The Sandaowanzi area is a typical shallow overburden area which hosts numerous gold polymetallic ore deposits in Heilongjiang Province，China.More than 10 gold deposits and ore occurrences have been found in the area，such as Sandaowanzi gold deposit，Beidagou gold deposit，Najinkouzi gold deposit，340 highland gold deposit，Sandaowanzi Nanshan gold deposit，etc.，with great prospecting potential.Many soil geochemical surveys have been carried out in the area，but no prospecting breakthrough has been made.Through the comparative tests of various sampling grids，grain sizes and horizons in the study area，the best geochemical sampling method was confirmed，and the 50 m×50 m gridded rock debris geochemical survey method was adopted.Based on the correlation analysis of geochemical characteristics and element symbiotic assemblage characteristics，and combined with regional ore-forming geological conditions，30 comprehensive anomalies were delineated.The main ore-forming elements Au and Ag are strongly enriched in favorable structural areas.Through anomaly verification，12 gold-silver orebodies and 23 gold orebodies have been found，and 3 prospective areas have been delineated，and good prospecting results have been obtained.The study shows that rock debris geochemical survey in Sandaowanzi area can quickly and accurately delineate the range of mine-ralization alteration and improve the prospecting effect，which is an effective prospecting method.It can provide an important reference for ore prospecting in the same type of forest swamp geochemical landscape area.
The Saibagou gold deposit is one of the medium-size gold deposits located in the Wulan-Dulan strategic metallic ore concentration area in northern Qaidam Basin.The regional tectonic location spans the Tanjianshan magmatic arc，ophiolite melange in the northern Qaidam Basin and Olongbulak microcontinent，and is located at the intersection of Wahongshan-Wenquan fracture and Yuka-Wulan fracture.The formation of the deposit is strictly controlled by the fracture structure.There are two groups of fracture belts in the mining area，namely the NW trending thrust fracture and the NE trending shift fracture，and the gold orebody are mainly developed in the NW brittle-ductile shearing belt in veins，irregular，branched veins and lenticular.The main ore types are structural altered rock type and quartz vein type.Magmatism in the mining area is strong，and the active ages mainly include Late Variscan-Indosinian and Neoproterozoic，especially the Variscan magmatic activity is the most significant.Magmatic rocks exposed in the mining area are mainly gabbro and granite，in which gabbro and ore body have close spatial correlation.The magmatic rock samples used in this study were all taken from fresh gabbro after stripping regolith around the orebody of Saibagou gold deposit.The element analysis of the whole rock was conducted by the Qinghai Nuclear Industry Geological Bureau，including the detection of major elements，trace elements and rare earth elements.The results show that all gabbro in Saibagou gold deposit are tholeiite basalt，mainly alkaline gabbro and subalkaline gabbro，most of which are calcalkaline series or low potassium （tholeiite） series gabbro，and a small amount of shoshonite series gabbro exist.Gabbros are characterized by high total alkali content，enrichment of Na，Al and light rare earth elements，strong enrichment of large ion lithophile elements Sr，and depletion of high field strength elements Nb and Ti.Through in-depth analysis and comparison of the La/Nb and Zr/Ba values，Hake diagram，Rb/Y-Nb/Y ratio diagram，La-La/Sm diagram，La/Yb-Nb/Ta diagram and Th/Nb-Ce/Nb diagram of gabbro in Saibaigou gold deposit，it is determined that the gabbro primary magma of Saibagou gold deposit originated from the lithospheric mantle magma which experienced fractional crystallization，assimilation and contamination，and partial melting during the the process of ascending and invaded，and intruded into the shallow crust to form gabbro primitive magma.
The Wangu gold deposit is one of the most important parts of the gold （polymetallic） metallogenic belt in the Jiangnan orogenic belt，in which the mineral element composition characteristics of sulfide has relatively few research on the enrichment mechanism of Au.For further exploration of the element composition characteristics of sulfide in Wangu gold deposit，85 representative samples were selected and made into thin sections.The ore mineral pyrite and arsenipyrite in the deposit was taken as the research object，and the basic characteristics of mineral assemblage and mineral structure were observed under the microscope.According to the characteristics of pyrite crystal form and other symbiotic minerals，the pyrite in Wangu gold mine is divided into three stages：Py1，Py2 and Py3.Laser ablation plasma mass spectrometry （LA-ICP-MS） and mapping was used to analyze the trace element composition in these three stages.There are obvious differences in Au con-centrations in Py1，Py2 and Py3 of pyrite in Wangu gold deposit.Au elements mainly exists in Py3 in the metallogenic stage，while Au concentration in Py2 is low.At the same time，As elements in Py3 also appear in the position corresponding to the enrichment of Au elements.There is a coupling relationship between Au and As in pyrite of Wangu gold deposit.Therefore，speculation is made that Au mainly migrates in the form of Au-HS in the fluid and is mainly assigned to the lattice of pyrite in the form of Au1+.In this process，As is likely to replace S with As1- and form Fe（As，S）2 solid solution between pyrite and arsenopyrite，which is arsenic containing pyrite.Combined with the previous study，the result is that Py1 does not contain gold and is primary pyrite，and Py2 exists symbiotically with siderite.It is considered that siderite was formed before mineralization and was caused by water-rock reaction between Caledonian CO2 rich fluid and surrounding rock.Therefore，Py2 has a certain inheritance to Py1.As the main gold mineralizeation stage of Caledonian period，Py3 exists with smoky gray quartz and arsenipyrite，and has a high percentage of sulfide in gold.The growth of pores on the surface of Py2 is the typical dissolution reprecipitation feature，indicating that pyrite in this period was dissolved by later fluid and reprecipitation into Py3.In this process，the Yanshanian gold bearing fluid reacts with early Py2，which destroys the stability of Au-HS complex in the fluid and forms gold bearing Py3 through pyrite dissolution and reprecipitation.Combined with previous studies，it is considered that sulfidation is the main gold precipitation mechanism of Wangu gold deposit，and early Py2 and siderite can also provide ideal chemical traps for gold precipitation.
The influences of blasting seismic waves on inclusion is crucial in the blasting excavation process. Part of the energy generated by blasting is used for the fragmentation of the rock mass，and the remaining part is propagated to a distance in the form of elastic waves.The scattering of stress waves at the structural discon-tinuity leads to the migration and accumulation of energy，resulting in local high energy and high stress，and then lead to rock failure.The plane P wave in the blasting seismic wave was taken as the research object and wave function expansion method was used to solve the scattering and dynamic stress concentration around the cylinder inclusion in the full plane under steady state linear elastic incident P wave.Under the cylindrical coor-dinate system，Bessel equation was obtained by separating variables from Helmholtz equation.Considering the simplicity of Bessel function in solving cylindrical boundary problem，the incident plane wave was expanded into the series of Bessel function，and the full wave function was obtained from the stress boundary condition of the cylindrical inclusion，then the response of the cylindrical inclusion subjected to the steady state linear elastic stationary incident P wave was obtained.Through the Fourier integral transformation of transient impact，the dynamic stress concentration of transient incident P wave around a cylindrical inclusion could be obtained.The effects of shear elastic modulus，Poisson’s ratio and wave number on the dynamic stress concentration factor were analyzed.The results show that the dynamic stress concentration factor reaches its maximum value when the wave number is 0.25，and the maximum value appears in the counterclockwise 90° and 270° directions of the inclusion.With the increase of wave number，tensile stress concentration occurs in the surrounding rock in the directions of 0° and 180°，which may lead to the failure of the surrounding rock. In addition，the finite element software LS-DYNA was used to establish a numerical model of wave incident rock mass with inclusions.The scattering and stress concentration of the transient wave at the inclusion were calculated，the pressure and effective stress chart around the inclusion and the rock mass failure were obtained.The distribution and numerical value of the stress concentration factor obtained by the simulation are very close to the numerical calculation，which proves the correctness of the numerical calculation.The results show that the larger the difference between the shear elastic modulus of the surrounding rock and the inclusion，the more obvious the dynamic stress concentration，and the larger the failure area of the surrounding rock is. The CSCM cap model material was used to establish a model，and the damage of surrounding rock under the action of transient wave incidence was obtained.The results show that the cracks appear in the counterclockwise 90° and 270° directions，that is，the position of the maximum value of the dynamic stress concentration factor.
The reasonable evaluation of rock quality is the basis for engineering design and construction，and it is of great significance to the safe production and economic benefits of mines.In view of the complex conditions and ambiguity of rock quality evaluation，on the basis of comprehensive reference to relevant research literature，five parameters were selected as rock quality evaluation indexes，including core quality index RQD value（X1），uniaxial compressive strength of rock σc（X2），rock integrity coefficient Kv（X3），structural surface strength coefficient J（X4）and unit time water seepage S（X5），and a rock quality evaluation model of G1-EW-TOPSIS method based on game theory idea was proposed and applied to the rock quality evaluation of the first mining middle section of a silver polymetallic mine in Inner Mongolia.To verify the validity of the model，firstly，a field survey was conducted to determine five measurement points for the structural surface condition and groundwater flow of the rock mass in the first mining middle section of the mine，and then the subjective weight ω1 and objective weight ω2 of the indexes of the measurement points were obtained by combining the G1 method and EW method through game theory to obtain the comprehensive weight ω.Finally，TOPSIS was used to calculate the relative closeness of each measurement point under each rock quality class to determine the rock quality class of the measurement point.The results show that the five rock quality grade evaluation indexes selected in this paper can better reflect the state of the rock mass.The method of calculating the com-prehensive weight of the model not only overcomes the shortcomings of the single assignment method，but also reduces the error and improves the ability of the model to deal with multi-objective decision problems.The rock quality in the first middle section of this mine is mainly evaluated as grade Ⅲ and grade Ⅳ，the rock quality is poor，and the support needs to be strengthened for the roadway and the exposed surrounding rock of the quarry where the rock quality is grade Ⅳ.The calculation results of the model completely match with the rock quality of 5 measurement points at the mine engineering site，which provides a new idea for rock quality evaluation.
When the mining method in the West No.2 mining area of Longshou mine was changed from down layered cemented filling mining method to sublevel caving mining method，it is necessary to form a loose overburden by caving or blasting the large area cemented filling.Using the traditional drilling and blasting method to form the loose overburden has a series of disadvantages，such as long period，large input and less output，which can not meet the production needs of the mine.A induced caving technical scheme of forming loose overburden by reserving ore bulk as safety cushion and uniformly expanding goaf was proposed，which combined the formation of overburden with the dual demand of stope productivity.Microseismic monitoring technology was used to monitor the caving process of cemented backfill.The monitoring results show that the caving mechanism of cemented backfill in West No.2 mining area can be divided into three types.The first type is the failure event of cemented backfill caused by the mining stress concentration within 20~45 m behind the goaf，which mainly occurs in the early to middle stage of drifts mining.The second type is that with the expansion of the goaf，the shear stress at the fulcrum of the suspended cemented backfill beam is also increasing，when the shear stress exceeds the shear strength of the cemented backfill，the beam will shear failure at the fulcrum at the rear edge of the goaf，this kind of failure event mainly occurs in the middle to end stage of drifts mining.The third is that when the exposed length of the cemented backfill beam increases to a certain extent，the cemented backfill beam bends and sinks under the ground pressure and its own gravity，resulting in tensile stress in the middle of the rock beam of the filling body，resulting in bending and tensile failure in the middle of the cemented backfill beam，this kind of failure event mainly occurs in the middle to end stage of drifts mining.Based on the comprehensive analysis of the results of microseismic monitoring，theoretical calculation and in-site ore drawing tracking，it can be seen that during 1 595 m sublevel mining，the caving of cemented backfill mainly occurs at the level of 1 610~1 630 m.Therefore，a loose overburden composed of residual ore and caving cemented backfill with a total thickness of about 30 m is formed on the floor of the first mining sublevel.This loose overburden thickness meets the safety requirements of mining and the requirements of relevant safety regulations，which shows that the preset goal of forming loose overburden safely，efficiently and at low cost has been successfully achieved by using induced caving technology in the West No.2 mining area.
The large storage of iron tailings not only causes environment pollution，but also has the risk of geological disasters.It can be used as paste filling material aggregate，which can solve the harm of tailings and ensure the safety and stability of underground stope.The Waitoushan iron mine adopts filling method.The filling material is composed of iron tailings，cement and water and the filling slurry has a mass concentration of 68%，which belongs to cemented filling with low-concentration whole tailings.Due to the low mass concentration of filling slurry， the whole tailings of iron tailings are coarse.Fine particles such as cement in the slurry are easily lost，which are not only waste cementing materials and affect the strength of the filling body，but also seriously pollute the underground environment.The filling material composition is fixed，and other admixtures and additives are not added，so the filling structure of the mine is single.Aiming at the problems of waste of filling materials and single filling structure in Waitoushan iron mine，the basic properties of Waitoushan iron tailings were studied by relevant tests.The test shows that the iron tailings have a large proportion，a small content of fine particles and poor gradation，so it is not suitable as paste aggregate alone.The fly ash was selected as admixture to supplement the fine particles in the iron tailings.The content of fly ash increased from 0 to 15% in a gradient of 2.5%，and the mass concentration of slurry was 72%，the paste filling material was prepared by mixing all materials.The slump，compressive strength，porosity and water absorption of filling materials with different fly ash content were tested.The results show that with the increase of fly ash content，the slump of slurry increases from 180.2 mm to 240.2 mm，the porosity decreases first and then slightly increases，and the water absorption rate increases.The unconfin compressive strength of filling material specimen could reach 1.359 MPa in 28 days.The results show that the fluidity and unconfined compressive strength of paste filling materials can be improved by adding fly ash，but the amount of fly ash should be no more than 12.5% of the solid mass.The results provide theoretical support for other metal mines to improve the filling structure.
As an important part of mine construction，shaft engineering is also a key project to ensure the normal operation of the mine.With the continuous development and utilization of resources，the difficulty of resource extraction also increases，and more and more shaft projects need to be constructed under complex geological conditions.Moraine layer is a special geotechnical material widely distributed in the western region of China，there is more and more construction projects on this type of soil.Compared with the general sur-rounding rock structure，the soil mass of the moraine layer is basically composed of debris，the surrounding rock is mostly in a soft plastic state，the degree of consolidation is low，and the stability of the soil body is poor. The pressure is high，and the general shaft construction method is difficult to apply to the construction of this type of soil.Therefore，in order to improve the construction efficiency of the shaft under the geological conditions of the moraine layer，control the deformation of the surrounding rock during the construction of the shaft under the soil condition of the moraine layer，and optimize the construction plan of the shaft under the soil condition of the moraine layer.Taking the 8# shaft project of Xiaomaliu tailings pond in Sichuan as an example，using the research method of numerical analysis，combined with the actual engineering situation，considering the influence of underground diving in the moraine layer soil on the construction operation of the shaft，the shaft construction process of the vertical shafts by forward excavation method，full-section reverse shaft method and reverse shaft pilot tunnel expansion method were analyzed，and the distribution of pore water pressure，stress，displacement and plastic zone after the construction of the three types of shafts were analyzed.It can be seen from the simulation results that the construction effect of the excavation method is better，followed by the forward excavation method，and the construction effect of the full-section reverse method is the worst.The pore water pressure of the shaft seepage field and the surrounding rock stress on the side wall of the shaft in the construction of the raised shaft excavation method are relatively small，and the maximum deformation of the surrounding rock on the side wall of the shaft is only 4 cm.Similar，the maximum displacement reaches 7 cm.The full-section back-well method has poor construction effect，the groundwater can’t be discharged in time，the pore water pressure on the side wall of the shaft is large，and the deformation of the surrounding rock on the side wall of the shaft is large，reaching 10 cm.Therefore，among the three types of shaft construction schemes，the excavation method of the raised shaft can effectively control the soil deformation around the shaft.
Most of the metal mines in China are combined vertical shafts and ramp roads.Under the joint action of multiple factors such as long-term ground pressure and frequent traveling，the dampers are severely damaged and extremely inconvenient to manage and maintain.In the context of intelligent ventilation development，the traditional manual or semi-manual airflow control measures can hardly meet the requirements of intelligent ventilation in mines，and the control of airflow can’t be realized or can’t achieve the expected effect in the special conditions of the tunnel.Mining air curtain is a new type of airflow control technology that can achieve intelligent control of airflow in more complicated conditions in the tunnel without affecting the transportation of equipment and the work of personnel in the tunnel.To investigate the effect of twin parallel air curtains in a non-coal tunnel to intercept the wind flow，a metal mine project tunnel in Gansu Province was taking as the background，based on Fluent numerical simulation technology，the K45-6 axial flow fan was selected，by changing the fan full pressure and jet angle to establish different mathematical and physical models of the original tunnel，the flow field inside the original tunnel for numerical simulation，according to the simulation results of the twin parallel air curtains on the tunnel flow field，the impact analysis was carried out based on the simulation results.The analysis was carried out in three aspects，namely differential pressure，air leakage，and air blockage rate.The main conclusions of this study include：（1）When the full pressure of the fan is a constant value，as the air curtain jet angle increases，the differential pressure and wind resistance show a trend of first increasing and then decreasing，and the differential pressure and wind resistance increase significantly when the jet angle is 5°~30°，the differential pressure and wind resistance increase significantly，and the air curtain gradually converges into a complete air curtain.When the jet angle reaches 30°，the differential pressure and wind resistance reach the maximum value，and the most complete air curtain is formed.But the rising trend in 15°~30° is flatter than 5°~15°.When the jet angle continues to increase to 45°，the differential pressure and wind resistance rate drop significantly.When the jet angle continues to increase to 60°，the differential pressure and wind resistance rate are the lowest.As the jet angle continues to increase，the lateral pressure from the tunnel can’t effectively block the wind flow.（2）The air leakage volume shows a trend of decreasing and then increasing as the jet angle increases，and the air leakage volume decreases more obviously when the jet angle increases from 5° to 15°.When the jet angle increases to 60°，the isolation capacity is the worst.（3）When the jet angle is too small or fans’ full pressure is too large，the phenomenon of induced airflow will occur，then the double machine parallel circulation type air curtain will be downstream of the tunnel air to the upstream，no longer can it intercept the tunnel wind flow.According to comprehensive analysis，obvious effect of air control can be obtained by setting double parallel circulating air curtain in the roadway，and the optimal parameter combination of double machine parallels circulation-type air curtain is that the fan full pressure blade angle is 30° at the same time jet angle is 30°.
With the depletion of shallow resources，deep mining has become the development trend of mines.Compared with shallow mining，one of the difficulties of deep mining is high temperature and heat damage.The ventilation lines of deep mining are long and complex，resulting in poor ventilation of deep working face，and the heat can’t be discharged in time.It is complex and difficult to improve the thermal environment of working face with the help of ventilation global optimization，while local ventilation optimization is economical，fast and efficient，so it has become the first choice to improve the thermal environment of working face.The selection of ventilation parameters in traditional local ventilation optimization usually depends on on-site test，which leads to high cost and poor repeatability，and can’t meet the requirements of parameter optimization.With the develop-ment of computer，numerical simulation is applied to the field of ventilation，which provides a new means for the research of local ventilation optimization.Taking a large underground metal mine in China as the research object，the wind temperature of excavation roadway at -945 m level in the mine was measured.Based on the roadway section size，the roadway model was constructed by FLUENT software，and the initialization setting of the simulation was completed in combination with the roadway boundary conditions.By changing the local ventilation parameters，the cooling effects under different ventilation parameters were obtained by numerical simulation of different inlet air temperature，inlet air volume，duct erection height and outlet position.The ventilation schemes under the above different parameters were applied in -945 m horizontal excavation roa-dway.The reliability of the numerical simulation results was verified by comparing the simulated temperature with the measured temperature under different schemes.While selecting the local ventilation parameters with the best cooling effect，taking into account the economy of local ventilation and the safety of underground operation.Finally，the optimal local ventilation parameters with good cooling effect，economy，safety and suitable for deep shaft excavation roadway were obtained.The conclusions are as follows：The comparison between the simulation results and the measured data shows that the two results are in good agreement，which proves that the numerical simulation is reliable and can be extended to other deep level local ventilation and cooling research.The research method of combining numerical simulation and experimental verification is scientific and effective，and improves the shortcomings of high cost and low repeatability of traditional relying solely on experiments.Numerical simulation intuitively shows the distribution characteristics of tunnel air temperature.The optimized local ventilation parameters can effectively improve the high-temperature environment of deep excavation roadway，and have certain guiding significance for local ventilation and cooling in deep mine mining.
In underground rock engineering，such as deep resource mining and underground nuclear waste repository construction，high temperature is one of the important factors affecting the stability of rock engine-ering structure.Meanwhile，compression-shear stress state is one of the common stress states of rock in engine-ering.Therefore，the research on acoustic emission characteristics and shear fracture micro mechanism of red sandstone under variable angle shear after high temperature treatment is of great significance to monitor and analyze the stability of rock in high temperature rock engineering.By analyzing the acoustic emission characteristics of red sandstone treated at 25~800 ℃ during the shear failure，it can be concluded that high temperature changes the acoustic emission characteristics and related parameters in the shear failure process of red sandstone，including AE event count，b value，RA-AF value and so on.At the same time，based on the acoustic emission characteristics，the influence of high temperature treatment on the shear failure characteristics of red sandstone was analyzed.In addition，the micro mechanism of shear fracture of red sandstone after high temperature was analyzed by electron microscope scanning technology.The test results show that： （1） High temperature makes the change trend of acoustic emission event of red sandstone from indirect activities with low-activity under room temperature to continuous activities with high-density，and the peak value of AE cumulative event count increases with the increase of treatment temperature.（2） According to the distribution characteristics of acoustic emission parameter RA-AF value，it can be concluded that high temperature treatment changes the crack type of red sandstone in compression shear failure，and the proportion of shear crack increases with the temperature increasing.（3） The change trend of AE cumulative event count can be used to judge the shear stress threshold of pore compaction，crack initiation and crack damage.According to the distribution characteristics of the proportion of shear stress threshold，it can be concluded that with the increase of temperature，the proportion of stable crack propagation stage decreases，but the proportion of unstable crack propagation increases.（4） The shear damage characteristics of red sandstone after high temperature treatment were defined by AE cumulative event count.It was found that when the shear angle is 55°，the high temperature treatment can inhibit the development of shear damage of red sandstone，and promote it at 65°.（5） The compression-shear fracture of the samples treated at different temperatures is mainly formed by cleavage along the crystal （trans-granular fracture），but at 800 ℃，it is more prone to failure along the grain boundary，the number of residual dimples increases，the plasticity increases and the degree of fragmentation decreases.The research results can provide reference for solving the problems of high temperature geotechnical engineering.
Underground geotechnical engineering is often located in high stress stratum，which is easy to cause disasters such as damage and expansion of surrounding rock，large-scale fracture and swelling.With the implementation of construction，it is inevitable to encounter composite rock with more complex stress distribution and rock mass failure.In view of the deep high in-situ stress and multi-rock complex geological conditions，the servo control testing machine was used to conduct indoor mechanical experiments on composite rock，and the failure process of composite rock under high stress was reproduced，so as to provide reference for the stability analysis of composite rock with different materials.Skarn，serpentine and sandstone were selected as the components of composite rock，and their strengths are 80.25 MPa，83.29 MPa and 87.41 MPa respectively.They have a relatively similar strength relationship with uniform gradient increase，which is convenient to compare the mechanical properties of composite rock.The composite rocks can be divided into two types，one is serpentinite and skarn assemblage，the other is serpentinite and sandstone assemblage.The combination mode is 0°contact surface，the volume proportion of components is the same，and the components with weak strength are located in the upper part of the combination rock.Through uniaxial compression tests，the mechanical properties and failure characteristics of skarn，sandstone and serpentinite in single and composite forms were obtained，including uniaxial compressive strength，peak strain，elastic modulus and failure mode.By comparing the stress-strain curves and the actual failure situation，it can be seen that the composite rock and single rock have similar failure modes，with obvious characteristics of compaction stage，elastic stage，plastic stage and failure stage，and the initiation position and development mode of the initial crack directly determine the final failure mode of the rock sample.Based on the experimental data，it is inferred that there is a quantitative relationship between the compressive strength of a single rock and its composite rock，and this inference was verified.According to the homogenization theory，the composite rock was compared to the ideal series spring model，and the formulas of elastic modulus，peak strain and volume of each component in the composite rock awere deduced by using Hooke’s law.The theoretical results are close to the experimental results.Under the condition of uniaxial compression，the compressive stress on the contact surface of composite rock specimen gradually changes to the tensile stress perpendicular to the compression direction，and the composite rock is mainly shear failure.Under the action of high stress，the deformation phenomena of the two kinds of rocks in the composite rock are not synchronous，and the part with low strength is destroyed first，this shows that in composite rocks，weak facies rocks play a major role in the overall strength of composite rocks.
Under the new normal of China’s economy，tax，as the key to the high-quality development of enterprises，has attracted extensive attention.As the basic industry of the national economy，mining industry is in a special institutional environment different from manufacturing industry，which plays a vital role in the high-quality development of China’s economy.Taking mining enterprises from 2014 to 2019 as the research sample，this paper studies the relationship between tax and high-quality development of enterprises.Among them，based on the input-output perspective，this paper selected the total output value of mining enterprises as the output index，the total assets as the capital input index，and the number of employees at the end of the year as the labor input index to construct the DEA-Malmquist index，and used the obtained value to measure the high-quality development level of enterprises.The results show that there are some differences in total factor productivity of Chinese mining enterprises from 2014 to 2019，and the average total factor productivity level is low，that is，the high-quality development level of mining enterprises is generally low.When discussing the impact of enterprise tax on the development level of China’s mining enterprises，the high-quality development level was selected as the explanatory variable，the ratio of the total tax paid by enterprises to the main business income was used to measure the tax of enterprises as the explanatory variable，and the rate of return on total assets，density of tangible assets，asset liability ratio，enterprise age，nature of enterprise property rights were selected as the control variables.Using panel regression analysis，property right and regional heterogeneity analysis，this paper tested the impact of enterprise tax on the high-quality development of mining enterprises，and further considered the regulatory effect of enterprise size on them.The results show that：（1）There is a significant negative rela-tionship between tax and the high-quality development of mining enterprises.（2）Compared with large-scale enterprises，small-scale mining enterprises have a stronger inhibitory effect on high-quality development.（3）In the further analysis of property rights and regional heterogeneity，it is found that non-state-owned enterprises and mining enterprises in the eastern region have a more significant inhibitory effect on high-quality development.According to the empirical results，this paper believes that the state should strengthen tax reduction and fee reduction to further improve the high-quality development level of mining enterprises.
Cyanide in cyanide-containing wastewater is a highly toxic substance.Leakage of cyanide-containing wastewater into the environment will cause environmental pollution of water and soil and damage human health.cyanide into the organism will release cyanide ion （CN-），which will combine with the ferric iron oxidase in the mitochondria of cells，inhibit the reduction of ferric iron，hinder the normal respiration of cells，make cells lose the function of oxygen transfer，resulting in tissue hypoxia，leading to biological asphyxia and death. China has formulated strict standards for the discharge of cyanide wastewater.Therefore，it is necessary to carry out harmless treatment of cyanide-containing wastewater.Adsorption method is widely used in the treatment of cyanide-containing wastewater due to its advantages of simplicity，efficiency and economy.The widely used cyanide adsorption materials in the field of water treatment were reviewed，including carbonaceous adsorption materials，mineral materials，resin materials and new micro/nano materials，etc.The advantages and disadvantages of different adsorption materials in treating cyanide wastewater were compared.At the same time，the adsorption performance and mechanism of different adsorbents were discussed，mainly including the specific surface area of ??adsorbent materials，the treatment depth of cyanide，adsorption capacity，adsorption thermodynamics and kinetics.Adsorption mechanisms such as physical adsorption，chemical bonding，electrostatic attraction and ion exchange all occur in the adsorption of cyanide by adsorbent materials，such as activated carbon，zeolite，bentonite and other materials with rich pore structure for physical adsorption of cyanide.Metallic elements such as Cu，Zn，Fe and other metal elements in adsorbent materials can form metal complex cyanide chemical bond with CN- in the solution.The anion in the ion exchange resin，quaternary ammonium salt or nitrate modified material can occur ion exchange with cyanide.The research directions of cyanide adsorption materials in the future are prospected to provide reference for the development and application of cyanide adsorption materials，such as further development of easy access，large adsorption capacity，small desorption coefficient，recyclable，easy to recover，green and environmental protection，no secondary pollution，high selectivity adsorption materials.
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