As the mining depth increases，the complexity of the mine ventilation system and the ven ⁃ tilation resistance significantly increase.Traditional ventilation risk control methods have problems such as low calculation accuracy and delayed emergency control.Intelligent optimization of ventilation risk control is one of the important ways to achieve safe and efficient operation in production.The research systematical⁃ ly reviewed the intelligent process of mine ventilation and focused on analyzing the research progress and existing bottlenecks of ventilation network calculation methods and air flow regulation technologies.The re⁃ sults showed that current intelligent ventilation still faces key challenges such as incomplete coverage of sensor information，insufficient efficiency of decision algorithms，unclear coupling mechanism of multiple physical fields，high difficulty in system integration，and the absence of a disaster emergency capability evaluation system.Based on this，from the four aspects of technology，system，standards and application， it was proposed that future mine intelligent ventilation should focus on the development of new sensors， multi-physical field coupling modeling，digital twin platform construction，standard unification in the in⁃ dustry，and emergency response assessment methods for deep complex environment systems.The research results can provide a reference for promoting the further development of mine ventilation safety，efficiency and intelligence.

In view of the relatively thin ore body at the north and south ends of Caolou Iron Mine，in order to avoid the arrangement of mining engineering in the 1st step filling body，reduce the middle mining preparation engineering，and ensure the safety of the high and middle section of the filling method，the structural parameters and stope stability are studied.Based on the investigation of the basic characteristics of mine rock mass and parametric processing，the 2nd step pillar mining scheme of north 4P and south 4P is designed.The rationality of stope span is analyzed by Mathews stability diagram method.The distribution of displacement，stress and plastic zone after mining in the middle section of -410 m and -350 m is simu⁃ lated by FLAC3D software，and the implementation effect is quantitatively evaluated by 3D laser scanning. The analysis of the relationship between the stability number of the roof and floor，ore body and filling body and the hydraulic radius of the stope by Mathews stability diagram method shows that the north 4P stope is 46 m long，23 m span，110 m high and 3.5 m wall protection pillar is set，and the south 4P stope is 30 m long，27 m span，110 m high and 2.5 ~3.5 m wall protection pillar is set.The structural parame⁃ ters of the two test stopes are reasonable and the stope can be kept stable.The maximum displacement of numerical simulation is small and concentrated in 1/3 of the hanging wall in the middle of the room and the top pillar，which are 4.48 cm and 5.56 cm respectively.The minimum tensile stress of the surrounding rock is 2.45 MPa and 3.1 MPa respectively，and the maximum compressive stress is 31 MPa and 27.5 MPa respectively，which do not exceed the strength of the surrounding rock.The distribution of plastic zone in stope is controllable.In the industrial test，there was no collapse of the filling body，the size of the empty area met the design requirements，the recovery rate was 90%，and the waste rock mixing rate was 7%.The study verified the technical feasibility of the 110 m parallel mining of the 2nd step pillar，and provided a theoretical basis and engineering reference for the efficient and safe mining of the 2nd step stope under sim⁃ ilar surrounding rock conditions.

After the conversion of an open-pit mine to a underground mine，in order to determine the reasonable safe thickness of the isolation pillars，various theories such as the K.B Rubeneyi method， the thickness-span ratio method，and the load transfer intersection line method were used to calculate the thickness of the boundary isolation pillars to be 12.0 ~14.33 m.Combined with similar engineering cases from both domestic and international sources，the reasonable thickness of the isolation pillars for this mine was finally determined to be 15 m.A three-dimensional numerical model was established for verification， and the impact of underground mining on the stability of the open-pit slope and the isolation pillars was an ⁃ alyzed.The simulation results show that after underground mining，the maximum surface displacement is generally at the millimeter level，the plastic distribution is mainly dominated by a stable plastic zone，the maximum minimum principal stress is much smaller than the tensile strength of the rock mass itself，and the stress concentration phenomenon is not obvious.The open-pit slope can maintain good stability，and no obvious failure characteristics are observed.The cross-sectional analysis of the top and bottom of the isolation pillar shows that the 15 m thick isolation pillar forms an effective stress buffering and deformation coordination structure，which reduces the stress disturbance of underground mining on the open-pit bot ⁃ tom，has certain safety，and can ensure the overall stability of the slope and production system of the open-pit to underground mining.Based on the comprehensive analysis of theory，engineering analogy，and numerical simulation results，it is recommended that the isolation pillar thickness for the open-pit to un ⁃ derground mining conversion of this mine be 15 m.The research and application of the reasonable thick ⁃ ness of the isolation pillar for the open-pit to underground mining conversion of this mine can provide tech ⁃ nical support for this mine's open-pit to underground mining.

In order to deeply understand the expansion deformation mechanism during the use of ar ⁃ gillaceous soft rock tunnels in skarn，and to evaluate the influence of clay minerals on the expansion char ⁃ acteristics of skarn.Firstly，sample rock point load tests and mineral composition analysis were conducted to clarify the composition and content of expansive minerals in skarn.Secondly，skarn with different clay mineral contents were selected，and the side-limit expansion rate method was used for measurement，and the relationship between the expansion characteristics of skarn and the type and content of clay minerals was analyzed.The test results showed that the maximum expansion rate of skarn with different clay mineral compositions within 100 h was 99.32%，and the minimum was 19.26%.The test results indicated that the influence degree of clay mineral composition on the expansion rate of skarn ranged from strong to weak: chlorite >kaolinite >limonite.The expansion modification test research using clay stabilizers was carried out，and it was shown that the free surface pressure of the clay stabilizer had a significant inhibitory effect on the expansibility of chlorite.For the skarn waterlogged tunnel，a new technology of surrounding rock modification +anchor-net-spray combined support was proposed.Engineering tests showed that the modi⁃ fied anti-expansion combined support technology could effectively extend the service life of skarn soft rock tunnels，and could be further promoted and applied.

As the mining depth of mineral resources continues to increase，the stability of large-sec⁃ tion deep soft rock chambers has become one of the main technical challenges faced in mineral mining.Tra⁃ ditional support methods often exhibit significant deformation and failure when dealing with soft and frac ⁃ tured surrounding rocks under high stress and strong mining-induced influence，failing to ensure the long term stability of the chambers.The second-phase construction project of Zhongjiu Iron Mine is a typical project in complex strata.The complex strata have significant differences in rock properties，with devel⁃ oped faults and fractures，and the surrounding rock in the mining area is mainly composed of Class IV ba ⁃ sic rocks，with poor rock integrity and a hardness coefficient ranging from 2 to 9，belonging to a weak rock group.In response to major safety issues such as the difficulty in supporting and large deformation of the roof of the underground -550 m level central water pump room and similar large chambers in the mine，the upper extremely fractured roof of the water pump room was supported by "advanced pipe frame +steel truss +long anchor cables +deep and shallow hole grouting"，and the arch roof was constructed by grouting and full-length anchoring of the anchor cables.Field application shows that this combined support technology can effectively control the deformation of the surrounding rock of the chamber，significantly improve the bearing capacity and deformation resistance of the support structure，and provide a reliable solution for the support of deep soft rock chambers.The study conducted a detailed discussion on the key technical parame ⁃ters，construction techniques，and application effects of the combined support，with the aim of providing reference and inspiration for the design and construction of chamber support in similar conditions.

Longqiao Iron Mine is in the stage of transition from mining to caving.In order to ensure the stability of deep caving，the distribution law of ground stress below the -420 m section of Longqiao Iron Mine was studied by the method of hollow package body strain through field tests.The results of the study show that the maximum principal stress at the 1#to 6#measuring points of Longqiao Iron Mine is 15.20 MPa， 17.13 MPa，17.47 MPa，19.98 MPa，23.58 MPa and 21.72 MPa respectively，and the maximum principal stress is generally close to the horizontal direction.The maximum principal stress at the western area of the -437.5 m and -472.5 m sections is greater than that at the eastern area，while the opposite is true at the -490 m section，the maximum principal stress at the western area is less than that at the eastern area，and the area with the maximum principal stress is located at the western area of the -490 m section，with the maximum principal stress value of 23.58 MPa.The original rock stress of Longqiao Iron Mine increases con ⁃ tinuously with the increase of burial depth，among which the -490 m section has a greater increase com ⁃ pared with the -472.5 m section，indicating that the value of ground stress in the mine area is greater than the self-weight stress of the overlying rock and soil，which belongs to medium high ;the ground stress field in the mine area is also affected by the geological structure，rock type and the shape of the ore body and other factors.According to the distribution law of ground stress，corresponding measures are put forward to provide the basis for the safe production of the mine.

As the mining depth of the Tong—Man Open-pit Mine increases，the proportion of diffi⁃ cult-to-blast rock increases.To address the problems of poor connection between hole blasting and subse ⁃ quent processes，as well as poor blasting quality，the 3DMine mining engineering software was adopted to implement a detailed blasting network design.In combination with the complex geological conditions of the mining area and production requirements，research and optimization were conducted on the perforation blasting technology from aspects such as optimizing the operation organization，improving the compatibility of mine rock and blasting technical parameters，and improving the blasting construction process.Through research and practice，an operation mode of alternating planning of blasting areas and organizing perfora ⁃ tion blasting construction was gradually formed.Combined with the geological differences between the blasting working face and the blasting area in the mining area，high-precision digital electronic detona ⁃ tors，3DMine software，and PVC pipe for protecting holes were used，effectively improving the quality of drilling boreholes and blasting，enhancing the efficiency of construction organization，improving the conti⁃ nuity of the perforation and blasting process and subsequent loading and transportation equipment opera ⁃ tions，and reducing the rate of safety accidents and overall costs.The practice shows that after optimiza ⁃ tion，the dynamic average of mining and stripping reserves in the mining area has increased to more than 1.22 times the current production plan ;the efficiency of 15 m³electric shovel shifts has increased by 15% compared with the same period last year，and the production efficiency of 4.5 m³excavator shifts has in⁃ creased by 11%compared with the same period last year;the accident losses caused by the influence of floating stones and scattered rocks on equipment have decreased significantly compared to 4 years ago;af⁃ ter the improvement of blasting technical parameters，the single consumption of explosives has decreased significantly.Overall，production costs have been saved by 9.52 million RMB per year，which can provide a reference for similar open-pit mines.

In the trenching blasting operations of large deep open-pit mines，to address the common problems such as insufficient looseness of the blasting piles，significant post-blast erosion，and higher blasting vibration intensity compared to other operation areas，based on the actual blasting cases of Nanfen Open-pit Mine and Limestone Mine，the blasting technology was innovatively applied by focusing on the optimization of the blasting parameters and the blasting method.In the selection of the blasting method， the applicable scenarios of vertical blast holes and inclined blast holes were compared and analyzed，and on this basis，three core technical means were adopted to improve the effect.First，the upper free surface was fully utilized to guide the blasting energy to be released in the predetermined direction，reducing inef⁃ fective impacts.Second the delay time，was reasonably controled，and adopted the millisecond delay initia ⁃ tion technology to make adjacent blast holes ignite successively，reducing mutual interference and improv ⁃ ing the dispersion degree of the blasting pile.Third，strictly controled the amount of explosives detonated simultaneously，was the single-stage detonation amount within the safety threshold was bept，reducing the blasting vibration intensity from the source.The application results show that the implementation of this technology has brought significant benefits，increasing the bucketing efficiency by approximately 30%，re⁃ ducing the post-blast erosion distance from 8 ~10 m to 2 ~5 m，achieving a dispersion degree of 1.4 ~1.5， reducing the blasting vibration intensity by more than 30%，effectively protecting the stability of the sur⁃ rounding slopes，significantly reducing the impact on important buildings and residential areas around， creating considerable economic benefits，and providing strong support for the safe and efficient mining of large deep and deep-cut open-pit mines.

In the layered mining of coal mine working faces，the overlying rock structure and stress field formed by the mining-induced subsidence of the upper working face will have a significant impact on the mining of the lower working face.To ensure the safe mining of the lower working face，based on the 2- 1 section 2109 working face of Jining Coal Mine，this study uses methods such as drilling observation，nat⁃ ural gamma（GR）rock type identification，and UDEC numerical simulation to analyze and study the rock layer structure of the layered mining working face，the fragmentation of the goaf area，and the movement of the overlying rock caused by the excavation of the working face.The research results show that the overly ⁃ ing rock layer of the 2#coal is a mutual layer structure of sandy mudstone and mudstone，which is prone to collapse and is beneficial for the mining of the lower working face.After the upper working face is mined， the roof collapses relatively fully，but the cementation degree is poor.After the upper layer mining，there is a stress concentration situation in the lower coal body below the remaining coal pillar.When the lower working face cuts through the coal pillar influence area，the stress concentration area shifts towards the edge of the goaf，which is likely to aggravate the risk of coal wall spalling and end face collapse.The study reveals the interrelationship between the movement of the overlying rock and the stress distribution under the condition of layered mining of thick coal seams，and proposes that for the lower working face mining under such conditions，the stability of the false roof and the influence of the coal pillar stress should be giv ⁃ en special attention，providing a reference for the safe mining of the lower working face under similar con ⁃ditions.

In order to accurately identify the extent of the loosening circle of the water-rich soft rock roadway at the -550 m level of the Zhongjiu Iron Mine，and to guide the support parameter design of unloading chamber，the following work has been carried out.A loose ring survey was conducted at the -550 m level using sonic and borehole imaging methods.Three sets of sonic tests and two sets of borehole imaging tests were designed and analyzed to determine the extent of the loosening ring.A simulation study on support scheme of unloading chamber was carried out based on it.The results show that the joint testing method is more effective in carrying out the test of the loose circle range of the roadway.The ultrasonic wave velocity and structural surface morphology information of different test hole depths were obtained by the sonic method and the borehole imaging method，respectively.The comprehensive analysis can accu ⁃ rately detect the loose circle range of the roadway.The loosening circle of the -550 m level roadway of Zhongjiu Iron Mine ranges from 2.2 to 5.2 m，accounting for 0.6 to 1.5 times of the roadway span.A con⁃ trol scheme for chamber deformation was proposed，and its effectiveness was verified by numerical simula ⁃ tion .

In response to the complex top coal collapse morphology，unclear coal-rock boundary， and unstable coal release efficiency in the comprehensive mining face of the Pangpangta Mine with a steep coal seam，the 1029 working face was selected as the research object to conduct research on the optimiza ⁃ tion and application of the coal release process.By establishing a top coal release body morphology model and constructing the PFC2D numerical simulation platform，the top coal collapse behavior and coal-rock boundary characteristics under different coal seam thickness and inclination combinations were analyzed， revealing the coupling relationship between the release body structure evolution and recovery efficiency . Based on this，the influence of four coal release methods on the release effect was simulated and com ⁃ pared，and it was clearly identified that the "two-stage sequential descent"coal release method had a high ⁃ er top coal recovery rate and clearer boundary.Combined with on-site experiments for verification，after optimizing the coal release process，the top coal recovery rate increased from 82.3%to 89.7%，an increase of 7.4 percentage points.The stability of the supports was enhanced，and the utilization rate of the coal source and the cycle efficiency were also improved.

The shallow ore rock in Zhongjiu Iron Mine is weak and broken，and the traditional sub⁃ level open stoping with subsequent filling mining method faces a serious risk of collapse.In order to im ⁃ prove the safety and efficiency of mining，aiming at the downward drift filling mining method，FLAC3D fi⁃ nite element numerical simulation is used to analyze the dynamic changes of stress and displacement of ar ⁃ tificial false roof and pillar under different drift width (4 .0 ~5.0 m)and height (3 .8 ~5.0 m).The safety factor (ratio of ultimate tensile strength to maximum tensile stress)is used to evaluate the stability of stope.The re⁃ sults show that the maximum displacement and maximum tensile stress of the stope increase with the in ⁃ crease of the width and height of the approach.The safety factor of the original rock pillar is 0.86 ~1.25， and the safety factor of the artificial false roof is 1.37 ~1.86.The safety factor of each scheme is greater than 1.0 in the two-step mining.Considering the safety and mining efficiency，the recommended stope structure parameters are 4.5 m wide and 4 m high (Scheme 5).The safety factor of artificial roof under this scheme is 1.53，which meets the stability requirements.The research results provide a scientific basis for the optimi ⁃ zation of stope structure parameters in Zhongjiu Iron Mine.

To explore the along-path resistance characteristics of the filling slurry during the filling process，study the influence of different ash-sand ratios on the along-path resistance of filling and deter ⁃ mine the slip coefficient，rheological experiments were conducted on different filling slurries of Fankou lead-zinc mine，and a rheological model was established.The on-site measured data was collected through the pressure gauge，and the wall slip coefficient was obtained from the on-site measured data to correct the rheological model.The results show that the tailings paste belongs to Bingham fluid.The along-path resis⁃ tances of the three types of tailings all increase with the increase of the ash-sand ratio.The magnitude rela⁃ tionship is:mixed tailings (4 .99 MPa /km)>fine-grained tailings (4 .19 MPa /km)>graded tailings (3 .14 MPa/km).During the slurry transportation process，there is a phenomenon of wall slippage.Classified by the type of tailings，without considering the influence of the ash-sand ratio，the slippage coefficients of graded tailings，fine tailings and mixed tailings are 0.86，0.88 and 0.84 respectively.Based on the rheolog⁃ ical models of the three types of tailings corrected by the slip coefficient，the drag errors along the way were calculated to be 7%，4%，and 5%respectively.The rheological model corrected by the slip coeffi ⁃ cient is more accurate and has smaller errors.

In order to solve the problems of poor stability of surrounding rock，complex geological structure and unclear in-situ stress conditions in the deep mining process of a lead-zinc mine in Longling County，Yunnan Province，ZK10306 borehole in the first mine section of the mining area is taken as the research object，and the in-situ stress test of five measuring sections was carried out in the depth range of 496.0 ~579.0 m by hydraulic fracturing method.Combined with impression test，linear fitting and Jethwa surrounding rock extrusion deformation classification method，the distribution characteristics of deep in-si⁃ tu stress and Rock Burst Risk in the mining area are systematically analyzed.The test results show that the vertical principal stress(Sv)，the maximum horizontal principal stress (SH)and the minimum horizontal princi⁃ pal stress(Sh)in the mining area increase linearly with the increase of depth.The three-dimensional princi⁃ pal stress relationship is Sv>SH>Sh，in which the maximum horizontal principal stress is 10.74 ~13.65 MPa， and the minimum horizontal principal stress is 7.32 ~9.03 MPa.The dominant direction of the maximum horizontal principal stress is northwest，and the stress structure type belongs to normal fault type.The strength stress ratio Rc/Smax of surrounding rock is between 0.74 and 0.94.The deep limestone and sand⁃ stone layers are mainly medium extrusion deformation，and the local part is slight extrusion deformation， which has certain extrusion failure and rock burst risk.The research results can provide reliable ground stress basis and theoretical support for the support design，mining layout optimization and geological disas ⁃ ter prevention and control of deep roadway in this lead-zinc mine.

In order to solve the problem that it's difficul to adopt traditional smooth blasting（requir⁃ ing the full-hole installation of bamboo strips and detonating cords，which is costly and involves complicat⁃ ed procedures）in small and medium-sized underground mines，due to their narrow tunnel sections and complex geological conditions，based on the engineering background of the Huaaobaote Ag-Pb Mine in In ⁃ ner Mongolia，low-cost and efficient smooth blasting technology without bamboo strips and detonating cords is proposed.Through theoretical analysis and numerous industrial tests，the explosive loading struc⁃ ture of the smooth blasting holes is optimized，the thickness of the smooth blasting layer（625 mm），the hole spacing（500 mm），and the line explosive density（150 g/m）are reasonably designed，and the maxi⁃ mum stable detonation distance of ϕ32 mm emulsion explosives in 4.0 m deep holes（1 050 mm）are fully utilized.A three-stage air interval filling structure combined with hole mouth blocking is adopted.The en⁃ gineering application results show that this method successfully eliminates bamboo strips and detonating cords，reducing the single-cycle operation time by 1.8 h，lowering labor intensity by 37%，and reducing the direct blasting cost by 50%（saving 235 RMB/m）;the semi-hole formation rate of the tunnel increases to over 92%，the contour over-cutings and under-cuttings are controlled within ±10 cm，the damage depth of the surrounding rock is reduced by 35%，the support engineering volume is reduced by 22%，and the formation quality reaches the leading level in the industry.This technology simplifies the process，is low in cost，and has stable effects，providing a replicable and easily-promoted green and efficient smooth blasting solution for small and medium-sized mines.

For the low utilization rate and difficult separation of a low-grade silver-vanadium ore re ⁃ source in Yichang，Hubei，copper and vanadium separation tests were conducted based on systematic pro ⁃ cess mineralogical analysis.The results showed that the ore has an Ag grade of 65.57 g/t，mainly occurring in pyrite，and a V2O5 grade of 0.65%，primarily hosted in potassium feldspar.Shaking table and spiral chute gravity separation tests indicated that gravity separation could not achieve the separation and enrich ⁃ ment of silver.Flotation condition tests revealed that at the grinding fineness of -0.074 mm accounting for 77.19%，using butyl xanthate +butyl ammonium aerofloat as the combined collectors and No.2 oil as the frother，closed-circuit test consisting of one roughing，two cleanings，and two scavenging stages with mid ⁃ dlings returned in sequence，silver concentrate with Ag grade of 675.25 g/t and recovery rate of 16.89% was obtained.Meanwhile，the recovery rate of vanadium in the tailings reached 98.86%，achieving partial recovery of silver from the silver-vanadium ore.The research results provide technical reference for the subsequent development and utilization of this silver-vanadium ore.

As mining depth increases in a domestic iron mine，the proportion of siderite-bearing iron ore rises.Due to its easy sliming characteristics，the traditional single reverse flotation process is un ⁃ able to produce qualified iron concentrate.To ensure stable operation of the processing plant and improve iron resource recovery，an optimization study on the beneficiation process of siderite-bearing iron ore was carried out based on process mineralogy analysis.The raw ore has an iron grade of 29.84%，with iron minerals mainly composed of hematite and limonite，accounting for a distribution rate of 54.26%.The sid⁃ erite content is 5.45%，with a distribution rate of 18.26%.The iron minerals are finely disseminated with a relatively narrow particle size distribution.A process of stage grinding—stage magnetic separation— stepwise flotation of mixed magnetic concentrate was adopted.Under the conditions of a grinding fineness of -74 μm accounting for 60%，a first-stage low-intensity magnetic separation field intensity of 135 mT， a high-intensity magnetic separation field intensity of 1.0 T，a tower mill grinding fineness of -45 μm ac⁃ counting for 90%，a second-stage low-intensity magnetic separation field intensity of 125 mT，and a high-intensity magnetic separation field intensity of 1.0 T，a mixed magnetic concentrate was obtained. Subsequently，through a process of direct flotation—reverse flotation of underflow—reverse flotation of froth，an iron concentrate with a yield of 26.62%，an iron grade of 65.36%，and a recovery rate of 58.31%was ultimately achieved，with an integrated tailings iron grade of 16.95%.The research results provide technical support for the efficient separation of siderite-bearing iron ore and have promising indus ⁃ trial application prospects.

In order to realize the synergistic recovery of iron，titanium and other strategic metal re ⁃ sources in a low-grade vanadium-titanium magnetite in Western Panzhihua，the mineral composition，dis⁃ semination characteristics and occurrence state of harmful elements of the ore were identified by means of chemical multi-element analysis，X-ray diffraction，optical microscopy and scanning electron microscopy. On this basis，the magnetic flotation combined process of three-stage grinding and step separation-magnet ⁃ ic separation tailings floating titanium was designed for closed-circuit test.The results show that the ore grade of TFe,TiO2,S and P is 15.19%,6.81%,0.36%and 1.24%,respectively,which belongs to the gab⁃ bro type high titanium lean ore.The main valuable minerals of the ore are titanomagnetite and ilmenite. The gangue is mainly composed of pyroxene,feldspar and chlorite.Phosphorus mainly occurs in apatite. The ore structure is complex,with meteorite structure,embedded crystal structure and solid solution separa ⁃ tion structure.Fine flake and tabular ilmenite exsolution are developed in titanomagnetite.Apatite often oc⁃ curs in the form of inclusions in the target minerals,which is the key factor affecting the quality of concen ⁃ trate.The vanadium-titanium magnetite concentrate with TFe grade of 55.94%and recovery of 37.75%can be obtained by three-stage grinding.The titanium concentrate with TiO2 grade of 47.26%and recovery rate of 23.23%was obtained by three-stage high-intensity magnetic separation-low-intensity magnetic separa⁃ tion-sulfur removal-one roughing and four cleaning flotation process for magnetic separation tailings，and the phosphorus content was reduced to 0.026%.The process realizes the efficient separation and synergis ⁃tic recovery of iron and titanium resources，and effectively controls the phosphorus impurities，which pro⁃ vides a technical reference for the clean utilization of similar refractory high phosphorus vanadium titano ⁃ magnetite.

A domestic concentrator now produces an iron concentrate with TFe grade of 70.08%and main impurity SiO2 content of 1.13%.The main iron mineral is magnetite，accounting for 98.92%.In order to determine the feasibility of processing this iron concentrate to produce ultra-pure iron concentrate，a systematic beneficiation test was carried out.The results show that the content of -0.076 mm in iron con⁃ centrate is 79.82%，the dissociation degree of coarse-grained monomer is low，the iron grade is low and the SiO2 grade is high.In order to obtain high-quality ultra-pure iron concentrate，fine grinding and deep separation must be carried out.The combined process of ball mill grinding（-0 .038 mm 95%）-one rough⁃ ing-one cleaning low-intensity magnetic separation-elutriation magnetic separation-one roughing-one cleaning reverse flotation was adopted.When the magnetic field intensity of low-intensity magnetic rough ⁃ ing was 128 kA/m，the magnetic field intensity of cleaning was 80 kA/m，the rising water volume of wash ⁃ ing was 1.0 m3 /h，the dosage of sodium carbonate in reverse flotation was 500 g/t，the dosage of MK618 roughing was 140 g/t and the dosage of cleaning was 60 g/t，the ultra-pure iron concentrate with yield of 32.60%，iron grade of 71.55%and SiO2 grade of 0.136%was obtained.This process provides a reliable technical basis for the industrial production of ultra-pure iron concentrate.

Aiming at the characteristics of very fine dissemination size，complex mineral dissemina⁃ tion relationship and difficult separation of a domestic refractory magnetic hematite mixed iron ore，the pro⁃ cess flow of stage grinding and stage separation was explored.The total iron grade of the raw ore is 31.52%，of which the distribution rate of magnetic iron is 62.31%，and the distribution rate of hematite is 27.54%.Through the roughing condition test，the primary grinding fineness of -0.074 mm is 50%，and the magnetic induction intensity of roughing is 500 mT.A selected magnetic induction intensity is 250 mT，the second stage cleaning adopts the fine sieve (0 .106 mm)screening and 200 mT magnetic separation scheme under the sieve，which can obtain higher grade concentrate than the elutriation magnetic separation meth ⁃ od.The middle ore in each section was combined and finely ground by tower mill to -0.038 mm accounting for 95%，and then subjected to one roughing and one cleaning scavenging (magnetic induction intensity was 500 mT and 250 mT，respectively ).Two kinds of iron concentrate were obtained by the whole process verification test.The yield of concentrate 1 was 25.31%，the total iron grade was 53.18%，and the total iron recovery was 41.20%.The yield of concentrate 2 was 16.74%，the total iron grade was 44.41%，and the total iron recovery was 22.76%.The total iron grade of the tailings was 18.14%，and the magnetic iron grade was 2.81%.The results show that the step grinding and step separation-medium ore regrinding and reconcentration process can effectively recover the iron resources in the fine-grained maghemite mixed iron ore，which provides a technical reference for the industrial separation of this kind of ore.

Aiming at the problems of high proportion of fine-grained tailings (-0 .025 mm content≥ 90%)and difficult recovery of molybdenum from a molybdenite concentrate tailings in Henan Province，cy⁃ clone-static microbubble flotation column was used to carry out fine-grained enhanced recovery test and industrial application research.The suitable process parameters were determined by single factor condition test in the laboratory:flotation time was 13 min，circulation pressure was 0.10 MPa，foam layer height was 25 cm，self-priming air inflow was 0.3 m3/h (opening 2/3)，copper inhibitor TT-1 dosage was 20 g/t.Un⁃ der this condition，the grade of molybdenum concentrate was 1.94%and the recovery rate was 79.65%. Based on Box-Behnken design，a quadratic regression model of molybdenum recovery rate was estab ⁃ lished.Variance analysis showed that the model was significant.The influence weight of factors is circulat⁃ ing pressure>foam layer height>flotation time.The average recovery rate of molybdenum obtained by the op ⁃ timization verification test was 80.62%，which was in good agreement with the predicted value.The results of 14 consecutive shifts in the industrial test showed that after the optimization of the flotation column pro ⁃ cess，the molybdenum grade of the molybdenum concentrate tailings decreased from 0.470%to 0.165%， the actual recovery rate increased to 88.15%，and the crude recovery rate of molybdenum sulfide reached 89.63%.This technology provides a feasible solution for the efficient recovery of fine-grained refractory mo ⁃ lybdenite and has a good application prospect.

In order to implement the concept of green mine,achieve the goal of emission reduction and efficiency increase,improve resource utilization rate and energy saving and consumption reduction , and draw lessons from the successful application of high pressure roller grinding-dry magnetic separation process in other mines,a systematic dry grinding and dry separation test was carried out for lean magnetite ore in Waitoushan Iron Mine.The effects of different screening particle sizes (3 mm and 5 mm)and whether the middle ore returns on the separation index were investigated ,and the key process parameters were opti⁃ mized.The results show that the return of medium ore can effectively improve the metal recovery rate ,and 3mm screening is more conducive to improving the tailings rate and achieving deep tailings discarding. Combined with the demand of reducing tailings and improving efficiency in Waitoushan Iron Mine ,it is rec⁃ ommended to adopt the closed-circuit process of dry grinding and dry separation with 3 mm sieve hole and middle ore return.This scheme can achieve excellent metal recovery rate and significant tailings discarding effect while ensuring high concentrate grade,which provides an important technical basis for subsequent in ⁃ dustrial application and clean production.

A systematic study on process mineralogy and beneficiation technology was conducted on a low-grade，high-calcium-type fluorite ore from Kazakhstan.The fluorite content in the ore was 18.04%， while the main gangue mineral，calcite，accounted for as high as 45.28%.The two minerals exhibited simi⁃ lar floatability and complex intergrowth relationships，making their separation particularly challenging.Un⁃ der the condition of a grinding fineness of 70%passing 0.074 mm，using ZH-T01 as a regulator，ZH-Y02 as a depressant，and oleic acid as a collector，a closed-circuit flotation process consisting of one rough ⁃ ing，seven cleaning，and two scavenging stages was employed.The obtained fluorite concentrate had a CaF₂ grade of 97.08%with a recovery of 87.24%，while the CaCO ₃content was reduced to 0.89%，meeting the quality requirements for acid-grade fluorite powder.The research results provide a feasible technical path ⁃ way for the efficient utilization of such resources.

In response to the challenges of low recovery rate and severe fine mud interference in the beneficiation of a low-grade,high-mud,and finely disseminated iron ore in China,process optimization research was conducted to improve the total iron recovery rate and obtain qualified iron concentrate. Based on the analysis of ore properties,systematic conditional experiments were carried out on grinding fineness,magnetic induction intensity,and screening pretreatment.A screening-stage grinding and separa ⁃ tion process was introduced.The results showed that with a primary rough grinding fineness of 40%pass⁃ ing -0.074 mm,a magnetic separation process consisting of one roughing ,two cleaning,and one scavenging was adopted,with a 0.15mm closed-circuit screening step added between roughing and cleaning.The closed-circuit full-process test ultimately achieved an iron concentrate with a TFe grade of 50.21%,a TFe recovery rate of 66.25%,and a magnetic iron recovery rate of 91.23%.The optimized stage grinding screening-multi-stage magnetic separation process,by controlling grinding fineness to suppress mudding, recovering qualified fine particles in advance through screening ,achieved efficient separation of finely dis ⁃ seminated and easily mudding iron ores.While ensuring the concentrate grade,it significantly improved the metal recovery rate,providing technical support for the industrial utilization of similar or

To ensure the safe operation of a certain open-pit coal mine，multiple sources of monitor⁃ ing data were integrated to conduct a time correlation analysis of the GNSS，slope radar，rain gauge，and water measurement weir data from the deformation area of the northern slope of the mining area.This fur⁃ ther analyzed the causes of the deformation in this area and quantitatively studied the slope stability of this area through numerical simulation.The results show that due to rainfall and the infiltration of water from the upper dump area，the groundwater level in the northwest loop area of the northern slope of the mining area has risen，which in turn triggered slope deformation.When the groundwater level in the core of the deformation area decreased from 1 153 m to 1 140 m，the safety factor increased from 1.057 to 1.207，in⁃ dicating that the groundwater level is an important influencing factor for the stability of the slope in this ar ⁃ ea.The numerical simulation results are consistent with the slope monitoring results，verifying the effec⁃ tiveness of the multi-source data fusion analysis in revealing the causes of slope deformation.The study proposed measures for preventing slope deformation，which can provide some references for slope treat ⁃ ment.

The existing numerical calculation methods for slope stability only consider the overall re ⁃ duction strength of rock layers，lacking the analysis of the influence of joint orientation and strength.Tak⁃ ing a high-angle rock slope of an open-pit mine as the research object，a comprehensive evaluation of slope stability based on rock joints was carried out to improve the accuracy of slope stability analysis. Based on engineering investigation，indoor experiments，and theoretical analysis，the rock mechanical pa⁃ rameters were obtained，and the finite difference numerical simulation method was combined.The calcula⁃ tion results of the Ubiquitous-Joint model and the traditional Mohr-Coulomb model under three working conditions (natural，blasting，and earthquake)were compared.The strength reduction method was adopt⁃ ed，and the "binary search"iterative strategy was written in FISH language to calculate the safety factor. The displacement field and the distribution characteristics of the plastic zone were analyzed.Under the three working conditions，the safety factors calculated by the two models both met the specification require ⁃ ments，but the Ubiquitous-Joint model results were more conservative.The Ubiquitous-Joint model shows that there is shear failure along the joint surface in the slope interior，the displacement concentration range is larger，and the distribution of the plastic zone is more in line with the actual situation of the rock mass with joints.The overall slope did not form a continuous potential sliding surface and was in a stable state. The study shows that the Ubiquitous-Joint model has higher accuracy and applicability in analyzing the sta ⁃ bility of jointed rock slopes，and can effectively reflect the influence of joints on the stability of the slope. The research results verify the rationality of the current slope design in the mine，and the proposed "joint control -strength reduction"coupling analysis technical route provides a scientific basis for the stability evaluation of similar open-pit mine slopes，and is of great significance for achieving safe mining and pre ⁃ cise slope management in the mine.

A landslide in a certain open-pit mine in the Democratic Republic of the Congo was se ⁃ lected as the object of the study.The research systemically analyzed the causes and mechanisms of the landslide on the open-pit slope，and based on the limit equilibrium analysis method and 2D finite element analysis method，the stability of the existing landslide body was evaluated.At the same time，a comprehen⁃ sive treatment plan of "slope cutting and load reduction +interception drainage +anti-seepage"was pro ⁃ posed and implemented on-site for treatment.The research results show that the slope collapse is the result of the combined action of multiple disaster-causing factors，mainly including geological structure fragmen ⁃ tation，weak rock quality，and rainfall-induced seepage，etc.The overall slope failure process presents a composite failure mode of local collapse -traction-type sliding -push-type sliding.Local collapse of the lower step triggers traction-type landslide failure of the upper step，and the accumulated landslide body generated by the collapse exerts a large thrust on the lower platform，causing push-type landslide failure of the lower platform，thereby leading to the occurrence of landslide disasters.Based on the numerical simula⁃ tion results of Slide and Phase，before the treatment，the safety factor of the slope was close to the critical state，and there was potential instability，urgently requiring slope treatment.The "slope cutting and load reduction +interception drainage +anti-seepage"comprehensive treatment plan was adopted to conduct construction treatment on the eastern landslide body.After long-term observation during the rainy and dry seasons，the stability of the treated slope was good，indicating that the treatment plan was truly effective. The research results can provide scientific basis and engineering reference value for the treatment of open pit mine landslide disasters in the Democratic Republic of the Congo and similar geological conditions.

To address the dual challenges of environmental risks caused by the storage of mine tail ⁃ ings and the instability of subsidence areas，and in response to the key influence of the control of the ratio of sand to cement on the dynamic mechanical properties and engineering applicability of the filling body，a Separated Hopkinson Pressure Bar（SHPB）dynamic impact test system was adopted to compare and ana ⁃ lyze the strength evolution laws and energy dissipation mechanisms of filling bodies with a ratio of 1 ∶4，1 ∶6， and 1 ∶8 under high strain rate loads.The research results show that at the same strain rate，increasing the sand-cement ratio increases the dynamic compressive strength by 13.5%to 107.4%，and reduces the impact damage degree.The analysis of impact failure morphology indicates that the high sand-cement ratio（1∶4） specimens exhibit brittle crushing failure，while the low sand-cement ratio（1 ∶8）specimens show axial splitting-shear composite failure.The study on energy dissipation mechanism reveals that under the same incident energy conditions，the energy absorption rate of the 1 ∶8 sand-cement ratio specimens is 43.75% higher than that of the 1 ∶4 specimens，verifying the ductile characteristic of the high sand-cement ratio filling body in dissipating impact energy through plastic deformation.Engineering applications demonstrate that through collaborative treatment of subsidence areas，this technology can reduce the accumulation vol⁃ ume of tailings by 85%，and the strength of the filling body after 28 d can reach 2.1 MPa.The research confirms that optimizing the sand-cement ratio to 1 ∶6 and 1 ∶8 can not only meet the dynamic bearing re ⁃ quirements but also achieve energy dissipation balance，providing theoretical support for the construction of a tailings-free mining mode.

To address the issues of insufficient coverage and limited abnormal data in the early explo ⁃ ration of the Nanqi iron mining area in Lingqiu County，it is necessary to clarify the spatial distribution， extension characteristics，and deepening patterns of the magnetite deposits，in order to provide scientific guidance for subsequent geological exploration.The study employed ground high-precision magnetic mea ⁃ surement technology，setting up a dense measurement network to collect magnetic anomaly data.At the same time，upward extension processing was used to eliminate shallow interference and highlight deep min ⁃ eral body information.The inversion method of human-computer interaction was applied to conduct quantita ⁃ tive analysis of the magnetic anomalies.Through detailed data processing and systematic analysis，5 signifi⁃ cant magnetic anomaly areas were successfully delineated.Among them，the 5#anomaly area is distributed in a north-westward direction，with a length of approximately 650 m and a width of 100 ~370 m.The anoma⁃ ly center has a ΔT ≥20 000 nT.The ore body is mainly distributed in the uplifted end of the anticline struc ⁃ ture and its two wings.The ore body is stable and concentrated，with a large extension，and has a certain scale.The C4 anomaly is caused by the relatively concentrated，parallelly arranged，deep and extended magnetite ore bodies that are inclined towards the south-west.Although it is a low-amplitude anomaly，it is actually the eastward extension of the northern anomaly belt due to the folding and structural influence of the iron-bearing rock strata.The 1#~3#anomaly areas have relatively smaller scales and shorter extensions. Comprehensive studies have shown that the high-precision magnetic survey technology can effectively iden ⁃tify the spatial distribution patterns of deep magnetite ore bodies，and the delineated anomaly areas pro ⁃ vide a reliable basis for the selection of iron ore exploration targets.It is recommended to prioritize the drill⁃ ing verification of the 5#anomaly area，laying the foundation for the estimation of the resource quantity and development planning of the mining area.

With the increasing demand for mineral resources，deep mining has become an inevitable trend in the development of the mining industry.However，the problem of mine heat hazard seriously threatens the safety of underground operations and production efficiency.Taking the Xindongzhuang mining area as the research object，this study systematically analyzed the causes and heat source characteristics of deep mine heat hazard，combined with on-site investigation and numerical simulation methods，and devel⁃ oped a new type of mobile cooling equipment for underground use.Based on on-site measurements of wind temperature，humidity and rock ground temperature，the study obtained the linear growth law of wind tem ⁃ perature with depth and the temperature gradient，and clarified the thermal environment characteristics of the deep part of the mining area.The heat source analysis showed that the heat dissipation of the surround ⁃ ing rock accounted for the highest proportion，followed by mechanical and electrical equipment and air self-compression.In response to the limitations of existing ventilation and cooling technologies，a mobile cooling device with an ice-water mixed cold source was proposed，which uses finned tube heat exchangers to enhance heat exchange efficiency.Through COMSOL Multiphysics numerical simulation，the perfor⁃ mance of the equipment was verified.This equipment，while having high flexibility，efficiency and energy saving，provides cooling for specific areas in the deep mine on demand，achieving a balance between ther⁃mal environment control and energy consumption optimization.This research provides theoretical reference and technical guidance for the study of heat hazard control in deep mines.

Aiming at the requirements of horizontal and vertical magnetic system performance com ⁃ parison,multi-magnetic induction intensity adjustment and multi-condition test of one machine in flat mag ⁃ netic separation experiment,in order to solve the problems of single function and limited experimental con ⁃ ditions of traditional experimental equipment,a multi-functional flat magnetic separation experimental ma ⁃ chine was developed.The device integrates two kinds of switchable magnetic systems ,horizontal and verti⁃ cal,and has the function of continuous adjustment of magnetic induction intensity (from 0.7 T to 1.0 T), which can realize multi-condition sorting experiment on a single device.The magnetic separation test was carried out with a titanium dioxide tail slag as the experimental object.The results show that under the two magnetic system layouts,when the magnetic induction intensity is 0.7 T and 1.0 T,the TiO2 grade of the concentrate can be more than 40%by one plate magnetic separation.Combined with the analysis of key in ⁃ dicators such as recovery rate,the magnetic induction intensity of 0.7 T with vertical magnetic system is se ⁃ lected,which can significantly reduce the equipment configuration and operation cost under the premise of meeting the separation requirements,and provide technical and economic basis for industrial selection.The development of the experimental machine not only realizes the systematic test and comparative analysis of ore separation performance under multi-magnetic system and multi-field strength conditions ,but also pro⁃ vides an efficient and reliable experimental platform for the optimization of beneficiation process parame ⁃ ters,equipment selection demonstration and separation effect prediction ,which has practical significance for improving the systematic and economic benefits of beneficiation experimental research.

To evaluate the impact of cylinder liner modification on the operational efficiency of a large semi-autogenous mill,a comparative industrial study was conducted on metal cylinder liners and rub ⁃ ber-steel composite cylinder liners in the concentrator of a large open-pit porphyry copper mine ,address⁃ ing the optimization of efficiency and steel consumption during liner selection and use.Under the same op⁃ erating conditions,the operational performance indicators of the two liner types were statistically analyzed. The results show that the rubber-steel composite cylinder liner exhibited issues such as easy detachment of wear blocks and significant deformation in the later stage of use.Its ore throughput was at least 5.41%low⁃ er than that of the metal cylinder liner,and the specific steel ball consumption increased from 0.517 kg/t to 0.566 kg/t,representing a 9.48%increase in steel consumption.It is concluded that under the given ore properties and operating conditions,the application performance of the rubber-steel composite cylinder lin ⁃ er is inferior to that of the metal cylinder liner.The findings provide a practical basis for the modification , selection,and engineering application of large semi-autogenous mill cylinder liners.

After the mining in the mine adopts the staged ore chamber backfilling method to form the collapse area，and before the tailings are cemented and filled，in order to solve the potential safety hazards such as roof collapse and pillar instability，firstly，the surrounding rock characteristics data are collected through the combination of digital close-range photography and manual measurement.Then，various meth⁃ ods such as Q system classification are used to evaluate the quality grade of the collapse area and its sur ⁃ rounding rock mass.Secondly，the stability of the pillars is analyzed and evaluated by using pillar stress calculation formulas，Bieniawski empirical formulas，etc.，and the roof stability risk is quantified by using Barton ultimate span analysis method and Mathews stability diagram method.Finally，based on the stabili⁃ ty analysis and evaluation results of the three sub-factors of pillar，roof span，and roof exposure area，the risk level of the collapse area is determined by the most unfavorable principle，and the safety control prin⁃ ciples of "strong mining，strong extraction，and strong filling"for the ore chamber mining and collapse ar⁃ ea treatment are adopted to ensure production safety.The research results show that in the Makeng Iron Mine，by applying the most unfavorable principle，when the rock mass quality grade is grade III and the most unfavorable rock mass is considered，the comprehensive determination of the safety risk level of the collapse area is as follows:when the mining length of the ore chamber is ≤48 m，the collapse area is of low risk.When it is 48 ~100 m，it is of general risk.After applying the safety control principles，the mining cy⁃ cle is shortened and the tailings cementation and roof backfilling to reinforce are carried out in time.In the application of the largest goaf volume of 67-7R-1 unit，after 6.5 months，the mine chamber is completely emptied，and through three-dimensional scanning analysis，the actual collapse volume of the goaf ac⁃ counts for 3.8%of the designed volume，achieving safe，stable，and efficient mining of Makeng Iron Mine.

A lead-zinc mine tailings pond in Guangxi has left a large number of high-sulfur tailings due to historical mining activities，and has been stacked in the open air for a long time.Under the dual in⁃ fluence of subtropical rain and karst development，the risk of heavy metal pollution is prominent.In order to explore the environmental status of the tailings pond and seek sustainable treatment approaches，the tail⁃ ings and surrounding water samples were systematically collected.The physical and chemical properties of the tailings，the occurrence characteristics of heavy metals and the law of water pollution were analyzed， the environmental risks were evaluated，and the feasibility of resource utilization was discussed based on the concept of "treating waste with waste".The results show that the tailings are mainly composed of quartz （65 .40%），rich in sulfides，such as pyrite，and the sulfur content is as high as 47.56 ~60.78 times of the background value，and the acid production potential is strong.The contents of Pb，Zn，Cd and As signifi⁃ cantly exceeded the standard，among which Cd exceeded the standard by up to 135 times，and Pb and Zn were mainly enriched in fine particles（-0 .045 mm distribution rate >71%）.The concentrations of Zn and Cd in the surrounding water were 4.24 times and 2 times higher than the groundwater Class III standard， respectively，due to the influence of tailings leachate.The karst medium had a certain interception effect on heavy metals，but extreme Hg pollution (up to 71 870 μg/L)occurred in the groundwater outlet and res⁃ervoir of the downstream cave，suggesting that there was an independent mercury source.Aiming at the characteristics of high proportion of fine-grained tailings and complex sulfide dissemination，a technical route with flotation recovery of lead-zinc mixed concentrate and sulfur concentrate as the core is proposed. Preliminary economic analysis shows that the output value of resource products can cover the treatment cost.According to the research，the treatment of the tailings pond should follow the phased strategy of pol ⁃ lution control first，resource recovery leading，terminal harmless disposal，ecological restoration，and es⁃ tablish a long-term monitoring network，which can provide reference for the collaborative treatment of his ⁃ torical tailings ponds in similar karst areas.

To address the problems faced by Zhangzhuang Mine during actual production ,such as fre⁃ quent placement of support materials and excessive burden on the auxiliary shaft hoisting system.A place⁃ ment drilling scheme was proposed to achieve the self-flow placement of support concrete and cement mor ⁃ tar.Through detailed analysis of the selection,design,and safety and environmental protection aspects of the scheme,the significant role of the rapid slagging technology in enhancing the safety level of the mine , improving the placement efficiency,reducing the hoisting cost,and promoting technological innovation and environmental protection concepts was demonstrated.Through numerical simulation,the bottom buffer scheme was optimized,and a buffer scheme combining multiple bends and variable diameter placement suitable for Zhangzhuang Mine was proposed.The investment budget of the project was estimated,and it is expected that the project can recover its cost within 5.8 a.

To reduce the vibration caused by large-scale open-pit mining blasting and weaken the damage to the slope caused by blasting，a combined air-spacing explosive blasting method in the middle and bottom sections was adopted.Based on the actual conditions of the mine，the main parameters of the blasting test were determined，and the blasting design was carried out.A blasting hole structure was pro⁃ posed，which consisted of air columns，emulsion explosives，air columns，emulsion explosives，and fill⁃ ing materials in the order from bottom to top.The length of the air columns at the bottom and middle of the hole was 1 and 2.5 m respectively.Three groups of interval and coupled blasting tests were carried out to compare the blasting effects.The test results showed that the overall blasting effect of the coupled blasting was better.Due to the large height of the upper filling，there were more large blocks after blasting.During the air-spacing explosive blasting，the surrounding rocks would be subjected to the simultaneous action of the upper and lower explosive columns，generating two-directional shock waves that superimposed，effec⁃ tively reducing the rate of large blasting blocks，improving the energy utilization rate of the explosives，re⁃ ducing the blasting cost，and achieving a vibration reduction rate of 15.68%.This effectively weakened the damage of blasting vibration to the slope，providing a basis for subsequent safe and efficient blasting in the open-pit mining area.

In order to solve the problems of high water hole punching rate，poor lithology adaptability and high blasting cost in the traditional explosive blasting of Tongjie-Manjiazhai open-pit mine，and fur⁃ ther improve the blasting technology level，ensure the safety of operation and reduce the production cost， the mine introduced the JWL-S type on-site mixed emulsion matrix production equipment and process of Shenzhen Jinaobo JWL-S from April to July in 2024，and applied the on-site mixed emulsion explosive to the deep hole bench blasting operation.In the research process，the performance indexes such as explosive density，temperature and detonation velocity were monitored by means of measuring cylinder method，ther⁃ mocouple and detonating cord method.The control variable method is used to carry out the test in two stag ⁃ es (60 blastings of 14 platforms are completed ).In view of the different lithology areas such as marble， skarn and schist in the mining area，the key blasting indexes such as hole network parameters，explosive unit consumption，charge structure and filling length were systematically optimized.The results show that the on-site mixed emulsion explosive has reliable performance (average density of 1.147 g /cm3，average detonation velocity of 4 300 m/s)，forming a blasting parameter system suitable for the actual working con ⁃ ditions of the mine.After optimization，the hole punching rate is reduced from 27%to 5%，the unit explo⁃ sive consumption is reduced from 0.45 kg/m3 to 0.40 kg/m3，and the annual production cost is reduced by 6.2 million RMB per year according to the annual blasting volume of 10 million m3.The bulk rate is con⁃trolled within 2%，and there is no obvious root residue.The research conclusion confirms that the on-site mixed emulsion explosive is suitable for the complex working conditions of multi-lithology and high-water holes in the mine，which can realize standardized and large-scale application，and significantly improve the safety，economy and efficiency of mine blasting operation.

In order to explore the application feasibility of flotation phosphate tailings in mine cement ⁃ ed filling，the material ratio test of phosphate tailings cemented filling was carried out，and the performance of filling body was optimized by using industrial solid waste and modifier.The test results show that when the full-size cemented filling is carried out with the flotation phosphate tailings of a chemical enterprise in Yichang，Hubei Province as the raw material，when the cement to sand ratio is 1 ∶4 and the filling slurry concentration is greater than 70%，the uniaxial compressive strength of the sample cured for 28 days is greater than 2.9 MPa，which meets the basic requirements of mine filling for strength (≥2 .0 MPa).After us⁃ ing industrial solid waste to replace about 35%of cement，and adding calcium oxide，sodium carboxymethyl cellulose (CMC)and sodium silicate (alkali activator)for optimization，the 28 d compressive strength of phosphate tailings cemented backfill can reach more than 3.3 MPa，and the pollutant release concentration meets the relevant environmental protection standards，which will not cause environmental pollution.This study provides a technical reference for the resource utilization of flotation phosphate tailings.

The underground rail transportation system of the Zhongguan Iron Mine was originally de ⁃ signed in a traditional mode，which had disadvantages such as large crew size，complex scheduling，low transportation efficiency，and high safety risks.To improve production safety and efficiency，through indus⁃ trial Ethernet and mobile 5G technology，an ethernet ring network and a fully covered wireless communica ⁃ tion network were established.Surface centralized control centers，communication terminals，and monitor⁃ ing systems were installed，enabling remote control of the rail transportation.The transportation route was simplified and adjusted，and a intelligent scheduling algorithm was introduced to achieve intelligent sched ⁃ uling throughout the process.Then，the three-dimensional joint application of physical equipment，trans⁃ mission technology，and intelligent protocols was employed to solve communication interference and attenu ⁃ ation problems caused by complex geological conditions，increasing the equipment availability rate from 86%to 98.6%.Finally，by integrating inertial positioning and RFID positioning methods，the positioning error of the locomotive was eliminated，achieving precise and real-time positioning of the locomotive. Through the integration and upgrade of multiple technologies such as AI，the Zhongguan Iron Mine achieved intelligent control of the entire process of loading，transportation，and unloading at the loading station of the rail transportation system，reducing the underground crew size by 40 people for the rail trans⁃ portation system.During the operation of the locomotive，the operation area was managed without human intervention.The use of the AI intelligent alarm system reduced the number of human errors and prevented safety accidents.The intelligent system automatically selected the optimal path，increasing the transporta⁃tion efficiency by 37%，and achieving the purpose of promoting the application of intelligent scheduling technology for underground magnetic iron mines with large water content.

With the advancement of deep mineral resource development，the ultra-deep shaft of San⁃ shandao Gold Mine faces engineering challenges of poor surrounding rock stability and difficult support due to high ground stress，complex joint development，and groundwater effects.This study integrates rock mass quality classification，mechanical parameter analysis，support design，and numerical simulation to construct a technical system for surrounding rock stability control suitable for this engineering context.The Q-system，RMR，and GSI methods were used to assess the rock mass quality at different depths of the shaft，identifying the distribution characteristics of higher-quality shallow surrounding rock，reduced deep quality，and significant integrity differences.Combined with laboratory rock mechanics tests and the Hoek Brown strength criterion，the heterogeneity law of rock mass mechanical parameters varying with depth was revealed.Based on the classification results and engineering analogy，a composite support scheme dominat⁃ ed by shotcrete with wire mesh and bolts，supplemented by cable bolts was determined.Parameters such as bolt length，spacing，and shotcrete thickness were optimized through empirical formulas and theoretical calculations，and a support structure of "energy-dissipating bolts +shotcrete with wire mesh and cable bolts +lining"was designed for deep areas.Phase2 simulations of different support conditions showed that the composite support of "shotcrete with wire mesh and cable bolts +lining"can effectively control sur ⁃ rounding rock deformation，reduce the plastic zone range，and optimize stress distribution.Compared with the unsupported state，the maximum surrounding rock displacement and plastic zone range were reduced by 42%and 68%，respectively，with significantly alleviated stress concentration.The research results pro⁃ vide an integrated solution of "grading evaluation-parameter optimization-composite support"for the ultra deep shaft of Sanshandao Gold Mine，which can offer reference value for surrounding rock stability control in similar deep mine shaft projects.

Targeting the dual challenges of high carbon emissions and significant natural resource consumption in the concrete industry，alongside the environmental pollution caused by the stockpiling of industrial solid wastes such as fluorogypsum and gold tailings in Fujian Province，multi-source solid waste composite concrete materials were investigated.An orthogonal experimental method was employed，utiliz⁃ ing fluorogypsum，gold tailings，and fly ash as composite admixtures.The study examined the effects of fly ash replacement rate，gold tailings replacement rate，and fluorogypsum content on the mechanical proper⁃ ties and durability of concrete.By testing compressive and flexural strength at seventh，fourteenth，and twenty-eighth day，combined with impermeability，freeze-thaw resistance，and sulfate corrosion resis⁃ tance tests，the comprehensive performance of the materials was evaluated.The results indicate that the concrete sample with a fly ash replacement rate of 23%，gold tailings replacement rate of 20%，and flu⁃ orogypsum content of 5%achieved a 28th day compressive strength of 34.5 MPa，a flexural strength of 3.6 MPa，an impermeability grade of P8，a freeze-thaw resistance meeting the F50 requirement，and ex⁃ cellent sulfate corrosion resistance.The synergistic use of fluorogypsum，gold tailings，and fly ash as multi-source solid wastes effectively enhances the comprehensive performance of concrete，providing a via⁃ ble technical pathway for the resource utilization of industrial solid waste and the low-carbon，green devel⁃ opment of the concrete industry.

In order to comprehensively recycle and utilize the tailings resources of sulfide ore in Da ⁃ tun concentrator of Yunnan Tin Company，the exploration tests of gravity separation，magnetic separa⁃ tion，flotation and combined separation process were carried out systematically.The chemical composi⁃ tion，mineral composition and particle size distribution of the samples were analyzed.It was found that the tin content of the tailings was 0.12%，the iron content was 5.84%，and the particle size distribution was uniform.The test results show that the enrichment effect of single gravity separation，magnetic separation and centrifuge process on tin is not ideal.The combined process of desliming-flotation-magnetic separa ⁃ tion increases the tin grade of the flotation rough concentrate to 1.15%after desliming，and the recovery rate reaches 25.77%.The tin concentrate with tin grade of 2.15%and comprehensive recovery of 38.63% is obtained by further cleaning and closed-circuit test of the whole process.The effective recovery of cassit⁃ erite is realized.

Aiming at the problems in the material performance，structural adaptation，installation process，and lifespan management of mill liners，systematic optimization is carried out in terms of material upgrades，structural optimization，and coordinated parameter regulation.By employing high-chromium al⁃ loy steel，metal-ceramic composite materials，and surface strengthening techniques，the service life of lin⁃ ers can be extended by 30%~50%.The structural characteristics of wave-patterned，step-type，and seg⁃ mented liners are compared and analyzed.In practical applications，liner structural forms should be rea⁃ sonably selected and matched to improve grinding efficiency.A coordinated regulation mechanism between liner parameters and mill operating conditions is established，grinding parameters are reasonably set，and the grinding process is promoted toward intelligentization and high efficiency，thereby enhancing the over⁃ all system energy efficiency.Combined with industrial practice at a mineral processing plant in northwest China，it is shown that through scientifically improving liner materials and structures，along with optimiz⁃ ing operational parameters，grinding efficiency is significantly improved.Finally，key technical points such as heat treatment control during manufacturing，installation accuracy assurance，and dynamic re⁃ placement management are clarified，providing a reference for grinding equipment to achieve efficient， low-consumption and stable operation.

Addressing issues such as reliance on manual experience，control lag，and poor stability in traditional grinding processes，this study focuses on the grinding system of Zhongguan Iron Mine.Based on an in-depth analysis of the current process conditions，including uneven ore feeding，load fluctua⁃ tions，and the lack of key parameter measurements，a technical framework for a grinding expert system in ⁃ tegrating "perception-decision-execution"is proposed，leveraging the core theories of expert systems in knowledge representation，reasoning mechanisms，and self-learning.The solution establishes a multi source，high-precision process parameter perception system by introducing advanced detection equipment such as ore AI blockage analyzers，grinding sound spectrum analyzers，Na-22 concentration meters，and laser-based particle size analyzers.Simultaneously，the basic automation system is upgraded to achieve functions such as one-click start-stop and automatic material diversion，providing reliable support for in ⁃ telligent control.For critical processes such as semi-autogenous mill load and concentration，as well as cy⁃ clone classification efficiency，a multi-variable coordinated control model and targeted control strategies are developed.A phased implementation roadmap is designed，encompassing data collection，model con⁃ struction，offline testing，and online deployment.The project is expected to achieve significant results in stabilizing production processes，optimizing process indicators，and reducing energy consumption and la⁃ bor costs，while delivering considerable economic and management benefits.This research holds exempla⁃ry significance and promotional value for advancing the transformation and upgrading of traditional mining industries toward intelligence and digitalization.

In a low-grade complex copper mine，the copper content in the copper middlings ob ⁃ tained during production is relatively high.However，due to the complex mineral composition and fine dis ⁃ semination size，effectively recover of the copper resources was hard to obtain by conventional beneficia ⁃ tion processes.To address this issue，a new technology for diversified treatment of middlings was adopted to improve the existing process.The results showed that using the original process and original reagents，a copper concentrate with recovery rate of 91.27%and concentrate grade of 22.06%could be obtained.In contrast，with the new process and new reagents，a copper concentrate with recovery rate of 92.87%and concentrate grade of 24.90%could be achieved.Compared with the original process and original reagents， the copper grade of the concentrate increased by 2.84 percentage points，and the recovery rate increased by 1.60 percentage points when using the new process and new reagents.

Against the backdrop of increasingly depleted,fine-grained,and complex mineral resourc⁃ es,and in response to the development demands for large-scale flotation machine and simplified processes in mineral processing,this study focuses on Dexing Copper Mine.Adopting a technical approach combining "experimental research +process simulation,"the applicability of large-scale flotation machines in short flow configurations was investigated.Through condition tests,the optimal roughing process parameters were determined:grinding fineness of -0.074 mm accounting for 65%,lime dosage of 300 g /t,and collector MAC-12 dosage of 44 g/t.Based on standard floatability tests and a first-order kinetic model ,the flotation kinetic parameters of chalcopyrite in four types of flotation machines with different volumes were obtained. It was found that large-volume flotation machines exhibit a significantly higher fast-floating rate constant , demonstrating their superior initial separation efficiency.These parameters were input into JKSimFloat soft ⁃ ware to establish a flotation process model,and simulation comparisons were conducted for configuration schemes involving flotation machines of different volumes（130 ~680 m³）.The results showed that the short-flow configuration using 680 m³ultra-large flotation machines achieved excellent indices ,with a cop⁃ per concentrate grade of 5.39%and a recovery rate of 85.19%.This study validates the feasibility of JKSim ⁃ Float simulations based on precise kinetic parameters for the selection of large-scale flotation machine and process optimization.It lays the foundation for a complete methodological framework ,from kinetic parame⁃ter measurement to process simulation and validation,effectively addressing the limitations of traditional se ⁃ lection methods.The findings provide theoretical basis and technical support for the efficient configuration of short flows and the scientific application of ultra-large flotation machines.

Baixiangshan concentrator is faced with the prominent problems of fine disseminated parti ⁃ cle size of raw ore and high magnetic iron content of total tailings.These two factors seriously restrict the improvement of metal recovery rate in the concentrator.Therefore,the research and industrial application of new high-efficiency coarse-grained wet magnetic separator and disc magnetic separator were carried out. On the basis of the laboratory test of the system ,it is determined that one T-CCT1550 new high-efficiency magnetic separator is used for coarse-grained wet separation ,and two PC16-8 disk magnetic separators are used for the technical transformation and industrial test of the total tailings scavenging.The application re⁃ sults show that the new high-efficiency coarse-grained magnetic separator reduces the total iron grade by 0.25 percentage points,the magnetic iron grade by 0.9 percentage points,and the concentrate TFe recovery rate by about 1.08 percentage points.The total iron grade of the total tailings of the disk magnetic separator is reduced by 0.63 percentage points,the magnetic iron grade is reduced from 1.82%to 1.29%,and the iron metal recovery rate is significantly improved.The research results not only bring considerable econom ⁃ ic benefits to Baixiangshan concentrator,but also provide valuable experience and technical support for tail ⁃ ings treatment and resource recovery of similar mines.

Aiming at the problems of tailings expansion,difficult consumption and waste of resources in a lepidolite concentrator,the tailings of the plant were taken as the research object,and the comprehen⁃ sive recycling technology was studied on the basis of property analysis.The results show that the grade of Li2O in the tailings is 0.33%,in which mica is the main carrier mineral of lithium ,and the distribution rate is 94.82%.By systematically studying the effects of magnetic separation parameters ,collector combination and inhibitor combination on the recovery of fine-grained lepidolite ,the optimal operating conditions were determined.The magnetic separation pre-concentration of tailings slurry was carried out by using the bristle medium and 1.5 T magnetic induction intensity,and the magnetic concentrate with Li2O grade of 0.68%and recovery rate of 78.11%was obtained,and the whiteness of tailings reached 56.2.In the flotation of magnet⁃ ic separation concentrate,the combined collector of cocoylamine and sodium oleate（dosage ratio 1 ∶2,total dosage 500 g/t）was selected,and the combined inhibitor system of sodium hexametaphosphate and baking gum (dosage ratio 1 ∶2,total dosage 400 g/t)was used.Through the closed-circuit flotation process of one roughing,two cleaning and one scavenging,the lepidolite concentrate with Li2O grade of 1.62%and recov⁃ ery rate of 79.56%was finally obtained,and the feldspar powder with whiteness of 56.2%was obtained. The process effectively realizes the efficient recovery of lithium resources in lithium tailings ,and provides a reliable technical basis for the resource utilization of tailings.

The gold recovery rate of a certain gold ore concentrator was 91.25%，and the tailings grade was 0.15g/t.To further increase the gold recovery rate and reduce the tailings grade，this study car⁃ ried out a systematic process mineralogical diagnosis.Through a comprehensive analysis of the flotation raw ore and tailings，the occurrence state of gold，the process characteristics of the main gold-bearing miner ⁃ als，and the loss mechanism of gold in the process were identified.Research has found that the gold miner⁃ als in the raw ore have a relatively small particle size，mainly fine particles.31.87%of the gold exists in pyrite in the form of fine particle inclusions，and about 6.27%of the gold is closely related to metal oxides and silicate gangles.The fine-grained gold associated with sulfides in the tailings has not been effectively recovered，followed by the loss of encapsulated gold in easily mudned silicate gangue due to the interfer ⁃ ence of mine mud.Based on the above understanding，a process optimization plan centered on adjusting the fineness of grinding，optimizing the flotation reagent system，and strengthening the dispersion pretreat⁃ ment of slime was proposed.Industrial tests show that after optimization，the total recovery rate of gold has increased to 93.79%，and the grade of tailings gold was decreased，with significant annual economic bene ⁃ fits.This study confirmed that process mineralogy plays an irreplaceable and crucial role in accurately diag ⁃ nosing bottlenecks in mineral processing and guiding process optimization.

In response to the challenges of the lack of design basis for the ultrafine tailings filling sys ⁃ tem and the low efficiency of natural sedimentation in the Tianxing Iron Mine，a systematic flocculation sedimentation experimental study was conducted using tailings similar to those from the Sijiaying Iron Mine as substitute samples.Based on particle size analysis and determination of physicochemical properties of the tailings，the appropriate flocculant type，optimal dosage，and key process parameters were determined through static flocculation sedimentation comparison，reagent dosage optimization，and dynamic thickening simulation validation.The results indicate that the tailings are ultrafine，with particles smaller than 38 μm accounting for 45.26%，a median particle size of 44.96 μm，and poor natural sedimentation performance. Static screening tests of five flocculants showed that the anionic flocculant 6920 performed best，with an optimal dosage of 20 g/t.Dynamic thickening tests further determined the optimal unit area processing ca ⁃ pacity to be 0.5 t/（h·m²），under which the underflow concentration reached 70.1%，the solid content of overflow water was 89.2 ppm，and the fluidity was 14.5 cm，meeting the requirements of the filling pro ⁃ cess.The research results achieved synergistic optimization of high underflow concentration and low solid content in overflow water，significantly improving the thickening efficiency of fine tailings while reducing reagent consumption.This provides key parameter support for the design of efficient thickening systems for ultrafine tailings and offers important reference value for similar mine filling processes.