To address the technical bottleneck of deep removal of key impurities such as Cu, Pb, As and Bi in the hydrometallurgical extraction of antimony, a process for producing low-impurity cathode antimony by diaphragm electrowinning in alkaline system was investigated. The effects of single-factor conditions, including current density, electrolysis temperature, electrolyte circulation rate, and electrode spacing, on the purity of cathode antimony and typical impurity content, surface morphology of the cathode deposit, cell voltage, current efficiency, and DC power consumption during the diaphragm electrowinning process in Na₂S-NaOH alkaline system were systematically analyzed. The results show that pre-electrolysis can significantly reduce and effectively control metal impurities with electrode potentials close to or more positive than that of antimony in the electrolyte. The appropriate pre-electrolysis pretreatment technology combined with the optimal alkaline diaphragm electrowinning process can achieve effective control of difficult-to-remove impurities such as Cu, Pb, As, and Bi in cathode antimony. Under the optimal process conditions, a dense, bright cathode antimony with excellent morphology and a purity of 98.61% can be obtained, with an average cell voltage of 2.3 V, a cathode current efficiency of 90.93%, and a DC power consumption of 1 667.2 kWh/t. The impurity As content meets the single impurity content requirement of 5N-grade high-purity antimony Sb-05 specified in the national standard "High Purity Antimony" (GB/T 10117—2021), and the removal rates of Cu, Pb, and Bi reach 66.41%, 99.62%, and 98.56%, respectively, which can provide stable raw materials for the subsequent low-cost preparation of high-purity antimony.

A one-step hydrothermal method was employed, using urea (H₂NCONH₂) as an interlayer modulation agent, to realize the in situ growth of molybdenum disulfide (MoS₂) within a three-dimensional conductive network constructed by carbon nanotubes (CNTs). MoS₂@CNT composite was prpared and used as anode materials for sodium ion batteries, and theri electrochemical properties investigated. The results indicate that the MoS₂@CNT composite materials can effectively alleviate volume expansion during sodium-ion insertion and extraction, thereby improving the sodium storage reaction kinetics and structural stability. Structural characterization results reveal that the incorporation of H₂NCONH₂ increases the interlayer spacing of MoS₂ from 0.62 nm to 0.71 nm, thereby providing additional active sites and shortening ion diffusion pathways. Electrochemical properties test results demonstrate that, after 100 cycles at a current density of 0.1 A/g, the composite maintains a reversible capacity of 387.2 mAh/g, corresponding to a capacity retention rate of 97.5%. Furthermore, after cycling at various current densities, the specific capacity recovers to 402.3 mAh/g, indicating excellent rate capability and superior cycling stability.

During the acid in-situ leaching of uranium, sulfuric acid readily reacts with calcite to form calcium sulfate precipitate and release CO₂, which causes pore blockage and permeability reduction in the ore-bearing layer, thereby hindering the efficient and green extraction of uranium resources. To reveal the reaction characteristics and blockage mechanism of calcite in acid in-situ leaching, single-factor immersion experiments were conducted under varying acidity, particle size, and solid mass to liquid volume ratios. The variations of pH, saturation index (SI), and concentrations of Ca²⁺ and during the reaction were analyzed, dissolution kinetics were examined based on the shrinking core model, and the microscopic morphology and phase composition of minerals before and after the reaction were investigated by SEM-EDS and XRD. The results show that the reaction between calcium carbonate and sulfuric acid exhibits distinct stages. In the system, pH generally increases, Ca²⁺ concentration initially rises and then declines before stabilizing, while concentration continuously decreases and then stabilizes. Increased acidity and reduced particle size both enhance the early-stage reaction intensity and prompt the system to reach CaSO₄ supersaturation earlier, thereby intensifying precipitate formation and blockage effects.A higher solid mass to liquid volume ratio increases the risk of supersaturation in the system. Kinetic fitting indicates that the reaction process better conforms to the internal diffusion control model. Microscopic characterization reveals that a flaky calcium sulfate precipitate layer forms on the mineral surface after the reaction, corroborating the above chemical analysis results. The findings provide a theoretical basis for blockage risk identification and process optimization in acid in-situ leaching of uranium.

Aiming at the problems of excessive local supersaturation in the traditional vanadium precipitation process of high sodium alkaline stripping vanadium-rich solution, which leads to explosive nucleation and serious mechanical entrainment of impurities, the preparation of ammonium metavanadate (AMV) precursor by constant pH two-fluid controlled crystallization process was studied, and then high purity V₂O₅ was obtained by calcination. The effects of ammonium addition coefficient, reaction time and temperature on the vanadium precipitation rate and product purity were systematically investigated by combining the slow flow of vanadium precipitation buffer and constant pH control. The phase composition, microstructure and impurity distribution of the product were analyzed by XRD, SEM and ICP-OES. The results show that the precipitation rate of vanadium can reach 98.5% under the conditions of ammonium addition coefficient of 1.5, reaction time of 120 min and temperature of 85 ℃. The precursor obtained by controlled crystallization exhibits an ordered stacking structure of short column and thick plate, which significantly improves the common disorderly flocculation and mother liquor encapsulation in traditional rapid precipitation. After calcination at 500 ℃ for dehydration and deamination, the morphology of the precursor is reconstructed. Despite the thermodynamic impurity concentration effect, the purity of the final V₂O₅ is still as high as 99.89%. This process can effectively inhibit impurity entrainment in high-sodium systems at the source, providing a feasible pathway for the green preparation of high-purity V₂O₅ and demonstrating certain application prospects.

In response to the demand for Sb(Ⅴ) pollution remediation in groundwater of mining areas, and to overcome the low adsorption capacity of conventional layered double hydroxides (LDHs), a urea-assisted hydrothermal method was adopted to modify MgAl-LDHs via Ni/Co co-doping. The results show that a nanosheet material with a Ni/Co molar ratio of 2∶1 (denoted as N₂C₁) was prepared and applied to adsorb Sb(Ⅴ). At room temperature, N₂C₁ exhibited a maximum theoretical Sb(Ⅴ) adsorption capacity of 60.04 mg/g, while the actual adsorption capacity was significantly enhanced from 11.6 mg/g for pristine LDHs to 41.7 mg/g. The adsorption behavior conformed to the Freundlich isotherm model and the pseudo-second-order kinetic model, with rapid uptake occurring within the first 20 min and equilibrium being reached at approximately 120 min. Column tests and coexisting ion interference experiments demonstrate that the material possesses favorable dynamic removal performance and anti-interference capability in complex groundwater environments. Environmental compatibility assessment indicates that the leaching concentrations of Ni, Co, and Al remained below the detection limits within the pH range of 4-12, with only a minor release of Mg observed under acidic conditions, suggesting a low environmental risk. Combined Zeta potential, FT-IR, and XPS analyses confirm that the enhanced Sb(Ⅴ) removal performance was attributed to the synergistic effects of strengthened electrostatic attraction, enhanced surface complexation, and interlayer anion exchange. This study provides a theoretical basis and material support for the application of Ni/Co co-doped LDHs in the in situ remediation of antimony-contaminated groundwater in mining areas.

Aluminum in decommissioned crystalline silicon photovoltaic modules exists in two forms: aluminum frames and aluminum back-surface fields on solar cells, which have significantly different recovery routes. Current technologies face bottlenecks such as complex pretreatment and high environmental load. The classified recovery process was studied. For aluminum frames, temperature-controlled remelting combined with second-phase strengthening technology was used to produce recycled aluminum ingots. For aluminum in solar cells, a citric acid-hydrogen peroxide green chelating leaching system was employed for selective leaching, and the leachate was concentrated, followed by ethanol anti-solvent precipitation to produce aluminum citrate particles. The results show that the remelted aluminum ingots have an average grain size of 162.11 μm and a Vickers hardness of 42.4 HV, meeting the requirements of the national standard (GB/T 1196—2023) standard. The comprehensive processing cost of recycled aluminum is approximately 1.3-2.0 CNY/kg, with energy consumption only 4.86% that of primary aluminum and carbon emissions only 1/24 that of primary aluminum. Orthogonal experiments determined the optimal leaching conditions as follows: reaction temperature 80 ℃, reaction time 5 h, and citric acid concentration 1.5 mol/L. Under the conditions, the leaching rate of aluminum reaches 95.15%. FT-IR characterization confirmed that the product is aluminum citrate, which can be used to prepare crosslinking agents for oilfield profile control and water shutoff. This process does not require deep pretreatment of aluminum frames, avoids the high environmental load of traditional strong acid systems, achieves efficient recovery of aluminum in different forms, and provides a new pathway for the green and large-scale recycling of aluminum from decommissioned photovoltaic modules.

In response to the current situation where the influencing factors of the efficiency of heavy medium cyclones in uranium ore separation are unclear and the parameter settings lack theoretical basis, taking the FX250 type heavy medium cyclone as the object, a multi-phase flow numerical simulation system was constructed using the CFD-DEM coupling method. Seven sets of different feed pressure and heavy medium density comparison conditions were set up. The effects of parameters on the characteristics of the cyclone and uranium ore separation were explored from three dimensions: flow field distribution, phase structure, and particle movement. Experimental verification was carried out in conjunction with the Jiangxi volcanic rock-type uranium ore. The results show that increasing the feed pressure can optimize the flow field and the gas core structure, promoting particle stratification; the influence of heavy medium density on the flow field is weak, but it can significantly improve the separation accuracy. The test results confirm that increasing the feed pressure or the heavy medium density can improve the grade of the concentrate, but it will reduce the yield and recovery rate. Based on the experimental results, the optimal parameter range for uranium ore separation using the heavy medium cyclone is determined as a feed pressure of 0.13-0.14 MPa and a dense medium density of 2.60-2.65 g/cm³.

Bauxite resources in China are predominantly sedimentary diasporic ores, characterized by well-developed clay minerals and the fine-grained intergrowth of aluminum-bearing minerals with siliceous gangue. These ores typically have high silica content and a low Al/Si ratio, making them unsuitable for direct processing by the Bayer method. With the depletion of high-grade resources, efficient desilication and beneficiation of low-grade bauxite have become essential for ensuring the security of the alumina industry. This paper systematically reviews desilication technologies for low-grade bauxite. It analyzes the distribution of bauxite resources and the characteristics of the ores, and further clarifies the constraints imposed by mineralogical features and mineral intergrowth on beneficiation performance. The review focuses on physical beneficiation methods, including gravity separation and flotation, as well as chemical methods, microwave activation, and the calcification-carbonation process. Their desilication efficiency, economic cost, and environmental impact are comparatively evaluated. Flotation remains the dominant technology, but its selectivity is significantly reduced by fine-grained mineral intergrowth. Chemical methods and energy-assisted techniques can help overcome the limitations of mineral liberation, but they are often associated with high energy consumption and complex process flows. The calcification-carbonation process integrates desilication with red mud valorization, representing a promising pathway for green metallurgy. Finally, desilication technologies should be tailored to differences in mineralogical characteristics. Process selection should move beyond a single-indicator criterion toward a comprehensive evaluation of energy efficiency, silica transformation pathways, and solid-waste properties. This approach will promote the efficient, green, and high-value utilization of high-silica bauxite.

In view of the complex state of vanadium occurrence in vanadium resources, the high difficulty in extraction and separation, and the increasingly strict environmental protection requirements, this paper systematically summarizes the research progress of vanadium extraction processes at home and abroad, and focuses on discussing the technical characteristics and existing problems of representative vanadium extraction processes such as roasting-leaching, hydrometallurgical separation, and others. According to the properties of different raw materials such as vanadium-titanium magnetite and vanadium-cotaining shale, the suitable routes of the listed vanadium extraction processes are compared and analyzed. Proposing that future vanadium extraction processes should develop towards the direction of low pollution, high recovery rate, intelligence, short process, and efficient comprehensive utilization of resources, is an important way to promote the improvement and innovation of vanadium metallurgy technology.

Recovery of titanium from coal gangue is significant for both high-value utilization of solid waste and resource security. This review systematically examines the occurrence of titanium in coal gangue and its influence on enrichment and extraction processes. It focuses on the applicable conditions and technical bottlenecks of mainstream hydrometallurgical techniques, such as acid leaching, alkali fusion, and roasting-leaching. Comparisons are made with physical sorting and emerging green technologies, including bioleaching and ionic liquid extraction. Future research directions are also discussed, aiming to provide a reference for the economical, environmentally friendly, and efficient recovery of titanium resources from coal gangue.