land use evolution model of " increasing bareness,reducing greenness and reducing water body" in Shendong mining area is highly consistent with the deterioration of ther mal environment.Land use change is the core driving force of thermal environment evolution in mining area.

Layered slopes are widely distributed in mountainous regions of China and are highly susceptible to dynamic disturbances such as earthquakes,which can trigger landslides and pose serious threats to infrastructure and public safety. In order to investigate the dynamic response characteristics of layered rock slopes under earthquakes,a representative layered slope in Fujian Province was selected as the study site.Three-dimensional finite element models of a bedding rock slope and an anti-dip slope were established,and synthetic seismic waveforms obtained from the local seismic monitoring agency were ap plied to simulate ground shaking.By analyzing peak ground acceleration (PGA) and acceleration amplification coefficients at different spatial positions,the influence mechanisms of topography and rock mass structure on seismic amplification were sys tematically revealed.The results demonstrate that weak structural planes exert a significant influence on seismic wave propaga tion within the slope,leading to pronounced local acceleration amplification or attenuation and consequently affecting the overall dynamic response characteristics.The layered slope exhibits typical near-surface and elevation amplification effects,and the presence of weak structural planes induces noticeable nonlinear amplification behavior.Under identical conditions,the bedding rock slope shows a markedly stronger dynamic response than the anti-dip slope,with PGA values of 3.84 m/s2 and 3.20 m/s2, respectively.The amplification factor of the bedding rock slope is approximately 1.2 times that of the anti-dip slope.Further more,seismic wave propagation within both slopes displays strong spatial heterogeneity,which may lead to distinct instability mechanisms and failure patterns between bedding rock slopes and anti-dip slopes.

It is an important goal of national mine safety supervision to realize the identification and monitoring of major safety risks in key areas and key links of open-pit mines.Based on the actual needs of safety identification and monitoring of tailings dam and dump slope in open-pit mines,the Lanxian-Loufan iron mine area in Shanxi Province was taken as the re search area.A total of 92 small baseline interference pairs composed of 35 scenes of Sentinel-1A SAR data were used.Based on the DS-InSAR technology of distributed scatterers,the effectiveness and applicability of this technology applied to the monito ring of mountain surface deformation in regional open-pit mines were verified,and the surface deformation characteristics of tailings dam and dump slope in this area were analyzed and studied.The monitoring results show that the DS-InSAR technology can effectively identify the surface deformation of three tailings dams and three dump slopes in the study area.Considering that these tailings dams and dumps are in the operation stage,the surface deformation is mainly consolidation subsidence and self compacting deformation.Compared with SBAS-InSAR technology,the coherence of target points is significantly improved after phase optimization and reconstruction of DS-InSAR technology.The number of coherent points increases to 6.5 times,and the correlation coefficient of surface deformation is 0.81.It provides technical and data support for the identification of surface de formation hazards and stability evaluation of tailings dam and dump slope,as well as the study of surface deformation mecha nism.The research shows that Yuanjiacun Iron Mine and Jianshan Iron Mine urgently need to strengthen the normalized moni toring of surface deformation of tailings dam and dump slope.

Achieving precise dynamic prediction of surface subsidence is a key technology for ensuring the safety of sur face structures in mining-affected areas and optimizing maintenance plans.The prediction accuracy of dynamic subsidence fore casting algorithms combining the probability integral method and dynamic time-series functions often fails to meet the require ments for maintenance and management.The primary reason for this phenomenon is the variation in parameters of dynamic time-series functions due to the complexity of mining subsidence.To address this issue,this paper proposes a high-precision dy namic prediction method based on the concept of "mechanism-constrained data-driven" modeling.The probability integral method is adopted as the physical framework for subsidence calculation,and the Knothe time function is used to describe the temporal evolution of surface point subsidence.Multi-period measured subsidence data are utilized to invert the optimal time parameter for each observation period using the Levenberg-Marquardt algorithm,thereby obtaining the dynamic evolution se quence of the time parameter.The metabolic grey model is then employed to predict future parameter values,enabling synchro nous dynamic updates of both the parameters and the predicted subsidence values,and consequently achieving high-precision dynamic surface subsidence prediction.Case studies were conducted,and the results show that compared with the method using fixed parameters in the dynamic time function,dynamically updating the time-series function parameters reduces the relative er ror of dynamic prediction from 25.1% to within 5%,significantly improving the prediction accuracy.In another case,the root mean square error in each period was reduced by more than 50% on average.This study provides a new technical approach for dynamicpredictionofminingsubsidenceandhas important implications forguidingengineeringpractice.

In order to improve the prediction accuracy of landslide displacement,a combined prediction model combining double exponential smoothing (DES) and particle swarm optimization extreme learning machine (PSO-ELM) is proposed. Based on the time series decomposition theory,the model uses DES to predict the trend term displacement controlled by geolog ical conditions,uses ELM to learn the periodic term displacement caused by external factors such as rainfall,and demonstrates the ignorability of the random term through the significance test.The GNSS monitoring data of a typical landslide in Chongqing is used as a case to verify.The results show that the mean absolute error,root mean square error and mean absolute percentage error of the proposed DES-ELM model in the total displacement prediction of GB07 monitoring points are 1.982 0 mm,2.679 4 mm and 1.372 3%,respectively,and the coefficient of determination is 0.909 1.The prediction accuracy is significantly bet ter than the comparison models such as polynomial-gated recurrent unit (GRU).Furthermore,after introducing the particle swarm optimization (PSO) to optimize the ELM hyperparameters,the mean absolute error and root mean square error of the pe riodic term prediction are further reduced by 76.33% and 76.70%,which effectively alleviates the phase lag of the original ELM model and improves the stability and goodness of fit of the model.This study provides an effective and reliable solution for high-precision prediction of landslide displacement.

Traditional methods for measuring rock mass data on slopes with complex terrain often suffer from low meas urement accuracy and poor safety.By integrating multi-view Unmanned Aerial Vehicle Surveying (UAVS),Principal Compo nent Analysis (PCA),and the Chinese Slope Mass Rating (CSMR) method,a novel slope stability analysis method,termed UAVS-PCA-CSMR,is proposed.In this method,UAVS is first employed to acquire various data of the slope rock mass and to construct a three-dimensional model;then,the PCA algorithm is applied to identify the structural features of the rock mass with in the model;finally,the CSMR method,combined with the identified structural features,is used to analyze the stability of a specific slope rock mass.The results demonstrate that when measuring rock mass data in different zones of the slope,the accu racy exceeds 90%,and the identification error for the dip angle of the slope structural planes is only ±3°.The gCSMR value ob tained for the slope rock mass is 85.4,indicating relatively high slope stability,and the analytical results are in good agreement with the actual field conditions.This study reflects that the integrated research approach of “measurement-modeling,structural identification,and stability analysis” provides a valuable reference for slope stability investigations.

Hyperspectral technology has the potential to retrieve heavy metal elements in soils of rare earth mining areas. However,complex competitive adsorption between rare earth elements (La,Ce) and heavy metals (Cu,Pb) in soil components leads to overlapping and masking of spectral response features,limiting retrieval accuracy.To address this issue,a typical rare earth mining area in southern Jiangxi Province was selected as the study area,and 153 soil samples were collected.Based on an in-depth investigation of the spectral competition relationships between rare earth elements and heavy metals,the Lotka-Volterra model was employed to quantitatively characterize the competition intensity among elements.Accordingly,a multi-objective hy perspectral band selection method incorporating the mechanism of spectral competition among soil heavy metals was proposed to effectively select characteristic spectral bands and construct band ratios.Additionally,terrain factors (e.g.,elevation,slope, curvature) and mining factors (distance from sampling points to sedimentation ponds) were introduced to establish a hyper spectral quantitative retrieval model using the XGBoost algorithm.The results show a significant competitive adsorption effect between Cu-La-Ce and Pb (p<0.01).The maximum correlation between the constructed characteristic indices and soil heavy metal contents significantly improved (Cu:from 0.32 to 0.70;Pb:from 0.33 to 0.49).After incorporating terrain and mining factors,the model accuracy further increased,with the full-variable model achieving validation set R2 values of 0.89 for Cu and 0.78 for Pb,representing improvements of 14.3% and 6.5%,respectively,compared to the sub-model using only band ratio features.This study provides a new approach for hyperspectral monitoring of heavy metal pollution in rare earth mining areas.

The efficient removal of high-concentration free fluoride ions from phosphogypsum leachate poses a significant environmental challenge for the phosphorus chemical industry.To achieve the goal of "waste control by waste",this study fabri cated a porous geopolymer using phosphogypsum,phosphate tailings,and blast furnace slag as primary raw materials via alkali activation and H2 O2 chemical foaming.The adsorption behavior and mechanism of the porous geopolymer towards fluoride ions were systematically investigated.Experimental results showed that the optimized porous geopolymer achieved a fluoride removal rate of 66.7% under the conditions of pH=4,initial fluoride concentration of 50 mg/L,and temperature of 25 ℃.The adsorp tion kinetics followed the pseudo-second-order model,indicating a chemisorption-dominated process.The adsorption isotherm was better fitted by the Freundlich model,suggesting multilayer adsorption on heterogeneous surfaces.Mechanistic studies re vealed that the adsorption involved synergistic effects of physical interception,ion exchange,and chemical precipitation.The dominant mechanism was identified as the chemical precipitation of CaF2 ,resulting from the reaction between Ca2+ dissolved from the geopolymer and F- in solution.This research provides a novel approach for the high-value-added utilization of phosph ogypsum and phosphate tailings,and the developed porous geopolymer demonstrates promising potential for application in fluor ide-containing wastewater treatment.

To address the issues of poor borehole sealing quality and rapid attenuation of extraction rates in coal seam mining,this study integrates the stress-seepage coupling theory with borehole sealing techniques.By modifying inorganic silicate materials with nano-oxides and surfactants,a novel inorganic nano-flexible sealing material was developed.Industrial-scale tri als were conducted in the No.3 coal seam of Changping Mine,where the developed material was applied to gas drainage opera tions and the existing process was optimized in conjunction with the "three-blocking and two-grouting" sealing technique.The results indicate that the experimental group employing the nano-diffusion expanding agent exhibited overall superior average gas drainage concentrations compared to the control group using ordinary sealing cement.The average net gas drainage rate in the experimental group reached 0.13 m3 /min,whereas that of the control group was only 0.06 m3 /min.Following secondary grou ting,the average drainage concentrations of the two representative boreholes increased by 21.3% and 69.0%,respectively.The findings demonstrate that the developed inorganic nano-flexible sealing material and the associated sealing process can effec tively improve borehole sealing integrity,which is also of great significance for mitigating mining-related risks.

To solve the problems of low comprehensive utilization rate and insufficient cementitious activity of iron ore tailings,and clarify the influence mechanism of mechanical activation on the particle characteristics and cementitious activity of iron ore tailings,four typical iron ore tailings (Type A,B,C,D) from Hebei Province were taken as the research objects.Me chanical activation was carried out with a planetary ball mill for different times (0~4.0 h).Combined with laser particle size analysis,XRD,SEM and mortar strength test methods,the influence laws of mechanical activation on the particle size,micro morphology,phase composition and cementitious activity of iron ore tailings were systematically explored,and the particle distri bution uniformity was analyzed by Rosin-Rammler (R-R) model fitting.The results show that the mechanical activation is dominated by particle crushing and refinement in the early stage.For all four types of iron tailings,there exists an optimal inter val characterized by the competition between particle refinement and agglomeration,with the ideal particle size distribution a chieved at activation times between 1.5 and 2.5 h.The R-R model has a good fitting effect (correlation coefficient COD is greater than 0.96),and both the characteristic particle size De and the uniformity constant n show a trend of "rapid decrease, tendency to fluctuate" with the increase of activation time.Mechanical activation is likely to lead to the lack of intermediate particle size and reduce the distribution uniformity.Mechanical activation can promote the transformation of the main phases of iron ore tailings to amorphous state,and an amorphous "diffuse package" appears in the XRD pattern.The optimal phase modi fication time is 2 h for Type A and D iron ore tailings (containing high-hardness minerals such as quartz and pyroxene),and 1.5 h for Type B and C iron ore tailings.After 0.5 h of mechanical activation,the activity indexes of the four types of iron ore tailings all meet the requirements of GB/T 2847—2005 (≥65%).The synergistic effect of particle refinement and crystal amorphization significantly improves their pozzolanic activity,among which the maximum activity index of Type B iron ore tail ings reaches 84.6%,and that of Type A iron ore tailings (high-silicon type) is the lowest at 74.2%.Considering the activation effect and process economy,it is suggested that the mechanical activation time of the four types of iron ore tailings should be controlled within 1.5~2.5 h.Introducing classification grinding process and adding grinding aids after 1 h of activation can op timize the activation effect.The research results can provide data support and theoretical guidance for the high-value resource utilization of iron ore tailings.

Semi-dry sintering desulfurization ash is a bulk solid waste generated by the steel industry,characterized by low utilization rate and high environmental pollution potential.River channel silt,on the other hand,exhibits high water content and significant pollutant loads,making it unsuitable for direct engineering application.To synergistically address the disposal challenges of these two types of solid wastes and achieve the concept of "treating waste with waste",this study developed a composite curing agent for river channel silt solidification using desulfurization ash as the main raw material,supplemented by cement clinker,fly ash,red mud,ground granulated blast furnace slag,and silica fume.The physicochemical properties of the desulfurization ash were characterized by XRF,XRD,and SEM.Ten formulations with different desulfurization ash contents (15%~60%) were designed,and the solidified silt was tested for unconfined compressive strength,California bearing ratio (CBR),free swell ratio,water content,pH value,and heavy metal content.The solidification mechanism was elucidated through microstructural analysis.The results show that the optimal desulfurization ash content is 15%,yielding a 28-day unconfined compressive strength of 1.44 MPa,CBR of 29.78%,free swell ratio of 2.45%,and water content of 19.6%,all meeting the re quirements for subgrade backfill.The strength decreases with increasing desulfurization ash content.After solidification,the contents of heavy metals such as Mn,Zn,Pb,and Cr are significantly reduced,far below the national standard limits.Microstructural analysis reveals that the alkaline components in the desulfurization ash activate the hydration reactions of the cemen titious materials,generating C-S-H and C-A-S-H gels,which fill pores,bind particles,and immobilize heavy metal ions through chemical complexation.The developed curing agent provides a feasible pathway for the resource utilization of desulfu rization ash and dredged silt,and the solidified soil exhibits both environmental safety and engineering applicability.

To reduce the reliance on cement in cemented ultra-fine tailings backfill (CUTB),achieve low-cost and low carbon backfilling,and improve its brittle failure characteristics,an all-solid-waste binder (ASWB) composed of ground granu lated blast furnace slag,oil shale residue,phosphogypsum,and carbide slag was developed to completely replace ordinary Port land cement.Recycled tire polymer fibers (RTPF) were incorporated for reinforcement.The macroscopic mechanical proper ties,microstructure,and reaction mechanisms of the all-solid-waste CUTB were systematically investigated through uniaxial compressive tests,thermogravimetric analysis (TG),scanning electron microscopy with energy dispersive spectroscopy (SEM EDS),etc.Furthermore,a damage constitutive model for RTPF-CUTB,incorporating a damage correction coefficient (m),was established based on Weibull statistical damage theory.The results indicate that:① The cementitious performance of the ASWB system for CUTB is significantly superior to that of the OPC system,with 7 d and 28 d compressive strength increased by 57.69%~196.15% and 94.96%~147.90%,respectively.Phosphogypsum effectively promotes early-age strength develop ment,and the 28 d compressive strength reaches a maximum of 2.95 MPa when its dosage is 5% of the ASWB mass.② The main hydration products of the all-solid-waste CUTB are C-(A)-S-H gel and ettringite crystals,which form a dense "gel crystal" interlocking structure,providing microstructural support for strength enhancement.③ The reinforcing effect of RTPF on CUTB outperforms that of polypropylene fibers,with an optimal dosage of 0. 4%,resulting in a strength increase of 10.17%~13.46% compared to the fiber-free system.The established damage constitutive model accurately describes the dam age evolution process of RTPF-CUTB.This study provides a theoretical and technical basis for the green resource utilization of ultra-fine tailings in backfilling and the performance optimization of backfill materials.

To investigate the release and immobilization characteristics of heavy metal copper in unfired bricks prepared from copper mine tailings,unfired bricks with different strength grades (MU10,MU20,MU30) were fabricated using copper mine tailings from the Shuimuchong tailings pond in Tongling,Anhui Province.The physicochemical properties were character ized by XRD,TGA,MIP and SEM.The occurrence forms of copper were determined by Tessier sequential extraction method, and continuous leaching experiments were conducted under different pH conditions (3.2,5.6,6.6) based on the NEN 7375 method to study the release behavior and long-term leaching patterns of copper ions (Cu2+).The results showed that:① With the increase of unfired brick strength grade,the proportion of cementitious materials increased,hydration products significantly increased,porosity decreased,and the microstructure became denser.② The total Cu content in copper mine tailings was 968.45 mg/kg.After solidification into unfired bricks,the residual fraction of Cu increased from approximately 17% to 96%, indicating significant immobilization efficiency.However,under acidic conditions at pH 6.6,the residual fraction decreased to 69% while the organic-bound fraction increased to 31%.③ The 20-day continuous leaching tests showed that Cu2+ leaching ex hibited a two-stage characteristic:rapid release in the early stage (0~30 h) followed by a slow approach to equilibrium.The leaching concentration increased monotonically with decreasing pH,reaching the highest value of 0.027 mg/L at pH 3.2,which was far below the limit specified in the Identification Standard for Hazardous Waste—Identification of Leaching Toxicity (GB 5085.3—2007).The release mechanism of Cu2+ was dominated by diffusion control and depletion effects,and the pseudo-sec ond-order kinetic equation could well fit the long-term cumulative leaching amount (R2>0.91),with 10-year predicted release amounts of 22.81~53.13 mg/kg.This study indicates that unfired bricks prepared from copper mine tailings can achieve effi cient immobilization of Cu2+,with good safety performance in neutral or weakly acidic environments,while protective measures are required under strongly acidic conditions.