The analysis of blasting vibration signals is of vital importance for enhancing the accuracy and safety of blasting operations. The core issue lies in the non-stationary nature of the signals and the limi⁃ tations of traditional stationary signal analysis methods. Through a systematic review of the development process of analysis methods in this field，it is found that the early Fourier transform and short-time Fourier transform based on the assumption of stationarity were limited by their fixed time-frequency resolution. Methods such as wavelet transform effectively capture the characteristics of non-stationary signals; the Hil⁃ bert-Huang transform，with its adaptive time-frequency analysis mechanism，demonstrates unique advan⁃ tages in handling complex transient signals，but requires the combination of improved algorithms such as EEMD and EWT to avoid end-point effects and mode aliasing. Intelligent information processing and multi-source data fusion are the key to breaking through the existing analysis bottlenecks and achieving precise assessment and real-time control of vibration effects. In the future，signal analysis based on deep learning，multi-modal data collaboration，and dynamic feedback systems will jointly drive the develop⁃ ment of blasting vibration analysis towards intelligence，precision，and real-time.

During the blasting excavation process of underground mine tunnels，in order to analyze the instability mechanism of dangerous rock masses，a 1 240 m leveldrift in a certain underground mine in the Western Panzhihua area was selected as the research object. The 3D laser scanning technology was used to identify the characteristics of the dominant structural planes of the rock mass，and on-site blasting vibration monitoring was carried out. Based on the Sadovsky empirical formula and the dynamic reduction coefficient，the equivalent static load borne by the rock mass under blasting was calculated. Finally，using the 3DEC discrete element software，a numerical model was established to systematically analyze the insta⁃ bility evolution process of dangerous rock masses in the tunnel surrounding rock under blasting distur⁃ bance. The results show that the three groups of dominant structural planes developed in the study area form a key geometric configuration through composite intersection，which is the main cause of block insta⁃ bility. It was calculated that the equivalent static load borne by the blocks in the study area under blasting is approximately 1.17g. Through discrete block analysis，two main dangerous blocks were identified，both located in the roof area of the tunnel. Their maximum spans are 1.12 m and 2.03 m，respectively，and their volumes are 0.48 m³ and 1.02 m³，respectively，and they are controlled by two different dominant structural planes and undergo sliding instability. The research results can provide theoretical basis and practical reference for the stability analysis of tunnel，the optimization of support structures，and the safety management of the roof.

The various blasting parameters used in mines play a decisive role in regulating the blast⁃ ing process. How to set reasonable blasting parameters efficiently and accurately is a significant concern for mining enterprises in actual operations. This study focuses on the Eastern Baluba Mine，which faces issues such as high blasting material consumption and large block rate. The study was conducted on the +1 240 m production bench，targeting the general rock and difficult-to-blast rock on the south and north sides re⁃ spectively. The blasting hole network，charge structure，and initiation network were regulated. The blast⁃ ing effects of different schemes at the test site were compared and analyzed. Different blasting optimization experiments were carried out on the +1 240 m bench of the Eastern Baluba quarry，achieving good blasting rock-breaking effects. According to the proposed blasting parameters，the blasting explosives consumption on the south bench decreased from 0.521 kg/m³ to 0.352 kg/m³ ，a reduction of 32.44%. When using bagged ammonium oil explosives and mixed emulsion explosives on the north bench，the blasting material con⁃ sumption could be reduced by 23.04% and 24.00% respectively. The study has solved problems such as high blasting material consumption，large consumption of blasting equipment，and high large block rate in mines，and has certain guiding and reference significance for similar mining operations.

In order to improve the problem of insufficient caving and low resource recovery rate of hard top coal in steeply inclined and extra-thick coal seam in the northern mining area of Wudong Coal Mine in Xinjiang，the pre-splitting technology of water injection-blasting coupling fracturing top coal is studied. According to the coal seam occurrence and working face space conditions，the theoretical calcula⁃ tion，parameter design，field test and multi-source monitoring are combined to determine the water injec⁃ tion pressure，water injection volume，hole sealing length，hole angle and charge parameters，and form the fan-shaped grouping staggered hole arrangement and the forward continuous charge scheme in the hole. By using KJ21 mining pressure monitoring system，bolt force sensor，borehole stress sensor and transient electromagnetic detection，the top coal stress，electrical characteristics and caving effect before and after the implementation of the measures are compared and evaluated. The results show that when the water in⁃ jection pressure is 10 MPa and the water injection amount of single hole is 39.09 t，the effect of coal infil⁃ tration and softening is better .After using 113 mm diameter blastholes，4 m hole spacing and 2 m staggered spacing，a continuous overlapping damage zone can be formed in the depth range of 20 m of top coal. After the coupling pre-splitting，the average stress of the bolt decreases from 11.5 kN to 6.6 kN，with a decrease of 42.6%. The average surrounding rock stress of the borehole decreased from 5.73 MPa to 4.89 MPa，with a decrease of 14.7%. The minimum apparent resistivity of the pre-splitting zone is 5~15 Ω · m，which is 62.5%~7.5% lower than that of the non-blasting zone. The low-resistance anomaly range has a good corre⁃spondence with the borehole action zone. The research shows that water injection softening and blasting fracturing can synergistically promote the stress release and fracture penetration of top coal，which pro⁃ vides technical support for efficient pre-splitting and safe mining of hard top coal in similar steeply in⁃ clined and extra-thick coal seams.

To address the problems of complex and variable lithology and difficult blasting fragmenta⁃ tion control at the Mirador Open-pit Copper Mine in Ecuador，field tests on delay time optimization were carried out for four typical rock masses based on rock mass blastability classification，and reasonable delay time parameters for different lithological zones were determined. The results show that according to the RMR classification system，granodiorite has a blastability grade of Class II，granodiorite porphyry and quartz sandstone are Class III，and breccia is Class IV. Granodiorite exhibits a weak response to delay ad⁃ justment，and shortening the inter hole delay time of granodiorite porphyry leads to a poorer fragmentation effect; therefore，the conventional scheme of 42 ms + 65 ms is recommended for both rock types. After adopting the“dual hole simultaneous initiation”scheme for quartz sandstone，the shape of large boulders changes from“pie type”to regular square，and the fragmentation uniformity is significantly improved. For breccia，using 25 ms + 42 ms combined with 600 ms in hole detonators completely eliminates boulders larger than 500 mm，and the fragment size is mainly concentrated in the range of 150~500 mm. The delay parameters determined by the tests can effectively improve the blasting fragmentation effect in different lith⁃ ological zones，providing a theoretical basis and engineering guidance for refined blasting design in mines with complex lithology.

In response to the problem of excessive length of blocked sections in the blasting of the open-pit mining platform of Dabaoshan，which leads to insufficient energy release at the top and high rate of large blocks，a field study on top layer detonation charge was conducted. A single-hole mechanism iden⁃ tification was carried out on the expansion mining platform 661，and a 75 holes group comparison was con⁃ ducted on the east slope platform 637. A layer detonation charge design was carried out and the top blocked length (5.5，4.0，3.5 m) was compared. Under the condition of maintaining the total charge amount basically unchanged and micro-differential initiation of each hole，the effect was evaluated by block size statistics. The results show that in the single-hole test，D50 decreased from 616 mm to 485 mm， D80 decreased from 947 mm to 834 mm，Dmax decreased from 2 074 mm to 1 443 mm，and the rate of large blocks greater than 1 m decreased from 15.2% to 6.1%. In the group comparison，the layer detonation charge + top blocked length of 3.5 m achieved the optimal and stable crushing effect，and the rate of large blocks decreased by 72% compared with the continuous detonation charge structure，while the blasting ef⁃ fect of the scheme with top blocked length of 4.0 m did not improve significantly. From the experiments，it can be known that without increasing the charge amount，top layered detonation charge can achieve energy and time-space redistribution，significantly improving surface crushing and pile shape. The blocked length is the key control quantity. Under the given rock properties and hole network conditions，3.5 m is the pre⁃ferred value. An excessively long blocked length is likely to cause insufficient energy release at the top，re⁃ sulting in incomplete top crushing.

In response to the problems such as fragmented systems，shallow data utilization and ho⁃ mogeneous solutions in the digital construction of metal mines，a differentiated digital R&D system based on types and stages was constructed. The research took Anhui Development Mining Co.，Ltd. in China and Las Bambas Copper Mine overseas as empirical cases，and proposed three differentiated implementation paths.In domestic operating mines，following the principle of "first connectivity then intelligence"，unified data standards and the construction of a data center were adopted to revitalize existing assets and achieve full value chain collaboration；in overseas operating mines，the "reuse of mature systems + local adapta⁃ tion" strategy was adopted to solve technical implementation problems in special conditions such as high al⁃ titudes；for new mines，the principle of "foundation first，forward-looking reservation" was adhered to to avoid repeated trial and error. The practice shows that this system effectively eliminated information silos， improved equipment operation efficiency and safety monitoring capabilities，reduced the digital trial-and�error costs of new mines，and provided a replicable scenario adaptation solution for the intelligent upgrade of mines.

In order to implement the national deployment requirements for the prevention and control of major risks in non-coal mines，and to solve the problem that the traditional video monitoring system of metal underground mines only has the function of post-event replay，lacking real-time warning and intelli⁃ gent recognition capabilities，based on the engineering background of Huaibei Dongxin Mining，an AI vid⁃ eo intelligent auxiliary supervision system based on deep learning was designed and constructed. The sys⁃ tem covers key areas underground and on the surface，and deploys 20 AI intelligent cameras，integrating 12 types of recognition algorithms，achieving real-time monitoring and warning of personnel behavior， equipment status，and environmental risks. The overall architecture，functional modules，key technolo⁃ gies，and engineering deployment requirements of the system were studied and analyzed，and the system was comprehensively tested in combination with the technical guidance document of Anhui Province. The trial operation results show that the recognition accuracy of the system for violations is above 95%，the alarm response is timely，and the operation is stable. This system，based on the integration of deep learn⁃ ing and edge computing，realizes closed-loop management of intelligent video recognition in multiple un⁃ derground scenarios，provides a replicable technical solution and engineering example for the intelligent supervision of non-coal mines.

In response to the frequent collision accidents of non-railroad wheeled vehicles in coal mines in complex tunnels，the high false alarm rate of traditional collision prevention systems，and the lag⁃ ging response time，a three-level intelligent collision prevention system integrating UWB positioning，mil⁃ limeter-wave radar，and automatic sensing anti-vehicle devices is proposed. This system realizes compre⁃ hensive real-time perception of vehicle spacing，speed，and environment through multi-technology integra⁃ tion，and builds a closed-loop active protection mechanism from the first-level audible and visual warning， the second-level radar automatic braking to the third-level flexible interception. The on-site application of this system in Tashan Coal Mine for 8 months indicates that the system successfully resolved 10 cases of out-of-control dangers，shortened the collision risk identification and response time to within 150 ms，re⁃ duced the false alarm rate to less than 1.5%，and significantly reduced the monthly average maintenance cost. The system significantly improves the safety and efficiency of auxiliary transportation in underground mines，possesses high automation and reliability，and provides effective technical support for the construc⁃ tion of intelligent mines.

With the widespread application of the staged backfill mining method in mines，a deeper understanding has been gained of the stress state changes of the first-step filling body during the second�step ore room mining process. During the mining process，the stress state of the filling body changes from three-dimensional compression to two-dimensional compression，and mining disturbances are prone to cause the filling body to collapse and fail at the exposure surface. To address this issue，the failure mecha⁃ nism of the lateral exposure surface collapse was analyzed in depth，and the original filling scheme of the mine was optimized and regulated by adding control layers. Through the FLAC3D numerical simulation tech⁃ nology，the variation laws of the development of the plastic zone，stress field，horizontal displacement and exposure surface displacement of the single-sided exposure cemented filling body with control layers under the condition of a main body sand ratio of 1∶9 were studied in detail. At the same time，the safety of the filling scheme was analyzed. The research results show that under the unilateral exposure condition，the filling body generates longitudinal cracks under the vertical stress，thereby deteriorating the performance of the cemented filling body. The introduction of the control layer can effectively reduce the formation of the plastic zone by 19.2%，and by blocking large-scale plastic zones，it effectively reduces the deforma⁃ tion and failure of the filling body. In addition，the application of the control layer makes the filling body with a main body sand ratio of 1∶9 have similar overall strength to the filling body without a control layer with a sand ratio of 1∶8. This technology not only successfully controlls the failure of the unilateral open faces，but also enhances the stability of the filling body，reduces cost.

To solve the problem of accurately predicting the gas emission volume in the fully mecha⁃ nized mining face of high-gas coal seams，taking the 15# coal seam of Tianchi Coal Mine as the research object，a study on the construction of a time series model for gas emission volume and its engineering appli⁃ cation was carried out. Firstly，based on the geological conditions and mining conditions，an index system for gas emission influence was established，clarifying the key correlation patterns among various influenc⁃ ing factors. Secondly，the recursive feature elimination cross-validation method based on random forest (RFECV) was used to screen the optimal features，and the core prediction features such as the average speed of the coal mining machine，the start-up time，the average advancing distance，and the daily output were determined. Finally，relying on the time series data processing advantages of the bidirectional long short-term memory network (Bi-LSTM)，a gas emission volume prediction model was constructed. The model validation results showed that the prediction values of this Bi-LSTM time series model had a very high fit with the on-site real values，and the overall prediction stability was excellent. In the small sample verification of the 61506 working face，the model's R² reached 0.842 4，demonstrating strong adaptability and robustness，and being able to effectively capture the dynamic time series characteristics of gas emis⁃ sion in high-gas coal seams. The model has been successfully applied in the 15# coal seam of Tianchi Coal Mine，providing precise data support for the optimization of the gas extraction system，adjustment of pro⁃duction processes，and other advanced prevention measures. It also provides a reference method framework for the prediction of gas emission in similar high-gas coal seams.

In order to study the stability control technology of the surrounding rock of extra-thick coal seams in a mine in Datong，Shanxi Province，and to ensure the safe and efficient excavation of the road⁃ way，based on the excavation working face of the coal mine，a combination of numerical simulation and on�site engineering practice was adopted to systematically study the stress and deformation evolution laws of the surrounding rock of the thick coal seam roadway under the influence of excavation disturbance. Based on the mechanism of the influence of the supporting structure on the stability of the surrounding rock，the supporting parameters of the surrounding rock at the excavation working face were optimized，and then a comprehensive stability control technology for the surrounding rock of the thick coal seam excavation work⁃ ing face was proposed，with the core of high-strength anchor rods and anchor cables. The results show that as the excavation length of the thick coal seam roadway increases，the stress and deformation of the cross�section at the connection point between the supporting section and the unsupported section of the surround⁃ ing rock continuously increase，and tend to stabilize when the excavation length increases to 6 meters. In⁃ creasing the pre-stress of the anchor rods can significantly increase the amplitude of the stress continuous band and maintain its distribution range. After the implementation of the surrounding rock stability control technology for the roadway of the thick coal seam excavation working face in the field，the deformation of the roadway has been effectively controlled，verifying the reliability and applicability of this technology. The research results provide important reference value for safe tunneling in similar conditions.

Geotextile tubes have broad application prospects in the treatment and reinforcement of fine-grained tailings dams. To investigate the shear characteristics of geotextile tubes filled with fine�grained tailings during the consolidation process，field-scale consolidation tests were conducted. Two types of tailings and four types of woven geotextiles with different specifications were selected to prepare geotextile tubes. Direct shear tests were performed to analyze the evolution of tailings dry density as well as the shear strength of both tailings and geotextile tubes under different consolidation durations. The influ⁃ ence mechanisms of tailings properties，geotextile parameters，and consolidation time on the mechanical behavior of geotextile tubes were revealed. The results show that with increasing consolidation time，the dry density of tailings increases following a quadratic function and gradually stabilizes，with an increase of more than 30% after 40 days of consolidation. The permeability and mechanical properties of geotextiles have significant effects on the consolidation efficiency and shear strength. A higher permeability coefficient leads to a higher degree of consolidation，while greater tensile strength of geotextiles results in more pro⁃ nounced strength improvement of the geotextile tubes. Compared with pure tailings，the cohesion of geotex⁃ tile tubes increases by 4~7 times，whereas the increase in internal friction angle is relatively limited. A sig⁃ nificant quadratic relationship exists between tailings dry density and shear strength parameters，allowing the prediction of strength indicators based on easily measurable dry density parameters. The findings pro⁃ vide a theoretical basis and engineering reference for the stability analysis of geotextile tubes and the selec⁃ tion of geotextiles in tailings dam engineering.

In-situ leaching of uranium is an important technical means for sandstone-type uranium mining. Acid in-situ leaching of uranium is widely used because of its low cost and good leaching effect. However，the phenomenon of pore blockage in the leaching process seriously restricts the leaching efficien⁃ cy and becomes the core bottleneck of the development of this technology. According to the cause of block⁃ age，the blockage can be divided into chemical blockage and physical blockage. Chemical blockage is mainly caused by insoluble precipitates such as calcium sulfate formed by the reaction of leaching agent and mineral layer. Physical blockage is divided into two types of solid phase particle migration deposition and gas phase accumulation plugging. On the basis of clarifying the formation mechanism，influence law and core characteristics of various types of blockages，the existing blockage removal technologies are sum⁃ marized into three categories of chemical blockage removal，material understanding blockage removal and source prevention blockage removal. The application effects，applicable scenarios and limitations of vari⁃ ous measures are analyzed. Furthermore，the idea of intelligent regulation and deblocking of production process parameters based on real-time monitoring and artificial intelligence algorithm is proposed. The ap⁃ plication prospects of machine learning agent model，physical information neural network and digital twin technology in in-situ leaching are discussed，which provides a reference for blocking prevention and con⁃ trol，deblocking process optimization and efficient mining in the process of in-situ leaching of sandstone�type uranium deposits.

An iron ore in Australian has a TFe grade of 36.36%，with magnetite as the main iron mineral，mFe distribution rate of 78.69%. The main gangue minerals are quartz，amphibole and mica， with SiO₂ content as high as 41.64%，while harmful impurities P and S are low. The ore is classified as acidic primary magnetite，with magnetite disseminated in a uniform medium-to-fine grain size，requiring fine grinding for satisfactory liberation. A beneficiation process comprising coarse wet pre-concentration， stage grinding and stage low intensity magnetic separation，reverse flotation and scavenging magnetic sepa⁃ ration was tested on this ore. The results show that the -4 mm HPGR product，after coarse wet pre-concen⁃ tration，can discard tailings with a yield of 20.16% and an mFe grade of only 0.21%，with an mFe loss rate as low as 0.14%，achieving effective early tailings rejection. The pre-concentrate，after first stage grinding to 87.70% passing 0.075 mm，yields a rougher concentrate of 56.66% TFe by low intensity magnetic sepa⁃ ration. After second stage grinding to 86.55% passing 0.038 mm，the second stage magnetic concentrate is further upgraded by cationic reverse flotation，and the flotation tailings are treated by scavenging magnetic separation followed by regrinding and reconcentration. The full scale locked cycle test finally produces an iron concentrate with a TFe grade of 67.15%，TFe recovery of 75.55%，and mFe recovery of 98.53%. This process effectively mitigates the adverse effects of increasing ore hardness and property fluctuations，signif⁃ icantly improves concentrate quality and recovery，and provides a technical reference for the efficient de⁃ velopment and utilization of similar magnetite resources.

Aiming at the problems of high energy consumption and large processing capacity in the traditional full roasting process of low-grade siliceous rock type vanadium ore，a combined process of high-pressure roller mill pre-enrichment-blank roasting-acid leaching was proposed. The amount of tail⁃ ings can be removed by 47.80% through high pressure roller mill-screening pre-enrichment，which greatly reduces the amount of subsequent roasting. The comparison test of raw ore and pre-enrichment concentrate shows that pre-enrichment does not increase the vanadium leaching rate，and its core value is to reduce energy consumption and production cost. The optimum process conditions are pre-enrichment to obtain va⁃ nadium concentrate with V2O5 grade of 1.22% and recovery of 81.18%. The vanadium concentrate was roasted at 860 ℃ for 24 h，and the roasted product was leached at room temperature（30 ℃），liquid-solid ratio of 2 mL/g，acid dosage of 6%，and leaching time of 2 h. The leaching rate of vanadium was 88.99%. The use of quasi-suspended layered thin-layer roasting to improve the heating uniformity of the material can provide a technical reference for industrial amplification.

To fully understand the ore properties of a certain lean and impure iron ore and facilitate the determination of a reasonable beneficiation process，chemical multi-element analysis，MLA and other techniques were employed to systematically investigate the mineral composition，dissemination characteris⁃ tics，particle size distribution，as well as the monomer dissociation degree and intergrowth relationships of the major minerals. The results show that the ore is a low phosphorus，sulfur bearing，single acidic，medi⁃ um grade primary magnetite ore，with an iron grade of only 32.80% and a SiO₂ content of 43.38%，which is the main gangue component to be removed. The ore exhibits disseminated or disseminated banded struc⁃ tures. The iron mineral is predominantly magnetite (accounting for 35.92% of the total minerals)，occasion⁃ ally with sporadic hematite and limonite；sulfide minerals are present in low contents，and the gangue min⁃ erals are mainly quartz，amphibole and mica. Magnetite is disseminated in the gangue in dense，moderate⁃ ly dense to sparse scattered forms or as disseminated bands，with a grain size generally ranging from 0.005 to 0.3 mm. It is mainly embedded along the edges and intergranular spaces of amphibole，mica and chlorite，which favours liberation；therefore，the grinding fineness can be appropriately coarsened based on -0.019 mm. At grinding finenesses of -0.074 mm 85%，-0.043 mm 75% and -0.038 mm 90%，the combined distribution rates of iron mineral monomers and rich intergrowths reach 87.55%，91.38% and 97.23%，respectively. The main intergrown minerals are quartz，amphibole，mica and chlorite，followed by feldspar，pyrrhotite and apatite. These findings provide a systematic fundamental basis for determining the beneficiation process for this ore.

The study focuses on a lead-zinc ore from Yunnan，employing various analytical methods such as chemical multi-element analysis，phase analysis，optical microscopy，and MLA for process miner⁃ alogy research. The results indicate that the useful elements in the ore are lead and zinc，with grades of 0.78% and 4.41%，respectively，and the associated precious metal silver content is approximately 15.31 g/t. The main metallic minerals in the ore are galena，cerussite，sphalerite，rhodochrosite，pyrite，and marca⁃ site，while the gangue minerals primarily consist of calcite，quartz，sodium feldspar，potassium feldspar， and montmorillonite. The particle size distribution of the ore minerals is uneven，with galena and sphaler⁃ ite at -0.16 mm accounting for 70.30% and 81.38%，respectively，classified as medium-fine particle em⁃ bedding. The pyrite has a coarser particle size，with +0.16 mm accounting for 60.04%. Most galena fills the gaps of sphalerite，while sphalerite primarily fills the fractures and interstices of pyrite (marcasite). The complex embedding relationships between the minerals may increase the difficulty of separating lead-zinc and zinc-sulfur.

Aiming at the problems of overgrinding of iron minerals，inclusions in the separation pro⁃ cess and low separation efficiency in the existing stage grinding-low intensity magnetic separation-fine screening classification-magnetic gravity combined process of a Anshan-type sedimentary metamorphic rock type lean magnetite in Daixian County，combined with the characteristics of uneven particle size dis⁃ tribution of magnetite in the ore，quartz-based gangue and high content of intergrowth，the iron-increasing and silicon-reducing tests of the grinding-low intensity magnetic separation-reverse flotation-tailings mag⁃ netic separation and re-separation process were carried out. The results show that when the grinding fine⁃ ness is -0.045 mm accounting for 90%，the flotation concentrate with iron grade of 71.05%，iron recovery of 92.00% and SiO2 content of only 1.10% can be obtained by the closed-circuit process of low intensity magnetic separation-anion reverse flotation. The quality of the concentrate fully meets the raw material re⁃ quirements for the production of high-quality pellets. Aiming at the problem that the grade of flotation tail⁃ ings is high and it is difficult to directly discard the tailings，under the condition that the regrinding fine⁃ ness of flotation tailings is -0.030 8 mm accounting for 90.18%，one roughing and one cleaning low intensi⁃ ty magnetic separation can be used to obtain a re-concentration concentrate with iron grade of 64.29%，op⁃ eration recovery of 89.98% and process recovery of 5.56%. The research results provide technical reference for the same type of magnetite iron and silicon reduction and plant process optimization，and have positive significance for promoting the low-carbon green development of the iron and steel industry.

Aiming at the practical problems of iron grade decrease and aluminum content increase caused by deep mining in Chengchao Iron Mine，taking the -535/-552 level raw ore and on-site iron con⁃ centrate of Ⅵ orebody as the object，the process mineralogy analysis，grinding-magnetic separation test and elutriation aluminum reduction test were carried out. The results show that the grade of TFe is 24.42%，the content of Al2O3 is 7.43%，and the content of SiO2 is 31.64%. The on-site iron concentrate has a TFe grade of 64.74%，an Al2O3 content of 1.71%，and a SiO2 content of 3.81%. The results of pro⁃ cess mineralogy analysis show that aluminum mainly occurs in magnetite，chlorite and mica，with the dis⁃ tribution rates of 38.64%，23.39% and 15.46%，respectively. The close dissemination of magnetite and aluminum-bearing gangue is the fundamental reason for the difficulty in removing aluminum. The grinding�magnetic separation test shows that when the raw ore is milled to 17 min，the magnetic separation concen⁃ trate index is consistent with the actual production. When the grinding time is 21 min，the TFe grade of the concentrate increases to 66.54%，the Al2O3 content decreases to 1.56%，the SiO2 content decreases to 2.85%，and the iron recovery rate is 76.29%. The on-site iron concentrate was reground for 11 min and then magnetically separated. The concentrate TFe grade reached 67.35%，Al2O3 content decreased to 1.44%，SiO2 content decreased to 2.65%，and the iron recovery rate was 98.73%. The aluminum reduction effect of the elutriation test is limited，which can only reduce Al2O3 by about 0.1 percentage points，and ac⁃ companied by obvious iron loss，which is not suitable as the aluminum reduction process of the mine.

To upgrade the quality of conventional iron concentrate and meet the specifications of DR�grade iron concentrate，this study proposed a combined separation flowsheet including pre-concentration and tailing discarding at a magnetic field intensity of 160 kA / m，ball milling to achieve 90% passing 0.038 mm，one-stage low-intensity rough magnetic separation (160 kA/m)，and concentration by a magnet⁃ ic separation column on the basis of process mineralogy analysis.Test results show that the concentrate with a yield of 79.47%，total Fe grade of 70.18%，and Fe recovery of 84.86% can be obtained. The contents of harmful elements (sulfur and phosphorus) and main gangue components including SiO2，Al2O3，CaO and MgO in the final product all satisfy the quality requirements of DR-grade iron concentrate. High product quality is achieved while ensuring effective recovery of iron resources. This research can provide technical references for upgrading conventional iron concentrate into feedstock for direct reduction ironmaking，and offer a feasible process route and experimental basis for the high-value utilization of similar iron ore re⁃ sources.

The TFe content of iron concentrate in Jinling Iron Mine is 64.80%，and the harmful ele⁃ ment S content is 0.44%. The desulfurization and upgrading test of the iron concentrate was carried out. With MK-S as activator and MK-207 as collector，the grade of S was reduced from 0.44% to 0.10% after one roughing and three cleaning desulfurization flotation. The desulfurization concentrate was ground to -0.038 mm accounting for 90%. Under the condition that the magnetic induction intensity of roughing was 200 mT and the magnetic induction intensity of cleaning was 160 mT，the concentrate with TFe grade of 69.55%，S grade of 0.08% and TFe recovery of 90.73% was obtained by one roughing and one cleaning low intensity magnetic separation. The research results can provide reference for desulfurization and up⁃ grading of iron concentrate.

The "Golden Triangle"（Yunnan-Guizhou-Guangxi border region) is an important Carlin�type gold metallogenic belt in China. This type of deposit is characterized by sediment-hosted，micro-dis⁃ seminated ores，where gold occurs in an "invisible" form（<1 μm），encapsulated within sulfides such as py⁃ rite and arsenian pyrite（arsenopyrite）. Conventional cyanidation processes result in extremely low gold leaching rates. Addressing the characteristics of such refractory ores，a gold mine in Guizhou has developed a complete integrated hydrometallurgical process encompassing "pre-treatment—extraction—environmen⁃ tal protection". The core of this process is high-temperature and high-pressure oxygen pressure leaching， which decomposes gold-bearing sulfides to fully expose the encapsulated gold，creating favorable condi⁃ tions for subsequent carbon-in-leach gold recovery. The overall gold recovery rate is increased by more than 30% compared to conventional processes. Simultaneously，under high-pressure oxidation conditions， arsenic is stabilized and precipitated in the form of crystalline scorodite（FeAsO4 ·2H2O），significantly re⁃ ducing the risk of arsenic environmental migration. This achieves the dual objectives of efficient resource recovery and in-situ pollutant control.

Regarding the engineering problem of the stability of rock slopes in open-pit mines being affected by the coupling of joint parameters and bench slope angles，Using numerical simulation methods， the influence of joint angle，joint density，and bench slope angle on the stability of the slope was ex⁃ plored，the safety factor of the slope under different schemes was obtained，the degree of influence of joint parameters on slope instability was analyzed，and significance tests were conducted. The results show that joint density and joint angle are the determining factors of the slope failure mode. Regardless of the joint density level，the inclined-slope joint slope is mainly subject to sliding failure. In the low joint density con⁃ dition，the failure mode of the reverse-inclined joint slope is independent of the joint; in the high joint den⁃ sity condition，the failure mode of the reverse-inclined joint slope will change to overturning failure. Under the combined effect of multiple factors，the higher the joint density，the more significant the decrease in the slope safety factor caused by the increase in the bench slope angle; an increase in joint density will re⁃ duce the influence of the joint angle on the safety factor，and an increase in the bench slope angle will cause a more significant decrease in the safety factor of the reverse-inclined joint slope. The influence of the three factors on the stability of the rock slope in open-pit mines is from large to small in the order of joint density，bench slope angle，and joint angle.

In the traditional flood regulation calculation for small watershed tailings ponds，to ad⁃ dress the issues of single solution，cumbersome operation，low efficiency，and susceptibility to human fac⁃ tors in terms of accuracy，a system integrating multiple methods of flood regulation calculation for small wa⁃ tershed tailings ponds has been developed. This system combines the reasoning formula method and the comprehensive unit line method in flood calculation，enabling automatic generation of the incoming flood process line. In the flood regulation calculation process，iterative method and semi-graphical method are integrated to achieve coupled calculation of the incoming flood process line and the discharge process line. In the system，only the basic parameters of the tailings ponds and the local hydrological manual parameters need to be input to complete the calculation，and results such as process line diagrams，key parameter ta⁃ bles，and detailed calculation tables can be output. The system also supports visual presentation. Engineer⁃ ing examples have verified that the results of the two flood calculation methods and the two flood regulation calculation methods within the system are highly consistent，with relatively small relative errors compared to manual calculations. The single flood regulation calculation of the system takes less than 10 s，signifi⁃ cantly improving work efficiency and meeting the needs of pre-flood flood regulation calculation and emer⁃ gency dispatch for small watershed tailings ponds，providing a practical tool for their flood prevention and safety management.

In view of the large output of fine-grained waste rock in open-pit mines，it is easy to form a water-proof weak layer and aggravate the hidden danger of landslide in the waste dump by stacking alone. Taking the high-bench wastedump of a zinc-indium mine in Yunnan as the research object，through on-site particle size screening，indoor penetration and direct shear test and Geo-Slope numerical simula⁃ tion，the hydraulic mechanical response law of waste rock mixture with different fine-grained content and its influence mechanism on slope stability are explored. The unsaturated samples are prepared according to the natural moisture content of 5% in the field. The results show that with the increase of the content of fine-grained waste rock，the pores filled by particles lead to the shrinkage of the seepage channel，and the permeability coefficient of the mixture continues to decay. The permeability coefficient of the high-fine�grained ratio material is 72.3% lower than that of the original broken waste rock. The fine-grained compo⁃ nents have the effect of increasing viscosity and reducing friction. The cohesion increases slightly and the internal friction angle decreases gradually. The simplified Bishop method is used to calculate the safety fac⁃ tor of the slope under natural，rainfall and earthquake conditions. It is found that the higher the fine parti⁃cle content is，the lower the safety reserve of the slope is，and the deterioration of the rainfall condition is the most prominent. The safety factor of the downstream slope of the high-fine mixture is reduced to 1.193， which does not meet the stability requirements of specification 1.20. The study clarified the disaster-caus⁃ ing path of " pore siltation-strength attenuation-slope instability " caused by the change of fine-grained content. Based on this，the graded storage control standard is formulated，and the disposal scheme of low�medium fine-grained mixture global stacking and high-fine-grained material limited to the local filling of non-goaf area at the foot of the slope is proposed，and the layered compaction，interception and drainage， and displacement-pore water pressure dynamic monitoring measures are matched. The research results can provide theoretical support and engineering guidance for the mixed discharge of wide -graded waste rock and the prevention and control of geological disasters in wastedumps in similar mines.

Multi-level simultaneous combined mining is easy to produce mining-induced superim⁃ posed disturbance，which induces stress redistribution，deformation and instability disasters of surround⁃ ing rock. It is a prominent problem faced by efficient mining of underground mines. Taking a sedimentary metamorphic iron mine as the engineering background，a three-dimensional numerical model with a size of 700 m×100 m×450 m was constructed by field engineering geological investigation，rock mass classifica⁃ tion and reduction of mechanical parameters of Hoek-Brown and M.Georgi criteria for the collaborative mining conditions of -400 m and -500 m double middle sections. FLAC numerical simulation system was used to explore the evolution law of surrounding rock displacement，stress and plastic zone in the whole process of multi-middle section progressive mining. The results show that the multi-middle superimposed disturbance mainly causes the roof subsidence of No.I ore body，and the maximum subsidence displace⁃ ment is 38.8 mm. In the later stage of mining，there is a significant tensile stress concentration in the 409 section of No.I ore body，with a peak value of 3.50 MPa，which exceeds the tensile strength of the ore rock by 2.50 MPa，and there is a risk of local tensile failure. The stress and deformation in the remaining areas are less than the ultimate strength of the rock mass，and the overall stability is controllable. The plastic zone is mainly developed in the top and bottom of the ore body and the segmented contact position，and there is no large-scale penetration failure. Based on the response characteristics of surrounding rock distur⁃ bance，the prevention and control scheme of staggered mining in the middle section，pilot stope first and filling with mining is established to effectively avoid the risk of ground pressure disaster. The research re⁃ sults can provide theoretical basis and engineering reference for safe and efficient collaborative mining of multi-level in similar mines.

To explore the intrinsic relationship between rock mechanical properties and infrared radi⁃ ation，an infrared monitoring test of the entire process of uniaxial loading of sandstone was carried out. The stress change rate was introduced to characterize the transient instability of the stress field，and the infra⁃ red radiation count was used as the core quantitative indicator for the evolution of the infrared radiation temperature field. The abnormal characteristics of stress and infrared radiation during the brittle fracture process of sandstone were studied，as well as the quantitative relationship between the two physical quanti⁃ ties. The results show that by calculating the stress change rate，the stress changes can be classified into three types. Type I is a small sudden change，Type Ⅱ is a medium-sized sudden change，and Type Ⅲ is a large sudden change. Among them，Type Ⅱ sudden changes account for 82.0%. The situation where the in⁃ frared radiation count and the stress change rate simultaneously change reached 76.8%，and the infrared radiation count responded most sensitively to the Type II sudden change of the stress change rate. After fit⁃ ting the cumulative infrared radiation count before the peak stress and the stress，it was found that the stress and the cumulative infrared radiation count show a highly linear positive correlation (correlation coef⁃ficient >0.98). Analyzing the relationship between the rock brittleness index and the temperature abnormal area in the infrared thermal image，it was found that when the brittleness index is ≤0.425，the temperature abnormal area during the sandstone failure is mainly a cooling area；when the brittleness index is >0.425， the temperature abnormal area is mainly a heating area；the maximum value of the infrared radiation count after the peak is strongly positively correlated with the brittleness index，with a correlation coefficient of 0.916，providing a basis for the infrared quantitative analysis of brittle rocks.

The Shiziling granite-type tungsten-tin deposit is one of the four core deposits in the Limu mining field of the Nanling mineralization belt in the western section. It is a typical concealed gran⁃ ite-type tungsten-tin deposit. To study the geological characteristics of the tungsten-tin deposit and pro⁃ vide certain assistance for prospecting prediction，through systematic drilling engineering documentation， microscopic identification of rocks and minerals，geochemical testing，in-situ micro-area analysis，and spatial coupling analysis of structure-weathering-mineralization，a vertical five-level alteration-mineral⁃ ization zoning sequence of the Shiziling deposit was systematically established. The mineralization types and element differentiation laws from the deep part to the shallow part of the deposit were clarified，and the main controlling factors of the spatial distribution of the ore body were identified. The F，Li jetting ha⁃ lo，Lepidolite-Fluorite vein zone were determined as direct prospecting indicators for the mining area，and a tripartite comprehensive prospecting model of "rock body top convex structure + alteration zoning + geo⁃ chemical anomaly" was constructed. The top convex area of the concealed rock body and its periphery，as well as the intersection area of fault structures，were identified as the core favorable target areas for miner⁃ al exploration，providing theoretical basis and exploration guidance for the prospecting breakthrough of similar concealed deposits in the deep part and periphery of the mining field.

Concealed goaf is easy to cause geological disasters such as collapse and water gushing， which seriously restricts the safe production of mines. It is of great significance for mine engineering design and safety production management to accurately explore the spatial location，scale and occurrence state of concealed goaf. The conventional transient electromagnetic method is susceptible to mutual inductance in⁃ terference of the transmitting and receiving coils，and has defects such as blurred detection boundary，low accuracy of abnormal body shape recognition，and multiple solutions of stratum inversion. It is difficult to achieve fine detection of shallow goaf. Based on Daye Dahongshan Mine，the combined detection of shal⁃ low concealed goaf is carried out by using microtremor exploration and equivalent anti-magnetic flux tran⁃ sient electromagnetic method. By constructing a three-dimensional inversion model of apparent shear wave velocity and apparent resistivity，the two types of detection results can be mutually confirmed and comple⁃ mented，and the detection blind spots and multi-solution problems of a single geophysical method can be effectively avoided. The results show that there are 19 pit backfill areas and concealed goaf anomalies in the exploration range from the surface to-80 m，including 2 shallow backfill areas，4 goafs above -60 m，3 goafs between -60 m and -70 m，and 3 goafs deeper than -70 m. The low resistivity anomaly zone delin⁃ eated by the apparent resistivity of 300 Ω·m has a high spatial matching degree with the low wave velocity anomaly zone in the range of 300 ~ 1 000 m/s. The combined detection technology can realize all-round high-precision non-blind area detection of underground structure and physical parameters，and is suitable for fine exploration of shallow to medium-deep concealed goafs in complex mine sites. It has significant technical advantages and engineering promotion value.

The Jinjishan manganese deposit in Hanpoao，Xinhua County，Hunan Province is a repre⁃ sentative oxidized manganese deposit. To better develop the Jinjishan manganese deposit the genesis and mineralization potential of the deposit were explored，the geological characteristics of the manganese depos⁃ it were analyzed and summarized，field geological surveys were conducted，and representative samples were collected in the tunnels. Combined with the geological characteristics of the deposit，the research fo⁃ cused on the study of trace elements in manganese ores and the state of manganese distribution. In the re⁃ search，the content of Mn was determined by ferrous sulfate titration，the content of Fe was titrated with potassium dichromate standard solution，the contents of other trace elements were analyzed by inductively coupled plasma emission spectrometer (ICP-OES)，and X-ray powder diffraction (XRD) was used to ana⁃ lyze the phase of manganese. The study showed that the ratio of Fe/Mn in the manganese ore was 0.06~ 0.98，which was lower than that of the surrounding rocks. The manganese ore was enriched in K，Ca，Mg， Co，Ni，etc. The Co/Zn value of the Hanpoao manganese deposit was 0.06~0.98，indicating that the man⁃ ganese ore might originate from hot water deposition. The Fe-Mn-(Co + Ni + Cu) × 10 and Co/Zn-Co + Ni + Cu diagrams indicated that the formation of the manganese ore might be the combined result of chemical precipitation after the mixing of hot water deposition and cold seawater. The XRD analysis results showed that manganese was present in the manganese ore in the form of Pyrolusite. Based on all the test results， the geological characteristics of the manganese deposit were studied. The deposit was formed first by hot water deposition and cold seawater mixing through chemical precipitation，resulting in manganese-bearing limestone and manganese-rich argillaceous siliceous rock. Then，it was formed through weathering，sedi⁃ mentation and secondary enrichment. The formation of the ore body was closely related to the oxidation pro⁃ cess. The deeper the weathering degree，the higher the manganese grade. The distribution areas of manga⁃ nese-bearing limestone and argillaceous siliceous rock in the areas near faults were the main favorable ar⁃ eas for prospecting.

In order to solve the problem of combined pollution of surface water and groundwater caused by industrial residual gangue and steel slag open-air solid waste yard in the area along the Yangtze River in Ma’anshan City，Anhui Province，aiming at the current situation of unclear pollution mechanism of regional solid waste and lack of basis for water environment control，the mechanism of pollutant migra⁃ tion and diffusion is studied. Taking the surface water and groundwater of the tributaries along the Yangtze River during the wet season as the research object，the multi-index laboratory quantitative detection meth⁃ od is used to systematically analyze the spatial distribution of water quality and pollutant migration charac⁃ teristics of surface water，shallow phreatic water and underlying aquifuge in combination with regional geo⁃ logical conditions. The results show that rainwater surface erosion and rainfall infiltration runoff are the main migration pathways of pollutants. The core endogenous pollution is the high alkaline wastewater pro⁃ duced by the leaching of solid waste CaO，and the secondary exogenous pollution is the ammonia nitrogen input from the extraterritorial agricultural non-point source. The concentration of pollutants gradually de⁃ creases from the center of the solid waste pile to the outside，and drops sharply near the river channel. The runoff process of surface water and groundwater determines the spatial gradient distribution of regional pH value. The two-way hydraulic exchange between surface water and groundwater in wet and dry seasons leads to seasonal differences in water dilution capacity. The dilution performance of the aquiclude is poor，and the risk of alkaline pollution retention is higher. The research results can provide measured data and mechanism support for the coordinated control of water and soil in solid waste dumps along the Yangtze River and the improvement of regional water environment carrying capacity.

In order to explore the influence of coal metamorphic degree on the characteristics of coal spontaneous combustion and the shortest spontaneous combustion period，five kinds of coal samples with different metamorphic degrees are selected to carry out industrial analysis，elemental analysis，tempera⁃ ture programmed oxidation and differential scanning calorimetry (DSC) test. The apparent activation energy of oxidation is calculated by water correction Kissinger method，and the prediction model of the shortest spontaneous combustion period is constructed by multiple linear regression. The results show that with the decrease of coal metamorphism，the moisture and volatile content of coal increase，the endothermic char⁃ acteristics of DSC increase，the zero point of heat flow advances，and the apparent activation energy of oxi⁃ dation decreases as a whole. The fixed carbon and oxygen contents are significantly positively correlated with the apparent activation energy，and the correlation coefficients are 0.942 and 0.901，respectively. The relative error of the measured verification of the model is not more than 4.4%，and the prediction accuracy is high. The average error of leave-one-out cross-validation is 12.5%，indicating that the empirical model has the ability to estimate quickly on site，but the generalization accuracy still needs to be optimized by ex⁃ panding the sample. Studies have confirmed that the degree of coal metamorphism dominates the spontane⁃ ous combustion tendency and ignition timing of coal by regulating the chemical composition and oxidation reaction energy barrier of coal. The prediction formula based on conventional detection indicators can quickly estimate the shortest spontaneous combustion period of coal seam at low cost，which is suitable for preliminary prediction of mine spontaneous combustion risk.

In order to promote the soilless reclamation in the process of closing and selling the iron tailings pond，realize the ecological bulk utilization of tailings mud and reduce the cost of ecological resto⁃ ration，taking the tailings mud of an iron tailings pond as the research object，through the systematic analy⁃ sis of material composition，toxicity leaching，particle size distribution，nutrient composition and heavy metal content，supplemented by the same tailings，inorganic compound fertilizer，organic fertilizer and wa⁃ ter retaining agent，the lemon grass planting experiment was carried out to comprehensively evaluate its soilization feasibility. The results show that the main chemical components of the tailings are silicon，calci⁃ um，iron，etc.，and the main phases are calcite，quartz and hematite，which belong to conventional miner⁃ al composition. The toxic leaching solution meets the first-level discharge standard of GB 8978—1996. The median particle size d50=106.84 μm，which is conducive to the formation of good soil structure and per⁃ meability；the heavy metal content meets the relevant requirements of“Green Planting Soil”and“Construc⁃ tion Land Soil Pollution Risk Screening Value”，which can support high-volume utilization ; the total nitro⁃ gen content reached the standard，but the organic matter，available phosphorus and available potassium were low. The planting experiment showed that the lemon grass grew well after supplementing the nutrient components，which directly verified the feasibility of the soil reconstruction of the tail mud. The research results provide basic data support and scientific basis for soilless reclamation of tailings reservoir.

In order to systematically clarify the pollution nature of acid mine drainage (AMD) and pro⁃ mote the upgrading of treatment mode to green，low-carbon and resource recycling，the formation mecha⁃ nism of AMD was firstly sorted out，and the limitations of traditional processes such as neutralization sedi⁃ mentation，coagulation flocculation and adsorption in terms of reagent consumption，sludge production，se⁃ lective removal and secondary pollution were comprehensively evaluated. Then，the technical advantages of combined processes such as grading neutralization，biological synergistic treatment and constructed wet⁃ land were summarized，and the mechanism of metal stepwise precipitation，reducing lime dosage and sludge yield by segmented pH regulation was clarified. The functions of sulfate reducing bacteria (SRB) -mediated biological reduction process in simultaneous neutralization of acidity，promotion of heavy metal sulfide pre⁃ cipitation and reduction of solid waste were further explained. At the same time，the feasibility of recycling valuable metals (manganese，zinc，etc.) and the preparation of phosphorus adsorption materials from waste residue were evaluated. Finally，the practical value of the integrated strategy of comprehensive management and ecological restoration in the coordination of source blocking，process control，end purification and eco⁃ logical reconstruction was pointed out. It is difficult for a single technology to balance efficiency，economy and sustainability. The customized solution of multi-technology coupling，refined process control and re⁃ source recovery can significantly improve governance efficiency and environmental compatibility. According to the hydrogeological conditions and pollution pedigree of different mining areas，it is the key path to real⁃ize the scientific management and control of AMD and the sustainable ecological restoration of mining areas to construct an integrated management model with strong adaptability，low carbon and long-term effect.

Aiming at the problems of poor caving，difficult caving and frequent rock burst of top coal in steeply inclined thick coal seam in north mining area of Wudong Coal Mine，based on the analysis of geological occurrence conditions，the mechanical degradation characteristics，stress field evolution law and pre-splitting effect of top coal under water-force coupling are systematically studied. Through uniaxial compression test，the uniaxial compressive strength，elastic modulus and poisson 's ratio of coal under nat⁃ ural water-bearing state are 13.59 MPa，1.324 GPa and 0.328 respectively，and the corresponding values under saturated state are 11.22 MPa，1.122 GPa and 0.383 respectively. The water action reduces the com⁃ pressive strength and elastic modulus of coal by 17.4% and 15.3%，respectively，and the Poisson 's ratio increases by 16.8%. The stress-strain curve shows that the natural water-bearing coal sample is dominated by tensile-shear composite failure，and the saturated coal sample is X-shaped conjugate shear splitting failure，and the fracture connectivity and fragmentation degree are significantly improved. Based on FLAC3D ，a three-dimensional numerical model of 600 m×350 m×96 m is established. The results showed that the maximum compressive stress of 45# coal seam decreased from 8.47 MPa to 7.22 MPa after water in⁃ jection，with a decrease of about 14.8%. The local stress gradient slowed down，and the high stress migrat⁃ ed to the adjacent complete coal body and deep area. Based on the effective stress principle，Mohr-Cou⁃ lomb strength criterion，water-induced weakening characteristics of coal samples and the safety boundary of on-site construction，it is suggested that the water injection pressure should be controlled at 10~15 MPa to promote the opening and shear slip of primary fractures and provide low-resistance channels for subse⁃ quent blasting fracture expansion. The research results can provide theoretical basis for top coal pre-split⁃ ting and safe and efficient fully mechanized caving mining in steeply inclined thick coal seam.

In view of the problem that the copper grade of molybdenum concentrate tailings is 3.42%, the copper recovery rate of traditional sedimentation tank process is only 60%~70%, and the loss of fine metal is serious, the research on resource recovery process is carried out. The laboratory test results show that butyl xanthate is the best collector, the flotation pulp concentration is 30%, the flotation process of one roughing, one cleaning and three scavenging is adopted, and no adjustment agent is added in the whole pro⁃ cess. Based on the static sedimentation test data, the ϕ6 m non-drive sedimentation tank was independent⁃ ly designed and applied, and the intermittent operation mode of feeding 2 d and flotation 1 d was matched. The low concentration pulp was efficiently concentrated to 30%. After industrial application, the compre⁃ hensive recovery rate of copper increased to 95.56%, the grade of copper concentrate reached 18.66%, and the grade of copper in tailings decreased to 0.18%. The process reagent system is streamlined, the equip⁃ ment has no transmission parts, and the investment in technical transformation is low, which provides a technical reference for the recovery of associated copper resources in small and medium-sized molybdenum mines under narrow site conditions.

In view of the high energy consumption in the flotation process of polymetallic ore，the tra⁃ ditional asynchronous motor with belt wheel drive has the problems of long transmission chain，low trans⁃ mission efficiency and high operation and maintenance cost. Taking XCF-30 m3 flotation machine as the re⁃ search object，the energy-saving transformation test of permanent magnet synchronous motor was carried out. By combining theoretical analysis with industrial field measurement，the structure，operating efficien⁃ cy，power factor and temperature rise characteristics of asynchronous motor and permanent magnet motor are compared. Two transformation schemes of permanent magnet direct replacement and permanent magnet direct drive are set up and industrial tests are carried out. The results show that compared with the tradi⁃ tional asynchronous belt drive system，the comprehensive power saving rate of permanent magnet direct drive is 24.66%，and the power saving rate of permanent magnet direct drive can reach 31.56%. The power factor of the permanent magnet motor is increased to 0.96，the operating current and the temperature rise of the equipment are significantly reduced，and the operation stability of the equipment is improved. The direct drive cancels the belt drive，and the transmission loss is smaller and the maintenance cost is lower. The research confirms that the permanent magnet motor adapts to the complex working conditions of flota⁃ tion，which can provide engineering reference for the energy-saving transformation of mine flotation system and help the development of low-carbon and cost-reducing in the mineral processing industry.

The total iron grade of a smelting slag floating copper tailings is 47.61%. Iron mainly oc⁃ curs in magnetite and iron silicate. The iron distribution rate in magnetite is only 34.60%，while the iron distribution rate in fayalite and vitreous body is as high as 63.74%. The process mineralogy analysis shows that the dissemination size of magnetite is fine，and the proportion of -0.019 mm particle size is 54.89%. About half of the particles are closely connected with fayalite and vitreous body，and it is difficult to dissoci⁃ ate the monomer. Based on the characteristics of the ore，the principle process of stage grindingstage low in⁃ tensity magnetic separation was developed. Under the condition of rough grinding，the tailings are discarded in advance，and the rough concentrate is reground and reselected to gradually increase the concentrate grade，avoiding over-grinding and mudding. Under the condition of final grinding fineness P90=19.95 μm， the whole process test can obtain the beneficiation index of concentrate iron grade 62.12% and recovery rate 42.42%. The efficient recovery of magnetic iron minerals in the tailings is realized.

Based on a full-process survey method，the operational characteristics of the production system at the Sishanling magnetite concentrator were systematically investigated. Under normal production conditions，the key operations including crushing and screening，high pressure grinding rolls (HPGR)， grinding and classification，magnetic separation，and dewatering were systematically sampled and tested. Combined with mass balance calculations，the material flow，metal distribution，and technical perfor⁃ mance indicators of each unit were comprehensively analyzed. The results show that the raw ore has a TFe grade of 27.47%，with magnetite and hematite finely to ultrafinely disseminated and closely intergrown with quartz，making liberation difficult; thus，a stage grinding-stage magnetic separation process is appro⁃ priate. In the crushing and screening system，the medium and fine crushing stages exhibit low reduction ra⁃ tios and coarse discharge particle sizes，resulting in underutilization of equipment capacity. The HPGR achieves an effective reduction ratio of 3.46，but its fine particle generation efficiency is relatively low. In the grinding and classification circuit，the first stage grinding operates stably，the second stage grinding suffers from overgrinding，leading to decreased classification efficiency and equipment utilization. The magnetic separation system performs well overall，with a concentrate TFe grade reaching 65.46%，but some iron loss remains in the tailings，mainly in the form of fine intergrowths. In the dewatering system， both concentrate and tailings moisture contents exceed the design specifications，and the circulation of slimes adversely affects system stability. To address these issues，measures such as optimizing crushing size control，improving the coordination between the crushing and main processes，optimizing the water system，and enhancing dewatering efficiency are proposed. The findings provide valuable reference for pro⁃ cess optimization and capacity expansion in similar magnetite concentrators.

For the purpose of investigating the influence of high-pressure grinding rolls (HPGR) ul⁃ tra-fine crushing technology on the grindability of Heishangou iron ore from Shaanxi，tests including open-circuit HPGR crushing，closed-circuit HPGR crushing，and pre-concentration tailings discarding were carried out by using the fine crushed product（16~0 mm）from the beneficiation plant. Open circuit roller pressing tests showed that increasing the roll surface pressure could improve the fines yield，while the roll speed had little effect on the product particle size. Under closed circuit conditions with a roll sur⁃ face pressure of 9 MPa and a screen aperture of 3.0 mm，the circulating load was 61.50%，the throughput was 32.3 t/h，the unit energy consumption was 2.04 kW·h/t，and the -0.075 mm content in the undersize product reached 28.86%，indicating good ultra fine crushing performance. In the pre-concentration tests， dry magnetic separation of the oversize product could discard tailings with a yield of 17.45% and a magnet⁃ ic iron grade of 0.92%，while the magnetic iron recovery of the concentrate was 99.36%; wet magnetic sep⁃ aration of the undersize product could discard tailings with a yield of 38.49% and a magnetic iron grade of 0.45%，with a magnetic iron recovery of 99.23% for the concentrate，and the feed iron grade increased by 12.28 percentage points. Relative grindability tests showed that the wet magnetic separation concentrate from the HPGR undersize was easier to grind than the run-of-mine ore; when both were ground to 60% passing 0.075 mm，the relative grindability coefficient was 1.08. The HPGR-pre-concentration process can significantly improve ore grindability and achieve effective tailings discarding，thus it can serve as a basis for energy saving，consumption reduction，quality improvement and efficiency enhancement in the beneficiation plant of Heishangou Iron Mine.

Fine-grained phosphorus-bearing iron tailings are difficult to recover effectively because of their fine particle size and severe sliming，while long-term stockpiling results in resource loss and in⁃ creased environmental burdens. Their comprehensive utilization therefore remains a major challenge in phosphorus resource recovery. In this study，the overflow from a lamella thickener at a mineral processing plant was investigated using an integrated process comprising secondary hydrocyclone desliming，reverse flotation desulfurization，and direct flotation phosphorus recovery. The results showed that，using a Hai⁃ wang FX100 hydrocyclone with a 20 mm underflow spigot，the thickening and desliming process produced an underflow with a solids concentration of 27.03% and a yield of 67.36%. Subsequent treatment through a closed-circuit flotation flowsheet consisting of one roughing，four cleaning，and one scavenging stage yielded a phosphate concentrate with a grade of 28.06% and a recovery of 43.95%. The integrated process exhibited stable operation and relatively low reagent costs，and the resulting concentrate met the required commercial grade. The process effectively recovered phosphorus from fine-grained phosphorus-bearing iron tailings and provides a technical reference for the utilization of similar secondary phosphorus resources.

The concentrator plant of Chengchao Iron Mine adopts magnetic separation followed by flo⁃ tation flowsheet to produce copper，iron，and sulfur concentrates. Thickeners with diameters of ϕ75 m， ϕ65 m，and ϕ30 m are used to treat different pulp streams. In view of the frequent problems of overflow turbidity and underflow density failing to meet requirements in each thickener，a systematic investigation was carried out on the thickening circuit. The feed properties，including chemical composition of the feed ore，pulp pH，apparent Zeta potential，feed solids concentration and fineness，as well as operating param⁃ eters such as thickener rake speed and throughput，were emphatically analyzed. The results show that the feed contains large amounts of calcium sulfate（gypsum）and chain and layer structured silicate minerals such as wollastonite and chlorite，which are prone to water absorption and sludging. The feed fineness se⁃ verely exceeds the design limit. The actual throughputs of the ϕ65 m and ϕ75 m thickeners exceed their design capacities，causing long term overloading. These factors collectively lead to reduced thickening effi⁃ ciency and overflow turbidity. It is recommended to strengthen pre classification before grinding，optimize grinding media to control over grinding，introduce flocculation sedimentation to enhance fine particle aggre⁃ gation，and upgrade the peripheral drive thickeners of ϕ75 m and ϕ65 m to central drive types to improve thickening performance.

Taking the total tailings of a metal mine in China as the base material, 16 groups of speci⁃ mens were prepared by selecting the cement-sand ratio, slurry concentration and curing age as the main factors, and each factor had 4 levels. The orthogonal test was carried out to determine the uniaxial compres⁃ sive strength and reveal the influence of various factors on the strength. The results show that each factor of the test on the compressive strength of the filling body follows the order of influence is curing age > ce⁃ ment-sand ratio > slurry concentration, in which cement-sand ratio plays a decisive role in the ultimate strength of specimens. At a fixed concentration and age, the greater the cement-sand ratio, the more obvi⁃ ous the strength increase ; prolonging the age or increasing the slurry concentration also contributes to strength growth. The optimal ratio selected by the orthogonal test is the slurry concentration of 74%, the ce⁃ ment-sand ratio of 1:4, the age of 28 d, and the corresponding compressive strength of 2.697 MPa, which is the maximum value of all combinations. It should be noted that the high cement-sand ratio will increase the cost of materials, the increase of concentration will generally deteriorate the fluidity, and the energy con⁃ sumption of transportation will increase. The economy should be further weighed in the construction of fill⁃ ing system.