Based on the experimental study on fragmentation and pulverization characteristics of polymetallic nodules in the process of ore lifting, it is found that there is obvious fragmentation of nodules during lifting process. With the volume concentration of 6.5%, the mass percent of polymetallic nodules with particle size larger than 50 mm decreases from 75.58% to 23.78%; with the volume concentration of 15%, the mass percent decreases from 51.51% to 10.08%. Pulverization of nodules was observed in the experiment. With the volume concentration of 6.5%, the mass percent of the polymetallic nodules powder with particle size less than 0.1 mm is 1.79%, and the median particle size is 10.07 μm; with the volume concentration of 15%, the mass percent of polymetallic nodule powder with particle size less than 0.1 mm is 1.99%, and the median particle size of the powder is 9.47 μm. Based on the experimental data, it is estimated that as per mining of 10 million tons of polymetallic nodules, the powder discharge will cause tens of thousands of tons of Fe and Mn losses, as well as hundreds of tons of Co, Ni and Cu losses. Besides, the maximum redeposition thickness of the sediment plume induced by mining is more than 3 mm after diffusion and settlement, which will bring a significant impact to environment.

In order to determine the reasonable air-deck length in underground vertical deep-hole blasting, the internal distribution function of impact pressure on hole wall with different air-deck length in multi-stage air deck blasting was analyzed based on the detonation wave theory. According to the Mises criterion, the reasonable reference values of air-deck length were obtained for different kinds of rock, which was verified by numerical simulation and on-site blasting test. The results show that the impact pressure on the hole wall of the air deck drops abruptly from both sides to the center along the axis of the hole, but increases slightly around the midpoint, and the pressure distribution presents a symmetrical W-shaped curve, with much higher values on two sides, lower in the middle section, and slightly higher around the center.

Based on the time-domain coupling analysis method, a three-dimensional nonlinear hydrodynamic model for mother vessel, deep-sea mining equipment and umbilical cable was established, and numerical calculation and analysis were also conducted for the hydrodynamic response characteristics of umbilical cable during launch and recovery. The results show that deep-sea mining equipment (weighing 10 t in water) can be safely launched and recovered at a speed of 0.8 m/s under condition of sea state 4. Due to the influence of both waves and currents, the deep-sea mining equipment will have strong oscillations and swings at the beginning of launch and at the end of recovery, which can be reduced by installing anti-swaying devices.

The influences of physical and mechanical properties of overlying filler on the shear strength characteristics of composite liner interface were studied by adopting a modified ZLB-1 triple rheological direct shear apparatus, and shear stress-strain curves of overlying filler under different normal stresses were obtained. The experimental results show that both clay and sand present displacement softening behavior, which becomes more obvious with the increase of sand content. Among the interface of composite liners, the interface between geomembrane and sodium bentonite pad has the lowest friction coefficient, and the friction coefficient in saturated state is significantly lower than that in the unsaturated state. As the sand content increases, the pseudo-cohesion between the interface of composite liner decreases, while the pseudo-friction angle initially decreases, and then increases followed by another decrease. As the water content increases, both the pseudo-cohesion and pseudo-friction angle decrease after an initial increase.

The stability of slope with fault under the impact of blast-induced seismic wave was analyzed by using simulation to study the dynamic response of slope with different fault thickness under the impact of explosive vibration. The results show that there exists elevation amplification effect when blast-induced seismic wave propagates along slope surface and fault area. The thicker the fault, the faster the attenuation of blast-induced seismic wave. As the fault becomes thicker, the displacement of slope under the action of blast-induced vibration gradually increases, and the overall deformation resistance becomes smaller. Under the action of blast vibration, the fault with different thickness obviously brings different influence to slope stability. With the fault thickness of 2-8 m, the slope stability decreases continuously and rapidly, and tends to be stable as the fault thickness exceeds 8 m.

Based on typical nonlinear negative exponent constitutive relations and catastrophe characteristic of weakened mineral rock, the variation of energy transformation and time effectiveness with mechanism stiffness in catastrophic and non-catastrophic breakup were analyzed. The results show that the catastrophic breakup induced by low mechanism stiffness will dramatically reduce the energy transformation efficiency of dynamical system and time effectiveness of rock breakage. From the perspective of energy utilization and rock-breaking efficiency, it is not appropriate to equip a dynamical system for rock breakage with low mechanism stiffness. Finally, an appropriate range of mechanism stiffness is provided for reference in design.

The single application of analytical hierarchy process (AHP) and grey relational analysis (GRA) algorithm is always affected by some subjective factors, leading to great deviation between the obtained evaluation result and the actual result. In view of this problem, a composite algorithm based on an integrated range analysis with GRA and AHP was proposed. Then, a phosphate mine in the southwest China was taken as an example, and this algorithm was adopted to analyze the sensitivity of factors, including gravity, internal friction angle, cohesive force, elastic modulus and Poisson's ratio, to the stability of slope in the Area A. The results show that the sensitivity of those influencing factors to the slope stability in Area A is in the following descending order: internal friction angle, cohesive force, gravity, elastic modulus, Poisson's ratio. It is found that the analysis result is consistent with the actual situation of the mine.

The project of transition from open-pit to underground mining in Panzihua Iron Mine was taken for study. Based on the analysis of relationship between storage and discharge in the stope, it is predicted that the accumulated water in open pit will be maximally 5 m deep in the event of a 50-year extreme rainfall, which has little influence on the stability of crown pillar. Numerical simulation of seepage in the case of fault occurring at the bottom of pit shows that fault zones are the main leakage channel of crown pillar. Some special anti-seepage measures can be taken to effectively reduce the leakage of crown pillar.

Based on an established three-dimensional analytical model for arching stress of cemented backfill, a calculation formula for vertical load of cemented backfill was obtained. According to a model of four-sided fixed roof and a criterion for ultimate tensile strength of rock mass, a method to determine the thickness of horizontal pillar for safe extraction was obtained. The application practice of horizontal pillar extraction in 612 stope of a lead-zinc mine shows that the vertical stress of cemented backfill calculated with this analytical model is basically consistent with the numerical simulation results, and no plastic zone occurs in the roof in numerical simulation, which verifies that the reserved roof thickness determined by calculation meets the requirement of safe production. The results of stoping process show that the maximum cumulative displacement near the monitoring point is lower than the displacement limit, and the reserved roof tends to be stable. It is concluded that the determined thickness of horizontal pillar is reliable for safe extraction.

Experimental studies on comprehensive recovery of valuable resources in iron-dressing tailings with TFe grade of 15.70% were conducted by adopting processes consisting of Cu-S bulk flotation, high intensity magnetic separation to reclaim Fe minerals, roasting reduction of Fe minerals, and shaking table gravity separation and flotation separation to recover barite and mica. As a result, the experiment produced an iron concentrate with TFe grade of 60.17%, S content of 0.11% and iron recovery of 66.74%, a sulfur concentrate grading of 47.86% S at 66.58% recovery, a copper concentrate grading 19.79% Cu at 31.24% recovery, a barite rough concentrate with BaSO₄ content of 86.96% and recovery of 9.15%, and a mica concentrate with K₂O content of 6.66% and recovery of 6.63%, respectively. In this way, comprehensive utilization of tailings can thus be realized.

Mineral processing tests were carried out for a low-grade copper ore from South America containing 0.027% Mo and 0.45% Cu. After optimization of the reagent regime, a close-circuit test by adopting a flowsheet of Cu-Mo bulk flotation plus Cu/Mo separation resulted in a copper concentrate grading 26.93% Cu at 81.96% recovery, and a molybdenum concentrate grading 25.32% Mo at 76.24% recovery. Therewith, copper and molybdenum resources in the lean ore can be effectively recovered.

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.

Flotation technique was introduced to reclaim copper resource from a copper smelting slag with Cu grade of 2.70%. With sodium sulfide as the regulator, the scavenger middling was collected for flotation and its tailings were classified into a size range of +20 μm to return, together with the cleaning concentrate of middling, to the quick flotation stage. With this optimized flowsheet, a stage of scavenging can be dislodged and the mud content in the middling can be reduced. Finally, a closed-circuit test produced a copper concentrate grading 20.59% Cu at 91.75% recovery, and the tailings with Cu grade reduced to 0.26%.

The kinetics and thermodynamics of oleate ion adsorption on the surface of fluorapatite and dolomite were studied by adopting TOC measurement and molecular simulation. The study on kinetics of adsorption shows that with HEDP as the depressant, the adsorption rate of oleate ions on fluorapatite is greater than on dolomite, and the adsorption on both minerals conforms to the quasi-second-order kinetic model. Furthermore, according to the study on adsorption thermodynamics, the characteristics of oleate ion adsorption on the inner pore surface of both fluorapatite and dolomite, on (001) surface of fluorapatite and (104) surface of dolomite nearly conform to Langmuir model. For identical specific surface area, the adsorption amount of oleate ions on dolomite is higher than that on fluorapatite, indicating that there are more active sites per unit surface area on dolomite than on fluorapatite.

Flotation tests were carried out for a fluorite-calcite symbiosis ore containing 31.09% CaF₂ and 53.23% CaCO₃, with the predominately valuable mineral of fluorite, and the dominantly gangue minerals of calcite, quartz and feldspar. After being milled to a fineness of -0.074 mm 75%, the ore was processed with acidized sodium silicate and EM-318 as depressants and EM-OL-3 as collector. Adopting a close-circuit flowsheet consisting of two stages of roughing, one stage of scavenging and eight stages of cleaning, a fluorite concentrate grading 97.26% CaF₂ at 86.55% recovery can be obtained. Qualified as an acid-grade fluorite powder (with grade FC-97A) according to the Industry Standard for Ferrous Metallurgy (YB/T 5217—2005 (Fluorspar)), this fluorite concentrate can be used as the raw material in high-end fluorine chemical industry.

The crystal structure and surface properties of minerals and the mechanism of interaction between minerals and flotation agents were systematically analyzed by means of quantum chemical calculation and molecular dynamics simulation. Meanwhile, the flotation mechanism of kyanite minerals and quartz was discussed. The results show that the differences in the surface properties of kyanite, andalusite, sillimanite and quartz determine the differences in floatability, and citric acid can increase the floatability difference between kyanite minerals and quartz. The simulation result of computational chemistry is consistent with the experimental result of flotation.

Aiming at problems of high mud content in tin tailings from Russia, finely disseminated particle size of cassiterite, and influence of sulfur and iron content on tin recovery rate, a combined process consisting of sulfide ore flotation, cassiterite preconcentration, and cassiterite flotation was adopted in a beneficiation test. It is found that the dominant tin mineral in tailings is cassiterite, and sulfide minerals therein include pyrite, pyrrhotite among others, while the dominant gangue includes quartz and tourmaline. The effect of sulfide ore and iron ore on subsequent cassiterite flotation can be reduced by adopting cassiterite preconcentration process for waste discarding. With the cassiterite grading 0.31% Sn, the beneficiation test with a combined process consisting of sulfide ore flotation, cassiterite preconcentration and cassiterite flotation can produce a concentrate grading 5.60% Sn at 34.01% recovery.

A process mineralogy study and mineral processing tests were conducted for a copper slag with Cu grade of 0.81%, and a beneficiation flowsheet for recovering copper resource and its technical parameters were determined. With Z-200 and 2^# oil respectively as collector and frother, the slag was processed after being milled to a fineness of -0.038 mm 85%, and a high-grade copper concentrate with Cu grade of 26.40% was collected by fast preferential floatation, while a low-grade copper concentrate with Cu grade of 3.58% was obtained from a subsequent flotation process consisting of one stage of roughing, two stages of scavenging and two stages of cleaning, resulting in the total copper concentrate grading 13.03% Cu at 76.47% recovery. This copper-recovering technique has been successfully applied in commercial practice, showing that the comprehensive utilization of Cu metal resource in a copper slag can be actualized.

The tailings of an iron mine in Baotou, Inner Mongolia, contain fluorite resources with large reserve and low CaF₂ grade. Unfortunately, the gangue minerals in the tailings, such as ankerite, calcite and barite, share similar floatability with fluorite, resulting in difficulty in fluorite recovery. With DKCS, FX-1 and starch introduced to depress ankerite, calcite and barite respectively, fluorite can be effectively separated from gangue minerals with modified oleate acid FH as the collector. It is shown that a closed-circuit test can result in a fluorite concentrate grading 90.68% CaF₂ at 64.69% recovery, showing a comprehensive recovery of fluorite resources from the tailings.

The dust generated during chlorination process in recovering titanium by metallurgical process was washed with water. Then, the residue left after water-washing was subjected to calcification roasting process, and the effects of roasting temperature and roasting time on the leaching rate of vanadium from the residue were studied. The results indicate that vanadium in the dust from chlorination process mainly exists as low-valent vanadium, and the vanadium leaching rate increases with the rising temperature. The vanadium leaching rate reaches 88% with the roasting temperature of 850 ℃. As the roasting time increases, the previously obtained different products undergo a secondary reaction, forming insoluble compounds of vanadium bronze, and also vanadate with different valences, which results in different vanadium leaching rates in Na₂CO₃ solution. It is concluded that the roasting process should be optimally at temperature of 850 ℃ with a roasting time of 120 minutes.

With orange residue extract and tetrasodium glutamate diacetate (GLDA) as raw materials, a green activator was prepared. Then, the effects of phosphate-solubilizing bacteria (PSB) combined with green activator on the enrichment, translocation and accumulation of cadmium from soil by ryegrass were studied. The results show that PSB can significantly promote the growth of ryegrass in cadmium-contaminated soil. However, the growth of ryegrass is inhibited by only using green activator, with the dry weight of ryegrass at the end of experiment decreased by 27.37%; while a combination of PSB and green activator can make the final dry weight of ryegrass become 1.29 times that in the blank group, indicating that the addition of PSB can alleviate the negative effect of green activator on the growth of ryegrass. A combination of both can increase the content of phytoavailable cadmium in soil, while decrease the total cadmium concentration in soil. It is shown that the enrichment coefficient of Cd in stem and root parts of ryegrass increases by 35.37% and 10.23%, respectively, and the translocation factor of cadmium by ryegrass increases by 22.58%. In addition, the total accumulation of cadmium in the stem and root parts of ryegrass is up by 87.90% and 32.69%, respectively. It is found that the total accumulation of cadmium in the stem is all greater than that in the root whether by using PSB and green activator separately, or by a combination of both, indicating that PSB combined with green activator can promote the phytoextraction efficiency of cadmium from soil by ryegrass.

The effects of the amount of NaFeS₂, which was used as an additive, on solid-state reduction and magnetic separation for enrichment of nickel and cobalt, and also the reduction behavior of nickel laterite ore were studied. The results show that with the increase of NaFeS₂ addition, the softening and melting temperature of nickel laterite ore decreases correspondingly during the reduction process; while particles of the Ni-Co-Fe alloy obtained by reduction increase accordingly. The enrichment and recovery effects of nickel and cobalt will be better by adding 10% NaFeS₂. The nickel laterite ore, after being pressed into briquettes, was subjected to reduction at 1 100 ℃ for 60 min, followed by a process of grinding and magnetic separation, resulting in a high quality nickel-cobalt-iron powder grading 7.89% Ni, 0.66% Co and 74.01% Fe, at corresponding recoveries of 97.13%, 86.78% and 35.81%.

In order to process copper complex wastewater from electroplating industry, a kind of kaolin was modified by using a modifier of 3-mercaptopropyl trimethoxysilane (MPTS) to be as an adsorbent, and its adsorption of E330-Cu was then studied. It is found that kaolin shall be properly modified at 50 ℃ for 6 hours with the modifier MPTS at an amount of 0.04 mL/g, which is then adopted as an adsorbent for E330-Cu. After 35 min- adsorption at 35 ℃, with E330-Cu at an initial concentration of 5 mg/L, adsorbent at an amount of 15 g/L, and pH value of 4.5, the final adsorption rate can reach 92.50%. It is shown that the adsorption process follows Langmuir isothermal adsorption model and quasi-second-order kinetic model. This kind of adsorbent can be repeatedly used for at least 3 times, and the wastewater after processing can meet the national classⅠdischarge standard. This research can provide reference for the treatment of copper-containing complex wastewater from electroplating industry.

The effects of excess coefficient of manganese fluoride, pH value of solution, reaction temperature and reaction time on the removal rate of calcium and magnesium from manganese sulfate solution were studied by performing single factor experiment with manganese fluoride as a removal agent. Under the optimum conditions, including an excess coefficient of manganese fluoride of 2.0, pH of 5, reaction temperature of 85 ℃ and reaction time of 80 min, the removal rates of calcium and magnesium can reach 97.06% and 95.48%, respectively. The kinetic study on this basis shows that the precipitation reactions of both calcium and magnesium in manganese sulfate solution conform to the Avrami equation, with apparent activation energies of 48.01 kJ/mol and 53.23 kJ/mol, respectively. The surface reaction is a factor to limit the precipitation rates of calcium and magnesium.

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.

An experiment of acid leaching was performed for the concentrate obtained by flotation pretreatment of a refractory sulphide ore. After leaching at 95 ℃ for 2 h, with nitric acid concentration at 9 mol/L, and liquid-solid ratio of 4∶1, the leaching rates of copper and zinc reach 90.46% and 85.34%, respectively, showing no lead leached out. The leaching process is mainly controlled by both solid film and chemical reaction.

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).

In order to study the effects of pores in surface-coated carbon layer on the rate performance of graphite cathode materials, a small amount of boric acid was added to generate gasification and effusion effect of boric acid during the softening stage of the coated asphalt. Then, a carbon layer with certain pores was formed on the surface of natural graphite tailings through carbonization, and graphite cathode materials with various proportions of pores were obtained. The results show that boric acid forms a carbon layer on the surface of particles containing mesoporous and macroporous pores. A higher proportion of mesopores in the surface carbon layer leads to more diffusion channels for Li⁺ in the carbon layer L_C, and lower diffusion impedance of Li⁺. In that case, the rate performance and cycling performance of the material are enhanced.

Nano ITO powders prepared by chemical coprecipitation plus calcination process were used as raw materials to prepare ITO sputtering target by molding and cold isostatic pressing, as well as conventional sintering. The effects of molding pressure on the relative density, resistivity, and grain size of ITO target were investigated. The results show that with the molding pressure of 60 MPa and the appropriate sintering conditions, the prepared ITO target has the relative density of 99.81% and resistivity of 1.707×10^-4 Ω·cm, with an average grain size of 7.62 μm. The research results can provide reference for densification and large-scale production of ITO sputtering targets.

As for the precision rolling process, a thickness prediction model was constructed for precision rolling exit by introducing a time domain convolutional network algorithm. The feature information of time-series data of the precision rolling process was extracted by using this time-domain convolutional network model, and the prediction performance of the precision rolling exit thickness was improved by optimizing the structure and parameters of the model. The simulation results of the actual steel dataset show that the proposed time-domain convolutional network algorithm, compared to traditional methods, has significant advantages in evaluation indicators, such as root mean square error, average absolute percentage error, and coefficient of determination, which can provide critical information for decision of on-site engineers.

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.

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.

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.

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.

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.

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.