为了深入交流与展示浆体浓缩与管道输送技术领域的工程经验、科技成果、先进技术、设备及相关信息，深度探讨行业发展趋势和前景，加强各单位及科技人员的技术交流与合作，理论联系工程实际，以成功应用案例为依托，探讨浆体浓缩与管道输送理论、输送工艺与装备技术，数字化和智能化与浓缩输送技术的发展和融合，为浆体管道输送技术的产学研用搭建交流平台，浆体浓缩与管道输送学术委员会、中国金属学会选矿分会、长沙矿冶研究院有限责任公司、陕西神渭煤炭管道运输有限责任公司等拟于2025年10月15~18日，在陕西省西安市举办2025年第六届全国浆体浓缩与管道输送技术与装备研讨会。届时将邀请政府相关部门领导、国内外著名专家以及矿山企业、设备制造公司技术专家进行学术交流与应用案例分析，开展全方位交流与座谈。欢迎国内外浆体浓缩与管道输送技术领域管理人员、专家、学者以及工程技术人员参会交流。现将有关情况通知如下。
一、会议主题  
        数智引领，创新图强，让中国浆体管道通向全球！
 二、会议内容  
        1.精彩报告
        (1)特邀院士、行业精英深度剖析行业现状，预测行业发展趋势；
        (2)学术论文报告、生产技术交流、设备厂家产品介绍；
        (3)标准规范及学术专著现场发布。
        2.技术与装备成果展览
        荟萃全球浆体管道领域头部企业、行业领军供应商与顶尖技术服务商，集中展示浆体浓缩与管道输送技术与装备领域的前沿突破与卓越成就。
        3.参观考察
        参观世界最长、中国唯一长距离的陕煤神渭输煤管道项目及先进耐磨管材展示区。
三、会议主办单位  
        浆体浓缩与管道输送学术委员会
        中国金属学会选矿分会
        长沙矿冶研究院有限责任公司
        陕西神渭煤炭管道运输有限责任公司
        清华大学水沙科学与水利水电工程国家重点实验室
        湖南大学
四、会议时间及地点  
        会议时间：2025年10月15~18日。会期4天，15日全天报到，16~17日会议，18日散会。
        会议地点：陕西省西安市，西安曲江惠宾苑宾馆（西安市雁塔南路388号）。
五、会议征文内容  
        1.管道数字化、智能化与智慧管道；
        2.国内外浆体管道现状与发展趋势；
        3.固液两相流理论与工程应用；
        4.浆体浓缩、脱水技术与装备；
        5.膏体流变学与充填管道输送技术；
        6.国内外浆体管道工程典型案例经验分享；
        7.浆体管道试验、设计以及工程建设技术；
        8.浆体管道测堵测漏、安全监测以及管道工程维护、抢修技术与装备；
        9.浆体管道动力泵、管材和阀门等技术与设备；
        10.深海采矿水力提升技术与装备；
        11.河海疏浚与泥沙管道输送技术；
        12.固废处置与管道输送技术应用；
        13.管道工程仪器仪表与自动检测技术及设备；
        14.管道施工技术与装备；
        15.气固粉体输送及气固液三相流管道输送技术。
        ……
六、会议论文  
        1.论文作者请于2025年7月31日之前将论文通过E-mail发送至论文评审组邹伟生教授处(E-mail:zouweisheng@sina.com)，需适当延缓提交论文的作者请与邹伟生教授联系。会议论文经专家审阅通过后，将以专刊形式出版。
        2.本次征文将由大会组委会指定的全国中文核心期刊《矿冶工程》公开出版。
七、会议报名  
        扫描以下二维码在线报名。
        
        联系人：陈光国13687399397（微信同号）
        周杨15111122546（微信同号）

Extreme high-speed laser cladding (EHLA) technology was used to prepare Al₂O₃-316L coatings on Ti6Al4V rods. The effects of scanning speed, powder feeding rate on single-track coating quality, and 316L powder content on multi-track coating quality and corrosion resistance were explored. Results show that with the following optimum process parameters, including scanning speed of 250 mm/s and powder feeding rate of 8 g/min, the coating can present superior quality with the 316L powder in a mass fraction of 20%. It is shown that all Al₂O₃-316L coatings exhibit superior corrosion resistance compared to the substrate. As 316L content increases, the corrosion resistance of coatings increases followed by decline. With 316L powder in a mass faction of 20%, the electrochemical impedance of the coating is 2.27 times that of the substrate.

To gain an in-depth understanding of research status of ceramic additive manufacturing, the technical processes of direct ink writing, fused deposition modeling, selective laser sintering, stereolithography and digital light processing, as well as the materials used in those  technologies are reviewed based on domestic and international researches on ceramic additive manufacturing. The advantages and disadvantages of those five technologies are summarized, which can provide references for their application scenarios. Finally, the prospect for the development of ceramic additive manufacturing is also discussed.

The relevant literature on laser-MIG hybrid welding of aluminum alloy from the China National Knowledge Infrastructure (CNKI) core journal database and Google Scholar database in 2000-2023 was systematically analyzed by using VOSviewer. Three primary research focuses were identified by analyzing citation frequencies of key literature and the evolution of research hotspots: ① the interaction between laser and MIG heat sources, particularly the effects of laser-arc distance and heat source leading modes on plasma behavior and molten pool stability|② hybrid welded joints, revealing the formation mechanisms and optimization strategies for defects such as porosity and cracks by investigation into morphological characteristics|③ mechanical properties of welded joints, focusing on microhardness distribution and softening mechanisms in the heat-affected zone. Results indicate that the transition of Mg and other alloying elements can be effectively achieved by adopting welding wire alloying, and after heat treatment of those heat-treatable aluminum alloys, the welded metal exhibit remarkably enhanced strength and hardness through aging. The subsequent researches can employ multi-scale numerical simulations to explore the dynamic coupling mechanisms between laser and arc, and the interaction between droplet transfer and keyhole stability, as well as to optimize process parameters to suppress porosity and overcome the technical bottleneck in simultaneously improving welding speed and quality. This review can provide insights for enhancing the performance of laser-MIG hybrid welding of aluminum alloy.

With bamboo as a raw material, different hard carbon materials were prepared by different impurity removal processes, and the effects of those processes on the impurity content, physical structure and sodium storage performance of hard carbon were explored. The results show that after impurity removal treatment, the bamboo-derived hard carbon has reduced impurity content and specific surface area, and increased interlayer spacing. With the preparation cost and the sodium storage performance of hard carbon comprehensively taken into consideration, acid leaching is chosen as the impurity removal process for hard carbon. It is shown that at a current density of 30 mA/g, the anode material with prepared hard carbon can have an initial Coulombic efficiency of 83.87% and a reversible specific capacity of 308.96 mAh/g; it demonstrates a capacity retention rate of 96.57% after 100 cycles at a current density of 300 mA/g, showing excellent sodium storage performance.

The thermal dissipation performance of a battery pack was optimized by thermal simulation, aiming to enhance safety and service life of batteries. A thermal simulation model of the battery pack was established with ANSYS software, and temperature distribution was analyzed for the battery discharged at 1C rate. It is found that the simulation results deviate from actual measurements by less than 0.5 ℃, confirming the high accuracy of the model. Two optimized thermal dissemination schemes were proposed, including I-shaped heatsink and thermally conductive adhesive filling. Study shows that both schemes can effectively improve the thermal dissipation performance, leading to the maximum temperature of cells reduced by 6.0 ℃ and 5.9 ℃, respectively. The scheme of I-shaped heatsink can not only reduce cell temperatures but also significantly reduce temperature differences, resulting in better thermal uniformity.

In a Hunan polymetallic ore concentrator, the tailings with CaF₂ grade of 26.56% exhibit certain economic value. However, due to the influence of  residue reagents in the upstream processing of main tungsten-molybdenum-bismuth minerals and the interference of calcium-bearing gangue, it is extremely difficult to recover fluorite from the tailings. A process consisting of selective regrinding, tailings discarding by high intensity magnetic separation, and fluorite flotation was adopted with a new reagent NH-1 as activator of fluorite, CY-63 as collector of fluorite, SWG+SZY as depressant of silicate and micro-fine gangue, and CYAB as depressant of calcareous gangue. As a result,  fluorite concentrate with CaF₂ grade of 90.50%, CaCO₃ content of only 1.35% and CaF₂ recovery of 79.50% was finally reclaimed in the closed-circuit test. It is concluded that such tailings resources can be comprehensively utilized by adopting this process.

In combination with experiments and multi-step finite element simulation, the residual stress distribution in components manufactured by laser powder bed fusion (LPBF) and the influence of the initial residual stress field on the laser shock peening (LSP)-induced compressive residual stress field. The validity of the simulation results was verified by the residual stress values measured with X-ray diffraction. The results show that the thermal stress of the lower and middle layer materials in the component fabricated by LPBF undergoes a transition from zero stress, compressive stress, tensile stress to compressive stress, while the top layer material shows a transition from zero stress, compressive stress to tensile stress, thus leading to tensile residual stress occurred on the surface layer of LPBF fabricated component, while compressive residual stress in the lower part. The action of initial residual stress field results in the reduced peak value but increased depth of LSP-induced compressive residual stress. The initial residual tensile stress field of LPBF components can exert a suppressive and dragging effect on the reverse plastic deformation caused by surface waves, leading to reduced intensity and changed position of the “residual stress hole”, which can improve the uniformity of LSP-induced residual stress distribution.

In order to accurately know the progress in frontier technologies and research hotspots in environmental monitoring and protection during deep-sea mining, after the patents and academic literature from January 1, 2005 to April 14, 2025 in the filed of deep-sea mining were retrieved with IncoPat and Web of Science, a statistical analysis was performed with bibliometric methods for542 published patents and 469 academic literature, and then the development trend in this field was also discussed. It is shown that a synchronous increase in both patents and academic literature highlights the support of basic research for technological innovation. By formulating corresponding policies and through institutional collaboration, China hasshifted its place from following others to keeping pace and even leading the pack in theoretical research. China has also put emphasis on the technologies of environmental monitoring and protection in its scientific research on deep-sea mining, and established a technical system and theoretical framework with in situ observation technologies for environmental impacts during deep-sea mining at the core. As a result, the research perspective has shifted toward understanding of complex system mechanisms. In the future, the environmental monitoring and protection system for deep-sea mining will be composed of four core modules, including environmental monitoring, environmental assessment, environmental management and environmental protection, and form an ecological risk supervision and management framework through the whole mining process, which will also becontinuallyupdated.

To improve the accuracy of fracture recognition in borehole images, a borehole fracture recognition approach for open-pit mine was proposed. First, borehole images of an open-pit mine is obtained with an intelligent borehole inspection camera, and then data augmentation is performed by using random cropping and image flipping, while median filtering is used for noise reduction and images are converted to grayscalere, so as to eliminate noise and reduce computational complexity. Next, spatial attention and channel attention mechanisms are integrated into the U-Net model to improve the semantic segmentation model for fractures, forming an AU-Net model, which can enhance the model′s ability to extract features from both overall and local image information. Experimental results show that compared to the original U-Net model, the AU-Net model can achieve lower loss and higher accuracy in the fracture recognition dataset by borehole imaging. Specifically, the mean intersection over union is improved by 4.38 percentage points, up to 82.34%, bringing better image segmentation effect.

Based on the analysis of patent application trend, major applicants and technological development in  recycling of spent lithium iron phosphate batteries by leaching process, a list of key patents of mainstream technologies is presented. The results show that the number of patent applications for recycling of spent lithium iron phosphate batteries by leaching process has been steadily increasing since 2015, and oxidative acid leaching is the mainstream technology at present, with other technologies keeping in pace. However, some outdated technologies are being phased out.

A new type of discontinuous mining system for deep-sea polymetallic nodules was proposed, consisting of collecting seafloor ore, conveying to buffer by flexible hose, and high-speed lifting of buffer. Then, the design and key equipment selection were carried out for the collecting system, flexible hose conveyance system and buffer lifting system  for comprehensively lifting 100 t/h of ores at water depth of 5200 m in the Minmetals′ Contract Area. Furthermore, flexible hose configuration and load characteristics, as well as cable load dynamics during buffer lifting were all analyzed by hydrodynamic simulation. It is shown that with the flexible hose equipped with 18 buoyancy blocks,  minimum bending radius of 1.6 m and a maximum tension of 4.98 kN, the whole mining system can satisfy requirements for the minimum bending radius and safe load capacity. During high-speed lifting of buffer, the cable can have the safety factor of comprehensive stress up to 5.22-6.03, exceeding the safety factor stated in national standard. These findings validate the reliability of this new type of deep-sea discontinuous mining system.

Extraction of rhenium from low-grade molybdenum concentrate by adopting a process of oxidative volatilization followed by ion exchange was explored in experiments. Firstly, a two-stage high-temperature oxidative roasting was adopted to oxidize rhenium into Re₂O₇. Rhenium and molybdenum were effectively separated due to rhenium volatilizing into the flue gas. The volatilization rate of rhenium reached 85.42% after roasting process at 675 ℃. Then, the rhenium-containing flue gas was eluted to get rhenium-containing solution, in which rhenium was selectively extracted with D201×7 ion exchange resin. With the solution pH of 9, liquid/solid ratio of 50 mL/g, a 20 min adsorption at temperature of 35 ℃ brought the adsorption rate of Re up to 97.52% and the adsorption rate of Mo less than 20%. Finally, a product of ammonium rhenate was prepared by stepwise desorption followed by concentration and crystallization. By this process, the total recovery of Re can reach 70.68%.

The mechanical properties and energy evolution law of dolomite under a combined action of dry-wet cycle and cyclic loading and unloading were explored. The results show that the structural damage caused by dry-wet cycles leads to the transformation of dolomite from brittle fracture to ductile fracture, which is manifested by an increase in the area of hysteresis loops and a decrease in peak strength. At the early stage of cyclic loading and unloading, a strengthening effect is observed, and then the dolomite develops into the strain-softening and damage stages. An energy analysis indicates that the total input energy is mainly stored in the form of elastic strain energy, and the proportion of dissipated energy increases slowly with the accumulation of damage. Additionally, based on the variation of the damage variable defined by dissipated energy, the damage evolution tends to be stable after a progressive and accelerated process.

An intermittent sedimentation test was performed for vanadium-titanium magnetite tailings to obtain settling curves of flocculated tailings, and then the solid flux in sedimentation by flocculation was calculated by Coe-Clevenger equation and material balance calculation. An innovative Φ38 m heavy-duty and efficient thickener is designed to have a unit area processing capacity of 1000 kg/(m²·h). The industrial application of this thickener in dewatering of vanadium-titanium magnetic tailings show that with dry ore processing capacity of 1100 t/h and the feed concentration of 20%－25%, its underflow has concentration of 45% and the overflow has solid content less than 200 mg/L. It is concluded that such thickener can solve the technical problems in the production faced by enterprises, and also bring enterprises enhanced economic and environmental benefits.

After an introduction of the current status of gallium resources and analysis of the occurrence state of gallium in sodium aluminate solution, zinc smelting slag, tailings from vanadium extraction and coal-based solid waste, progress in the research of gallium extraction processes is elaborated and the adaptability, advantages and disadvantages of each technique are also summarized. Finally, based on the discussion of problems faced by the gallium industry and the development direction in the future, it is suggested that iteration and upgrading of gallium extraction processes should be vigorously promoted based on China’s scale advantage in alumina industry.

Effects of roasting temperature and heating rate on the crystalline form evolution of calcium arsenate during heat treatment were investigated. The heat-treated calcium arsenate was leached by strong acids (sulfuric acid, nitric acid, hydrochloric acid, aqua regia), and the relationship between the crystalline form of calcium arsenate and arsenic concentration in leaching solution was investigated. The results show that calcium arsenate undergoes significant crystalline form transition during roasting process, and higher roasting temperature can result in higher degree of crystallization. The heat-treated calcium arsenate is leached with acids and it is shown that less arsenic is leached out as the roasting temperature rises. After calcium arsenate is subjected to roasting at 500 ℃, the concentration of arsenic in the leaching solution can meet GB 5085.3—2007. After calcium arsenate is subjected to a roasting process at 900 ℃ and above, the concentration of arsenic in the leaching solution satisfied GB 3838—2002.

Several pieces of hard paper with different numbers, dip angles and widths were embedded into specimens to simulate structure of closed joint in rock masses and prepare rock mass models with different joints. Effect of joints on blast-induced failure characteristics of rock mass was analyzed with a high-speed camera and a 3D laser scanner, so as to explore the rules of crack propagation and fragment size distribution during rock blast. It is found that joints can disperse blasting energy and hinder crack penetration, leading to a decrease in the average size of blast-induced fragments as the number of joints increases. Wider joints can make diffraction and reflection of stress waves much more complicated, intensify energy dissipation, and also hinder crack propagation; while joints with small width are prone to make blast-induced fragments smaller in size. The interaction between joint dip angle and the propagation direction of the blast stress wave can significantly affect the crack propagation mode, and excessively large dip angles can easily hinder stress wave propagation.

There are well-developed faults in an open-pit molybdenum mine, which may lead to slope instability during open-pit mining. Three typical faults running through the ultimate boundary were selected to investigate progressive instability mechanism of the slopes in the open-pit mine under coupling effect of multiple faults by integrating Rhino+Griddle 3D geological modeling and FLAC^3D multi-field coupling simulation. Furthermore, the safety factors of slopes under different working conditions were calculated, and relatively unstable slopes were also identified for addressing the subsequent safety of the ultimate boundary. The simulation results show that, plastic failure and tensile stress concentration will occur in the slope at the junction of Zone C and Zone D, while local plastic failure will occur in the faults, which, however, won’t induce instability failure in the surrounding slopes; there won’t be much displacement in the slope at the ultimate boundary, with the maximum displacement (2.44 cm) at the toe of slope; the safety factors of the ultimate boundary of open pit under natural working conditions and rainfall are 2.48 and 2.36 respectively, indicating that the slope is stable. However, slope at Zone E with F1 fault is considered to be with a relatively instability, for which comprehensive measures including real-time monitoring, prevention and reinforcement can be taken to ensure the safety.

In order to address the poor presplit blasting effect on the final slope of the Yulong Copper Mine in Xizang Autonomous Region, the engineering applicable ranges of parameters such as decoupling coefficient, borehole diameter, linear charge density and hole spacing were calculated in consideration of the combined effects of explosion-generated gases and air shock waves, and the presplit blasting parameters were also optimized by performing orthogonal experiment. The results indicate that with a borehole diameter of 120 mm, a linear charge density of 800-1000 g/m and a hole spacing of 0.9 m, the half-borehole rate after blasting exceeds 95%, the unevenness between adjacent holes is much less than ±5 cm, and the slope gradient deviation is less than ±2°, forming a continuous and regular presplit surface. This confirms the engineering applicability of the theoretically calculated parameter ranges.

To reveal the relationship among uniaxial compressive strength, tensile strength and shear strength, 159 sets of rock mechanics data collected from 38 mines were taken as samples. Firstly, the relationship between uniaxial compressive strength and tensile strength was characterized by data analysis, and the range of uniaxial compressive and tensile strength in the formulae for calculating shear strength was calibrated. Then, a BP neural network prediction model was constructed, with which the shear strength of rocks can be predicted with uniaxial compressive strength and tensile strength as the input layer. The results show that: the uniaxial compressive strength of rock is 7.6-27.8 times tensile strength; the cohesion value obtained from multiple comparison tests is 1.0-2.2 times that from the original empirical formula, and the tangent value of internal friction angle is 0.35-1.00 times that from the original empirical formula, presenting high confident and reliable results;  based on comparison between the predicted value with BP neural network and the actual value,  the cohesion deviation ranges from -10.53 MPa to 20.12 MPa, and the internal friction angle deviation ranges from -18.43° to 28.97°, exhibiting an overall normal distribution.

The polymetallic ore from Shizhuyuan of Hunan Province was taken for research. Based on the characteristics of uneven coarse-fine dissemination of minerals and insufficient deliberation of Mo-Bi sulfide ore for flotation, an enhanced recovery technology by stepwise separation was developed for the low-grade Mo-Bi sulfide ore. The results show that an experiment by adopting such stepwise separation technique produced a bulk flotation concentrate grading 1.31% Mo and 2.83% Bi at corresponding recoveries of 88.43% and 85.99%, presenting 5.34 and 4.80 percentage points up, respectively, compared to on-site conventional bulk flotation process. This creates favorable conditions for the following tungsten flotation from the bulk flotation tailings. It is shown that a closed-circuit tungsten flotation can produce a tungsten concentrate grading 44.64% WO₃ at 84.12% recovery.

This paper presents the evolution path of intelligent technologies, from automated monitoring at early stage to modern AI-based decision support, and focuses on analysis of research results and application cases of key technologies, such as neural networks, the Internet of Things (IoT), digital twins and big data. It also presents discussion of the latest progress in application of a new generation of intelligent technologies represented by machine learning in safety management of non-coal mines. Specifically, technologies including deep neural networks, support vector machines, decision trees and random forests have shown advantages in aspects such as personnel safety management and positioning, monitoring and early warning of mine disasters, safe operation of mine equipment, and safety in mine blasting operation. Finally, the development trends of non-coal mine safety management are proposed, in terms of in-depth application and integration of intelligent technologies, compatibility of old equipment with modern intelligent technologies, and integrated management.

A new short-process preparation technique for battery-grade iron phosphate was explored with iron powder and phosphoric acid as main raw materials. The effects of iron powder dissolution mechanism, iron phosphate reaction conditions, and mother liquor recycle on product indicators were investigated. The results show that the dissolution rate of iron powder can reach 97.92% at a temperature of 70 ℃, with phosphoric acid at a concentration of 20%, iron and phosphorus at a ratio of 1/3, and iron powder at a size of 150 μm; after 1 h  precipitation at 100 ℃, with an addition of hydrogen peroxide at 110% of the theoretical amount, an iron phosphate with D₅₀ of 2 μm was prepared with the precipitation rate of 98.86%. The obtained iron phosphate has stable crystal form with uniform crystal grains, and the contents of elemental impurities are significantly lower than the requirements specified in the HG/T 4701—2021 standard. The precipitated mother liquor in the process can be recycled, leading to actualization of  low-carbon and green production.

Effects of quenching and tempering at different temperatures on the microstructure and hardness of annealed W6Mo5Cr4V2 steel were studied by means of OM, SEM, XRD analysis and hardness test. The results show that the microstructure of quenched W6Mo5Cr4V2 steel is mainly composed of martensite, MC carbide rich in V, W and Mo, and M₆C carbide rich in W and Mo, as well as residual austenite. As tempering temperature rises, the carbide in the microstructure of W6Mo5Cr4V2 steel grows in size, and the hardness decreases after an initial increase. After quenching at 1160 ℃plus three times of tempering at 540 ℃, W6Mo5Cr4V2 steel has its carbide become smaller and evenly distributed, and its residual austenite almost eliminated, showing the hardness up to 64.2HRC.

The 3104 aluminum alloy treated by hot tandem mills at different finish rolling temperature (FRT) was taken as the samples in the experiment to investigate the effect of FRT on its microstructure and texture evolutionduring the subsequent cold rolling and intermediate annealing processes. It is found that as the FRT for the 3104 aluminum alloy sample rises, the hot-rolled sheet presents highly recrystallization level, with increased volume fraction of Cube texture and decreased volume fractions of Brass, S and Copper textures. Furthermore, as FRT rises, the average grain size of the intermediate annealed sheet increases, and also the volume fraction of Cube texture in the cold-rolled sheet before intermediate annealing process increases, which is unfavorable for the formation of a strong Cube texture after annealing. As a result, the volume fraction of Cube texture in the final cold-rolled sheet decreases.

Based on the causes of historical dam failure accidents in tailings ponds, a safety grade evaluation index system was built for tailings ponds. The correlation between safety evaluation indexes was demonstrated with Pearson correlation analysis method. An in-depth analysis was conducted for the distribution of sample data to confirm that the sample data met the requirements of the Kriging method for data distribution. Then, the weight of each safety evaluation index was calculated with entropy weight method. The two safety evaluation indexes with higher sensitivity were selected as the X-axis and Y-axis of the Kriging geostatistical model. A geostatistical model was established by using the Kriging method and was verified with empirical case data. The results show that the predicted safety grades of 12 groups of tailings pond data with known safety grades in the geostatistical model are completely consistent with the actual safety grades, which verifies the feasibility and high accuracy of this method.

A refractory ore characterized by ultra-fine gold particles disseminated therein was taken for flotation test. A technique of re-grinding and re-flotation of the middlings, together with the self-developed collector of ZHS-3, was adopted to enhance the collection of fine-grained gold, resulting in a gold concentrate grading 43.70 g/t Au at 74.29% recovery, and a secondary concentrate grading 15.60 g/t Au at 4.28% recovery. Two obtained products had a total gold grade of 39.79 g/t and recovery of 78.57%. It is shown that both gold grade and recovery are improved compared with conventional flotation processes. This processing technique can achieve efficient recovery of fine-grained gold, thus improving resource utilization.

A novel low-temperature collector was adopted in the reverse flotation of Qidashan iron ore. Based on a reverse flotation condition test at low temperature, closed-circuit reverse flotation tests at room temperature and low temperature, as well as the study on the mineral adsorption mechanism, it is found that under conditions including pulp temperature at 10 ℃, pH of 11.0, caustic starch as a depressor at an amount of 600 g/t, CaO as an activator at an amount of 750 g/t, CH collector at an amount of 1050 g/t, and pulp density of 30%, the reverse flotation consisting of one stage of roughing and one stage of cleaning can produce an iron concentrate grading 68.32% Fe at 70.76% recovery; the closed-circuit tests by adopting a process consisting of one stage of roughing, one stage of cleaning and three stages of scavenging at 10 ℃ can yield an iron concentrate grading 66.32% Fe at 85.14% recovery; while the close-circuit test at room temperature (25 ℃) results in 85.45% Fe recovery into an iron concentrate grading 67.31% Fe. It has proven that CH collector can bring good flotation effect at low temperatures. Infrared spectroscopy analysis, quartz contact angle testing and surface tension measurements indicate that CH collector has a stronger adsorption on quartz surfaces compared to traditional anionic collector sodium oleate.

The ultra-fine low-grade calcite-containing apatite concentrate that comes from Hebei Province cannot meet the grade 
requirementand is difficult to be utilized. For solving this problem, an experimental research was carried out to improve the concentrate grade. A depressant of CD-8 was adopted for calcite, the dominate gangue mineral affecting the grade of apatite concentrate, and a collector of CK-P with high selectivity was adopted for apatite. A closed-circuit experiment was performed with a direct flotation flowsheet, consisting of one roughing, one scavenging and three cleaning, with middlings sequentially returned. As a result, a phosphate concentrate with P₂O₅ grade of 32.02% was finally obtained with a recovery of 70.92%. This flowsheet was applied to industrial production with normal operation and stable flotation indicators，indicating that efficient utilization of such ultra-fine and refractory phosphorus resource was actualized.

Based on the Derwent Innovations Index (DII), the technologies for recycling cathode materials in spent lithium-ion batteries were analyzed in terms of patent indicators, including the number of patent applications and patent holders, the number of priority rights in countries/regions, patent citations, patent H-index among others. It is found that the recycling technologies are in rapid development, and the Chinese research organizations have created a patent portfolio plan, including a large number of high-quality patents that can improve competition. Over the past five years, the technologies, including pretreatment processes of discharge and separation, recovery of lithium, nickel, cobalt and manganese, extraction of precious metals by hydrometallurgical and pyrometallurgical processes, as well as recycling equipment, have become hotpots in this field. China has a relatively large number of core patents, mainly involving hydrometallurgical process, direct recycling process, and a combination of pyrometallurgical and hydrometallurgical processes. Finally, some countermeasures and suggestions are proposed for enhancing the competitiveness of China’s industry in recycling cathode materials in spent lithium-ion batteries, which provides references for promoting the healthy development of China’s lithium battery recycling industry.

With nickel laterite ore from Morowali of Indonesia as the raw material, effects of various factors, including reaction time and temperature, stirring speed, acid-to-ore ratio, and slurry concentration, on the leaching rate were systematically investigated. Additionally, the leaching mechanism was explored by using the PHREEQC, a thermodynamic calculation software. The results show that after one hour reaction at 250 ℃, with acid-to-ore ratio of 300 kg/t and slurry concentration of 25%, the leaching rates of Ni and Co can reach 98.40% and 99.90%, respectively, while the leaching rates of Fe and Al are just 3.84% and 40.25%, respectively. The high selectivity of high pressure acid leaching (HPAL) is attributed by the factor that at high temperatures, not only the hydrolysis reaction of Fe and Al can be promoted, but also the pOH can be decreased from 14 to 10,  which thereby inhibits leaching of Fe and Al. As the temperature rises to above 200 ℃, the number of H+ increases, which can ensure a sufficient amount of H+ for leaching of nickel and cobalt metals.

As for fracture development and potential instability in the open-pit bench slopes in Dabaoshan in Guangdong Province, the blockiness was proposed to be taken as a quantitative measure of rock mass integrity. Based on the existing data, 72 potentially unstable zones on the western slope were identified. The structural characteristics of the rock mass were analyzed based on investigation of fracture occurrence characteristics and 3D fracture network modeling, and rock mass integrity was also evaluated by blockiness analysis. It is found that there are fully-developed fractures with good ductility in all the zones, creating the structural conditions for block formation; in 84.9% of the zones, the inclination angle of superior fractures and the slope inclination angle are supplementary, which can significantly reduce sliding risks; in 97.3% of the zones, the blockiness of rock mass is less than 27, indicating mild blockiness, good integrity of rock mass, and overall high stability. There are only rock mass with blockiness over 27 in Zone 6^# and Zone 46^#, presenting moderate blockiness. In these two zones, the rock mass structure is significantly degraded, leading to reduction in damage tolerance. It is concluded that there are potential risk of slope instability in those two zones, which should be taken as the focus in the subsequent disaster prevention and control for the slopes in Dabaoshan.

An experimental research was conducted on efficient recovery of ilmenite from Panzhihua City by magnetic fluid coupling high-gradient magnetic separation. With MnCl₂ concentration of 40%, magnetic induction intensity of 0.6 T, and pulsation frequency of 400 r/min, the ilmenite was processed by magnetic fluid coupling high-gradient magnetic separation, including one roughing and three cleaning, resulting in a titanium concentrate grading 46.89% TiO₂ at 38.30% recovery. It is shown that the obtained indices are comparable to those obtained from industrial production by adopting magnetic separation combined with flotation process.

A  low-grade manganese carbonate concentrate was processed by adopting direct sulfuric acid leaching.  The effects of leaching parameters on the leaching rates of manganese, calcium and magnesium were investigated, and changes in phase composition and microstructure before and after leaching process were also discussed. The results show that under the optimized conditions, including acid and ore in a mass ratio of 0.6, liquid-solid ratio of 4∶1, leaching temperature of 60 ℃, and leaching time of 3 h, the leaching rates of manganese and magnesium reach 99.36% and 83.97% respectively, while calcium is hardly leached out and mainly left in the residue as calcium sulfate.

Based on experimental studies on separation and quality improvement for a boron-bearing iron ore, a scheme for boron extraction and sulfur reduction was proposed, and a metallurgical process combined with mineral processing was determined, which consists of activation roasting, grinding, alkali leaching and magnetic separation. After activation roasting at 650 ℃ for 90 min in a neutral atmosphere, the obtained roasted ore was ground to a fineness of -0.075 mm 83.28%, and then leached for 60 min at 100 ℃, with liquid-to-solid ratio of 3∶1, leaching reagent of NaOH at a concentration of 15%, and stirring speed of 180 r/min. A boron-bearing mother liquor was obtained, with leaching rate of B₂O₃ at 94.62%. The leaching residue was subjected to conventional magnetic separation, resulting in an iron concentrate grading 54.94% TFe, containing 0.24% B₂O₃ and 0.077% S. It is concluded that boron can be fully recovered and the quality of iron concentrate can be also improved by adopting this processing scheme.

The flotation reagent system was optimized for a lead-zinc ore in Qinghai based on experimental studies. It is shown that a new chelating agent (PT-8) combined with the conventional 25^# xanthate can effectively enhance the flotation recovery of copper-lead sulfide minerals. A new collector (SXF-10) at a low dosage can efficiently recover marmatite from the ore, significantly improving the recoveries of Cu, Pb and Zn from flotation process. With raw ore at a grinding fineness of -0.074 mm 70%, 25^# xanthate and PT-8 are used for Pb flotation, and SXF-10 is used for Zn flotation. A closed-circuit test with such process flow can produce a Cu-Pb concentrate grading 3.52% Cu and 62.53% Pb at corresponding recoveries of 70.08% and 93.75%, respectively, and a Zn concentrate grading 48.19% Zn at 87.97% recovery.

A copper-gold ore from Xizang grades 0.50% Cu and 0.24 g/t Au, in which chalcopyrite as the dominant copper mineral is finely disseminated. It was proposed that a stepwise flotation process be employed to process this ore. At the first-stage roughing, a non-polar collector CM-2 was adopted under low-alkaline conditions to recover those easily floatable copper and gold minerals, and at the second-stage roughing, Z-200 was adopted to enhance copper flotation effect, so as to improve the recovery rates of copper and gold. A closed-circuit experiment yielded a copper-gold concentrate grading 22.33% Cu and 9.96 g/t Au at the corresponding recoveries of 90.57% and 79.83%, respectively. Compared to high-alkaline flotation processes with ethyl xanthate or Z-200 as collectors, this stepwise flotation process can increase gold recovery by more than 10 percentage points. This technical process can not only avoid depression effect of lime on gold minerals, but also strengthen the collecting effect of copper and gold minerals, thus achieving efficient resource recovery. This study can provide a reference for exploitation and utilization of similar ores.

A beneficiation experiment for super enrichment was carried out with the low-grade niobium ore from western zone of Bayan Obo mine. In the experiment, a process of magnetic separation followed by gravity concentration for tailings discarding was firstly adopted for pre-concentration, and the obtained rougher concentrate grading 2.61% Nb₂O₅ was subjected to a reverse flotation for desulfuration, followed by a direct flotation with CYN-7 as a collector and CYD-2 as a depressant  for recovering Nb minerals, resulting in efficient separation between Nb and other gangue minerals. It is found that the raw ore grading 0.06% Nb₂O₅, with a grinding fineness of -0.074 mm 85% is treated by magnetic separation and gravity concentration for tailings discarding, followed by a reverse flotation for desulfuration, and a direct flotation consisting of one stage of roughing and three stage of cleaning. As a result, a Nb concentrate grading 22.37% Nb₂O₅ at 33.64% recovery can be finally obtained.

Martensitic steel with different ferrite content and distribution was firstly fabricated by heat treatment. Then, the effects of ferrite content and distribution on the microstructure and properties of such ultra-high strength martensitic steel with yield strength more than 1100 MPa was explored based on microstructure characterization and mechanical property tests. The microstructure evolution and strengthening and toughening mechanism were also analyzed. The results show that with a small amount of ferrite uniformly distributed in the martensite matrix, the steel sample in the experiment can exhibit not only ultra-high yield strength (1245.44 MPa) and tensile strength (1411.96 MPa ), but also higher impact energy (80 J) at low temperature, presenting the optimal comprehensive mechanical properties. A small amount of ferrite in the local area continuously distributed  along the rolling direction can slightly improve the tensile strength, but the unevenly distributed  ferrite can improve the stress concentration and reduce the toughness. An increase in the content of continuously distributed ferrite can improve the tensile strength, but the formation of banded martensite and improved stress concentration make the toughness of the steel sample in the experiment substantially reduced.