To address difficulties in separating arsenic (As) from antimony (Sb) and tin (Sn) in arsenic-antimony-tin residue, a thermodynamic analysis of Sb(Ⅲ)-Sn(Ⅳ)-H₂O system was conducted, and pH control window for phase separation was determined to be 9.0~10.3. Accordingly, a two-stage alkaline leaching process consisting of first-stage soda leaching and second-stage alkaline oxidative leaching was proposed for arsenic removal, supplemented by oxidative precipitation of antimony for its recovery. Effects of key parameters on As removal and Sb/Sn separation were systematically investigated, and the optimal conditions for each stage were determined. Under the optimized conditions, As content in the residue decreased from 17.52% to 1.81%, achieving an overall As removal rate of 92.14%, while direct recovery rates of Sb and Sn reached 97.74% and 95.44%, respectively. Mechanistic analysis revealed that during the first-stage leaching, arsenate decomposed to release AsO₄³⁻, while simultaneous hydrolysis of Sb³⁺ and Sn⁴⁺ generated colloidal Sb₂O₃·xH₂O and Sn(OH)₄, which adsorbed and encapsulated arsenic. In the second-stage leaching, H₂O₂ oxidized the colloidal Sb₂O₃·xH₂O to crystalline NaSb(OH)₆ precipitate, disrupting encapsulation structure and enabling further release of arsenic. Phase and valence transformations were verified by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope with energy dispersive spectroscopy (SEM-EDS) characterizations. This process enabled selective removal of As and simultaneous enrichment of Sb and Sn.

To reveal damage evolution and brittle-ductile synergistic behavior of the gypsum-slag-cement (GSC) ternary cementitious system under uniaxial compression, this study conducted uniaxial compression tests at different curing ages by adjusting the ratios of gypsum, cement, and slag. Combined with digital image correlation (DIC) and scanning electron microscopy (SEM) techniques, a systematic analysis was performed from three perspectives: macroscopic mechanical response, crack propagation characteristics, and microstructural evolution. Results indicated that with extension of curing age, compressive strength, elastic modulus, as well as crack initiation and damage stresses of GSC system significantly increased, while post-peak failure gradually transitioned from typical brittleness to quasi-ductility. Increasing the proportion of cement content helped enhance the material's strength, stiffness, and overall bonding capacity, but led to increased brittleness. Gypsum content exhibited a significant nonlinear influence on material properties. A proportion of 10% effectively promoted internal stress redistribution and synergistic multi-crack propagation, thereby improving toughness and cracking resistance, whereas excessive gypsum tended to cause a decline in structural continuity and deterioration of mechanical performance. Comprehensive comparison revealed that the formula G10S70C20 demonstrated the highest compressive strength and superior deformation coordination ability at curing age of 28 d, with cracks exhibiting a typical symmetrical "X" pattern, indicating optimal comprehensive performance. The findings suggested that synergistic regulation of gypsum and cement was the key to achieving both strength enhancement and an optimized brittle-ductile balance in the GSC system.

In order to explore new pathways for large-scale and value-added utilization of copper tailings, this study utilized copper tailings to prepare anti-corrosion composite plates. Chemical composition, particle size and phase structure of copper tailings were analyzed by X-ray fluorescence (XRF), laser particle size analysis and X-ray diffraction (XRD). Influence of copper tailings addition on bending strength, compressive strength, density, water absorption, and corrosion resistance of anti-corrosion composite plates was investigated. Results indicated that the maximum incorporation level of copper tailings was 30%. At this point, mechanical properties or corrosion resistance of anti-corrosion composite plates did not show a significant decrease, meeting anti-corrosion and load-bearing requirements for floors in hydrometallurgical workshops. This demonstrated the feasibility of using copper tailings to prepare anti-corrosion composite plates, providing a new idea for large-scale and value-added consumption and utilization of copper tailings.

Alkali residue, a solid waste with potential cementitious properties, poses severe environmental risks when piled in a large amount. To enable large-scale utilization of alkali residue, this study partially replaced cement with alkali residue to prepare alkali residue modified cemented backfill. Dynamic impact tests were conducted to investigate mechanical behavior and energy evolution characteristics of alkali residue modified cemented backfill. Results indicated that incorporation of alkali residue altered the mechanical performance and enhanced compressive strength of the backfill. With increasing alkali residue replacement proportion, compressive strength first increased and then decreased, peaking at an alkali residue replacement proportion of 5%. Energy evolution of alkali residue modified backfill can be categorized into three stages: linear elastic stage, plastic yield stage, and instable failure propagation stage. Addition of alkali residue brought elastic strain energy closer to total input energy during the first stage, reduced instances of negative dissipated energy, and rendered the energy curves more physically realistic. As alkali residue content increased, the maximum elastic strain energy initially rose and then declined, reaching its peak at an alkali residue replacement proportion of 5%. These findings demonstrated that alkali residue improved mechanical performance of cemented backfill, thereby providing a theoretical basis for the application of alkali residue in mine backfilling operations.

To achieve large-scale and high-value utilization of copper tailings, copper tailings were compounded with mineral powder and fly ash, and then ground by an ultra-fine ball mill with special grinding media to obtain copper-tailings-based ultrafine composite admixtures with specific surface areas of 755 m²/kg and 730 m²/kg, respectively. Basic properties of these admixtures and their effects on workability, mechanical properties and durability of concrete were studied. Results showed that compared with conventional fineness S95 mineral powder, flow ratio of copper-tailings-based ultrafine composite admixtures was slightly lower, but they had higher early activity. 7-day activity index was increased by 10% and 7%, respectively, and 28-day activity index was slightly lower than that of S95 mineral powder. Addition of fly ash can improve flow ratio and 28-day activity index. In C30 grade concrete, copper-tailings-based ultrafine composite admixtures can completely replace original slag powder in mix proportion and further reduce cement dosage by 20 kg. Compressive strength of the concrete showed an increasing trend. Impermeability, chloride ion penetration resistance, carbonation resistance, sulfate resistance and freeze-thaw resistance of the concrete were all improved. This study provided an effective approach and theoretical support for high-value-added resource utilization of copper tailings.

Copper and copper alloys are considered the primary structural material for fusion reactor divertor heat sinks due to their excellent thermal conductivity, thermal stability, mechanical properties, and relatively good resistance to neutron irradiation. However, a lack of in-depth understanding regarding the mechanisms of displacement damage in copper induced by synergistic effects of neutron irradiation and transmuted helium still exists. In this study, the synergistic effects were investigated using molecular dynamics simulations, with a focus on dislocation nucleation mechanisms. Influences of transmuted helium concentration (2000~8000 appm), primary knock-on atom (PKA) energy (1.0~7.0 keV), and simulation temperature (100~900 K) were systematically examined. Results showed that increased helium concentration raised the number of point defects, enhanced pinning effect, and promoted dislocation density and the formation of complex entanglement structures. Higher PKA energy led to a notable rise in length and density of dislocation line. At lower temperatures, rising temperature promoted development of dislocation entanglement structures in the cascade center, while at higher temperatures, it facilitated dislocation annihilation and break-up, resulting in the collapse of these entanglement structures. These findings provided important insights for the design of irradiation-resistant copper alloys for fusion reactors.

C19210 is one of the Cu-Fe-P alloys extensively employed in the electronics industry. In order to enhance strength and electrical conductivity of the alloy, thermo-mechanical treatment was applied. In this work, the influences of deformation heat treatment on the mechanical properties, electrical conductivity, and microstructure of C19210 were investigated. Results showed that the optimal properties, including a Vickers hardness of 134HV, tensile strength of 445 MPa, electrical conductivity of 88.4%IACS, and elongation of 16.3%, can be achieved through an optimized combinatorial process: solution treatment at 900 ℃ for 120 min, primary cold rolling (80% reduction) with aging at 450 ℃ for 240 min, followed by secondary cold rolling (50% reduction) and aging at 450 ℃ for 60 min. Microstructural observations revealed that combined effects of precipitation strengthening from dispersed precipitates and grain refinement from fine recrystallized grains contributed to the improvement of strength and electrical conductivity. These findings provided a theoretical and practical foundation for optimizing the performance and engineering application of Cu-Fe-P alloys.

In response to the high hardness of discharged water (350~900 mg/L CaCO₃), seasonal water scarcity, and pipeline scaling risk at Wushan Copper Mine in Jiangxi, this study developed a softening and reuse process based on ion exchange resin. Laboratory-scale tests were conducted to select a domestic Zhengguang (working exchange capacity 550~600 mmol/L). Operating parameters were optimized (flow rate 12 m/h, regenerant concentration 6%~8% NaCl), and the feasibility was verified at an industrial scale of 120 m³/h. Results showed that the softened water hardness was stably controlled at 0~130 mg/L CaCO₃, with a Ryznar stability index of 6.0~7.3. Regenerant salt consumption was 210~245 g/mol, and treatment cost per ton of water was 0.686 RMB/ton, of which the salt cost was 0.684 RMB/ton. Resin cost per cubic meter of softened water was 0.069 RMB/m³, and the average electricity cost for recycled water was 0.002 RMB/m³, comparable to current water intake cost. Concentrations of heavy metals in the regeneration waste complied with the GB 25467—2010 discharge standards (Pb<0.37 mg/L, Zn<0.45 mg/L). This technology addressed the production risk caused by seasonal water interruptions of the Nanyang River, achieved 100% wastewater reuse, and provided a solution for treating high-hardness mine wastewater.

Injection characteristics of side-blown lance in a bath smelting furnace directly govern reaction intensity and smelting efficiency. In this study, stirring enhancement mechanism of a novel side-blown lance with an adjustable rotation angle was investigated by computational fluid dynamics (CFD), and structural parameters of the lance were optimized. A volume-of-fluid (VOF) multiphase flow model coupled with the realizable k-ε turbulence model was employed to conduct transient simulations of gas-liquid two-phase flow in an oxygen-enriched side-blown smelting furnace. Influence of lance rotation angle (0°, 15°, 30°, 45°, and 60°) on flow field and mixing performance of the molten bath was analyzed. Results indicated that lance rotation angle exerted a nonlinear control effect on bath hydrodynamics. A moderate rotation angle (around 30°) effectively enlarged gas-induced disturbance region, accelerated interfacial renewal, and improved the uniformity of bath stirring. In contrast, either a non-rotating angle (0°) or an excessively large rotation angle (60°) led to pronounced flow drift and deteriorated local mixing. Overall, the proposed side-blown rotatable lance, through appropriate optimization of rotation angle, can enhance bath stirring while simultaneously ensuring furnace lining integrity and prolonging lance service life. The findings provided a theoretical basis and engineering guidance for lance design and optimization in large-scale oxygen-enriched side-blown smelting furnaces.

Metal/diamond composites with excellent thermal and mechanical properties are promising materials for thermal management applications, but the weak interfacial bonding between metals and diamond restricts industrialization processing. In this study, first-principle calculations based on density functional theory were employed, focusing on the (111) planes of three face-centered cubic (FCC) metals (Al, Cu, and Ag) and the (111) plane of diamond. A series of Cr-doped interface models with a concentration gradient of 12.5%~62.5% were constructed to systematically investigate the regulatory effect of Cr doping on interfacial bonding performance. Combined with calculations of surface relaxation, surface energy, and interfacial adhesion work, as well as analyses of charge density difference and partial density of states (PDOS), the microscopic mechanism of interfacial strengthening was revealed. Results showed that Cr doping exhibited a significant strengthening effect on Cu/diamond and Ag/diamond interfaces: adhesion work presented a distinct increasing trend with the rise of doping concentration, reaching 0.265 J/m² and 0.254 J/m², respectively, at a concentration of 62.5%, both significantly higher than those at 12.5% concentration. In contrast, due to the strong intrinsic Al-C polar covalent bonds and saturated electronic structure at the Al/diamond interface, Cr doping only slightly improved adhesion work to 0.293 J/m², showing low sensitivity to concentration changes. Analysis of interfacial electronic structure confirmed that introduction of Cr can form stable Cr-C covalent bonds through strong hybridization between Cr-3d orbit and C-2p orbit, thereby reconstructing interfacial electronic structure. However, Al formed saturated covalent bonds with C, making it difficult for Cr to participate in effective hybridization. This study provided an important theoretical basis for optimization interfacial design of metal/diamond composite materials and offered guiding significance for promoting their applications in fields such as thermal management.