[Objective]To address the environmental pollution caused by acid leaching of a low-grade phosphate iron ore,reduce the production cost of synthetic iron phosphate,and achieve comprehensive utilization of resources,[Method]doping-type iron phosphate was prepared by an acid leaching and co-precipitation method using low-grade phosphorite as the raw material and precursor of a lithium iron phosphate battery.The effects of different experimental parameters on the composition,morphology,and particle size of doped iron phosphate were systematically studied using XRD,SEM-EDS,particle size analysis,atomic absorption,and carbon sulfur analysis.[Result]The optimum acid leaching conditions were as follows:initial sulfuric acid concentration of 0.5 mol/L,acid leaching time of 30 min,stirring speed of 300 r/min,liquid-solid ratio of 4∶1,and acid leaching temperature of 25℃.The optimum conditions for the synthesis of doped iron phosphate were a pH value of 2.0,phosphorus iron ratio of 1.5,reaction time of 240 min,and reaction temperature of 85℃.The doped iron phosphate obtained after the calcination of the sample was evenly distributed without a large amount of agglomeration.After analyzing the SEM spectrum points,it is known that the product contains some doping elements,such as AlPO4 in addition to FePO4,and the particle size D50 of the sample after ball milling is 2.695 pm,which accords with the industry standard of battery-grade iron phosphate.After washing with citric acid 15 times,the sulfur content was＜0.04％.[Conclusion]Doped iron phosphate can be used as a precursor material for lithium iron phosphate batteries with a good electrochemical performance.

Bio-oxidation pretreatment of refractory sulfide gold ore followed by thiourea leaching is a suitable method for gold extraction compared to cyanidation due to its environmental friendliness and compatibility between the two systems. The issue of high thiourea consumption, however, hinders the commercial application of this technology. After bio-oxidation, gold extraction was 79.6 %, whereas the thiourea consumption reached 9.48 kg/tore. Additives, namely oxalate (ox(2-)), citrate (cit(3-)), phosphate (PO43-) and glycine (gly(-)), were evaluated to improve the thiourea leaching of gold. Among them, ox(2-)demonstrated the most significant improvement in both gold extraction and recovery via resin adsorption. With ox(2-)addition, gold extraction increased to 86.7 %, and thiourea consumption decreased to 6.57 kg/t-ore. Compared with 91.5 % gold adsorption achieved in 60 min without additive, a higher gold adsorption of 96.9 % (ox(2-)) was obtained. ox(2-)complexes with the oxidant Fe3+, forming the complexes Fe(ox)(+), Fe(ox)(2)(-)and Fe(ox)(3)(3-), This complexation stabilizes Fe3+, lowers the solution potential, thus reducing thiourea consumption. Analytical results indicated that although ox(2-)addition suppressed marcasite formation (a passivating product), its low content exerted a negligible impact on gold leaching. Furthermore, potassium jarosite dissolution in an ox(2)(-)-containing acidic solution releases gold encapsulated within it, thereby enhancing gold extraction. For gold adsorption, the formation of Fe(ox)2-and Fe (ox)(3)(3-)reduced the Fe adsorption onto the resin due to the electrostatic repulsion, releasing more active sites for Au adsorption.

This study presents a bromide-modulated electrolytic route for producing ultralight copper powder (UCP) through the coupled regulation of copper deposition behavior and hierarchical microstructure evolution. Electrochemical measurements, potential-dependent phase identification, and time-resolved ex situ characterization support the transient participation of CuBr-rich species during Br--modified copper deposition. The results are consistent with a proposed additional CuBr-mediated route involving Cu2+ → CuBr-rich species → Cu0 that operates alongside direct Cu2+ reduction, thereby altering the nucleation and growth behavior of copper deposits. Based on the observed temporal evolution, a four-stage growth model is proposed: (i) formation and assembly of CuBr-rich particles, (ii) progressive disappearance and structural collapse of the early deposits under continued cathodic polarization, (iii) emergence and fractal reconstruction of Cu-rich particles, and (iv) diffusion-dominated growth of fern-like dendrites. The resulting UCP exhibits an ultralow apparent density of 0.18 g cm-3 and a specific surface area of 4.9 m2 g-1, which is 6.1 times that of a commercial copper powder reference, owing to the multiscale porosity of its fractal dendritic architecture. This hierarchical structure also imparts a static water contact angle of ∼151°, consistent with air retention at the interface. In antibacterial tests, 0.50 g L-1 UCP-30Br with 12 h exposure reduced culturable Escherichia coli and Staphylococcus aureus to below the detection limit. This efficacy is consistent with enhanced physical contact and interfacial interactions enabled by the hierarchical architecture, coupled with a higher endpoint concentration of soluble copper. Notably, the Br--modified process achieved a current efficiency of 89.7% and a specific DC energy consumption of 1050.9 kWh t-1 under the optimized conditions, representing a 21.9% decrease relative to the Br--free control.

For slightly and moderately cadmium (Cd)-contaminated paddy soils, in situ stabilization technologies such as biochar amendment provide a sustainable way of safe agricultural production. A two-year study was conducted to investigate soil microbial communities responses to biochar amendment in a slightly Cd-contaminated paddy field. Soil Cd fractions, organic carbon content, microbial communities, and their relationships were analyzed. The results showed that biochar application decreased Cd accumulation in brown rice by 13.56-24.56% and HOAc-soluble Cd content by 35.65-52.5%. It mainly induced the transformation of soluble Cd to oxidizable and residual Cd. Soil organic carbon (TOC), total nitrogen (TN), available potassium (AK) and available phosphorus (AP) contents tended to increase with biochar amendment. Biochar application significantly increased bacterial diversity but had no significant effect on fungal diversity. Soil oxidizable Cd contents were the most influencing environmental factors of bacterial communities, whereas soil pH were the most influencing environmental factors of fungal communities. These results indicate that the fungal community structure was influenced mainly bychanged soil pH, whereas the bacterial community structure was influenced by biochar application mainly due to Cd immobilization.

This study investigated the effect of rolling strain paths on the texture and microstructural homogeneity of high-purity tantalum plates. High-purity tantalum ingots (electron beam melting-prepared) were subjected to multidirectional forging and vacuum annealing, then cold-rolled to 85 % total deformation via unidirectional rolling (UR) and cross rolling (CR: 45 degrees, 60 degrees, 120 degrees). Texture, grain fragmentation, geometrically necessary dislocation (GND) density, and stored energy were characterized by XRD and EBSD. Results show UR induced significant through-thickness texture gradients: weak alpha/gamma/theta-fiber textures in the surface and complete gamma-fiber in the center. CR mitigated gradients by altering strain paths, with 120 degrees CR achieving the most uniform gamma/theta-fiber distribution. The ta plates after rolling have differences in shape, especially when comparing single-pass single-rolling with the other three types of cross-rolling. Parameters such as the cross-rolling angle, rolling passes, and deformation amount all affect the final shape of the rolled plate. Based on our previous research results on the microstructure and texture of Ta deformation, the influence of the final rolled plate shape on the uniformity of the texture and structure can be ignored. Since the main topic of this paper is to study Texture and Micro-structural Homogeneity, the shape of the rolled plate was not analyzed or discussed.; 120 degrees CR minimized this orientation dependence, balancing {111}/{100} stored energy ratios to 1.37 (surface) and 1.28 (center). After annealing, 120 degrees CR samples exhibited uniform recrystallized grains (average 57.1 mu m) due to homogeneous stored energy, while UR samples formed strong {111} textures and coarsened grains (average 64.7 mu m) via preferential recrystallization. This work clarifies how CR enhances homogeneity via strain path modulation, providing insights for optimizing high-purity tantalum processing.

In this work, ferric oxide prepared from an industrial liquid waste was loaded with chitosan, then the as-received ferric oxide loaded with chitosan (FOLWC) was utilized as a novel adsorbing material for the elimination of trace cadmium(II) ion from cadmium(II)-containing solution. First, the microstructure and phase composition of FOLWC was explored. Then, the effects of initial pH, contact time and adsorbent dosage on the cadmium(II) ion adsorption were investigated. An empirical quadratic polynomial equation which could predict the response value of cadmium(II) ion removal efficiency was obtained as follow: W = 93.69 + 11.38A + 2.90B + 0.99C 1. 36 AB 1.51A C 0 .15B C 7.7 0 A 2 2.35B 2 + 1.76C 2 , where A, B and C represent the initial pH, adsorbent dosage and contact time, respectively. In addition, the optimization study of adsorption parameters was carried out using response surface methodology. The pH value of cadmium(II)containing solution has a most significant effect on the cadmium(II) ion removal onto from FOLWC. The pH value, contact time and adsorbent dosage corresponding to the optimum conditions were obtained to be 6.77, 15.27 min and 1.71 g/L, respectively. The cadmium(II) ion removal efficiency was reached nearly 100 % on the optimum conditions. The adsorption kinetics result implies that a pseudo-second-order model can be consistent with the adsorption process. The cadmium (II) ion adsorption isotherm accords with Langmuir model. The studied maximum cadmium(II) ion adsorption capacity of 17.08 mg/g by FOLWC reached at 55 degree celsius. In addition, thermodynamic experimental data indicates that the whole removal process of cadmium(II) ion by FOLWC is not only endothermic but spontaneous as well. The principal adsorption mechanism is surface complexation, where the dominant surface groups including-OH, C ]O and N-H of FOLWC were replaced by the cadmium(II) ions. In summary, it shows that FOLWC can be taken as an efficient adsorbent for Cadmium ion removal from polluted water.

Generally, hydrometallurgy process is adopted in factory to recover valuable metal from anode materials in lithium ion battery. The mother liquor generated from the precipitation of lithium carbonate in this process is often managed by evaporative crystallization process which is high energy-consuming and expensive. The methodology employed in this research involves pretreatment and bipolar membrane electrodialysis to partition salts within the mother liquor into acids and bases, thereby achieving cost savings. The findings reveal that a significant 76.5% reduction in COD is achievable through the application of potassium permanganate and activated carbon in the treatment of the mother liquor. Subsequently, the treated mother liquor can be transfer to electrodialysis process for further treatment. During this process, desalination of the mother liquor occurs, leading to the decomposition of sodium sulfate into sulfuric acid and sodium hydroxide. Analysis of the experimental data reveals that optimizing the initial concentrations of sulfuric acid and sodium hydroxide within the acid and alkali collection chambers, along with the application of elevated electric current density and maintaining a high pH value of the mother liquor, yields improvements in current efficiency and concomitant reductions in energy consumption. Under optimal conditions, the current efficiency of acid and alkali preparation is 52.53% and 62.12% respectively, along with energy consumption of acid and alkali preparation is 8.68kWh/kg and 8.99kWh/kg respectively. The pretreatment and bipolar membrane electrodialysis process is low-energy consumption and inexpensive, facilitating a reduction in processing expenses to $6.659 per ton of mother liquor.

Tantalum samples were dynamically deformed at liquid nitrogen (LN) temperature to obtain one pass (LN-DPD-1pass) and three pass LN-dynamic plastic deformation (LN-DPD-3pass) samples, and Ta was also dynamically loaded at room temperature (RT-DPD) for comparison. Results showed that although all the three DPD samples are essentially formed by {100} and {111} grains, the LN-DPD-3pass sample is significantly more severely fragmented. The low-angle grain boundaries are fairly uniformly distributed indicating a high homogeneity of the deformed microstructure. Meanwhile, the proportion of random texture in LN-DPD-3pass sample is higher as compared to the other two samples due to the rotation of dynamic recrystallization grains during DPD. Uniform deformation structure and similar stored energy of the deformed grains lead to the formation of excellent microstructure in the annealed LN-DPD-3pass samples.

With advanced integrated circuit semiconductor chips, the uniformity of microstructure and texture is increasingly required for tantalum (Ta) targets. A combination of warm rolling and 135° cross rolling (CR) at the temperature of 500 °C and 800 °C, i.e., warm cross rolling (WCR), was carried out in tantalum (Ta) plates to investigate the evolution of deformed microstructure and texture. Subsequently, these rolled samples were annealed to analyze the recrystallized microstructure. Results exhibited that WCR samples formed a relatively uniform and weak texture distribution along the thickness direction. The reduction in the proportion of low-angle grain boundaries (LAGBs) was associated with the lower Peierls stresses to be overcome for dislocation motion due to thermal activation in the WCR sample. High grain boundary energy was observed in WCR samples, and WCR can promote dynamic recovery of samples to produce sub-crystals (thermodynamically unstable and serving as nuclei for subsequent recrystallization). Fine average grain size and high content of recrystallized grains with random orientation were obtained after annealing in the WCR sample. This study will provide a theoretical reference for the precise optimization of tantalum process parameters and the improvement in the target material’s performance.

In this paper, dynamic plastic deformation (DPD) of tantalum (Ta) was achieved by split Hopkinson pressure bar and a variety of DPD conditions were set to systematically investigate the microstructure of the deformed samples, focusing on the twinning behavior. Results showed that the deformation conditions have a significant effect on the number and distribution of {112}<111>twins. Compared with {100} and {111} grains, {110} grains are more prone to twinning due to the fewer slip systems. As the strain rate increases or the deformation temperature decreases, the number of twins increases dramatically. In addition, the texture of Ta samples gradually changes from {110} to mixed {100} and {111} textures with the increasing deformation, and the number of twins first increases and then decreases. After calculation, it is found that the selection of twin variants in Ta under DPD not only follows Schmid law but is also influenced by strain coordination. The research in this paper deepens the understanding of tantalum as a material for armour-piercing projectile.

Quantitative analysis of silicon tetrachloride, carbon disulfide, and dichloroethane concentrations to obtain vapor-liquid equilibrium data of the SiCl4-CS2 and SiCl4-C2H4Cl2 binary systems was established by Raman spectroscopy. The cheap glass sampling pipe was used as a carrier for Raman spectroscopy measurements. The Raman peak height of the internal standard was used to remove interference factors such as sampling pipe diameter, temperature, laser power, and other effects from the instrument. The peak height ratio between the Raman characteristic peak of the analyte and that of the internal standard was proportional to the analyte concentration. During the measuring process of vapor-liquid equilibrium data for the SiCl4-C2H4Cl2 binary system, the linear equation of y = 0.0068 + 0.75x with R2 of 0.9939 was used for the determination of SiCl4 concentration at the 422 cm−1 band. The linear equation of y = 0.0019 + 0.2266x with R2 of 0.9966 was used for the determination of C2H4Cl2 concentration at the 754 cm−1 band. For the SiCl4-CS2 binary system, the linear equation of y = 0.0494 + 4.7535x with R2 of 0.9962 was used for the determination of SiCl4 concentration at the 422 cm−1 band. The linear equation of y = 0.8139 + 8.7366x with R2 of 0.9973 was used for the determination of CS2 concentration at the 654 cm−1 band. The concentration of standard samples calculated by these standard curves was compared with the actual value to verify the accuracy of this method. The reproducibility is good when determining silicon tetrachloride and dichloroethane concentrations for the SiCl4-C2H4Cl2 binary system, with RSEP values of 2.81% and 2.17%, respectively. Meanwhile, the RSEP values are 3.55% and 4.16%, respectively, when determining silicon tetrachloride and carbon disulfide concentrations for the SiCl4-CS2 binary system.

In the paper, mechanical properties and microstructure of pure Mg hat-shaped samples after dynamic impact and quasi-static compression were studied. Results showed that the maximum peak strength 241.46 MPa and yield strength 51.65 MPa at 1.8 × 104 s−1 were obtained, and strain rate sensitivity and hardening rate under dynamic impact were much higher than those under quasi-static compression. Grains in matrix region kept the size of the original grains, and the 〈0001〉 direction was parallel to the loading direction. A strong texture appeared within the shear bands, and the maximum intensity between 15 and 21 increases as increasing strain rate. The <0001> direction of most grains with the sizes between 3 and 4.5 μm, in general, was perpendicular to shear band direction or shear direction. {10−12} 〈10−11〉 tension twins played an absolute leading role in twins, while the fraction of other types of twins was negligible. The temperature within adiabatic shear band (ASB) reached the maximum value of 376 K at 1.8 × 104 s−1, and the maximum absorbed energy density (ΔE) of 226.37 MJ·m−3 also was obtained. The average ASB widths between 87 and 135 μm decreased with increasing strain rate, and the trend was the same with that predicted by Bai-Dodd model. Dynamic recrystallization (DRX) grains slip and rotate under the action of normal stress Fn, and form ASB together. Fracture occurred along shear band, and brittle fracture characterized by cleavage surface and ductile fracture characterized by dimples both existed during the fracture progress.

赤泥是氧化铝生产过程中产生的强碱性固体残渣,其环境污染大,安全隐患高,综合利用难,严重制约了氧化铝行业的可持续发展.赤泥作为水泥等生产原料是实现大规模综合利用的可行途径之一,但碱含量超标使得水泥制品出现开裂、鼓包和泛霜等现象,目前只能少量掺合使用,亟待系统开展赤泥脱碱研究.本文基于氧化铝生产工艺流程分析了拜耳法赤泥中各碱性物质的形成过程,综述了赤泥脱碱的方法与技术、热力学原理和动力学机理,分析了当前赤泥脱碱存在的问题,并展望了未来脱碱技术的发展方向,可为氧化铝行业赤泥脱碱和综合利用提供科学参考.

In this paper, the mechanical properties of pure tantalum (Ta) hat-shaped samples during dynamic impact were studied, and microstructures at different reductions were characterized. Results showed the ultrafine grains formed in adiabatic shear band (ASB). When the reduction is 40%, that is to say that the shear strain is 4, the shear yield strength is about 703.65 MPa, and then the shear stress decrease with increasing strain. ASB is formed and could be divided into transition and central regions. Most of the grains in the central region are ellipsoidal dynamically recrystallized (DRX) grains with a size of about 760 nm, while numerous grains in transition region are split. The geometric necessary dislocations (GNDs) density (20.13 x 10(14) m(-2)) in the transition region is greater than the density (18.28 x 10(14) m(-2)) in the central region. The average hardness of the matrix region is about 88.80 HV, and the value in the ASB reaches 239.08 HV. The maximum temperature within the ASB is calculated to be approximately 1100 K before ASB formation. According to the mechanically driven subgrains rotation model, subgrains inside ASB slip and rotate under the action of shear forces or normal stresses, and finally a texture (110) // shear plane normal (SPN) near the top of ASB and (110) // shear direction (SD) near the bottom is formed.

In the paper, tantalum (Ta) samples were processed with one pass (1-pass), two passes (2-pass) and three passes (3-pass) dynamic plastic deformation (DPD). The deformed and annealed microstructures were studied by using multiple characterization techniques, such as electron backscatter diffraction (EBSD) and X-ray diffraction (XRD). Results showed that the yield strength increases from 611.81 MPa at the first DPD to 1055.19 MPa at the third DPD and all samples reached a 70% reduction finally. The deformed samples are mainly composed of {111} (< 111 >//LD) and {100}(< 100 >//LD) grains, and the grains are arranged alternately. Meanwhile, numerous micro shear bands (MSBs) appear in {111} grains of the 1-pass sample. In contrast, they are rarely observed in 2 pass and 3-pass samples, and the distribution of low-angle grain boundaries (LAGBs) and kernel average misorientation (KAM) are more uniform than 1-pass samples. Compared with the 1-pass sample, the 3-pass sample exhibits lower geometrically necessary dislocations (GND) density differences between {111} and {100} grains. The relative Schmidt factor (SR) results indicate that the 2-pass and 3-pass sample is more likely to activate multiple slips than the 1-pass sample. The stored energy variance between {111} and {100} grains in deformed samples is significantly weakened after increasing DPD passes, resulting in that microstructure and texture homogeneity after annealing are improved.

Two tantalum plates with strong (110)// loading direction (T110 sample) and (111)// loading direction (T111 sample) texture, respectively, were processed to 70% reduction by means of dynamic plastic deformation (DPD). Subsequently, the microstructure and texture after DPD and annealing were investigated in detail. Results showed that yield strengths of T110 and T111 samples during DPD are 683.07 MPa and 546.12 MPa, respec-tively. The microstructure of DPD samples consists mainly of {100} and {111} grains, and grains in T111 DPD sample are arranged alternately. Compared with T110 DPD sample, the deformation degree difference between {111} and {100} grains is slight of T111 DPD sample, which can be illustrated by kernel average misorientation and geometrically necessary dislocations distribution. Relative Schmidt factor of {111} grain in T110 DPD sample is 22.54%, indicating that {111} grain in T110 DPD sample is likely to activate single-slip. As an unstable texture, the {111} initial texture, can be chosen for the DPD preparation of Ta to obtain a relatively excellent microstructure.

In this work, low grade oolitic hematite tailing with phosphorus (LGOHTWP), an industrial solid waste was adopted as adsorbent to remove Cu(II) ion from aqueous solution. Influences of experimental factors including initial pH, initial Cu(II) concentration and LGOHTWP dosage on the Cu(II) ion removal were analyzed, and the related adsorption mechanism was discussed. Aiding by Box-Behnken design based response surface methodology, an empirical quadratic equation expressing the relationship between the Cu(II) removal efficiency and adsorption parameters including initial pH, adsorbent dosage and initial Cu(II) ion concentration was obtained. In addition, the optimum conditions (initial Cu(II) concentration = 21.60 mg/L, adsorbent dosage = 79.23 g/L, initial pH = 5.71) were obtained by plotting 3-D response surfaces from the mathematical model. On the optimum conditions, the experimental Cu(II) ion removal efficiency reached 99.98%, which was in accordance with the predicted value. The results indicate that the adsorption of Cu(II) ion onto LGOHTWP is strongly dependent on pH value of the solution. Adsorption kinetics accords with the pseudo-second-order model, and the equilibrium adsorption data fits well with Langmuir isothermal model. The maximum capacity of adsorption is 26.95 mg/g at 50 degrees C. Thermodynamic study reveals that adsorption of Cu(II) ion onto LGOHTWP is spontaneous and endothermic. In general, LGOHTWP is an efficient and promising adsorbent for Cu(II) ion removal from wastewater.

《轻金属冶金学》课程涉及概念、理论、工艺、设备等诸多内容,具有很强的工程实践性.本文尝试将案例教学引入课堂,设计了一则包括知识讲授、问题引导、效果评价在内的完整案例.案例从生产实践出发,提出问题,分析问题,探讨可能的解决方案,并对案例进行了拓展延伸,以激发学生创新思维,培养可迁移能力.

The copper powder produced by electrolysis has a dendritic structure, which gives it excellent green strength as a raw material for producing powder metallurgical components. Yet its large specific surface makes it susceptible to oxidation. Although the oxidation tends to occur only on the surface, it still needs to be reduced. The partially oxidized cauliflower-like copper powder was reduced by hydrogen in this paper. Internal diffusion was found as the rate controlling step for the hydrogen reduction reaction, in which the apparent activation energy was determined to be 14.18 kJ/mol using the Arrhenius-based expression for the diffusion coefficient. Controlling copper powder particles were still compact after reduction, and the tips of dendrite arms became round and smooth. The apparent density decreased after reduction, but excess temperature led to sintering, and as a result, increased apparent density of metallic powder. Therefore, lower reduction temperature and appropriately long reduction times yielded better apparent density. These research results can provide reference for metallic powder plants.

阐述了有色金属设计与计算课程的教学目标与育人目标,探讨了课程思政育人实践,包括讲好有色设计故事,传承优秀文化,激发学生家国情怀;科研反哺教学,强化科技强国理念,培养科学系统思维;虚拟、竞赛进课堂,提高专业自信,培养大国工匠精神;注重工程伦理教育,关注环保与可持续发展,强化使命担当.