Rare earth elements are important resources for national development and industrial upgrading, and it is critical to establish an improved rare earth policy system. Based on the constructed analysis framework of rare earth policies, 48 rare earth policies issued from 1985 to 2022 in China were evaluated by using text data mining, social network and policy modeling consistency (PMC)-index model from three aspects, including the evolution process of rare earth policies, policy network and quantitative policy analysis. It is found that the evolution of China's rare earth policies can be divided into four stages, among which standardizing the exploitation procedure for rare earth resources and rectifying the order of rare earth market have always been the focus of China's rare earth policies. A policy network has been initially constructed, but there is poor correlation among policies and there are many isolated policies, which indicates that the correlation among policies needs to be strengthened. The overall design of the polices is reasonable, but there are some deficiencies in incentive measures and effectiveness. Finally, some suggestions are put forward to optimize and improve China's rare earth policies based on the features and shortcomings.

Acting as a raw material, mangosteen peel was subjected to decolorization with isopropanol and activation with alkaline reagent for preparing a kind of adsorbent, which was then used to adsorb copper ions in solution. The result from an adsorption experiment shows that increasing pH value can be beneficial to the adsorption of copper ions onto mangosteen peel, with the maximum adsorption capacity up to 1.5 molCu²⁺/kg. The adsorption can reach equilibrium within 30 min. The amount of loaded copper ions has a significant effect on the characteristic temperature of thermal decomposition of adsorbents during combustion. When the concentration of copper ions is lower than 2 mmol/L, there are higher number of loaded copper ions, and the temperature at which thermal decomposition begins and violent combustion decomposition ends becomes lower. When the concentration of copper ion is higher than 2 mmol/L, the characteristic value of thermal decomposition temperature no longer changes significantly. Copper ion plays a role of catalyst in the combustion process, which can effectively promote the combustion reaction.

Fe₃O₄@SiO₂@IL was prepared by immobilizing imidazole based ionic liquids on the surface of magnetic nanoparticles with impregnation method, and was then used to remove Hg²⁺ in the water. The effects of pH value, adsorption time, and adsorbent dosage on the Hg²⁺ removal rate were investigated. The results show that Fe₃O₄@SiO₂@IL can have a wide application, and Hg²⁺ removal rate can exceed 99.1% with pH of 7.2-9.5. Fe₃O₄@SiO₂@IL presents a high rate of Hg²⁺ adsorption, and the adsorption can reach equilibrium within 90 minutes. For 25 mL Hg²⁺ solution with a concentration of 2 μg/mL, Hg²⁺ can be completely removed by adding 20 mg of adsorbent. The adsorption isotherms of Fe₃O₄@SiO₂@IL indicate that the saturated adsorption capacity of the adsorbent for Hg²⁺ is 548.37 mg/g.

The influence of Mg and Si content on the types and properties of actual precipitates in Al-Cu-Mg-Ag-Si alloy was investigated. The results show that a large amount of S phase and coarse second phases exist in the Al-Cu-Mg-Ag-Si alloy with high Mg content and regular Si content; the common θ phase and Ω phase are precipitated in the low-Mg and low-Si alloy; the common second phases in 6xxx aluminum alloys, such as σ and β″phases, appear in the alloy with low Mg content and regular Si content, and also fine and dispersed θ phases are precipitated in the alloy, which results in excellent strengthening effect of the alloy. Both Si and Mg greatly alter the precipitation sequence of the alloy, and the effect of Si cannot be offset by increasing Mg content. The addition of Si significantly inhibits the precipitation of Ω phase, while a considerable increase of Mg content can promote the precipitation of S phase.

The effects of aging treatment on the microstructure and properties of Al-Zn-Mg-Cu extruded bars were investigated. The results show that the alloys treated by two-stage aging and re-aging (TSR), retroregression and re-aging (RRA), and non-isothermal aging (NIA), compared to the treatment with T73, all present better intergranular corrosion (IGC) resistance, with the maximum corrosion depth down from 70 μm to 19, 48, and 30 μm, respectively. Compared to those treated by RRA and NIA, the TSR-treated alloy has the similar tensile strength and yield strength, but obviously superior IGC. After the treatment of T73, TSR, RRA, and NIA, the alloy has its grain boundary precipitates with average size of 27.7, 39.2, 31.6, and 25.5 nm, respectively, and matrix precipitates with average size of 8.1, 10.2, 10.9, and 11.0 nm, respectively.

The effect of strain rate on susceptibility of TB6 titanium alloy to adiabatic shear was investigated through dynamic loading of hat-shaped specimen of TB6 titanium alloy by using a split-Hopkinson compression bar at room temperature. The following results are obtained: all four groups of specimens exhibit obvious strain hardening effects at a strain rate of 1 950-2 510 s^-1; with the rising of adiabatic temperature, adiabatic shear bands (ASBs) form in all four groups of specimens due to thermoplastic instability; there is no obvious deformation gradient in the transition zone between the matrix and the adiabatic shear band due to the influence of impact load and material grain size; the equiaxed grains with size of 100 nm are formed in the hot shear band due to rotational dynamic recrystallization. By observing the metallographic structure, characterizing the adiabatic shear sensitivity, and calculating the expansion energy, it can be inferred that the susceptibility of TB6 titanium alloy to adiabatic shear increases with the increase of strain rate.

In order to study the corrosion mechanism of welded material of Q370qENH weathering steel by submerged arc welding (SAW), experiments were conducted on immersion corrosion and electrochemical corrosion of Q370qENH substrate samples and weld seam samples after SAW process, and the morphology and composition of the surface rust formed after immersion corrosion were characterized. The results indicate that the corrosion resistance of the weld seam of Q370qENH by SAW process is lower than the substrate, and its electrochemical impedance is 38% of the substrate. The reason for the lower corrosion resistance of weld seam than the substrate and the formation mechanism of surface rust were all analyzed. The research results can provide scientific and theoretical basis for the safety assessment for the service of weathering steel in engineering projects of steel bridges for high-speed railway, as well as its following maintenance.

To solve problems of high power-consumption and difficulty in load prediction of a ball mill, a comprehensive detection system based on non-magnetic sensing was proposed. The non-magnetic coupling sensing technology is used to monitor the mill load without being affected by the magnetism of materials therein. Combined with the low-power cylinder vibration detection unit, which can more accurately reflect the actual load characteristics, the vibration data can be transmitted to the signal acquisition unit via wireless transmission, through which the difficulty for signal acquisition unit to take electric power from cylinder can be solved. By integrating the mill sound collection data, the loading characteristics of a mill can be predicted adopting the edge algorithm unit aided by in-depth learning. Then, the prediction can be fed back to the PLC controller for real-time adjustment of ore feeding and ball-adding, so as to realize the closed-loop control of the system. This system can greatly improve the milling efficiency, stabilize the production indicators, and reduce the energy consumption. The trial test result in an ore dressing plant has verified that this system demonstrates a satisfying effect in detecting mill load.

A side blowing furnace was adopted to treat the leaching residue of copper anode slime and recover valuable metals therein comprehensively. The effects of soda dosage, granular coal dosage, precipitation time and top flue gas temperature on the recovery rates of main metals Pb, Sb, Bi, Au and Ag were investigated. The results show that with soda at an amount of 2.5%, granular coal at an amount of 3%, the precipitation time of 1.5 h, and the top flue gas temperature of 750 ℃, the precious lead product is obtained after processing, grading 1 544 g/t Au (1.84 times enrichment), 10.37% Ag (1.4 times enrichment), 22.89% Pb (2.1 times enrichment), and 27.45% Bi (2.2 times enrichment).

A statistical analysis was conducted for patents on acid-free descaling of strip steel in terms of the number of patents and main applicants, and those patents on typical acid-free descaling process for strip steel were specially discussed. Finally, the developing trend of acid-free descaling technology for strip steel in the future is presented, which can provide reference for R&D and application of acid-free descaling technology.