The Xihuashan gold mining area is located in the Qilian tectonic metallogenic belt of the Qinling-Qilian-Kunlun orogenic belt，Machang and Liugou gold deposits have been found in the mining area.The ore-bearing strata in the area are the metamorphic strata of the Haiyuan group，and the veins are controlled by the fault zone.The ore types are mainly altered lamprophyre type，quartz vein type and altered rock type.In order to find out the genetic type and metallogenic process of the Xihuashan gold deposit，the field geological survey，microthermometry of fluid inclusionsand H-O-S isotope geochemistry of Machang and Liugou gold deposit were carried out.The results show that the homogenization temperature of quartz fluid inclusions in Machang gold deposit ranges from 140.1 ℃ to 382.6 ℃，and mainly concentrated in 250~260 ℃，the corresponding salinity is 2.57%~10.72% NaCleq.The homogenization temperature of quartz fluid inclusions in Liugou gold deposit ranges from 203.2 ℃ to 353.9 ℃，and mainly concentrated in 270~280 ℃，and the freezing point temperature is -8.2~-3.2 ℃，the corresponding salinity is 5.28%~12.08% NaCleq，mainly concentrated in 7%~8% NaCleq.The δD values of quartz in Machang gold deposit are -86.5‰~-87.2‰，and the δ18O values are 15.4‰~16.7‰.The δD values of quartz in Liugou gold deposit are -90.2‰~-91.6‰，the δ18O values are 15.7‰~17.0‰.Therefore，the ore-forming fluid belongs to the medium-low temperature medium-low salinity fluid，the main source of magmatic water.Additionally，the δ34S values in the pyrite of the Machang and Liugou mine areas range from -1.00‰ to 0.27‰.The combination of the S isotopic composition in the regional stratigraphy and electron probe analysis of pyrite suggests that the sulfur source of gold-bearing sulfides（with δ34S values close to zero） is primarily derived from deep magma，whilesulfides containing trace amount of gold or without gold are derived from the surrounding rock stratigraphy.During the Late Garidonian period，the magmatic dynamic and thermal influence of the Juewushan rock mass made the ore-forming materials in the white schist such as muscovite albite quartz schist in the Xihuashan area concentrated in fracture fissures to form early hydrothermal quartz veins. Simultaneously，in the late stage of magmatic differentiation and evolution，the ore-froming materials were separated from the magma，forming mineralized veins such as lamprophyre veins and quartz albite veins.When the solution temperature eventually dropped to the temperature of gold precipitation，the ore-forming hydrothermal fluid precipitated and enriched in the favorable position of the fault zone，forming gold deposits such as quartz vein types and fracture alteration rock types.
The Xiling gold deposit，located on the east side of the Sanshandao gold deposit，is currently the largest gold deposit and deepest gold deposit newly discovered in the Jiaodong gold concentration area.Based on the geological observations，the thermoelectric characteristics of pyrite with different depths（-699 m，-1 190 m，-1 602 m，-2 274 m，and -2 615 m below sea level） in the Xiling gold deposit were analyzed.The results show that the dispersion range and degree（14.59~46.72） of pyrite thermoelectric coefficient in the Xiling gold deposit are generally wide and relatively steady.The thermoelectric conductive type of pyrite at the shallow elevations，such as the -699 m and -1 190 m below sea level，is N-type，while that of pyrite at the deep elevations（-2 615 m below sea level） is P-type.The ore-forming temperatures are mainly concentrated at 250~360 ℃，which is generally consistent with the homogenization temperatures of quartz fluid inclusions，thus belongs to a medium-high temperature hydrothermal gold deposit.The calculated gradient value（0.00~0.29） of the thermo-electric conductive type of pyrite is small，and the estimated denudation rate of the orebody is 75%.Combined with the various parameters of the thermoelectric characteristics of pyrite，it is considered that there is a great potential for exploration in the deep part of the Xiling gold deposit，and the metallogenic depth can reach to -3 000 m below sea level. According to the known regularity of lateral prostration that gold orebodies plunge NE，it is proposed that the potential deep gold orebodies plunge NE to the -3 000 m below sea level is an effective location for deep exploration targets.Through the study of the thermoelectric properties of pyrite in the Xiling gold deposit，it can provide a scientific basis for the deep exploration and prediction of many gold deposits in the Jiaodong gold concentration area.
The Paleoproterozoic potassic-ultrapotassic magmatic rocks are widely developed in western Yunnan，forming an alkali-rich magmatic rock belt along the Jinshajiang-Ailaoshan fracture zone.Due to the lack of systematic research on these potassic-ultrapotassic magmatic rocks，there are still many debates on the petrogenesis and their relationship with mineralization.In this paper，through the collection of published whole-rock major and trace element，Sr-Nd isotope，zircon Hf isotope and geochronology data of the whole rock in the alkali-rich magmatic belt，the rock belt is divided into three parts，namely，south，central and north rock belts according to the tectonic position.Through systematic comparative analysis，it is concluded that the diagenetic age of Paleoproterozoic potassic-ultrapotassic rock formation in western Yunnan is basically the same，with a peak value of 35 Ma，which is the product of the same period of tectonic thermal events.The basic-ultramafic and intermediate-acid rocks have different genesis.The former enriched in LILEs，deficit HFSEs，high （87Sr/86Sr） i，and low εNd（t） values，probably originating from a slab-accounted enriched lithospheric mantle.The latter may be the product of crust-mantle mixing due to its higher SiO2 content.The formation of both is related to the shear slip and tensile action of the Jinshajiang-Ailaoshan fault，which is the product of partial melting of the lithosphere at different depths under the same tectonic thermal event.The potassic-ultrapotassic rocks of the southern and central rock belts are closely related to porphyry Au-（Cu-Mo） deposits.The magmatic formation process may provide favorable conditions for mineralization with high oxygen fugacity and water content，as well as ore-forming materials and ore-forming fluids.
The Lajiu area in Longzi County，Tibet，has superior metallogenic geological conditions and great potential for prospecting for gold polymetallic deposits.On the premise of comprehensive analysis of the regional geological background，the favorable position for mineralization was judged by remote sensing geo-logical interpretation，and the Lajiu area was identified as Zone Ⅳ for mineralization prediction. The 1∶50 000 stream sediment survey was used to sweep the surface，and multiple geochemical comprehensive anomalies were delineated. Then other large-scale geophysical and geochemical exploration work such as 1∶10 000 soil geochemical profile measurement，mercury vapor in soil and induced polarization medium gradient survey were carried out within the Lajiu anomaly（HS-13-B2）.Two geochemical comprehensive anomalies，three polarizable bodies and two apparent polarizability anomalies were delineated，among which favorable mineralization target areas were selected.Anomaly verification and trenching engineering reveal that three gold mineralized alteration zones had been found，which had realized new discovery of ore prospecting. Finally，a comprehensive information prospecting model based on geological，geophysical，geochemical and remote sensing charac-teristics had been preliminarily established.The practice has proved that the application of integrated geo-physical，geochemical and remote sensing prospecting methods can greatly improve the ore prospecting rate，and this work provides a reference for the future development of polymetallic prospecting and exploration in plateau mountainous areas.
Jiuzhanggou gold deposit in Songxian County，Henan Province，is located in the northern section of the Manyu-Dianfang gold ore belt in the Xiong’ershan-Waifangshan ore concentration area.It is a typical large-scale tectonic altered rock type gold deposit.Firstly，the prospecting target area was delineated by 1∶50 000 stream sediment survey.Secondly，the mineralization enrichment site was determined by 1∶10 000 soil geochemical survey.Finally，the tectonic fracture zone and mineralization intensity were identified by rock geochemical（primary halo）survey，and the relative denudation degree of orebody was predicted.The results show that geochemical measurements at different scales provide prospecting information at different stages for the exploration of the gold deposit.Among them，the stream sediment survey delineated the 11-C-Au anomaly in the Jiuzhanggou mining area.The soil geochemical survey found the 1-A1-Au-Ag-Pb-Cu-Hg-As-Bi-Ni anomaly in Jiuzhanggou.The peak position of trace elements in the primary halo profile determined the mineralization alteration zone of F1 structure，and finally obvious prospecting results was achieved.By summarizing the geochemical anomaly characteristics and prospecting indicators of the deposit，an exploration geochemical model was established to provide theoretical guidance for the exploration of the same type of gold deposits in the region and around the mining area.
Rock mass quality classification is the foundation of initial underground engineering design and construction.In order to evaluate rock mass quality more accurately，this study used beluga whale optimization（BWO）to optimize random forest model（RF），a BWO-RF model which can be used for rock mass quality evaluation was proposed.At the same time，the rock mass quality evaluation models of sparrow search al-gorithm optimized random forest（SSA-RF），particle swarm optimization optimized random forest（PSO-RF）and non-optimized random forest（RF） were constructed for comparison.Before the models construction，a data-base containing 131 engineering cases data was established through literature review and field test data collec-tion.After writing the code of models construction，the training and testing of the four models were completed by using the database.Based on the model test results，five model evaluation indexes，accuracy，precision，recall，F1 score and AUC，were used to compare and select the best model of the four kinds of rock mass quality eva-luation models.The results show that the BWO-RF model has the best performance among the four kinds of rock mass quality evaluation models，and each evaluation indexes of model are better than the other three mo-dels，indicating that the BWO-RF model has better practicability in the evaluation of rock mass quality.Through the test set，the prediction accuracy of BWO-RF model proposed in this study is 90%，which can provide a reliable reference for practical engineering construction and has practical engineering application value.
In view of the low accuracy and uneven water distribution of water content in rock samples with different water saturations，a preparation method of rock samples with different water saturations and uniform distribution of water content was proposed based on the principle of osmotic technology and chemical thermodynamics.The basic principle consists of two parts：One is to control the concentration and molecular weight size of polyethylene glycol（PEG） in organic solution，so as to precisely control the matrix suction values of the solution water and water in the sample to determine the final water saturation of the sample.The other is to control the type of supersaturated solution placed in the constant humidity environment of the rock sample，so as to precisely control the chemical potentials of the component water when the total weight of the sample is stable，and the final water saturation of the sample is determined. The water saturation of rock samples prepared by this mothed are qualified samples with uniform saturation distribution.The water rationality of the method for accurately preparing rock samples with uniform water saturation distribution was also verified by nuclear magnetic resonance imaging（NMRI） experiments.Meanwhile，a device is designed independently to prepare rock samples with different saturations under constant humidity environment，and the constant strain rate compression test of sandstone under different saturation conditions was carried out by using the device.The test results show that the uniaxial compressive strength and elastic modulus of sandstone decreases with the increase of water saturation.After the peak，the post-peak stress decline slows and the brittleness of the sample decreases with the increase of water saturation. With the increase of confining pressure，the compaction stage of sandstone sample is weakened，and the deformation of the sample undergoes the process of elastic-brittle→elastic-plastic→strain hardening.The results of the study provide new methods and ideas for the accurate preparation of rock samples with different water saturations.
To delve into the size-related effects and directional properties of the roughness on rock fracture surfaces，this paper focus on analyzing the roughness correction coefficient C within the refined formula of the cubic law，as it effectively characterizes the roughness of natural rock fractures. Since Louis first introduced the cubic law，numerous scholars have since proposed numerous modified formulas，including those by Zhang Youtian，Zimmerman，and Xiong et al. Through conversion，we acquire the calculation formula for the roughness correction coefficient and utilize collected natural fractures for related computations.High-precision 3D scanning technology was used to scan natural rock samples and acquire roughness data of fracture surfaces. By combining this data with publicly available high-precision CT scan data of rough rock fractures，we generate spatial coordinates.Both formulaic and numerical methods were used to calculate and analyze the roughness correction coefficient C. Using the formulaic approach，the roughness correction coefficient for sample sizes ranging from 10% to 100% of the fracture surface were calculated and varying results were obtained，which indicates that roughness exhibits a scale effect. According to the numerical method，a well-fitting ellipse was obtained，indicating that the roughness correction coefficient possesses directionality and can be expressed using tensor notation. This conclusion is further supported by calculating the JRC value of rough fractures and their surface and crack width fractal dimensions，revealing that the roughness of fracture surfaces exhibits scale effects and anisotropy. Upon further investigation，it is discovered that the roughness correction coefficient tensor or roughness tensor，when combined with average crack width，can be utilized to form a single crack permeability tensor that quantifies the rough surface in complex rough crack network models
A suitable charging structure in blasting engineering can effectively improve the utilization rate of explosives and thus improve the blasting effect.Based on the RHT（Riedel-Hiermaier-Thomamodel）dynamic response mechanics relationship，ANSYS/LS-DYNA software was used to study the effect of the uncoupling coefficient K on the blasting load of rock body under the condition of eccentric uncoupled charge and the damage of rock body during blasting.The effective stress，vibration velocity，seismic wave energy and damage conditions under uncoupling coefficients K=1.0，1.5，2.0，2.5，3.0 and 3.5 were analyzed by establishing a single-hole eccentric uncoupled blasting model.In addition，the relationship between burst center distance l and damage degree D，mass vibration velocity PPV and burst center distance l，and vibration velocity vpp and damage degree D under different conditions of uncoupling coefficients K were investigated.The results show that with the increase of the uncoupling coefficient K，the effective stress and peak vibration velocity of the coupled and uncoupled sides and the peak energy of the seismic wave decreases slightly.The range of the crushed zone and the fracture zone decreases gradually，and the radius of the damage in the crushed zone is larger than the rate of decrease in the fracture zone.The damage degree of rock body and the mass vibration velocity vpp are gradually reduced with the increase in the burst center distance. The greater the particle vibration velocity vpp is，the larger the damage degree is.When vpp reached 50.4 cm/s， the damage variable D in the rock body reached the damage failure threshold of 0.19.When vpp>140.6 cm/s，the damage degree D>0.80.
The bunch holes，which consist of multiple dense and parallel holes and detonated simultaneously，are widely used in mines because of its high rock-breaking efficiency.With the worldwide depletion of resources in the shallow part of the earth，many mines are transitioning to the deep mining stage，and the influence of the complex high stress environment on the effect of blasting on rock breaking in the deep mining process needs to be further studied.In order to explore the law of blasting damage and fracture of bunch holes cutting blasting in deep mining under high stress stope environment，LS-DYNA finite element numerical analysis software was used to study.Combined with the mine blasting engineering practice，the planar numerical model with the same size as the actual working conditions was established，which contained four charge holes and one auxiliary empty hole.The rupture damage process of the bunch holes under no static stress was analyzed.On this basis，in the case of one-way static stress and two-way equivalent static stress，when the static stress is 20 MPa and 40 MPa respectively，the blasting fracture damage of the bunch holes cutting blasting was analyzed，and the number of failures units of the numerical model under different static stress states was compared. In addition，the hole spacing and the arrangement of peripheral auxiliary holes were optimized under different static stress conditions，and engineering experiments were carried out to verify the reliability of the optimization results by counting the chunk rate of different schemes.The results show that compared with the no static stress condition，the expansion of the bunch holes blasting damage cracks will be suppressed under the unidirectional static stress and bidirectional equivalent static stress conditions.With the increase of static stress，the number of model failure units decreases gradually，and the inhibition of crack extension is more significant.When the static stress reaches 40 MPa，no penetration crack can be formed between the four bunch holes and the center empty hole.In particular，in the bidirectional equivalent static stress state，the inter-hole crack penetration mode of the bunch holes changes from a square penetration to a circular penetration.Practice shows that according to the size of the static stress to adjust the bunch holes spacing and peripheral auxiliary holes arranged way can reduce the rate of large pieces of slot blasting，so as to obtain a good slot blasting rock-breaking effect.
As the demand for transportation increases in China，more and more highway tunnels adopt the form of super-large section.However，there is still a lack of clear guidance for the design and construction of super-large section tunnels with four lanes or more in the current highway tunnel specifications. There is still a need for in-depth research on the section shape，construction methods，and construction mechanics of super-large section tunnels. Existing research indicates that the use of the benching method for excavation construction of super-large section tunnels is feasible. To obtain the optimized schemes for bench length and anchor rod spacing，numerical simulation was performed in this study to investigate seven different scenarios based on the upper and lower bench construction sections of a certain super-large section flat structure tunnel.The scenarios included bench lengths of 30 m，40 m，50 m，and 60 m，as well as anchor rod longitudinal spacings of 1.0 m，1.5 m，and 2.0 m. The distribution patterns of the plastic zone in the surrounding rock mass，the stress of the surrounding rock，and the deformation of the surrounding rock were analyzed.The study results indicate that the overall maximum principal stress around the tunnel shows a trend of “arch foot>arch waist>arch crown”.An increase in bench length or anchor rod spacing leads to a significant increase in the maximum principal stress at the arch crown. Overall，the settlement and horizontal convergence values of the tunnel arch crowns increase with the increase in bench length. An increase in anchor rod spacing requires other support structures in the initial support to exert stronger control over surrounding rock deformation，potentially leading to the destruction of the support structure. Based on the numerical results and on-site monitoring data，considering factors such as construction efficiency and rock stability，the optimized scheme with a bench length of 50 m and an anchor rod spacing of 1 m was applied in the construction site.The results of this research has high reference value for the optimal selection of excavation and support parameters for super-large section flat structure tunnels.
The open-pit mining area is a complex scene，and the traveling obstacle detection is seriously interfered by dust noise such as dust and particles，which makes it difficult to accurately identify obstacles，especially at night when the light is poor，which is not conducive to correct decision-making，thus affecting the safety and overall efficiency of unmanned operation.In view of the above problems，a YOLOv8n-based YOLOv8n-Enhanced algorithm for detecting traveling obstacles in open-pit mining areas was proposed.The algorithm is mainly improved in three aspects：Firstly，for the problems of serious interference by dust noise and poor light at night，a C2fCA module structure was proposed instead of the original C2f module，which utilizes the shared weights and context-aware weights to enhance the dependency relationship between different locations of the image，mitigate the noise interference，and improve the feature extraction ability of the model.Secondly，to trade-off the accuracy and real-time performance of the open-pit obstacle detection model，the Neck end of the model was reconstructed，and the lightweight convolutional techniques GSConv and VoV-GSCSP modules were used to reduce the complexity of the computation and network structure，and realize a higher computational cost-effectiveness of the detector.Finally，for the situation that there is a large gap between the quality of data in the open-pit mining area，especially at night when there is insufficient light，and low-quality data will affect the ability of the model to learn features in training，the loss function was optimized to solve the problem of the bounding box regression equilibrium between the samples of different qualities，to improve the ability of the model to generalize and accelerate the convergence.The experimental results show that the improved algorithm in this paper reduces the computational GFLOPs of the model by about 8.5% and the number of parametric params by about 3% while maintaining the real-time performance，and improves the mean Average Precision（mAP） of the YOLOv8n by 1.8% and 2.6% in daytime and nighttime scenarios，respectively，and realizes obstacle recognition at different scales in daytime and nighttime scenes.
Intelligent mining is an important direction for the future development of the mining industry.The construction of mine intelligent ventilation system is a key part of promoting the digital and intelligent development of mines.Under the current background of energy conservation and emission reduction，the ways of digital and information technology to achieve low-carbon mining，efficient utilization and intelligent control of non-ferrous metal resources，is the important technical guarantee to achieve the strategy of “carbon peaking and carbon neutrality”.The key to realize the high-efficiency utilization of non-ferrous metal resources is to adopt the intelligent ventilation technology to reduce the energy consumption.In the current process of pro-moting the construction of intelligent mine ventilation system，a common hot and difficult issue is to realize the optimal regulation of airflow of mine ventilation system under the condition of ventilation on-demand.The ventilation optimization regulation of intelligent ventilation system requires that on the premise of satisfying the dynamic ventilation on-demand in different periods，the ventilation optimization theory based on fluid network was adopted to obtain a ventilation optimization regulation scheme that meets the requirements of safety，technology and economic.Then the airflow distribution and air pressure distribution of the ventilation network were adjusted to ensure the safe，reliable，stable and economic operation of the mine ventilation system.In order to solve the problem of difficulty in solving the optimization and regulation model of nonlinear mine ventilation network，based on the basic mathematical model of ventilation network airflow regulation，the method of airflow control and optimization of ventilation network was analyzed，and the objectives and constraints of the airflow regulation optimization model based on multi-objective mixed integer programming were analyzed.A two-step airflow control optimization mathematical model based on the mixed integer programming method by improving the two-step ventilation optimization method was proposed.The mathematical model is a multi-objective programming linear model with the goals of minimum ventilation energy consumption，minimum number of regulation equipment and optimal position of regulation equipment，so that the solution result of the mathematical model is more in line with the actual regulation needs.The mathematical model can constraint the number and regulating ways of regulation position by introducing the mixed integer programming method，and constraint the position of regulation schemes according to the actual situation of the mine by introducing the regulation level of branches，which improve the flexibility of ventilation regulation optimization schemes.In addition，by solving the corresponding regulation schemes of airflow distribution multiple times，the mathematical model can obtain a solution scheme that approximately satisfies the solution result of regulation mathematical model with unknown airflow，while avoiding the problem of non-convergence in solving nonlinear models.We construct a calculation example for the mine ventilation optimization regulation problem，and verify the reliability of ventilation regulation mathematical model based on the calculation of airflow distribution.
The high and steep slopes formed by open-pit mining have potential safety hazards due to landslides，posing a significant threat to the safety of downstream residents’ lives and property.Using modern monitoring technology to monitor the stability of high and steep slopes is a necessary means to prevent disasters.The existing research theory basically relies on the corresponding monitoring technology to realize the slope monitoring and management，and lacks the system information integration platform，which is not conducive to the management of the mine in the overall safety production operation process.Therefore，a comprehensive framework for online monitoring data integration on the internet has been designed in this paper by using the principles of radar and GNSS monitoring technology.This framework allows for full time and comprehensive monitoring of displacement，blasting vibration，and other aspects of high and steep slopes in the Nannihu mining site and waste dump.Based on the data information obtained by the monitoring system，the landslide deformation characteristics and landslide inducing factors are analyzed.The appropriate monitoring indicators are selected to establish the threshold model，and the early warning threshold is calculated according to the model，which can divide the corresponding early warning level.The on-line monitoring system realizes the modern slope monitoring target of high precision，large area，non-contact，all-day，all-weather and early detection.The on-line monitoring system is safer，more efficient and more accurate than traditional manual monitoring，and plays a significant role in disaster warning.
Copper is an important key metal raw material.It is of great significance to comprehensively recover and utilize copper ores containing precious metals such as gold and silver.The process mineralogy and beneficiation test of a copper sulfide ore containing gold and silver in Henan Province have been carried out.The results show that the main useful element copper content is 0.82%，the associated beneficial groups are sulfur，gold and silver，the main useful metal minerals are chalcopyrite，chalcocite，pyrite，gangue minerals are mainly quartz.The combined collector of butyl xanthoxanthate and butyl ammonium black is used in mixed flotation，the total amount of agent is 120 g/t，and the process flow of one coarse，two fine and three sweeps is adopted.The new collector TB1021 is used in copper sulfur separation flotation，and the process flow of one coarse，three fine and three sweeps is adopted.Finally，a copper concentrate with a copper grade of 15.21% and a copper recovery of 80.13%，a gold grade of 3.02 g/t，a gold recovery of 66.51%，a silver grade of 160.43 g/t and a silver recovery of 41.82%，and a sulfur concentrate with a sulfur grade of 49.13% and a recovery of 54.34% were obtained.
