A study was conducted on blank roasting and sulfuric acid leaching process for vanadium extraction from vanadium-bearing stone coal. Effects of ore sample particle size, roasting time, roasting temperature, sulfuric acid dosage, leaching time and leaching temperature on the vanadium extraction performance were investigated. Based on the optimized processing conditions, including sample with particle size of-0.15 mm, roasting temperature of 900 ℃, roasting time of 6 h, sulfuric acid dosage of 5%, liquid-solid ratio of 2 mL/g and stirring leaching at room temperature for 3 h, a scale-up verification experiment was conducted with increased ore sample feed. As a result, a vanadium leaching rate was 78.2%, and the main impurities and corresponding contents in the stock solution were found to be as follows:Fe 0.154 g/L, Al 0.578 g/L and Si 0.617 g/L. It is found that blank roasting effectively reduces sulfuric acid consumption and results in low impurity contents in the leaching solution, thus reducing difficulty in subsequent impurity removal process.

The effect of ultrasonic melt treatment (UMT) on the microstructures and hardness of Al-Si-Cu alloy was investigated by Vickers hardness test, optical microscopy, scanning electron microscopy, electron backscatter diffraction and transmission electron microscopy (TEM). The results show that UMT promotes the dispersion of Si phase, reduces the area fraction of secondary phase and refines grains, thereby raising the hardness of Al-Si-Cu alloy. After 2 min UMT, the hardness of T6-tempered Al-Si-Cu alloy sheet increases by 9.2% compared to that of UMT-free sheet. Quantitative TEM analysis indicates that UMT can significantly promote the precipitation of θ' phase and inhibit its rapid coarsening during the aging process, which enhances the hardness and microstructural thermal stability of Al-Si-Cu alloy.

Retrogression and re-aging (RRA) treatment is adopted for 7B50 aluminum alloy plate. To obtain the parameters of pre-aging process in RRA treatment, the effect of pre-aging process on the microstructural evolution and properties of 7B50 aluminum alloy were systematically investigated via Vickers hardness testing, electrical conductivity measurement, transmission electron microscopy for characterization, and differential scanning calorimetry technique. The results show that pre-aging at 110 ℃ for 16 h, compared to at 120 ℃ for 24 h, can result in the precipitates in the alloy smaller in size and completely redissolved after retrogression process. It is also found that pre-aging at 110 ℃ for 16 h is conducive to the aggregation, growth and complete discontinuity of grain boundary precipitates at elevated temperatures, thus suitable for production engineering of RRA treatment of large-size thick plates.

It gives a detailed introduction of requirements of electrolytes and anode materials as the core materials of all-solid-state batteries (ASSBs), presents a summarization of technical challenges faced by silicon anodes in ASSBs, in terms of interfacial contact, volume expansion, kinetics, chemical stability and manufacturing processes, as well as corresponding solutions. Furthermore, prospects of the research and development of ASSBs are proposed, which can provide a reference for researchers in the development of next generation ASSBs.

In order to understand the development of patented technologies regarding high-nickel ternary cathode materials, a patent analysis is provided here in terms of patent layout, principal applicants for technical innovation and key technologies of structural regulation. It is found that the patents for high-nickel ternary cathode materials are still increasing, and the key technologies of structural regulation with single crystal structure as the hotspot of research are gradually developed in a trend towards composite structural regulation in combination with modification means of doping and coating.

Firstly, Cu-Al alloy was doped with selected elements of Fe, Mn and Ni, and Cu-Al-Fe-Mn-Ni alloy, after being synthesized by adopting hot-pressing sintering process respectively at different temperatures, was subjected to solution-aging treatment. The microstructure of the alloy was characterized by means of metallographic microscope, scanning electron microscope, X-ray diffractometer among others, and the density, hardness and electrical conductivity of the alloy were tested. It is found that at a low temperature (750 ℃), the synthesized alloy has lower density, around 7.946 g/cm³, and poor mechanical properties, with Vickers hardness of 253.9HV. Both density and hardness of the alloy increase with the rise of temperature. At 950 ℃, the density increases to 8.058 g/cm³ and the Vickers hardness rises to 281.5HV. But the hot-pressing sintering temperature hasn' t significant impact on the electrical conductivity of the alloy. The solution-aging treatment can improve the density of the alloy. Meanwhile, solution treatment leads to slight reduce in the hardness and electrical conductivity of the alloy, while aging treatment brings the reverse effect.

The influence of adding trace of La/Ce on the as-cast microstructure, precipitation behavior and thermodynamic properties of A356.2 alloy was systematically investigated by means of metallographic observation, transmission electron microscopy, differential scanning calorimetry among others. The results show that adding trace of La or Ce has little effect on the morphology of primary α-Al and eutectic Si in the as-cast microstructure, but can induce the formation of new La- or Ce-containing phases, i.e. Al₂LaSi₂ and Al₂CeSi₂. During aging process, an addition of La/Ce significantly delays the precipitation of β″, β′ and β phases, resulting in a postponed occurrence of hardness peak and a slight decrease in hardness. TEM analysis shows that an addition of La/Ce refines the precipitated phases, with more uniform size and distribution. By calculation of the activation energy for precipitate formation, it is found that La/Ce addition increases the thermal stability of the precipitated phases, and Ce brings a more pronounced effect than La. Although traces of La and Ce do not significantly refine the grains in A356.2 alloy, they effectively enhance the stability and refinement degree of the precipitated phases, exhibiting the potential in regulating the strengthening behavior of alloy.

Erbium oxide (Er₂O₃) with a relative purity of 99.99% was separated and purified at room temperature (25 ℃) by ion exchange, and effects of acidity and flow rate of eluent on the separation and purification were investigated. Two ion exchange columns were connected in series, and hydrochloric acid with acidity of 1.5 mol/L was taken as the eluent at a flow rate of 5 L/h in column 1 and 10 L/h in column 2. After separation and purification under the above optimal conditions, erbium oxide had a relative purity greater than 99.999 9%, with the total content of rare earth impurities less than 1 μg/g. This study provides an effective process, featuring low energy consumption, short flow and low costs, for separation and purification of heavy rare earths.

After systematical analysis of the material characteristics of lithium manganese iron phosphate (LMFP) and comprehensive summarization of all preparation technologies based on the current research status of enterprises, the mechanisms of modification strategies, including optimization of manganese-iron ratio, nano-crystallization, morphology and structure regulation, surface coating and ion doping, for enhancing electrochemical performance of LMFP are reviewed. Besides, aiming at the pain points in industrialization, a feasible development path is proposed, which can provide theoretical support and guidance in engineering projects of transition of LMFP from laboratory innovation research to large-scale production, and also facilitate the breakthrough in its commercialization in the fields of energy storage and power batteries.

The distribution of global rare earth elements (REEs) resources and comparative advantages in exploitation and utilization of REEs are analyzed based on literature research and empirical research. It is pointed out that the global rare earth sector is currently confronted with a competition pattern in which global industrial chains are dominated by China and the United States. The competitiveness of rare earth industrial chain lies not only in reserves, but more importantly in the production, processing and utilization of resources, as well as in its role in boosting the industry's added value in the national industrial system. In terms of resources, in consideration of heavy dependence on external import of medium and heavy REE resources, without advantages such as in light REEs, China should not only strengthen the security assurance of medium and heavy REEs, implement the strategic mineral reserve system, but also make good use of domestic and international medium and heavy REE resources and actively strive for the rights and interests of international mineral resources. In terms of industrial policies, China should continuously implement favorable policies for its domestic rare earth industry, to maintain the global competitive advantages in rare earth industrial chain and industrial clusters, and avoid shifts of its rare earth industry and transfer of related technologies abroad.