The toxic gases present in confined space work environments have significantly affected the physical and mental
health of the workers. To effectively prevent the hazards of toxic gases and reduce occupational health risks,and to ensure
the safety of the workers′ lives,based on the safety requirements of confined space operations,this paper analyzes the main
types and hazards of toxic gases in confined spaces,and summarizes the current development status of confined space toxic gas
control technologies from four aspects:ventilation detoxification,gas absorption,membrane separation,and individual protection.
It elaborates on the progress of toxic gas control in four typical industries:food processing industry,paper industry,farm facilities
and leather manufacturing industry,and summarizes the corresponding toxic gas control measures. The findings revealed
that:① Hydrogen sulfide,carbon dioxide,methane and carbon monoxide are common toxic gases in confined spaces,with their
distribution differing due to their physical and chemical properties. The accumulation of these gases leads to a decrease in oxygen
concentration,posing a severe threat to worker health. ② Among the methods for controlling toxic gases in confined spaces,
ventilation and gas removal,gas absorption,membrane separation,and personal protective technologies are the primary approaches.
However,in practical applications,these methods often suffer from low efficiency and limited control effects of individual
technologies. ③ Industries such as food processing,papermaking,agricultural facilities,and leather manufacturing,due to their diverse production environments and process characteristics,exhibit significant differences in the types and concentrations of
toxic gases. In these typical confined space work environments,risks such as poisoning and asphyxiation cannot be overlooked,
and the typical operations and their respective control technologies also vary. On this basis,a systematic and in-depth analysis
of the deficiencies in current toxic gas control technologies in confined space work environments is conducted,highlighting insufficient
understanding of the properties and mechanisms of toxic gases,limited effectiveness of control technologies,and low
intelligence levels of control equipment. For the period of the "15th Five-Year Plan" and beyond,research in this field should
focus on:① Deepen the theoretical research on the movement and prevention of toxic gases in confined spaces;② Continuously
conducting research on key technologies for efficient prevention and control of toxic gases in confined spaces;③ Developing integrated,automated and intelligent equipment for the prevention and control of toxic gases;④ Conducting engineering application
demonstrations of typical toxic gas prevention and control equipment for confined spaces.

Unstructured road potholes in open pit mining areas have always been one of the important problems plaguing
the safety of unmanned mining cards. In order to solve the safety problems caused by potholes,such as the bumpy and even
rollouts of unmanned mining cards,a YOLOv7-RFEM model for road pothole detection in open pit mining areas was proposed
in this paper. Firstly,for potholes with different sizes,irregular shapes and not obvious features,a Scale-Aware RFE module
based on cavity convolution and shared weights is introduced into Neck to further expand the sensitivity field of feature maps
and improve the multi-scale detection performance and accuracy of the model while reducing the number of parameters. Secondly,
in view of the actual situation of the integration of road background and pothole features,the model adds an Efficient Multi-
Scale Attention mechanism (EMA) for cross-space learning to ELAN,which enhances the characteristics of small targets of
potholes and weakens the background interference of potholes. Finally,to solve the problem of inaccurate location of the pothole
boundary frame,CIoU Loss was replaced by NWD Loss,so that the model paid more attention to the overlap between the predicted
frame and the real frame,and adapted to the changes of the shape and size of the pothole. The experiment of a large
opencast mine in Hami,Xinjiang proves that the model has good detection effect in many cases,and can meet the demand of
accurate detection of unmanned mining cards in opencast mine.

The Rock Block Index(RBI) is a crucial metric for assessing the integrity and structural characteristics of
rock masses. However,the traditional calculation method of RBI often leads to low correlation with the Rock Mass Integrity Index(
Kv) and significant deviations in integrity evaluation,as it overlooks the influences of varying regional lithology,structural
features,and in-situ stress conditions. To address this issue,this study takes a large-scale mine slope in western Sichuan as the
research object. Based on data from 28 exploration boreholes and 10 wave velocity test holes,the eigenvalue analysis method is
employed to replace the fixed weights in the traditional RBI formula with characteristic lengths corresponding to rock masses of
different integrity levels,and the classification boundaries are redefined,thereby obtaining a revised RBI. The research demonstrates
that the correlation coefficient between the revised RBI and Kv has significantly improved,along with a substantial increase
in the consistency ratio of rock mass integrity evaluation results and a notable reduction in cross-grade deviations. These
findings are further confirmed by validation group data. By introducing dynamic weights and characteristic lengths,this method
effectively overcomes the limitations of traditional RBI. It offers an economical and reliable alternative for rock mass integrity evaluation
in projects lacking wave velocity testing conditions,further enriches the connotation and application scenarios of RBI,
and provides a new approach for quantitative evaluation of rock mass integrity.

Aiming at the problem of insufficient accuracy of joint roughness coefficient evaluated by single statistical parameter
and traditional machine learning,an integrated tree estimation method of rock joint roughness coefficient based on multiple
statistical parameters is proposed. Based on the data set of 112 rock joint roughness profiles,eight statistical parameters
representing the geometric shape of joint profiles are selected,and six representative ensemble tree models,including bag method,
random forest,extreme random tree,adaptive lifting,extreme gradient lifting tree and lightweight gradient lifting tree,are
constructed. Combined with Bayesian algorithm to optimize its hyperparameters,and compared with five traditional single machine
learning models,the applicability and performance differences of six ensemble trees in joint roughness prediction are systematically
analyzed. Finally,the influence of each statistical parameter in the ensemble tree model on the prediction results of
joint roughness is revealed by Shapley additive feature interpretation method. The experimental results show that the prediction
effect of the integrated tree model is better than that of the traditional single machine learning model,especially the extreme
random tree model. The mean square error is 0. 081 0,the average absolute error is 0. 066 6,the coefficient of determination is
as high as 0. 995 6,the prediction accuracy is high,and the generalization ability is strong. This study provides a method basis
and reference for the determination of rock joint roughness,and it is recommended to use the extreme random tree algorithm to
predict the joint roughness coefficient.

The hydraulic characteristics of slag in dump are the key factors affecting the stability of slope and the development
of post-construction settlement. At present,there is still a lack of systematic understanding of the hydraulic characteristics
of slag materials in compacted state. Taking the slag of an open-pit mine dump as the research object,the saturated permeability
coefficient and soil-water characteristic curve of slag under different compaction conditions were measured by variable
head permeability test and pressure plate instrument test,and the unsaturated permeability coefficient was predicted based on
the Childs & Collis-George model. It is found that with the increase of dry density of slag,its pore structure tends to be dense,
resulting in a significant decrease in saturated permeability coefficient. When the dry density of slag increased from 1. 50
g/ cm3 to 1. 90 g/ cm3,the permeability coefficient decreased by 99. 63%. Under the same matric suction,the higher dry density
sample has stronger water holding capacity,and its soil water characteristic curve can be well fitted with the Van Genuchten
model,and the correlation coefficient can reach more than 0. 996. The saturated permeability coefficient decreases with the increase
of dry density. When the dry density increased from 1. 60 g/ cm3 to 1. 80 g/ cm3,the permeability coefficient decreased
from 2. 0×10-4 cm/ s to 7. 0×10-5 cm/ s. And it decays in power function with the increase of matrix suction. When the suction
increases from 0. 01 kPa to 400 kPa,the permeability coefficient decreases by three orders of magnitude. This study reveals the
influence mechanism of compaction degree on the hydraulic characteristics of slag from the perspective of microscopic pore evolution
and macroscopic hydraulic response. It is suggested that the seepage stability of dump can be optimized by controlling the
compaction quality in practical engineering. The research results can provide theoretical support and practical guidance for
dump slope design and long-term safety assessment.

Water and joints have a significant effect on the mechanical properties and failure modes of slope rock mass.
In order to further reveal the influence of joint inclination angle (β) on the deterioration effect and sensitivity of rock mass under
fluid-solid coupling,uniaxial compression tests of rock mass with different joint inclination angles were carried out based on
RFPA2D-Flow numerical software. The results show that joints significantly reduce the peak strength of rock mass,but the evolution
of deformation stages of different β rock samples is consistent. The evolution process of acoustic emission (AE) (quiet
period,stable development period,sharp rise period,attenuation period) can effectively characterize the damage evolution. The
peak strength and peak strain have a quadratic function relationship with β,and the elastic modulus and AE parameters are
positively correlated with β. The quantitative model of β and macro-micro mechanical parameters is established. The degradation
sensitivity of rock mass parameters is significantly different with the boundary of β≈30°:when β<30°,the deformation capacity
(peak strain) degradation of rock mass is the most sensitive. When β>30°,its ability to resist deformation (elastic modulus) is
the most sensitive deterioration index. This law provides a clear basis for slope stability control,and deformation control should
be given priority to gently inclined jointed slopes (β<30°). Steeply inclined jointed slopes (β>30) need to focus on preventing
stiffness degradation and instability. This study not only clarifies the inherent law of rock mass degradation under the fluid-solid
coupling of joint dip angle,but also provides a refined sensitivity criterion for slope engineering stability evaluation.

As a key material for controlling the deformation of surrounding rock and buffering dynamic disasters in mining,
the dynamic mechanical properties of gangue cemented fill are crucial for stope stability. In order to explore the mechanical
properties and failure characteristics of gangue cemented backing under impact load,the uniaxial impact test under different
impact air pressures was carried out by using the separate Hopkinson pressure bar test system(SHPB). The test results show
that the dynamic stress-strain curve of the gangue cemented filling body under different impact air pressures shows significant
nonlinear characteristics,and with the increase of impact air pressure,the peak stress of the gangue cemented filling body increases
significantly,and the peak point shifts to the left. With the increase of impact pressure,the reflected energy in the proportion
of incident energy of gangue cemented filling decreases from 78. 3% to 69%,and the absorption energy increases from
21. 6% to 30. 5%,indicating that the energy dissipation ability increases with the increase of impact pressure. With the increase
of impact load,the damage degree of gangue cemented filling gradually deepens,only a small amount of debris falls at
low impact load,internal cracks begin to develop and spread under medium impact load,and appear in a serious fracturing state
under high impact load.

Studying the unloading mechanical properties and energy dissipation law of rock is of great significance for understanding
the damage mechanism of surrounding rock,accurately judging the stability of surrounding rock,and economically
and reliably supporting underground engineering. In order to study the influence of unloading rate on the unloading mechanical
properties and damage of granite rock,constant axial pressure unloading confining pressure tests under different unloading rates
were carried out. The study found that in the case of rapid unloading,its mechanical properties accelerated degradation,from
the stable damage development stage directly to the damage stage. When the unloading rate is small,during the unloading
process,the stress is continuously adjusted,the mechanical properties are slowly deteriorated,and the plasticity is gradually enhanced.
As the unloading rate decreases,the elastic energy accumulated at the peak point of the rock sample gradually increases,
but the proportion of elastic energy continues to decrease. The damage variables of granite are obtained from the law of energy
dissipation and the law of acoustic emission,respectively. The variation of the two under unloading conditions is highly
consistent. At high unloading rate,the acoustic emission ringing count of the sample before fracture has strong suddenness. The
research results have important scientific value and engineering guiding significance for the safety design and disaster prevention
and control of deep buried tunnels,mines and other underground projects.

In view of the problem that the anchor bolt is prone to corrosion and deterioration under the action of water
spray in deep roadway,the accelerated corrosion treatment of anchor bolt by water immersion is designed and carried out. The
tensile tests of bolts with different corrosion time were carried out,and the mechanical characteristics and corrosion mechanism
of bolts before and after corrosion were analyzed. The influence of bolt corrosion on the stability of roadway surrounding rock
was studied by numerical simulation. The results show that the corrosion pits of the bolts gradually connect with each other during
the corrosion process,and change from local corrosion to comprehensive corrosion. The mass loss rate of the bolt gradually
increases with the increase of the corrosion age,but the corrosion rate gradually slows down. The mechanical properties such as
yield load,fracture load and elongation of the bolt show a downward trend with the increase of corrosion age,and the brittleness
is significantly enhanced. The fracture morphology of the bolt changed from the tensile dominant mode before corrosion to the
tensile-shear mixed mode. Bolt corrosion will also aggravate the stress concentration and deformation of roadway surrounding
rock,which is not conducive to the stability of roadway. It is proposed that the adverse effects of watering on the stability of
roadway surrounding rock can be effectively alleviated by adopting anti-corrosion materials,increasing support strength and water
drainage.

To address the inefficiency of traditional spherical grinding media in achieving selective mineral liberation and
to meet the escalating demands for grinding processes in processing low-grade,fine-grained,and complex ores,this study conducted
a systematic comparative investigation on steel balls,steel tetrahedral,and ceramic balls,focusing on their capture performance,
ground product size distribution,and mill operational indicators. The results demonstrate that the steel tetrahedral
media significantly outperforms its counterparts. Its average capture area was increased by 25. 08% to 80. 38% compared to
steel balls and ceramic balls. The grinding products obtained with steel tetrahedral exhibited the highest b value (2. 799 55) in
the Rosin-Rammler size distribution model,indicating the most concentrated size distribution and superior uniformity. Furthermore,
it increased the yield of the easily-separable size fraction (from 0. 15 to 0. 019 mm) to 68. 36%. Consequently,the
mill′s utilization coefficient for -200 mesh,technical efficiency,and grinding efficiency reached 0. 243 3 t/ (m3·h),80. 01%,
and 0. 006 0 t/ (kW·h),respectively,all of which were significantly superior to those achieved with the other media. This research
confirms the comprehensive advantages of steel tetrahedral media in enhancing grinding efficiency,optimizing product
size distribution,and reducing energy consumption,providing crucial theoretical support and practical guidance for developing
and applying new high-efficiency grinding media.

To investigate the mineral occurrence characteristics and chemical beneficiation adaptability of sedimentary
anatase ore,a systematic process mineralogy study was conducted on the Xuanwei Formation anatase ore from Junlian County,
Sichuan. The results show that the TiO2 content of the ore is 6. 62%,with 83. 37% of the titanium existing in the form of anatase.
X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analyses revealed
that the anatase grains are predominantly euhedral to subhedral tabular and columnar crystals with fine particle size. They commonly
occur as independent particles,intergrowths,or inclusions within clay minerals such as kaolinite (47. 8%) and illite
(10. 3%),resulting in complex mineral dissemination and making monomer liberation difficult. Based on these mineralogical
characteristics,a multi-metal stepwise recovery process centered on "pretreatment,two-stage acid leaching,stepwise precipitation"
was designed and proposed to achieve the synergistic separation and high-value utilization of elements such as titanium,iron,
and aluminum. This research provides an important theoretical basis and technical support for the resource evaluation and
green efficient development of similar refractory sedimentary titanium ores.

To efficiently utilize a refractory iron ore containing sulfur from Liaoning and achieve the comprehensive recovery
of iron and sulfur resources,this study conducted a detailed process mineralogy analysis. It revealed that the characteristics
of close symbiosis between iron minerals (mainly magnetite) and sulfur minerals (mainly pyrrhotite and pyrite) in the ore and
their adverse effects on separation were clarified. Accordingly,a novel "magnetic-flotation-magnetic" separation flowsheet was
proposed. Through systematic conditional tests,an effective reagent regime was established,employing isopropyl xanthate as the
collector and a combination of oxalic acid and copper sulfate as activators. The closed-circuit test results demonstrated that a final
iron concentrate with yield of 30. 12%,iron grade of 67. 20%,and sulfur content of 0. 36% could be obtained,alongside
sulfur concentrate with yield of 3. 75% and sulfur grade of 32. 30%. This process successfully achieved the efficient separation
and comprehensive recovery of iron and sulfur,offering a viable technical solution for processing similar refractory iron ore resources
containing sulfur.

Aiming at the problems of low cobalt grade,fine dissemination grain size,and difficult recovery in an iron-cobalt
ore from Xinyu,Jiangxi Province,this study conducted systematic mineral processing tests for comprehensive utilization.
Process mineralogy analysis showed that cobalt mainly occurs in sulfide minerals,and thus a principle flowsheet of “flotation
first to recover sulfur-cobalt minerals,followed by magnetic separation to recover iron” was proposed. Through systematic conditional
tests,the optimal parameters were determined:grinding fineness of 65% passing 0. 074 mm;Using sodium carbonate
(500 g/ t) as inhibitor,copper sulfate (50 g/ t) as activator,and a novel ternary sulfhydryl composite collector CJ-1 (150
g/ t). The results showed that compared with traditional butyl xanthate,CJ-1 could simultaneously improve the grade and recovery
of sulfur and cobalt concentrate. The closed-circuit test finally obtained two qualified products:the sulfur-cobalt concentrate
with S and Co grades of 37. 44% and 0. 32%,and recoveries of 95. 54% and 60. 35%,respectively;The magnetite concentrate
with TFe and mFe grades of 60. 50% and 56. 47%,and recoveries of 66. 28% and 96. 42%,respectively. This study provides a
feasible technical route for the comprehensive utilization of this type of low-grade iron-cobalt ore resources.

Aiming at the problem of low recovery rate of silver and copper in the on-site separation process of a high silver-
tin-copper-zinc associated ore in Inner Mongolia (with Sn grade of 0. 86%,Ag grade of 125. 5 g/ t,Cu grade of 0. 32%,Zn
grade of 1. 14%),mineral processing technology optimization tests were carried out. On the premise of rough grinding of raw
ore (with the fraction of -0. 074 mm accounting for 55%) while ensuring tin preservation,a new process of "silver-copper rapid
flotation,sulfide ore bulk flotation,separation of silver-copper from zinc-sulfur,zinc-sulfur separation" was proposed,which
realized the efficient recovery of Ag,Cu and Zn. The closed-circuit test yielded a comprehensive Ag-Cu concentrate with Cu
grade of 9. 62%,Ag grade of 4 104. 99 g/ t,Cu recovery rate of 82. 94%,and Ag recovery rate of 90. 29%. Meanwhile,the zinc
concentrate achieved Zn grade of 42. 85%,Ag grade of 316. 80 g/ t,Zn recovery rate of 69. 94%,and Ag recovery rate of
4. 70%. The research results indicated that this process not only ensures Sn recovery,but also significantly improves the recovery
rates of Ag and Cu,providing a technical basis for the comprehensive utilization of this mineral resource.

To efficiently exploit a typical refractory chrysocolla ore resource from Xinjiang,this study established a combined
leaching-replacement-precipitation process as the suitable route after evaluating the poor performance of sulfide flotation.
The research systematically investigated the effects of key parameters,including feed particle size,acid concentration,acid-toore
ratio,leaching cycle,and temperature on copper leaching efficiency,and optimized the replacement conditions for the leach
solution. The results showed that under room temperature,the optimal column leaching parameters were:feed size of 30~3 mm,
sulfuric acid concentration of 10%,acid consumption of 100 kg/ t,and a leaching cycle of 40 days,achieving a copper leaching
rate of 85. 61%. Simulated high-temperature experiments,considering the climate in Xinjiang,demonstrated that the leaching
cycle could be shortened to 20 days in summer. For the obtained leach solution,under the conditions of iron filings dosage at
twice the theoretical amount and a replacement time of 6 h,the operational replacement efficiency exceeded 96%,producing
sponge copper with a grade higher than 95%. The Cu2+ concentration in the residual solution after replacement dropped to
0. 048 g/ L,confirming highly efficient copper recovery. This work provides a reliable technical reference for the resource utilization
of this type of refractory copper oxide ore.

To achieve the efficient utilization of high-sulfur bauxite from Guizhou,this study employed process mineralogy
analysis system (BPMA) based on Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) to conduct
a systematic mineralogical characterization of an ore sample assaying Al2O3 of 56. 16% and S of 4. 58%. The study accurately
revealed the occurrence states of aluminum and sulfur,as well as the dissemination characteristics of the main minerals,
which guided the subsequent flotation desulfurization tests. Through condition optimization,the optimal parameters were determined
as follows:grinding fineness of 85% passing 75 μm,natural pulp (pH=6),CuSO4 as activator (50 g/ t),and butyl xanthate
mixed with ammonium butyl aerofloat as combined collector (30+120 g/ t). A closed-circuit flotation flowsheet consisting
of "one roughing,two cleaning,and three scavenging" stages was finally adopted,successfully producing a high-quality aluminum
concentrate with a yield of 82. 85%,containing 65. 05% Al2O3 and only 0. 48% S,corresponding to an aluminum-silicon
ratio (A/ S) of 12. 19. The Al2O3 recovery and desulfurization rate reached 95. 96% and 91. 29%,respectively. This research
demonstrates that BPMA technology can provide critical mineralogical basis for flotation process development,offering a reliable
technical solution and practical reference for the efficient beneficiation and utilization of such high-sulfur bauxite resources.

To study the influence of different air gaps on the damage of rock at the bottom of the blast holes,a cylindrical
concrete model with a size of ϕ400 mm×400 mm was cast using a steel mold. Blast simulation experiments were conducted by
setting different lengths of bottom air gaps. The longitudinal wave velocity of the model before and after blasting was measured
using a non-metallic ultrasonic detector to reflect its integrity and the degree of internal damage;at the same time,the strain
changes during the blasting process were tested using an ultra-dynamic strain gauge. Additionally,numerical simulation analysis
of the rock damage at the bottom of the blast holes under different air gap lengths and explosive structures was carried out using
the ANSYS/ LS-DYNA finite element software. The simulation results were in good agreement with the experimental data. The
results show that the air gap in the blast hole plays a buffering role during the propagation of the explosion shock wave,which
can effectively reduce the damage of the rock at the bottom of the blast hole and protect the underlying rock mass. However,an
excessively long air gap will reduce the utilization rate of blasting energy and affect the blasting effect. Based on the combined
analysis of experiments and simulations,when the air gap length is set at 20 mm,it is possible to effectively control the damage
at the bottom while ensuring good blasting efficiency.

To investigate the pressure load characteristics generated by the reaction of liquid oxygen/ liquid nitrogen
(LO2 / LN2) energy storage cylinders,experiments on the reaction output process and air shock wave tests were conducted
based on LO2 / LN2 energy storage cylinders. According to the test results,the action process can be divided into three stages:
low-speed combustion stage,deflagration-phase transition stage,and continuous-decay stage. Within a certain range,both the
peak overpressure and positive pressure duration of the air shock wave increase with the increase of liquid filling amount,indicating
that the energy of the air shock wave enhances as the liquid filling amount increases. By combining theoretical calculations,
numerical simulations,and other methods,the measured data of combustion-phase transition shock waves from LO2 / LN2
energy storage cylinders were compared with the shock waves generated by spherical and strip-shaped TNT explosions. The load
characteristic parameters,such as energy release rate,peak overpressure of air shock waves,and positive pressure duration,
were focused on. The results show that compared with the strip-shaped TNT charge deduced by the overpressure criterion equivalence,
at distances of 2 m and 3 m,the peak overpressure of the shock wave generated by the strip-shaped TNT charge is
34. 9% to 80. 8% higher than that of the energy storage cylinder,while the positive pressure duration of the shock wave is
7. 9% to 25. 8% shorter. The shock wave generated by the reaction of LO2 / LN2 energy storage cylinders exhibits the characteristics
of "low peak value and high energy". Compared with TNT explosions,at the same distance,its shock wave has a smaller
peak overpressure,a longer positive pressure duration,and slower energy decay. The energy release rate and work process of the
energy storage cylinder are fundamentally different from those of TNT. These results can provide important references for the basic research and engineering applications of LO2 / LN2 energy storage cylinders.

Blasting fragmentation is an important factor affecting the production efficiency and cost control of open-pit
mines. Accurate prediction of fragmentation is of great significance for optimizing the design of blasting parameters. To this
end,an XGBoost hybrid integration model based on Alpha Evolutionary Algorithm (AEA) optimization is proposed. The model
uses AEA to optimize the hyperparameters of the XGBoost model through 97 sets of blasting sample data,and combines crossvalidation
to evaluate its performance. The results show that the AEA-XGBoost model performs well in prediction accuracy,stability
and generalization ability. The highest determination coefficient of the model is 0. 921 4,the variance interpretation rate is
92. 75%,and the root mean square error is 0. 045,which is significantly better than the traditional artificial neural network,Knearest
neighbor algorithm,gradient boosting decision tree,LightGBM and AEA optimized random forest model,showing stronger
robustness and anti-overfitting ability. In order to further improve the interpretability of the model,the Shapley additive interpretation
algorithm is used for analysis,and it is revealed that the elastic modulus,the ratio of blockage length to resistance
line and the original rock fragmentation are the key characteristics affecting the prediction of blasting fragmentation. Finally,
based on 8 actual blasting engineering cases,the application effect of AEA-XGBoost model is verified. The predicted value is
highly consistent with the measured value,which proves the feasibility and effectiveness of the model in complex geological conditions
and actual blasting environment.

Aiming at the problems of low efficiency of manual discrimination and insufficient classification accuracy of
traditional machine learning methods for complex non-stationary signals in microseismic monitoring of deep mines,an automatic
classification model of microseismic signals based on Transformer architecture is proposed. Based on the real mine data,an annotated
data set including microseismic events,blasting vibration and noise was constructed. By extracting the time-frequency
features of the signal and combining the self-attention mechanism of Transformer,the model effectively captures the long-range
dependence and global features in the waveform,significantly improves the classification accuracy,and enhances the identification
ability of the waveform confusion phenomenon,showing good generalization and engineering applicability. The experimental
results show that the model achieves an overall classification accuracy of 96. 3% on the test set,and the recognition rate of microseismic
events and blasting signals exceeds 97%. It is significantly better than SVM,KNN,CNN-BiLSTM and VGG16 in
many performance indicators. This model provides technical support for the intelligent upgrading of mine microseismic monitoring
system and real-time accurate early warning of ground pressure disaster by effectively solving the problem of waveform confusion.

Drilling parameters directly affect the vibration characteristics,drilling efficiency and rock breaking energy
consumption. The drilling tests of three kinds of strength rocks(cyan sandstone 84. 47 MPa,limestone 77. 60 MPa,red sandstone
43. 73 MPa) under different axial pressures(100~140 N) and rotational speeds(800~1 100 r/ min) were carried out,
and the drilling depth,speed,energy consumption and vibration signal characteristics were analyzed. The results show that the
drilling speed are positively correlated with the axial pressure and rotation speed. For medium-strength rocks(green sandstone
and limestone),increasing the rotation speed is helpful to improve the drilling rate. For soft rock (red sandstone),adjusting the
axial pressure is more significant for the improvement of drilling efficiency. The energy consumption of rock breaking is approximately
linearly positively correlated with the drilling depth,and the parameters with the lowest energy consumption can be obtained
by optimizing the axial pressure and rotational speed. In addition,the vibration displacement and vibration frequency are
positively correlated with rock strength. The vibration displacement range and characteristic peak frequency of different rocks
are different. The characteristics of rock can be identified by the characteristic frequency of rock vibration,so as to optimize the
configuration of drilling parameters. Therefore,reasonable selection of drilling parameters can improve drilling efficiency,reduce
energy consumption,and provide optimization schemes for drilling different rocks.

During the tailings dam construction in the seasonally frozen areas,the external temperature can easily cause
the formation of seasonal frozen soil layers within the dam,significantly affecting the seepage characteristics and stability of the
tailings dam. To study the influence of the presence and melting process of the frozen soil within the dam on the stability of the
tailings dam,taking a tailings dam in the northeastern region in China as an example,drilling,well temperature testing,and indoor
triaxial shear tests were used to determine the initial temperature distribution within the dam area and the variation patterns
of the mechanical parameters of the tailings soil samples. Based on the thermal-hydro-mechanical coupling characteristics
of the tailings sand,an analysis method suitable for the stability of tailings dams in high-altitude seasonally frozen areas was
proposed. The research results show that the cohesion,internal friction angle,and moisture content of the tailings soil samples
have a relatively obvious negative correlation;the melting of the frozen soil is prone to causing instability and failure of the tailings
dam. During the entire melting period,the safety coefficient of the dam body decreases by approximately 11. 8%. In addition,
the influence of the external temperature on the tailings dam mainly occurs in the upper and middle layers of the dam
body,and the temperature variation range within the dam decreases with the increase in depth. When encountering extreme
weather conditions,multiple layers of frozen soil may exist in the reservoir area,which can easily cause the elevation of the water
table of the tailings reservoir and reduce the stability of the dam body. By conducting ice-breaking operations to break the
integrity of the frozen soil,the rate of frozen soil melting can be accelerated to ensure the stability of the tailings dam. The research
results can provide a theoretical basis for the analysis of the evolution of frozen soil within the tailings reservoir and its impact on the stability of the dam body,and can also provide a reference for other similar engineering studies.

The surface deformation,water accumulation expansion and vegetation degradation caused by coal mining subsidence
have become the key problems restricting the ecological security and sustainable development of mining areas. The existing
research focuses on the change of single environmental factor,and lacks systematic analysis of the nonlinear coupling
mechanism of subsidence-hydrology-ecosystem. Taking Huainan mining area as a typical case,the analysis framework of multisource
remote sensing data and machine learning model (XGBoost-SHAP) was constructed,and the evolution of surface subsidence,
dynamic monitoring of water accumulation area,land use change and ecological response threshold identification were
systematically carried out. The study reveals that the subsidence pattern has changed from wide-area continuous subsidence
from 2000 to 2015 to the coexistence of scattered subsidence and local uplift from 2015 to 2020. The spatial coupling strength
of water accumulation-subsidence was significantly enhanced,and the area of water accumulation area expanded by 37. 6% in
20 years. There was a significant threshold response of the ecosystem to environmental factors. NDVI showed a significant nonlinear
threshold effect on factors such as slope (1. 37°) and temperature (16. 8 ℃). This study innovatively realized the systematic
analysis of the three elements of ′subsidence-water-vegetation′ in the mining area,and provided a scientific basis for
ecological restoration zoning,risk early warning and sustainable management of coal mining subsidence areas.

In order to realize the accurate prediction of surface subsidence and conduct in-depth interpretation of the prediction
results to guide the actual project,a SHAP interpretable model of surface subsidence based on improved generative adversarial
network (WGAN-GP) and Transformer is proposed. The model is used to predict the surface subsidence,the tangent
of the influence angle and the offset of the inflection point,so that the prediction parameters are combined with the probability
integral method to establish the surface subsidence formula. Firstly,the Wasserstein distance and gradient penalty strategy are
used to improve the traditional generative adversarial network to enhance the surface subsidence data and enrich the training
set. Then,the Transformer architecture based on the multi-head self-attention mechanism is used to perform deep learning on
the enhanced data,and the hyperparameters are optimized by Bayesian optimization. Finally,based on the SHAP method,the
prediction process and results are comprehensively analyzed and explained to reveal the influence of different characteristics on
the prediction parameters. The results show that WGAN-GP-Transformer has excellent prediction ability for subsidence,tangent
of influence angle and offset of inflection point on the test set,indicating that the model can effectively capture the complex
nonlinear characteristics of predicting surface subsidence and effectively deal with the scene of data scarcity. It is revealed that
there are significant differences in the characteristic contribution intensity and direction of action that affect the three prediction
parameters. The thickness of the loose layer has the greatest influence on the predicted subsidence,and the mining depth has
the greatest influence on the predicted influence angle tangent and the inflection point offset. The practical application of the
model in the 3301 working face of a mine in southwest Shandong shows that the predicted subsidence curve is highly consistent
with the actual situation,which verifies its reliability and generalization performance in practical engineering.

Aiming at the complex situation of dust,metal reflection,uneven illumination and inconsistent target scale in
mine smoke detection,which leads to slow detection speed and low accuracy,a mine smoke detection model YOLO-MSD based
on improved YOLOv8 n is proposed. Firstly,RepVGGBlock is introduced into the backbone network to improve the detection
performance under complex interference. Secondly,a shared convolutional pyramid (FPSC) is designed to replace SPPF,which
effectively improves the multi-scale feature perception ability and reduces the amount of calculation. Finally,the weighted fusion
idea of BiFPN is used to improve the multi-branch auxiliary feature pyramid network (MAFPN) as the network structure.
By designing shallow auxiliary weighted fusion (SAWF) and deep auxiliary weighted fusion (AAWF) modules,the accuracy of
small target smoke detection is improved and the number of parameters is effectively reduced. The experimental results show
that YOLO-MSD achieves 91. 7% AP50 and 74. 5% AP50-95 while maintaining the reasoning speed of 255 FPS,which is 4. 0
and 6. 1 percent points higher than that of YOLOv8n,respectively. It can still maintain stable smoke detection performance in
complex mine environment.

The flow law of flood overtopping dam-break slurry in valley-type tailings reservoir is significantly affected by
valley topography. At present,most of the research focuses on V-type valleys,while there are few studies on U-type valleys. In
order to explore the flow law of overtopping dam-break slurry in valley-type tailings reservoir with U-shaped valley,a refined
three-dimensional dam-break finite element model was established based on a practical project,and the influence of dam-break
location and size on the flow law of dam-break slurry was studied. The results show that the discharge process of dam-break
slurry under the condition of U-shaped gully can be divided into three stages:start-up,circulation and gradual flow. Compared
with V-shaped gully,the lateral expansion ability of slurry is significantly enhanced,and the submerged range shows a fanshaped
trend. When the breach size of the U type gully tailings reservoir is constant,the breach is located in the riverbed position,
and the kinetic energy of the slurry is greater,which is the most unfavorable working condition of the dam break. When the
breach position is fixed,with the increase of the breach width,the impact on the downstream has a significant increasing trend.
The research results provide a theoretical reference for risk prevention and control and emergency plan preparation of similar
tailings reservoirs.

In order to further improve the safety management and monitoring and early warning efficiency of tailings reservoir,
a real-time analysis system of tailings reservoir based on digital twin technology is proposed in view of the shortcomings
of traditional tailings reservoir management methods. Firstly,the basic principle of digital twin technology and its application in
the safety management of tailings pond are expounded,and the architecture design of the system and the realization of key technologies
are discussed in depth. Taking the tailings reservoir project of a large metal mine as an example,the effectiveness of
the system in real-time monitoring,risk early warning and decision support is verified. The practical results show that the system
can significantly improve the management level of tailings reservoir,predict the instability risk of tailings reservoir in advance,
and strive for valuable time for emergency response. The real-time analysis system based on digital twin provides new
technical support for mining safety,and provides more efficient and reliable safety management solutions for mining enterprises
and local governments.

In response to the severe fluoride contamination in mine water from coal mining areas of Northwest China and
the limitations of conventional treatment methods such as high cost and secondary pollution,this study developed Al3+ -doped
nano-hydroxyapatite (Al-nHAP,with nAl / nCa+Al = 3%) via a hydrothermal method,systematically evaluating its performance
and mechanism for fluoride removal from simulated mine water. The optimal synthesis conditions for nHAP were determined as
follows:reaction temperature of 120 ℃,time of 12 h,and Ca/ P molar ratio of 1. 67,under which the maximum adsorption capacity
of nHAP for an initial fluoride concentration of 10 mg/ L reached 3. 57 mg/ g. After Al3+ modification,the material exhibited
enhanced crystal growth along specific facets (XRD),partial substitution of surface hydroxyl groups and strengthened
phosphate coordination (FTIR),while maintaining a mesoporous structure (BET). These changes collectively contributed to a
fluoride removal efficiency of 91. 48% and an adsorption capacity of 4. 96 mg/ g under the same conditions,representing an approximately
39% improvement over unmodified nHAP. The adsorption process was better described by the pseudo-second-order
kinetic model (R2 =0. 998 3) and the Langmuir isotherm model (maximum adsorption capacity of 16. 61 mg/ g at 25 ℃),indicating
chemisorption-dominated monolayer adsorption. Interference tests confirmed that Al-nHAP maintained strong tolerance
towards common anions such as Cl^- ,NO^-₃ ,and SO^2-₄ ,although the presence of CO^2-₃ and PO^3-₄ led to a decrease in fluoride removal
by approximately 30% due to competitive adsorption. This study provides an efficient and environmentally adaptable adsorbent
for treating high-fluoride mine water,demonstrating promising application potential.

To scientifically evaluate the solidification/ stabilization efficacy for lead (Pb) and nickel (Ni) co-contaminated
soil at a construction site in Yunnan,this study investigated the performance of lime,sulfate-reducing bacteria (SRB),and
their combined application through laboratory solidification experiments,chemical analysis,and in vivo tests. The remediation
effectiveness was comprehensively assessed using available content,relative bioavailability (RBA),and non-carcinogenic risk
quotient (HQ). The results showed that after 30 days of remediation with 11% lime,the reduction rates of Pb and Ni bioavailability
in low,medium,and high-level contaminated soils were 91% & 90%,86% & 87%,and 81% & 79%,respectively. Subsequent
inoculation with 10% (by valume) SRB for another 30 days further enhanced the reduction rates to 93. 57% &
92. 34% and 89. 77% & 89. 79% for the medium and high-level contaminated soils,respectively. In vivo tests revealed that
compared to the original highly contaminated soil (RBA:64. 82% for Pb,67. 47% for Ni),the RBA of Pb and Ni decreased to
32. 72% and 37. 63% after lime treatment,and further declined to 21. 44% and 25. 84% after the combined lime-SRB treat
ment. The non-carcinogenic risk assessment indicated that after combined remediation,the HQCS values of Pb for adults and
children were 0. 77 and 0. 86 (acceptable level),respectively,while those for Ni were 0. 95 (adults) and 1. 07 (children),
indicating an unacceptable health risk for children from residual Ni. This study confirms that the combined lime-SRB technology
effectively immobilizes Pb and Ni in soil and reduces their bioavailability. However,the potential health risk of Ni to children
after remediation requires attention. The integrated evaluation system combining bioavailability and health risk provides a
more scientific basis for assessing the remediation effectiveness of contaminated soils in construction sites.

Analyzing and predicting the characteristics and trends of the surface deformation of open-pit mines is an important
part of ensuring the safe and green operation of mines. For large-scale open-pit mines,taking the Junning Gobi No. 2
open-pit mine in Xinjiang as an example,based on the SBAS-InSAR method and the particle swarm optimization algorithm′s
long short-term memory network (PSO-LSTM) model,a method for analyzing and predicting the surface deformation of openpit
mines is proposed. This method first calculates the surface deformation of the mine using the SBAS-InSAR method,and
then,in response to the problems such as low efficiency and limited spatial coverage of current deformation monitoring methods
like leveling measurement and GNSS in large-scale open-pit mines,the particle swarm optimization algorithm (PSO) was used
to optimize the long short-term memory model (LSTM),and a PSO-LSTM model was constructed for deformation prediction.
The research shows that:① The overall average deformation rate of the mining area is -2. 832 mm/ a,showing a downward
trend. The surface deformation rate of the inner waste dump area is significantly higher than other areas;spatially,the inner
waste dump area and the east waste dump area are distributed relatively evenly;temporally,the deformation rates of the east
and north waste dump areas are lower,and the rates are relatively constant. ② Through the profile lines,it can be found that
the spatial deformation distribution of the north waste dump area shows non-uniformity,while the east waste dump area exhibits
relatively balanced deformation characteristics. The Root Mean Square Error (RMSE),Mean Absolute Error (MAE),Mean
Absolute Percentage Error (MAPE) and coefficient of determination (R2) are adopted as the evaluation indicators for the prediction
accuracy. The results show that compared with support vector regression (SVR) model and LSTM model,the RMSE and
MAE of the PSO-LSTM model are at least reduced by 16% and 30%,respectively. The PSO-LSTM model has better stability
and smaller deviation,reflecting that this model can effectively capture the fluctuation trend of the surface deformation of the
mining area and has certain stability. The research results provide new ideas for the analysis and early warning of surface deformation
of open-pit mines and have certain reference significance for the monitoring and prediction of surface deformation of
large-scale open-pit mines.

Aiming at the problems of low efficiency and strong subjectivity in the traditional manual interpretation method
for identifying abandoned mining subsidence areas,a new method for identifying abandoned mining subsidence areas based on
Unmanned Aerial Vehicle (UAV) photogrammetry and deep learning algorithms is proposed. Firstly,the DJI Phantom 4 RTK
UAV is used to conduct oblique photography in a mine subsidence area to obtain high-resolution image data and 3D point cloud
data. Secondly,the Context Mapper 3D reconstruction software is used to process the obtained data to generate the DOM image
(with a resolution of 2 cm) and DSM data (with a resolution of 5 cm) of the survey area. Finally,a subsidence area identification
model based on deep learning is constructed by combining morphological and spectral features to achieve efficient and accurate
automatic identification of subsidence areas. The experimental results show that the overall accuracy of the proposed
method in identifying abandoned mining subsidence areas reaches 94. 3%,with a Kappa coefficient of 0. 91,which is significantly
better than the traditional manual interpretation method. In addition,compared with the traditional method,the working
efficiency of the proposed method is higher,significantly reducing the influence of subjective factors on the identification results.
Among the 50 validation samples,the proposed method successfully identified 47 subsidence areas,with only 2 missed
and 1 misjudged,demonstrating the high reliability of the method. This provides a new technical path for the rapid identification
and dynamic monitoring of geological disasters and has good application value.

The large-scale resource utilization of solid waste iron tailings (IOT) in the iron and steel industry is crucial
for the sustainable development of the concrete industry. This paper provides a systematic review of the comprehensive application
potential,performance modification mechanisms,and environmental benefits of using IOT as a raw material (fine aggregate
and cementitious material) in concrete. Analysis shows that the physical properties of IOT comply with standards for construction
sand,and its irregular particle morphology enhances mechanical interlocking at the interface. Chemically,IOT is primarily
composed of SiO2 (27. 65%~76. 83%) and Fe2O3 (2. 89%~46. 11%). Ternary diagram analysis of Si-Ca-(Al+Fe) indicates
that most samples possess the potential to replace cement. As a fine aggregate,IOT at replacement rates of 20% to 40% can optimize
the performance of various concrete systems,such as ultra-high performance concrete (UHPC) and sprayed concrete. As
a cementitious material,mechanical or chemical coupling activation is required to enhance its pozzolanic activity. After activation,
its strength activity index can exceed 72. 7%,meeting the requirements for supplementary cementitious materials. Life cycle
assessment confirms that the application of IOT can reduce the carbon footprint of concrete by 15% to 40% and resource
consumption by 29%. Furthermore,the leaching concentrations of heavy metals from IOT within the dense cementitious matrix
are significantly below the limits set by national standards,indicating controllable environmental risk. This review provides a systematic theoretical and technical basis for the large-scale application of IOT in low-carbon concrete.

To reduce the cost and environmental burden of supersulfated cement caused by using Portland cement as an
alkaline activator,this study completely replaces Portland cement with strongly alkaline solid waste calcium carbide residue
(main component Ca(OH)2) and its modified product (calcined at 520 ℃) to prepare super sulfate cement. The effects of
Portland cement,raw calcium carbide residue,and modified calcium carbide residue as activators on cement fluidity,setting
time,compressive strength,and hydration products were systematically studied. The results show that raw calcium carbide residue,
due to its larger particle size,increases mortar fluidity by 6. 42% but significantly delays setting due to low reactivity.
Modified calcium carbide residue,with increased specific surface area and formation of highly active CaO,effectively shortens
setting time. Although the 7-day compressive strength of the modified calcium carbide residue system (11. 73 MPa) is lower
than that of Portland cement (15. 96 MPa),its 28-day compressive strength reaches 42. 81 MPa,equivalent to Portland cement
(43. 58 MPa) and meeting the national standard requirement for 42. 5-grade cement. XRD and FTIR analyses indicate that hydration
products in all systems are primarily ettringite and C-S-H gel,with calcium carbide residue promoting ettringite generation
at later ages. This study proves that modified calcium carbide residue can serve as an effective alkaline activator to achieve
equivalent long-term mechanical performance with low-carbon preparation of super sulfate cement.

To achieve large-volume utilization of gold tailings and develop green alternatives for road construction materials,
this study employed a solid waste-based cementitious material (SWCM),prepared from red mud,desulfurized gypsum,and
fly ash,to stabilize gold tailings for use in road subbase mixture. A comprehensive laboratory investigation was conducted to evaluate
the compaction characteristics,unconfined compressive strength,splitting tensile strength,flexural strength,compressive
resilience modulus,and drying shrinkage properties of the stabilized mixtures. A comparative analysis with conventional cementstabilized
mixtures was performed,and microstructural tests such as XRD were utilized to elucidate the underlying performance
mechanisms. The results demonstrate that the SWCM-stabilized gold tailings mixtures have a maximum dry density of 1. 968~
1. 978 g/ cm3 and an optimum water content of 11. 62%~13. 10%. The mixtures exhibit excellent early-age mechanical properties,
with a 6% binder content meeting the 7-day unconfined compressive strength requirements for subbase layers across all
road classes. The drying shrinkage behavior is stable,with a shrinkage coefficient (174. 8~196. 2 με/ %) comparable to that
of cement-stabilized macadam,and the SWCM mixture shows superior crack resistance due to the micro-expansion from ettringite
formation and the morphological effects of fly ash. Field trials and long-term monitoring confirmed the structural integrity of
the subbase without loosening or cracking,demonstrating satisfactory road performance. This research provides a viable technical
pathway for the full-volume resource utilization of gold tailings.

This study aims to clarify the influence mechanism of soluble phosphorus impurities on the preparation,hydration,
and properties of α-hemihydrate gypsum (α-HH),a key product for the high-value utilization of phosphogypsum. An integrated
process simulation strategy was adopted,where KH2PO4 was added to natural gypsum at different contents (0,0. 1%,
0. 3%,0. 6%) to simulate the soluble phosphorus impurities. Their effects throughout the autoclave preparation and subsequent
hydration processes were systematically investigated. The results indicated that soluble phosphorus impurities significantly altered
the crystal habit of α-HH,transforming its morphology from regular hexagonal prisms to short-prismatic,irregular rodlike,
and granular particles,accompanied by crystal refinement. Meanwhile,the impurities markedly accelerated the hydration
process,with the most pronounced accelerating effect observed at the content of 0. 3%,showing the shortest initial and final setting
time (3 min and 5 min,respectively) and the earliest hydration exothermic peak. However,this acceleration led to the deterioration
of the dihydrate gypsum crystal morphology in the hardened paste,evolving from dense,thick rods to loose,porous
fine rods,flakes,and irregular blocks,with weakened interlocking between crystals. Consequently,the macroscopic mechanical
properties were compromised:the absolute-dry compressive strength decreased continuously,and the 2 h flexural strength decreased
significantly after a slight increase at low impurity content. In summary,to achieve high-performance α-HH (meeting
strength grade α40 or above),the soluble phosphorus impurity content in phosphogypsum must be strictly controlled below
0. 1%. This research provides a crucial theoretical basis for the high-value utilization of phosphogypsum.

In order to develop efficient grouting repair materials for cracks in existing lining structures in complex geological
environments such as mines and tunnels,and to realize the utilization of solid waste,it is proposed to use slag and fly ash
as precursors,water glass and sodium hydroxide as alkali activators to prepare solid waste-based repair agents. Based on the orthogonal
experimental design,the response law of the working performance and mechanical properties of the repair slurry was
studied under the changes of alkali activator modulus,precursor ratio,water-binder ratio and alkali activator content,and the ideal
ratio of the material was recommended according to the requirements of the repair operation. The results show that the precursor
ratio has the most significant effect on the performance indexes of the repaired slurry except fluidity. Increasing the slag
content in the precursor can significantly shorten the setting time of the slurry and increase its 28 d compressive strength. The
effect of water-binder ratio on the fluidity of slurry is more prominent than the other three factors. In addition,increasing the amount
of alkali activator can also effectively improve the fluidity. The optimum ratio of crack repair materials is recommended:
the modulus of alkali activator is 1. 2 or 1. 4,the ratio of fly ash / slag is 7∶3,the ratio of water to binder is 0. 5,and the content
of alkali activator is 40%. The research results provide a theoretical basis for the application of green repair materials in infrastructure
such as mines and tunnels,especially in the repair scene of concrete lining structure.