In order to effectively predict blast-induced rock fragmentation, a distribution of normalized rock fragmentation under different conditions was obtained by performing a designed experiment on drilling and blasting of a concrete specimen, and then the rock fragmentation exceeding 40 mm was selected for study. The correlation among variables under different testing conditions was analyzed by using Spearman correlation statistics, and the initial weights and thresholds of the BP neural network were optimized by using the ant colony optimization (ACO) to construct an ACO-BP model. The model was then trained with rock fragmentation by on-site blasting, and tested. Based on the comparison of such prediction mode with BP neural network model, random forest (RF) model and extreme gradient boosting (XGboost) model, it is found that the ACO-BP model is highly reliable in predicting blast-induced rock fragmentation, presenting a root mean square error of 0.13, an average absolute error of 0.11, and a coefficient of determination of 0.92. It is concluded that this model, with higher accuracy in prediction and applicability, can accurately predict blast-induced rock fragmentation.

Based on the combination of the hunger games search (HGS) algorithm and the artificial neural network (ANN), a new hybrid model of HGS-ANN was developed to predict blasting vibration. Four different prediction models were established based on group method of data handling (GMDH), support vector machines (SVM), ANN and Sadov′s empirical formula, and compared with HGS-ANN model in evaluating the performance of models. For this purpose, 32 sets of blasting data of an open-pit mine were collected. 7 independent variables, including detonation distance, maximum single-stage charge, total charge, burden, hole spacing, number of holes and hole depth were selected as inputs, while the particle vibration velocity was selected as the output. With the root-mean-square error (RMSE) and the decisive factor (R₂) as the evaluating indicators, the established models was compared in terms of their performances. The results show that the HGS-ANN model, with the RMSE and R₂ of 0.833 and 0.963, respectively, has performance better than the other four models. It is proposed that the HGS-ANN model can be used as an auxiliary tool to optimize the blasting design for reducing the blasting-induced seismic effect.

An argyrodite-type sulfide solid electrolyte Li₆PS₅Cl (LPSC) was solid-phase synthesized by adopting high energy ball milling in combination with heat treatment. It is found that prolonging ball milling time is conducive to crushing, mixing, grain refinement and amorphization reaction process of raw material powder; increasing sintering temperature is beneficial to the formation of a single pure phase, but too high temperature for sintering can make electrolyte melted and decomposed, leading to destroyed crystal structure. It is found that after 10 hours of ball milling and 8 hours of sintering at 550 ℃, the synthesized sulfide solid electrolyte exhibits higher ionic conductivity, reaching 3.57×10^-3 S/cm.

The basic flow of Midrex and HYL/Energiron technologies for direct reduction in a shaft furnace and the direct reduced iron output by each processing technique in recent years are firstly introduced, and then the equipment, raw materials and process characteristics of those two technologies are analyzed based on comparison. Based on the expounding of technical R & D and investment of global steel companies in these two technologies, it is pointed out that the development of hydrogen-based direct reduction process in a shaft furnace is closely related to grade of pellet ore, heat adsorption during hydrogen-based reduction reaction process, technologies for large-scale green hydrogen production and  production cost among others. It is important for sustainable development of Chinese iron and steel industry to adopt hydrogen-based direct reduction in a shaft furnace  that conforms to the national conditions.

A FeCoCrNiMn high-entropy alloy (HEA) coating was prepared on the 201 stainless steel surface by adopting high-speed laser cladding technology, and then the microstructure, phase distribution, microhardness of FeCoCrNiMn coating, as well as its wear properties in dry sliding condition were all investigated. It is found that such laser cladded FeCoCrNiMn HEA coating consists of a single FCC structure, with no obvious cracks observed. It also forms a good metallurgical bond with the substrate. The microhardness of the coating is around (439±2.1)HV, nearly two times that of 201 stainless steel substrate, and the strengthening mechanisms mainly include strengthening by grain refinement and solid solution strengthening. Also, the FeCoCrNiMn coating presents an obviously better wear resistance than 201 stainless steel, with an average  friction factor of 0.246 and a specific wear rate of about 2.59×10^-6 mm³/(N·m).The wear mechanisms for it include adhesive and abrasive wear. It is concluded that such FeCoCrNiMn HEA coating prepared by high-speed laser cladding technology can significantly improve the surface hardness, wear resistance and service life of machine components.

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.

The acid leaching solution of cathode materials from spent lithium iron phosphate batteries was taken as raw material, and iron, phosphorus and lithium elements therein were recovered by adopting an oxidation-precipitation process. The effects of factors, including endpoint pH value of reaction system, reaction temperature, concentration of sodium hydroxide, dripping rate of sodium hydroxide, and the volume ratio of hydrogen peroxide to acid leaching solution, on the precipitation rates of iron and phosphorus and the loss of lithium during the precipitation process were all investigated. Results show that with the endpoint pH value of 2.5, temperature of 75 ℃, sodium hydroxide with concentration of 1.5 mol/L, sodium hydroxide solution at a dripping rate of 7.7 mL/min, and hydrogen peroxide and acid leaching solution in a volume ratio of 1∶60, the average precipitation rates of iron and phosphorus are 99.86% and 98.23%, respectively, and the average loss of lithium is just 1.23%. Under the above-mentioned conditions, iron and phosphorus in the solution can be effectively removed and recycled in the form of iron phosphate, presenting a lower loss rate of lithium. After 5 h-heat treatment at 700 ℃, it is shown that the chemical composition of iron phosphate can meet the industrial standard.

The influence of polyether additives on performance of ultra-thin Li-ion battery copper foil with thickness of 5 μm was studied by electrochemistry, scanning electron microscopy, and X-ray diffractometer. The results show that addition of polyether additives into electrolyte can promote  negative shift of Cu deposition potential, and polyether additives with suitable concentration can lead to finer grains of copper foil, which is conducive to improving the surface flatness of copper foil. When the mass concentration of polyether additives is 2.3 mg/L, the obtained copper foil has tensile strength of 620.43 MPa, elongation of 3.67%, glossiness of 161 GU, and surface roughness of 1.02 μm, presenting excellent overall performance. The electrolytic copper foil with high tensile strength has a preferred orientation of (111) plane.

In order to recover metal elements from the cathode materials of spent Li-ion batteries in an environmentally friendly and efficient way, three deep eutectic solvents (DES) were synthesized with choline chloride as  hydrogen bond acceptor, malonic acid, succinic acid and adipate respectively as  hydrogen bond donors. Then, Co and Li in the cathode materials of spent Li-ion batteries were leached by adopting these three DESs respectively. The effects of leaching time, liquid-solid ratio and reaction temperature on the leaching rates of Co and Li were explored, and the leaching residues were also characterized in terms of morphology and phase. The leaching mechanism was analyzed by FT-IR spectrum and UV-Vis absorption spectrum. It is shown that the leaching efficiency of metal elements can be enhanced by prolonging leaching time, increasing liquid-solid ratio and temperature. It is found that under the optimal conditions, including leaching time of 300 minutes, liquid-solid ratio of 100 mL/g, and temperature of 110 ℃, malonic acid-based DES, among those three kinds of DESs, can bring better leaching effect, with leaching rates of Co and Li all exceeding 99%. During the leaching of lithium cobalt oxide with those three DESs, Co exists in the form of bivalent in the leaching solution, and the coordination compound is in a tetrahedral structure.

        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）

In order to improve the surface hardness and wear resistance of Ti-6Al-4V alloy, a cladded coating of TiO₂ and TiN was prepared on the surface of Ti-6Al-4V alloy by laser cladding, and the microhardness, wear resistance, microstructure and element distribution of the coating were explored. Compared to the substrate, the surface hardness and wear resistance of the coating are significantly improved. It is shown that with TiO₂ and TiN powder in a mass ratio of 1∶9, the hardness and specific wear rate of the coating can reach 1936.1HV_0.1 and 2.06×10^-14 mm³/(N·m), respectively, which are 5.4 times and 3.26 times those of the substrate. The main components of the coating include α-Ti, TiN, and TiN_0.6O_0.4, which is the reason for the significant increase in hardness and wear resistance of the TiO2-TiN cladded coating. The research results provide a theoretical and experimental basis for improving the hardness and wear resistance of Ti-6Al-4V alloy by laser cladding technology.

Based on an introduction of the structural characteristics of single-crystal Ni-rich ternary cathode material, the common preparation techniques of such material are summarized. Besides, the main strategies for improving the performance of this material in recent years are also discussed, which can provide a reference for large-scale production of such high-performance single-crystal Ni-rich ternary cathode material.

Nickel, Cobalt and Manganese in the cathode materials of spent ternary lithium-ion batteries were recovered by leaching with a combination of citric acid and hydrogen peroxide. The possible reactions during the leaching process were analyzed, and the effects of factors, including citric acid concentration, mass fraction of hydrogen peroxide, leaching temperature, leaching time and liquid-to-solid ratio on the leaching rates of nickel, cobalt and manganese from cathode materials were also investigated. It is found that after 60 min leaching at 80 ℃ with citric acid at a concentration of 1.5 mol/L, hydrogen peroxide at a mass fraction of 8%, and a liquid-to-solid  ratio of 25 mL/g, the leaching rates of nickel, cobalt and manganese are 97.58%, 97.35% and 96.12%, respectively. Then, an antisolvent crystallization method is adopted with ethanol as antisolvent agent to recover metals from the obtained leach liquor, leading to the crystallization rates of nickel, cobalt and manganese at 92.34%, 93.07% and 99.69%, respectively.

Effects of heat treatment system and Cu content on the microstructure and mechanical properties of two conventionally cast Al-Cu-Mn alloys were investigated. It is found that after treatment at proper temperatures, including 525 ℃×16 h+170 ℃×8 h for Cu2.8 alloy, 525 ℃×16 h+170 ℃×14 h for Cu5.7 alloy, the Cu2.8 alloy and Cu5.7 alloy have their tensile strength up to 209.76 MPa and 349.15 MPa respectively, and yield strength reaching 107.15 MPa and 216.21 MPa correspondingly. The detailed exploration of precipitation behavior of the alloy after aging indicates that Cu content brings an important influence to the precipitation behavior. The precipitation of the T phase leads to depletion of Cu atoms in low-Cu alloy during solid solution process. The θ' phases only adhere near the T phase, and dispersed θ" phases are only precipitated in the high-Cu alloy, which contribute mainly to higher strength of high-Cu alloy.

A kind of silicon monoxide-based anode material coated with layers of lithium titanate and carbon was synthesized by chemical vapor deposition and sol-gel method. The electrochemical measurement shows that with lithium titanate coating at an amount of 3%, the anode material presents good performance, showing that the specific capacity is 1 485.4, 1 443.8, 1 386.4, 1 341 and 1 276.2 mAh/g correspondingly at 0.2C, 0.5C, 1C, 2C and 4C rate respectively, and the specific capacity is 1 138.1 mAh/g after 150 charge-discharge cycles at current density of 750 mA/g. The flexible carbon layer can buffer volume expansion of the internal silicon core and improve the conductivity of the material. The rigid lithium titanate can ensure structural integrity of the material. The synergy of two layers of coatings can effectively improve cycle stability, rate performance and reversible capacity of electrode material.

Ball milling was adopted to assist leaching of valuable metals from the cathode powder of spent batteries in citric acid and hydrogen peroxide system. It is found that ball milling can exert mechanical energy on the reaction solution, leading to changes in its structure and physical and chemical properties. As a result, chemical reactions can occur, which not only increases reaction rate, but also shortens leaching time. It is shown that after 30 min leaching at 60 ℃, with citric acid concentration of 0.8 mol/L, H₂O₂ at a mass fraction of 20%, liquid-solid ratio of 6∶1, and rotation speed of 60 r/min for a ball mill, the leaching rates of lithium, nickel, cobalt and manganese can reach 99.6%, 99.5%, 99.3% and 98.5% respectively. It is concluded that this processing technique, being characterized by low cost and high efficiency, can provide a certain reference for recycling of spent batteries. 

To investigate directional independence of multistage stress memory during progressive cyclic loading of granite under compression with a series of deflection angle, experiments were conducted on cyclic loading and unloading of granite with different deflection angles by using a self-made deflection device. The Kaiser effect (KE) and the incomplete erasion phenomenon (IEP) of the maximum stress in previous multistage cycles after progressive cyclic loading with deflection angles were explored in the experiments. Results show that both KE and IEP in granite exhibit directional independence. The directional independence of KE has a critical angle of 10° and the directional independence of IEP has a critical angle of 12°. With a deflection angle of 12°, the IEP will interfere with the memory of historical maximum stress by KE. 

In order to explore the overall stability of slope before and after local failure, as well as the effect of excavation method on slope stability, the slope project on the north side of Jingxi-Barak mining area in Jinchuan of Xinjiang was taken to study local failure characteristics of slope and slope stability under different excavation state by adopting distinct element method. It is found that the distribution of the maximum main stress has a great impact on the slope stability, and the factor of safety for slope stability tends to decrease first and then increase from the stage before local failure to the stage after failure; with more excavated benches, the factor of safety for slope stability tends to increase first and then decrease; with the excavated benches more than 1, the overall factor of safety of the slope meets the requirements; with slope angle less than or equal to 60°, the overall factor of safety also meets the requirements, and the suitable slope angle is 60°.

In order to know the status quo of technologies for deep-sea mineral resources development, the related patents were briefly analyzed. A total of 3236 patents regarding deep-sea mineral resources development technologies published worldwide from 2000 to 2023 were taken from the incopat global patent database, and analyzed in terms of number of patent applications, geological distribution, subdivision of technologies, time of Chinese patents applications, as well as nationalities of Chinese patent applicants among others. It is found that the patents regarding deep-sea mineral resources development are mainly from China, United States, Korea, Russia and Japan, focusing on technologies including detection system, mining system and transportation system. In recent years, Chinese patent applicants have gradually predominated in the related patent application worldwide, reflecting China′s great potential in R&D and market expansion of deep-sea mineral resources development technologies.

A single-factor experiment was conducted to explore the influence of rotation speed and lateral swing speed of polishing brush, and polishing current on the performance of copper foil and pinholes. Based on that, the polishing process was also optimized by applying response surface methodology, and thus the performance and apparent quality of copper foil was also improved. The results show that by using on-line polishing, with the rotation speed of the polishing brush at 450 r/min, the lateral swing speed of 350 r/min, and the polishing current of 0.50 A, the smooth surface (S surface) of the generated copper foil is uniform, and the pinhole defects are significantly reduced.

A cathode material (NaNi_0.5Mn_0.5O₂) for sodium-ion batteries was synthesized by adopting solid-state, co-precipitation and sol-gel methods, and the effects of synthesis methods on crystal structure, microscopic morphology and electrochemical performance of the cathode material were also explored. The results show that the materials synthesized respectively by those three methods all have O3-type structure, but exhibit different morphology. The cathode material synthesized by solid-state method has a special layered structure, which is conducive to sodium ion de-intercalation. The cathode materials synthesized by solid-state, co-precipitation and sol-gel methods, respectively, deliver an initial specific discharge capacity of 96.1 mAh/g, 92.8 mAh/g and 92.3 mAh/g at 0.1C, with retention rate of 64.3%, 46.5% and 36.5% respectively after 100 cycles at 0.5C. It is concluded that the solid-state synthesis is an appropriate method.

A cyanide-free leaching test was performed for the arsenic-carbon bearing gold ore from Laos, and effects of grinding fineness, pH value of pulp, concentration of slurry, and the dosage of golden cicadas environment-friendly leaching agent for gold on gold leaching effect were investigated. The results show that pre-treatment with hydrogen peroxide can improve the leaching rate of gold. With a grinding fineness of -0.074 mm 95% and an agitating speed of 2000 r/min, the pulp is pre-oxidized with 500 g/t of hydrogen peroxide for 3 h, and then treated by 30 h agitation leaching with addition of lime at an amount of 3000 g/t and golden cicadas environment-friendly leaching agent for gold at 5000 g/t, leading to the residue grading 0.25 g/t Au and gold leaching rate of 92.27%. It is shown that this pretreatment with hydrogen peroxide can make gold leaching rate up by 1.96 percentage points.

To improve the interfacial stability of spinel phase LiNi_0.5Mn_1.5O₄ cathode material in deeply charged state, a nanoscale Al₂O₃ film was deposited on the surface of single-crystal LiNi_0.5Mn_1.5O₄ by atomic layer deposition in a controlled manner. The modified cathode material exhibits excellent long-cycle performance and corrosion resistance (with capacity retention rate up to 94.7% after 500 cycles at 1C). The surface and interface analysis shows that the nanoscale Al₂O₃ coating deposited by atomic layer deposition technology can significantly inhibit the corrosion reaction between material and electrolyte, and also constrain the irreversible dissolution and precipitation of transition metal ions. In addition, AlF3 produced by HF surface etching can enhance corrosion resistance of LiNi_0.5Mn_1.5O₄ cathode material, which can thus improve its long-cycle performance and the service performance at high voltage.

As for the open-pit slope with fault structure, studies on its deformation and failure characteristics were carried out by means of remote sensing images, field investigation and numerical simulation, and its safety factor was also calculated, so as to explore the influence of fault structure on slope stability. Then, based on the analysis of deformation and failure process of slope, the failure rule for open-pit slope with fault structure was discussed. It is found that the landslide hazard occurring on the north slope of the open-pit mine is attributed to an internal factor of fault structure combined with an external factor of unloading by underground mining. Under the combined action of disturbance by underground mining and cutting by F15 fault, a landslide is prone to occur along the fault structure, and then the failure zone will be gradually expanded. The deformation and displacement of upper slope above the F15 fault structure becomes relatively larger, and proceeds towards the eastern bottom along the F15 fault structure. The F15 fault structure changes the deformation and failure trend of the upper part of the northern slope. It is shown that when the safety factor of open-pit slope is 1.45, F15 fault zone is the potential sliding plane, and no larger deformation has occurred along the fault zone of the northern slope.

An iron concentrate obtained from magnetic separation of red mud from Shandong was used in an experimental study on the effect of titanium removal by reverse flotation. In the experiment, with sodium oleate as collector, corn starch as hematite depressant, sulfuric acid as pH regulator, pulp pH of 9, and the addition of corn starch and sodium oleate at an amount of 500 g/t and 1500 g/t, respectively, the iron concentrate was produced, with the TiO₂ grade fell down from 6.90% to 2.73%, and the TFe recovery reaching 41.80%. The results of collector adsorption and IR analysis show that sodium oleate exhibits selective adsorption characteristics, which has further confirmedthe feasibility of sodium oleate used in removing titanium by reverse flotation of iron concentrate obtained from magnetic separation of red mud.

Red mud was pre-treated with process of reduction roasting followed by magnetic separation, and the obtained non-magnetic material was calcined and then dissolved in hydrochloric acid. After that, it was filtered after addition of saturated sodium meta-aluminate polymerizing agent, and then matured to prepare polymeric aluminum chloride (PAC) base liquid, which was used in a purification test. With PAC-base liquid and manganese-containing wastewater in a volume ratio of 1∶120, stirring speed of 140 r/min, pH of 8, reaction temperature of 30 ℃, and addition of polyacrylamide (PAM) at an amount of 20 mg/L, the manganese mass concentration in the wastewater reduced from 325.3 mg/L to 1.5 mg/L after 5 hours of settlement, showing manganese removal rate up to 99.5%. It is shown that the manganese mass concentration in the purified liquid can meet class Ⅰ limit in the national  discharge standard.

A review of comprehensive recycling technologies for graphite anodes in spent lithium-ion batteries is presented, including hydrometallurgical process, a combination of pyrometallurgical and hydrometallurgical process, as well as mechanical recycling. And then, an in-depth analysis of advantages and disadvantages of each technology is also presented. It is particularly pointed out that there are various recycling technologies, but the development of an efficient and environmentally-friendly closed-circuit recycling process still faces challenges. The recycling approaches of graphite anodes in spent lithium-ion batteries are discussed in details, such as usage as anodes of rechargeable batteries, or for preparation of graphene. The research direction in the future is also forecasted aiming to provide theoretical and technical support for reutilization of graphite anodes in spent lithium-ion batteries with high-value added. It is suggested that research should focus on developing a simple, efficient and clean closed-circuit recycling processes to improve the recovery rate and purity of graphite anode materials while reducing environmental pollution. The research hotspots in the future should include lattice reconstruction and repairing technologies for graphite anode materials, as well as exploration of new applications of graphite anode materials in the fields of energy storage materials, catalysts, adsorbents among others.

With silicon material (BFSi) extracted from blast furnace slag as silicon source and polyacrylonitrile (PAN) as carbon source, a kind of silicon-carbon anode material for lithium-ion batteries was synthesized. And the influence of ratio of silicon to polyacrylonitrile on the BFSi@C material was investigated. Results show that BFSi@C synthesized with BFSi and PAN in a mass ratio of 3∶1 delivers an initial charge capacity of 1884.99 mAh/g at a current density of 0.5 A/g. After 100 cycles, it still delivers a specific charge capacity of 1509.32 mAh/g, with a capacity retention rate of 80.07%. Moreover, it presents excellent rate performance at high current densities. Compared with commercial silicon materials, BFSi@C demonstrates higher cycle capacity and superior rate performance, delivering a specific capacity up to 538.31 mAh/g at a current density of 5 A/g.

LiMn_0.6Fe_0.4PO₄/C (LMFP) composite synthesized by a combined process of co-precipitation and solid-phase sintering not only has low impurity content, uniform phase distribution, but also exhibits excellent electrochemical performance. It is shown that such process can inhibit the formation of Mn₂P₂O₇ phase and improve the lithium ion diffusion rate of LMFP, while removing NH₄⁺ and H₂O. The Li-ion batteries assembled with LiMn_0.6Fe_0.4PO₄/C exhibit excellent electrochemical performance, showing initial specific discharge capacity of 145.5 mAh/g at 1C and 111.9 mAh/g at 5C. It is concluded that this process, being simple and cost-effective, is suitable for industrial production. Such study provides a feasible scheme in designing cathode materials for commercialized high-performance Li-ion batteries.

According to the relative position between interbedded surrounding rock and the peripheral holes, the relationship between bedding planes and the connecting line of the adjacent blastholes was classified into three kinds. Mechanism for bedding planes bringing impact to crack propagation in rocks between blastholes by blasting under typical work conditions (with bedding planes on the perpendicular bisector of the connecting line of blastholes) was explored by the LS-DYNA numerical simulation; and the effect of bedding planes in a different relative position to the connecting line of blastholes on the blasting effect of surrounding rock was also studied. It is found that the propagation speed of blasting vibration waves in sandstone is slightly higher than that in sandy mudstone. Under blasting loads, the surrounding rock above both softer layer and the beddings suffer severe damage. The superposition of two-blasthole blasting vibration wave peaks intensifies the damage to the surrounding rock. The blasting effect is poor when the bedding plane penetrates the blastholes, but the blasting effect is ideal if the bedding plane is on the perpendicular bisector of the connecting line of blastholes.

TiO₂ was coated on the surface of LiMn₂O₄ by thermal decomposition of titanate coupling agent, and the effects of coating treatment on the structure and electrochemical performance of LiMn₂O₄, as well as material structure in the cycling  were all explored. The results show that TiO₂ can be uniformly coated on the surface of the LiMn₂O₄ by thermal decomposition of titanate coupling agent at 550 ℃. Surface coating does not change the crystal structure of LiMn₂O₄, but obviously improves its electrochemical performance, especially high temperature rate performance and cycle performance. At 55 ℃, LiMn₂O₄ with TiO₂ coating delivers a specific capacity of 75.34 mAh/g at 5C, which is higher than that without coating (43.05 mAh/g). After 150 cycles, the capacity retention rate of the material with TiO₂ coating and without coating is 77.27% and 62.85%, respectively. The improvement of electrochemical performance is attributed to reduction of Mn dissolution in the cathode material by TiO₂ coating, which thus inhibits the change of crystal structure during cycling process, reduces the electrode polarization and charge transfer impedance, as well as improves the charge-discharge reversibility of the material and the Li⁺ diffusion.

The stability of goafs in a mine was analyzed. Firstly, the current situation of the goafs was investigated in detail to clarify the distribution and volume of goafs. Secondly, the stability variation of goafs before and after backfill was evaluated based on the FLAC^3D simulation results. It is found that there are five main goafs in the mine, which are distributed in the middle section of 700-860 m, with total volume of around 404500 m³. Currently, the roof of goaf is unstable, posing a greater potential risk of collapse. The rock mass that is not connected together from 1^# to 4^# goaf has concentrated force on it and a plastic zone penetrates through, possibly causing large-scale instability. After the goafs in the middle section of 700-820 m are gradually backfilled, the risk of goaf instability can be gradually eliminated, and production activities in the middle section below 700 m won′t be affected. It is recommended that 1#-4# goafs should be preferably backfilled to reduce the risk of roof collapse and penetration.

Based on comparison of cadmium immobilization with 4 types of minerals originated from 14 places in Hunan Province, four kinds of natural and efficient remediation materials (including limestone from Yujiaao of Ningxiang County, low-grade manganese ore from Nanmuchong of Xiangtan County, bentonite from Mazongling of Taoyuan County, and sepiolite from Xingang of Shimen County) were selected. The kinetic rate of cadmium immobilization by these four natural minerals is in the following descending order: bentonite > limestone > sepiolite > manganese ore. The cadmium adsorption by four kinds of minerals increases as the initial cadmium mass concentration increases. With cadmium mass concentration no higher than 10.0 mg/L, the cadmium adsorption by these four minerals is in the following descending order: limestone > bentonite > manganese ore > sepiolite; with cadmium mass concentration exceeding 10.0 mg/L, the cadmium adsorption by these four minerals is in the following descending order: bentonite > limestone > manganese ore >sepiolite. The adsorption behavior follows Langmuir adsorption model, and the maximum adsorption capacities of bentonite, limestone, manganese ore and sepiolite are 29.38 mg/g, 14.51 mg/g, 9.67 mg/g and 5.27 mg/grespectively. With pH of solution within the range of 6 to 9, the removal efficiency of cadmium by four minerals is in the following descending order: limestone > bentonite > manganese ore > sepiolite. It is concluded that the cadmium immobilization with natural minerals is related to  chemical composition of minerals,  initial cadmium mass concentration, and pH value.

In order to balance productivity against safety in the mining of high-level stope with gently-dipping and extra-thick orebody, an iron mine adopting sublevel open stoping with backfill was taken as an example to optimize the mining sequence. Firstly, pillars was determined to at a reasonable spacing from 14.2 m to 47.2 m based on the theory of bearing capacity of pillars. Secondly, according to stope structure parameters, the pillars were designed to be 15 m, 30 mand 45 m in thickness, respectively. An orebody model was also established with FLAC^3D and then was used to analyze the roof subsidence and pillar stability based on comparison of each mining scheme. Finally, a judgment matrix of mining sequence was constructed based on analytic hierarchy process and fuzzy comprehensive evaluation method, with both factors of safety and productivity taken into consideration in the numerical simulation. The comprehensive membership degrees of those three schemes were calculated to be 0.86, 0.79 and 0.80, respectively, and pillars in the best scheme were determined to be in the thickness of 15 m. The results of an industrial experiment have proven that this scheme can ensure stope with relative stability while achieving the maximum production capacity.

The expanded graphite (EG) derived from the graphite anodes of spent lithium-ion batteries was taken as conductive substrate, and then Sn/Co-based bimetallic sulfide was loaded by using a hydrothermal method to synthesize SnCoS₄@EG nanocomposite. And such EG presents a cross-linked porous three-dimensional lattice, and the SnCoS4 nanocrystals in the synthesized composite are uniformly dispersed in the EG, which enhances electrical conductivity of electrode material and stability of metallic sulfide, but also increases the contact area between active sites and electrolyte, leading to a higher exchange rate of Li⁺ ions at electrode/electrolyte interface. It is shown that SnCoS₄@EG electrode can exhibit a reversible specific capacity of 1195.90 mAh/g at 1.0 A/g after 500 cycles, presenting excellent durability over a large number of cycles.

Surface mechanical attrition treatment (SMAT) was adopted for low-carbon steel materials to achieve surface nanonization, and then the influence of surface nanonization on corrosion resistance of low-carbon steel was also discussed. The results show that due to surface nanonization, the low-carbon steel has a greater plastic deformation on the surface as the carbon content decreases, and the X-ray diffraction of its surface presents obviously wider peaks. It is found that after nanosizing treatment for the surface of low-carbon steel with different carbon content, the lower the carbon content, the rougher the surface and the worse the corrosion resistance.

In the flotation process of electrode materials from spent LiFePO₄ batteries, the occurrence of entrainment and entrapment usually leads to poor separation effect. Aiming at such problem, selective flocculation with polyvinylpiroxanone (PVP) and polyacrylic acid (PAA) was adopted to enhance the flotation effect in an experimental study, and the interaction mechanism between PVP and PAA and electrode materials was also analyzed. Results show that the firstly added PVP can be selectively adsorbed on the graphite surface by hydrogen bonding, thus inhibiting the spontaneous hydrophobic flocculation of graphite. Then, due to site-blocking effect, the subsequently-added PAA is inhibited to be adsorbed on the graphite surface, leading to selective flocculation of LiFePO₄ by PAA. A combined usage of PVP and PAA can not only make graphite effectively dispersed, but also lead to apparent particle size (D₅₀) of LiFePO₄ cathode material increased from 15.01 μm to 26.17 μm. As a result, the loss of LiFePO₄ due to entrainment in the flotation process of mixed electrode can be effectively reduced, thus the recovery rate of LiFePO₄ cathode material by flotation process can be improved from 71.41% to 83.59%.

A heap leaching test was carried out for the low-grade copper-cobalt oxide ores from Congo (DRC), and effects of spray intensity, spray acidity and ore particle size on the leaching rates of copper and cobalt were investigated. The results show that both acidity and intensity of spray bring significant impact to the speed and cumulative rates of copper and cobalt leaching, while the ore particle size has little effect on leaching process. And finally, the optimal conditions for heap leaching of low-grade copper-cobalt ore were determined, including spray acidity at 20 g/L, spray intensity of 15 L/(m²·h), and ore particle size of less than 40 mm. It is shown that the cumulative leaching rates of copper and cobalt can reach 90.89% and 82.27%, respectively, after 100 days of heap leaching. 

Cathode and anode materials in spent lithium iron phosphate battery powder are difficult to be separated by flotation. In order to solve this problem, it was proposed that lithium iron phosphate battery powder was pretreated by oxidative roasting, and then subjected to a flotation process for seperation between the cathode and anode materials of lithium iron phosphate. The results show that after lithium iron phosphate battery powder is pretreated by oxidative roasting at 500 ℃ for 30 minutes, the subsequent flotation process can lead to the graphite-based anode material with carbon grade up from 47.63% to 97.70%, and the cathode material with carbon grade down from 24.00% to 1.01%, presenting a significant separation effect. In comparison, the battery powder without pretreatment has cobweb-like long carbon-chain organic matter on its surface, which causes adhesion between cathode and anode materials of batteries, resulting in poor separation effect by flotation. The pretreatment of oxidative roasting can effectively eliminate the long carbon-chain organic matter on those cathode and anode materials, thus enhancing the difference in surface properties between cathode and anode materials. As a result, the enhanced flotation separation effect makes graphite-based anode material recycled from spent lithium iron phosphate batteries.

Lithium sulfide was prepared by solid phase syntheses, with lithium metal as the lithium source, sulfur powder as the sulfur source, and lithium nitride as the additive. Thermodynamic analysis results show that lithium nitride can promote the reaction of lithium metal with sulfur powder to synthesize lithium sulfide; Li₃N firstly reacts with sulfur powder to release N₂, leading to  holes formed on the molten lithium metal sheet and the contact area between lithium metal and sulfur powder further expanded. Thus a loose and porous skeleton structure is formed, which is conducive to subsequent crushing and can reduce the risk of secondary reactions in the following ball milling process. With Li∶S∶Li₃N=2∶2∶0.4 (molar ratio), crude lithium sulfide can be obtained after 8 hours reaction at 100 ℃. It is then subjected to calcination, impurity removal and ball milling processes, and a kind of lithium sulfide products with purity greater than 99.95% and particle size less than 15 μm can be obtained, which can be used in EV. This method provides a new idea for industrial production of lithium sulfide products.