Aqueous zinc metal batteries(AZMBs)are promising candidates for next-generation energy storage due to the excellent safety, environmental friendliness, natural abundance, high theoretical specific capacity, and low re...Aqueous zinc metal batteries(AZMBs)are promising candidates for next-generation energy storage due to the excellent safety, environmental friendliness, natural abundance, high theoretical specific capacity, and low redox potential of zinc(Zn) metal. However,several issues such as dendrite formation, hydrogen evolution, corrosion, and passivation of Zn metal anodes cause irreversible loss of the active materials. To solve these issues, researchers often use large amounts of excess Zn to ensure a continuous supply of active materials for Zn anodes. This leads to the ultralow utilization of Zn anodes and squanders the high energy density of AZMBs. Herein, the design strategies for AZMBs with high Zn utilization are discussed in depth, from utilizing thinner Zn foils to constructing anode-free structures with theoretical Zn utilization of 100%, which provides comprehensive guidelines for further research. Representative methods for calculating the depth of discharge of Zn anodes with different structures are first summarized. The reasonable modification strategies of Zn foil anodes, current collectors with pre-deposited Zn, and anode-free aqueous Zn metal batteries(AF-AZMBs) to improve Zn utilization are then detailed. In particular, the working mechanism of AF-AZMBs is systematically introduced. Finally, the challenges and perspectives for constructing high-utilization Zn anodes are presented.展开更多
To improve the strength, hardness and heat resistance of Mg-Zn based alloys, the effects of Cu addition on the as-cast microstructure and mechanical properties of Mg-10Zn-5Al-0.1Sb high zinc magnesium alloy were inves...To improve the strength, hardness and heat resistance of Mg-Zn based alloys, the effects of Cu addition on the as-cast microstructure and mechanical properties of Mg-10Zn-5Al-0.1Sb high zinc magnesium alloy were investigated by means of Brinell hardness measurement, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, XRD and tensile tests at room and elevated temperatures. The results show that the microstructure of as-cast Mg-10Zn-5AI-0.1Sb alloy is composed of α-Mg, τ-Mg32（Al, Zn）49, Ф-Al2MgsZn2 and Mg3Sb2 phases. The morphologies of these phases in the Cu-containing alloys change from semi-continuous long strip to black herringbone as well as particle-like shapes with increasing Cu content. When the addition of Cu is over 1.0wt.%, the formation of a new thermally-stable Mg2Cu phase can be observed. The Brinell hardness, room temperature and elevated temperature strengths firstly increase and then decrease as the Cu content increases. Among the Cucontaining alloys, the alloy with the addition of 2.0wt.% Cu exhibits the optimum mechanical properties. Its hardness and strengths at room and elevated temperatures are 79.35 HB, 190 MPa and 160 MPa, which are increased by 9.65%, 21.1% and 14.3%, respectively compared with those of the Cu-free one. After T6 heat treatment, the strengths at room and elevated temperatures are improved by 20% and 10%, respectively compared with those of the ascast alloy. This research results provide a new way for strengthening of magnesium alloys at room and elevated temperatures, and a method of producing thermally-stable Mg-10Zn-5Al based high zinc magnesium alloys.展开更多
This paper includes studies on the influence of grain refinement treatment with respect to the composition and structure of high zinc aluminium casting alloys on the changes of their tensile properties. The Al-20 wt.%...This paper includes studies on the influence of grain refinement treatment with respect to the composition and structure of high zinc aluminium casting alloys on the changes of their tensile properties. The Al-20 wt.%Zn alloy was inoculated with master alloys Al Ti5B1 and Al Ti3C0.15 to determine the impact of a variable titanium addition on the tensile properties of Al Zn20 alloy, and determine on this basis an optimal addition of Ti that would ensure the improvement of elongation of alloys cast in the sand mould, at the same time maintaining high tensile strength. Within the studies, light microscopy(LM) and strength tests were applied. Experimental results showed that the inoculation of high zinc aluminium alloy Al Zn20 with the master alloys Al Ti5B1 and Al Ti3C0.15 causes intensive structure refinement, while the intensity of reaction of both master alloys is comparable. The Al Ti3C0.15 master alloy addition, selected for further studies, introducing about 100 ppm Ti, enhances the tensile properties of the alloy; the elongation increases about 20% and tensile strength increases about 10% against the initial values(uninoculated alloy). Further increase of the Ti addition up to 500–600 ppm leads to the "overinoculation" effect that is accompanied by the decrease of elongation. Therefore,the Ti addition should be reduced to the level of about 100 ppm which ensures obtaining a set of optimal properties.展开更多
The phase selection of ternary intermetallic compound τphase (Mg32(Al, Zn)49 ) and φ phase (Al2Mg5Zn2) in high zinc magnesium alloys was studied by using scanning electron microscope, X-ray diffractometer and differ...The phase selection of ternary intermetallic compound τphase (Mg32(Al, Zn)49 ) and φ phase (Al2Mg5Zn2) in high zinc magnesium alloys was studied by using scanning electron microscope, X-ray diffractometer and differential scanning calorimeter, etc. The results indicate that, when adding element Si in Mg-8Zn-4Al-0.3Mn (ZA84) alloy, φ phase is promoted, whereas τ phase is inhibited. The Chinese script-type Mg2Si and matrix microstructure are greatly refined, the formation of τ phase is facilitated and φ phase is restrained when modifier Al-AlP master alloy is added in ZA84 alloy containing Si. The kinetics study of phase selection indicates that there is a critical degree of undercooling of the melt. If the undercooling exceeds the critical value, τ phase preferentially forms while φ phase is restrained; otherwise, φ phase preferentially forms while τ phase is restrained.展开更多
The determination of trace impurities in high purity zinc oxide by high resolution inductively coupled plasma mass spectrometry （ HR-ICP-MS ） was investigated. To overcome some poteutially problematic spectral iuter...The determination of trace impurities in high purity zinc oxide by high resolution inductively coupled plasma mass spectrometry （ HR-ICP-MS ） was investigated. To overcome some poteutially problematic spectral iuterference, measurements were acquired in both middle and high resolution modes. The matrix effects due to the presence of excess HCl and zinc were evaluated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits ranged from 0.02μg/ g to 6 μg/ g depending on the elements. The experimental resalts for the determination of Na, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Mo, Cd, Sb and Pb in several high purity zinc oxide powders were presented.展开更多
Rechargeable aqueous zinc-ion batteries(AZIBs)have their unique advantages of cost efficiency,high safety,and environmental friendliness.However,challenges facing the cathode materials include whether they can remain ...Rechargeable aqueous zinc-ion batteries(AZIBs)have their unique advantages of cost efficiency,high safety,and environmental friendliness.However,challenges facing the cathode materials include whether they can remain chemically stable in aqueous electrolyte and provide a robust structure for the storage of Zn2+.Here,we report on H11Al2V6O23.2@graphene(HAVO@G)with exceptionally large layer spacing of(001)plane(13.36?).The graphene-wrapped structure can keep the structure stable during discharge/charge process,thereby promoting the inhibition of the dissolution of elements in the aqueous electrolyte.While used as cathode for AZIBs,HAVO@G electrode delivers ideal rate performance(reversible capacity of 305.4,276.6,230.0,201.7,180.6 mAh g?1 at current densities between 1 and 10 A g?1).Remarkably,the electrode exhibits excellent and stable cycling stability even at a high loading mass of^15.7 mg cm?2,with an ideal reversible capacity of 131.7 mAh g?1 after 400 cycles at 2 A g?1.展开更多
Sulfuric acid leaching of high iron-bearing zinc calcine was investigated to assess the effects of sulfuric acid concentration, liquid-to-solid ratio, leaching time, leaching temperature, and the stirring speed on the...Sulfuric acid leaching of high iron-bearing zinc calcine was investigated to assess the effects of sulfuric acid concentration, liquid-to-solid ratio, leaching time, leaching temperature, and the stirring speed on the leaching rates of zinc and iron. The results showed that the sulfuric acid concentration, liquid-to-solid ratio, leaching time, and leaching temperature strongly influenced the leaching of zinc and iron, whereas stirring speed had little influence. Zinc was mainly leached and the leaching rate of iron was low when the sulfuric acid concentration was less than 100 g/L. At sulfuric acid concentrations higher than 100 g/L, the leaching rate of iron increased quickly with increasing sulfuric acid concentration. This behavior is attributed to iron-bearing minerals such as zinc ferrite in zinc calcine dissolving at high temperatures and high sulfuric acid concentrations but not at low temperatures and low sulfuric acid concentrations.展开更多
The effects of Cl-concentration,temperature,pH,flow velocity,soluble oxygen content of seawater and anodic current on the potential of high purity zinc and Zn-Al-Cd reference electrodes were investigated. The results ...The effects of Cl-concentration,temperature,pH,flow velocity,soluble oxygen content of seawater and anodic current on the potential of high purity zinc and Zn-Al-Cd reference electrodes were investigated. The results show that the investigated metal materials are liable to establish stable potential and act as reference electrodes in seawater,diluted seawater and urban tap water. Cl-concentration,temperature,seawater flow velocity and anodic current have an obvious effect on zinc potentials. However,seawater pH has no obvious effect on zinc potentials.展开更多
A beneficiation-metallurgy combination process is developed to recover Zn, Fe and to enrich In, Ag from high iron-bearing zinc calcine based on our former researches. In gaseous reductive roasting process, the roastin...A beneficiation-metallurgy combination process is developed to recover Zn, Fe and to enrich In, Ag from high iron-bearing zinc calcine based on our former researches. In gaseous reductive roasting process, the roasting conditions were tested by magnetic separation of roasted product. It is found that the V_(CO)(P_(CO)/(P_(CO+CO_2)) in roasting atmosphere should be maintained below 30% to avoid the generation of zinc iron solid solution(Fe_(0.85-x)Zn_xO), which can bring a decrease of iron recovery in magnetic separation. After roasting, acid leaching and multistage magnetic separation are carried out for the recovery of Zn, Fe and enrichment of Ag and In. About 90% of zinc is extracted and 83% of iron is recovered in the whole process. The Ag mainly enters the tailings with a recovery of 76%, the Ag grade increases from 0.12 g/t in raw materials to 1.18 g/t in the tailings. However, the In mainly enters the iron concentrations and the recovery reaches 86%. This process was proved to be technically feasible and may be a favorable option in the treatment of high iron-bearing zinc material with high Ag or In content.展开更多
In order to get foam zinc materials of porous metal electrode,a novel method for preparing foam zinc was proposed,in which the polyurethane foam with diameter of 0.3 mm as substrate was processed by degreasing,roughen...In order to get foam zinc materials of porous metal electrode,a novel method for preparing foam zinc was proposed,in which the polyurethane foam with diameter of 0.3 mm as substrate was processed by degreasing,roughening,activating,electroless plating and electrodeposition.The main factors affecting the process,such as ZnSO4 content,temperature,pH value,current density,and electrodes distance,were investigated comprehensively.The optimal process conditions are 250 g/L ZnSO4,20 g/L Al2（SO4）3,40 g/L KAl（SO4）2,30 g/L Na2SO4,pH=3.5,4.0 cm of electrodes distance and 0.04 A/cm2 current density at 30 ℃.The result shows that adding ultrasonic on the process can elevate the deepening plating ability and current efficiency.Foam zinc material with a high porosity of 92.2% and a three-dimensional network structure can be fabricated by electrodeposition.展开更多
An ever increasing demand for zinc has resulted in worldwide efforts to exploit complex and lean grade reserves of zinc oxide ore. In this study experiments were done on zinc recovery from high-fluorine bearing zinc o...An ever increasing demand for zinc has resulted in worldwide efforts to exploit complex and lean grade reserves of zinc oxide ore. In this study experiments were done on zinc recovery from high-fluorine bearing zinc oxide ore. First the effect of different variables on fluorine removal was investigated. Optimum experimental conditions occurred when the temperature was 1173 K, roasting time was 90 min and air flow was at a velocity of 5 m/min, the fluorine removal from the samples reached over 93%. The results obtained indicate that fluorine removal is not enhanced by adding diluted sulfuric acid or water as a binder. Second the roasted materials were leached with a diluted sulfuric acid, neutralized, flocculated and filtrated. The which satisfies the requirement of fluorine residual fluorine content in the leached content in the leached solutions for the solutions was less than 38 mg/L production of electrolytic zinc.展开更多
A historical review is presented on the experimental and theoretical studies on Zn under high pressure. Based on our high-pressure powder x-ray diffraction experiments that have been done for nearly a decade, we descr...A historical review is presented on the experimental and theoretical studies on Zn under high pressure. Based on our high-pressure powder x-ray diffraction experiments that have been done for nearly a decade, we describe the structural change of Zn up to 126 GPa at room temperature. Although several experimental and theoretical studies indicated an anomalous change of the c/a axial ratio with pressure, we found no such an anomaly within our experimental uncertainty. Our high-pressure low-temperature experiments up to 18 GPa at 40 K also gave no evidence of the c/a anomaly. We suspect that the pressure-transmitting media played an important role in producing the anomaly. The structural anisotropy of Zn is drastically reduced at high pressures, which would be a general trend for hexagonal close-packed (hcp) metals.展开更多
In the present work, scandium elements with a series of contents(0.06 wt.%, 0.10 wt.%, 0.14 wt.%,0.17 wt.%, 0.20 wt.% and 0.25 wt.%) were added in a high Zn-containing Al-Zn-Mg-Cu-Zr alloy and the corresponding as-cas...In the present work, scandium elements with a series of contents(0.06 wt.%, 0.10 wt.%, 0.14 wt.%,0.17 wt.%, 0.20 wt.% and 0.25 wt.%) were added in a high Zn-containing Al-Zn-Mg-Cu-Zr alloy and the corresponding as-cast microstructure characteristics including grains and phases were thoroughly investigated. The results indicated that fine grain boundaries existed in these alloys and fine MgZn2phases discontinuously distributed on them. Besides,AlZnMgCu eutectic phases and Sc, Zr-containing phases with flocculent morphology were observed. As scandium contents vary from 0.06 wt.% to 0.17 wt.%, the average grain size continuously decreased and its equiaxial characteristics were strengthened. Meanwhile, the content of AlZnMgCu eutectic phase showed a decrease trend. When scandium contents were 0.20 wt.% and 0.25 wt.%, no further enhancement on grain refinement was observed, so as to the reduction of AlZnMgCu eutectic phase content. Besides, Sc, Zr-containing phases with blocky morphology were observed and the alloy with a scandium content of 0.25 wt.% possessed a larger amount of blocky Sc, Zr-containing phase than the alloy with a scandium content of 0.20 wt.%. Grain refinement and reduction of AlZnMgCu eutectic phase content associated with scandium addition were discussed.展开更多
Aqueous Zn//MnO2 batteries are emerging as promising large-scale energy storage devices owing to their cost-effectiveness,high safety,high output voltage,and energy density.However,the MnO2 cathode suffers from intrin...Aqueous Zn//MnO2 batteries are emerging as promising large-scale energy storage devices owing to their cost-effectiveness,high safety,high output voltage,and energy density.However,the MnO2 cathode suffers from intrinsically poor rate performance and rapid capacity deterioration.Here,we remove the roadblock by compositing MnO2 nanorods with highly conductive graphene,which remarkably enhances the electrochemical properties of the MnO2 cathode.Benefiting from the boosted electric conductivity and ion diffusion rate as well as the structural protection of graphene,the Zn//MnO2-graphene battery presents an admirable capacity of 301 mAh g^-1 at 0.5 A g^-1,corresponding to a high energy density of 411.6 Wh kg^-1.Even at a high current density of 10 A g^-1,a decent capacity of 95.8 mAh g^-1 is still obtained,manifesting its excellent rate property.Furthermore,an impressive power density of 15 kW kg^-1 is achieved by the Zn//MnO2-graphene battery.展开更多
Comprehensive utilization of pyrite cinders is increasingly important because of their huge annual outputs and potential valuable metals recovery to cope with the gradual depletion of high-grade mineral resources. In ...Comprehensive utilization of pyrite cinders is increasingly important because of their huge annual outputs and potential valuable metals recovery to cope with the gradual depletion of high-grade mineral resources. In this work, a new process, i.e., a high-temperature chlorination–magnetizing roasting–magnetic separation process, was proposed for recovering Fe and removing Zn, Pb from a low-grade pyrite cinder containing 49.90 wt% Fe, 1.23 wt% Zn, and 0.29 wt% Pb. Various parameters, including the chlorinating conditions(dosage of Ca Cl2, temperature, and time) and the magnetization roasting conditions(amount of coal, temperature, and time) were investigated. The results indicate that the proposed process is effective for Fe recovery and Zn, Pb removal from the pyrite cinder. Through this process, 97.06% Zn, 96.82% Pb, and approximately 90% S can be removed, and 89.74% Fe is recovered as magnetite into the final product under optimal conditions. A purified magnetite concentrate containing 63.07 wt% Fe, 0.16 wt% P, 0.26 wt% S, and trace amounts of nonferrous metals(0.005 wt% Cu, 0.013 wt% Pb, and 0.051 wt% Zn) was obtained. The concentrate can be potentially used as a high-quality feed material for producing oxidized pellets by blending with other high-grade iron ore concentrates.展开更多
Zinc(Zn) is an essential micronutrient for humans,but Zn deficiency has become serious as equally as iron(Fe) and vitamin A deficiencies nowadays.Selection and breeding of high Zn-density crops is a suitable,cost-effe...Zinc(Zn) is an essential micronutrient for humans,but Zn deficiency has become serious as equally as iron(Fe) and vitamin A deficiencies nowadays.Selection and breeding of high Zn-density crops is a suitable,cost-effective,and sustainable way to improve human health.However,the mechanism of high Zn density in rice grain is not fully understood,especially how Zn transports from soil to grains.Hydroponics experiments were carried out to compare Zn uptake and distribution in two different Zn-density rice genotypes using stable isotope technique.At seedling stage,IR68144 showed higher 68Zn uptake and transport rate to the shoot for the short-term,but no signifi-cant difference was observed in both genotypes for the long-term.Zn in xylem sap of IR68144 was consistently higher,and IR68144 exhibited higher Zn absorption ratio than IR64 at sufficient(2.0 μmol/L) or surplus(8.0 μmol/L) Zn supply level.IR64 and IR68144 showed similar patterns of 68Zn accumulation in new leaves at seedling stage and in de-veloping grains at ripening stage,whereas 68Zn in new leaves and grains of IR68144 was consistently higher.These results suggested that a rapid root-to-shoot translocation and enhanced xylem loading capacity may be the crucial processes for high Zn density in rice grains.展开更多
ZA27 alloy has the best performance and the widest applications in high aluminum zinc based die casting alloy series. One of its main applica-tions is used as abrasion resistant alloy,instead of nonferrous alloys such...ZA27 alloy has the best performance and the widest applications in high aluminum zinc based die casting alloy series. One of its main applica-tions is used as abrasion resistant alloy,instead of nonferrous alloys such as copper alloy.The frictional wear p展开更多
基金the financial support from the National Natural Science Foundation of China (Grant Nos. 52201201, 52372171)the State Key Lab of Advanced Metals and Materials (Grant No. 2022Z-11)+1 种基金the Fundamental Research Funds for the Central Universities (Grant No. 00007747, 06500205)the Initiative Postdocs Supporting Program (Grant No. BX20190002)。
文摘Aqueous zinc metal batteries(AZMBs)are promising candidates for next-generation energy storage due to the excellent safety, environmental friendliness, natural abundance, high theoretical specific capacity, and low redox potential of zinc(Zn) metal. However,several issues such as dendrite formation, hydrogen evolution, corrosion, and passivation of Zn metal anodes cause irreversible loss of the active materials. To solve these issues, researchers often use large amounts of excess Zn to ensure a continuous supply of active materials for Zn anodes. This leads to the ultralow utilization of Zn anodes and squanders the high energy density of AZMBs. Herein, the design strategies for AZMBs with high Zn utilization are discussed in depth, from utilizing thinner Zn foils to constructing anode-free structures with theoretical Zn utilization of 100%, which provides comprehensive guidelines for further research. Representative methods for calculating the depth of discharge of Zn anodes with different structures are first summarized. The reasonable modification strategies of Zn foil anodes, current collectors with pre-deposited Zn, and anode-free aqueous Zn metal batteries(AF-AZMBs) to improve Zn utilization are then detailed. In particular, the working mechanism of AF-AZMBs is systematically introduced. Finally, the challenges and perspectives for constructing high-utilization Zn anodes are presented.
基金financially supported Supported by the National Natural Science Foundation of China (Grant Nos.51001079,51044007,50571073)the National Natural Science Foundation of Shanxi Province (2009011028-3)the Research Fund for the Doctoral Program of Higher Education of China (20111402110004)
文摘To improve the strength, hardness and heat resistance of Mg-Zn based alloys, the effects of Cu addition on the as-cast microstructure and mechanical properties of Mg-10Zn-5Al-0.1Sb high zinc magnesium alloy were investigated by means of Brinell hardness measurement, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, XRD and tensile tests at room and elevated temperatures. The results show that the microstructure of as-cast Mg-10Zn-5AI-0.1Sb alloy is composed of α-Mg, τ-Mg32（Al, Zn）49, Ф-Al2MgsZn2 and Mg3Sb2 phases. The morphologies of these phases in the Cu-containing alloys change from semi-continuous long strip to black herringbone as well as particle-like shapes with increasing Cu content. When the addition of Cu is over 1.0wt.%, the formation of a new thermally-stable Mg2Cu phase can be observed. The Brinell hardness, room temperature and elevated temperature strengths firstly increase and then decrease as the Cu content increases. Among the Cucontaining alloys, the alloy with the addition of 2.0wt.% Cu exhibits the optimum mechanical properties. Its hardness and strengths at room and elevated temperatures are 79.35 HB, 190 MPa and 160 MPa, which are increased by 9.65%, 21.1% and 14.3%, respectively compared with those of the Cu-free one. After T6 heat treatment, the strengths at room and elevated temperatures are improved by 20% and 10%, respectively compared with those of the ascast alloy. This research results provide a new way for strengthening of magnesium alloys at room and elevated temperatures, and a method of producing thermally-stable Mg-10Zn-5Al based high zinc magnesium alloys.
基金financially supported by the European Union for the project Marie Curie TOK-DEV MTKD-CT-2006-042468
文摘This paper includes studies on the influence of grain refinement treatment with respect to the composition and structure of high zinc aluminium casting alloys on the changes of their tensile properties. The Al-20 wt.%Zn alloy was inoculated with master alloys Al Ti5B1 and Al Ti3C0.15 to determine the impact of a variable titanium addition on the tensile properties of Al Zn20 alloy, and determine on this basis an optimal addition of Ti that would ensure the improvement of elongation of alloys cast in the sand mould, at the same time maintaining high tensile strength. Within the studies, light microscopy(LM) and strength tests were applied. Experimental results showed that the inoculation of high zinc aluminium alloy Al Zn20 with the master alloys Al Ti5B1 and Al Ti3C0.15 causes intensive structure refinement, while the intensity of reaction of both master alloys is comparable. The Al Ti3C0.15 master alloy addition, selected for further studies, introducing about 100 ppm Ti, enhances the tensile properties of the alloy; the elongation increases about 20% and tensile strength increases about 10% against the initial values(uninoculated alloy). Further increase of the Ti addition up to 500–600 ppm leads to the "overinoculation" effect that is accompanied by the decrease of elongation. Therefore,the Ti addition should be reduced to the level of about 100 ppm which ensures obtaining a set of optimal properties.
基金Project(50571092) supported by the National Natural Science Foundation of ChinaProject(0523020500) supported by the Excellent Young Scholars Foundation of Henan Province, China
文摘The phase selection of ternary intermetallic compound τphase (Mg32(Al, Zn)49 ) and φ phase (Al2Mg5Zn2) in high zinc magnesium alloys was studied by using scanning electron microscope, X-ray diffractometer and differential scanning calorimeter, etc. The results indicate that, when adding element Si in Mg-8Zn-4Al-0.3Mn (ZA84) alloy, φ phase is promoted, whereas τ phase is inhibited. The Chinese script-type Mg2Si and matrix microstructure are greatly refined, the formation of τ phase is facilitated and φ phase is restrained when modifier Al-AlP master alloy is added in ZA84 alloy containing Si. The kinetics study of phase selection indicates that there is a critical degree of undercooling of the melt. If the undercooling exceeds the critical value, τ phase preferentially forms while φ phase is restrained; otherwise, φ phase preferentially forms while τ phase is restrained.
文摘The determination of trace impurities in high purity zinc oxide by high resolution inductively coupled plasma mass spectrometry （ HR-ICP-MS ） was investigated. To overcome some poteutially problematic spectral iuterference, measurements were acquired in both middle and high resolution modes. The matrix effects due to the presence of excess HCl and zinc were evaluated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits ranged from 0.02μg/ g to 6 μg/ g depending on the elements. The experimental resalts for the determination of Na, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Mo, Cd, Sb and Pb in several high purity zinc oxide powders were presented.
基金supported by National Natural Science Foundation of China(Nos.51972346,51932011,51802356,and 51872334)Innovation-Driven Project of Central South University(No.2018CX004).
文摘Rechargeable aqueous zinc-ion batteries(AZIBs)have their unique advantages of cost efficiency,high safety,and environmental friendliness.However,challenges facing the cathode materials include whether they can remain chemically stable in aqueous electrolyte and provide a robust structure for the storage of Zn2+.Here,we report on H11Al2V6O23.2@graphene(HAVO@G)with exceptionally large layer spacing of(001)plane(13.36?).The graphene-wrapped structure can keep the structure stable during discharge/charge process,thereby promoting the inhibition of the dissolution of elements in the aqueous electrolyte.While used as cathode for AZIBs,HAVO@G electrode delivers ideal rate performance(reversible capacity of 305.4,276.6,230.0,201.7,180.6 mAh g?1 at current densities between 1 and 10 A g?1).Remarkably,the electrode exhibits excellent and stable cycling stability even at a high loading mass of^15.7 mg cm?2,with an ideal reversible capacity of 131.7 mAh g?1 after 400 cycles at 2 A g?1.
基金financially supported by the National Natural Science Foundation of China (Nos. 51774099 and 51364003)the Ministry-Province Jointly Constructed Cultivation Base for State Key Laboratory of Processing for Non-ferrous Metal and Featured Materials,Guangxi Zhuang Autonomous Region, China (GXKFJ16-01)
文摘Sulfuric acid leaching of high iron-bearing zinc calcine was investigated to assess the effects of sulfuric acid concentration, liquid-to-solid ratio, leaching time, leaching temperature, and the stirring speed on the leaching rates of zinc and iron. The results showed that the sulfuric acid concentration, liquid-to-solid ratio, leaching time, and leaching temperature strongly influenced the leaching of zinc and iron, whereas stirring speed had little influence. Zinc was mainly leached and the leaching rate of iron was low when the sulfuric acid concentration was less than 100 g/L. At sulfuric acid concentrations higher than 100 g/L, the leaching rate of iron increased quickly with increasing sulfuric acid concentration. This behavior is attributed to iron-bearing minerals such as zinc ferrite in zinc calcine dissolving at high temperatures and high sulfuric acid concentrations but not at low temperatures and low sulfuric acid concentrations.
文摘The effects of Cl-concentration,temperature,pH,flow velocity,soluble oxygen content of seawater and anodic current on the potential of high purity zinc and Zn-Al-Cd reference electrodes were investigated. The results show that the investigated metal materials are liable to establish stable potential and act as reference electrodes in seawater,diluted seawater and urban tap water. Cl-concentration,temperature,seawater flow velocity and anodic current have an obvious effect on zinc potentials. However,seawater pH has no obvious effect on zinc potentials.
基金Project(2014FJ1011)supported by the Major Science and Technology Project of Hunan Province,ChinaProject(51574295)supported by the National Natural Science Foundation of China
文摘A beneficiation-metallurgy combination process is developed to recover Zn, Fe and to enrich In, Ag from high iron-bearing zinc calcine based on our former researches. In gaseous reductive roasting process, the roasting conditions were tested by magnetic separation of roasted product. It is found that the V_(CO)(P_(CO)/(P_(CO+CO_2)) in roasting atmosphere should be maintained below 30% to avoid the generation of zinc iron solid solution(Fe_(0.85-x)Zn_xO), which can bring a decrease of iron recovery in magnetic separation. After roasting, acid leaching and multistage magnetic separation are carried out for the recovery of Zn, Fe and enrichment of Ag and In. About 90% of zinc is extracted and 83% of iron is recovered in the whole process. The Ag mainly enters the tailings with a recovery of 76%, the Ag grade increases from 0.12 g/t in raw materials to 1.18 g/t in the tailings. However, the In mainly enters the iron concentrations and the recovery reaches 86%. This process was proved to be technically feasible and may be a favorable option in the treatment of high iron-bearing zinc material with high Ag or In content.
基金Funded by the Science and Technology Planning Project of Hunan Province,China(No.2010FJ3117)
文摘In order to get foam zinc materials of porous metal electrode,a novel method for preparing foam zinc was proposed,in which the polyurethane foam with diameter of 0.3 mm as substrate was processed by degreasing,roughening,activating,electroless plating and electrodeposition.The main factors affecting the process,such as ZnSO4 content,temperature,pH value,current density,and electrodes distance,were investigated comprehensively.The optimal process conditions are 250 g/L ZnSO4,20 g/L Al2（SO4）3,40 g/L KAl（SO4）2,30 g/L Na2SO4,pH=3.5,4.0 cm of electrodes distance and 0.04 A/cm2 current density at 30 ℃.The result shows that adding ultrasonic on the process can elevate the deepening plating ability and current efficiency.Foam zinc material with a high porosity of 92.2% and a three-dimensional network structure can be fabricated by electrodeposition.
文摘An ever increasing demand for zinc has resulted in worldwide efforts to exploit complex and lean grade reserves of zinc oxide ore. In this study experiments were done on zinc recovery from high-fluorine bearing zinc oxide ore. First the effect of different variables on fluorine removal was investigated. Optimum experimental conditions occurred when the temperature was 1173 K, roasting time was 90 min and air flow was at a velocity of 5 m/min, the fluorine removal from the samples reached over 93%. The results obtained indicate that fluorine removal is not enhanced by adding diluted sulfuric acid or water as a binder. Second the roasted materials were leached with a diluted sulfuric acid, neutralized, flocculated and filtrated. The which satisfies the requirement of fluorine residual fluorine content in the leached content in the leached solutions for the solutions was less than 38 mg/L production of electrolytic zinc.
文摘A historical review is presented on the experimental and theoretical studies on Zn under high pressure. Based on our high-pressure powder x-ray diffraction experiments that have been done for nearly a decade, we describe the structural change of Zn up to 126 GPa at room temperature. Although several experimental and theoretical studies indicated an anomalous change of the c/a axial ratio with pressure, we found no such an anomaly within our experimental uncertainty. Our high-pressure low-temperature experiments up to 18 GPa at 40 K also gave no evidence of the c/a anomaly. We suspect that the pressure-transmitting media played an important role in producing the anomaly. The structural anisotropy of Zn is drastically reduced at high pressures, which would be a general trend for hexagonal close-packed (hcp) metals.
基金Projects(2020YFB0311400ZL, 2020YFF0218202) supported by the National Key R&D Program of ChinaProject supported by Youth Fund Project of GRINM Group Co.,Ltd.,China。
文摘In the present work, scandium elements with a series of contents(0.06 wt.%, 0.10 wt.%, 0.14 wt.%,0.17 wt.%, 0.20 wt.% and 0.25 wt.%) were added in a high Zn-containing Al-Zn-Mg-Cu-Zr alloy and the corresponding as-cast microstructure characteristics including grains and phases were thoroughly investigated. The results indicated that fine grain boundaries existed in these alloys and fine MgZn2phases discontinuously distributed on them. Besides,AlZnMgCu eutectic phases and Sc, Zr-containing phases with flocculent morphology were observed. As scandium contents vary from 0.06 wt.% to 0.17 wt.%, the average grain size continuously decreased and its equiaxial characteristics were strengthened. Meanwhile, the content of AlZnMgCu eutectic phase showed a decrease trend. When scandium contents were 0.20 wt.% and 0.25 wt.%, no further enhancement on grain refinement was observed, so as to the reduction of AlZnMgCu eutectic phase content. Besides, Sc, Zr-containing phases with blocky morphology were observed and the alloy with a scandium content of 0.25 wt.% possessed a larger amount of blocky Sc, Zr-containing phase than the alloy with a scandium content of 0.20 wt.%. Grain refinement and reduction of AlZnMgCu eutectic phase content associated with scandium addition were discussed.
基金financially supported by the Guangdong Power Grid Co.,Ltd.(Grant No.GDKJXM20160000)。
文摘Aqueous Zn//MnO2 batteries are emerging as promising large-scale energy storage devices owing to their cost-effectiveness,high safety,high output voltage,and energy density.However,the MnO2 cathode suffers from intrinsically poor rate performance and rapid capacity deterioration.Here,we remove the roadblock by compositing MnO2 nanorods with highly conductive graphene,which remarkably enhances the electrochemical properties of the MnO2 cathode.Benefiting from the boosted electric conductivity and ion diffusion rate as well as the structural protection of graphene,the Zn//MnO2-graphene battery presents an admirable capacity of 301 mAh g^-1 at 0.5 A g^-1,corresponding to a high energy density of 411.6 Wh kg^-1.Even at a high current density of 10 A g^-1,a decent capacity of 95.8 mAh g^-1 is still obtained,manifesting its excellent rate property.Furthermore,an impressive power density of 15 kW kg^-1 is achieved by the Zn//MnO2-graphene battery.
基金financially supported by the National Natural Science Foundation of China(No.51574281)the National Torch Program of China(No.2011GH561685)the Hunan Provincial Co-innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources
文摘Comprehensive utilization of pyrite cinders is increasingly important because of their huge annual outputs and potential valuable metals recovery to cope with the gradual depletion of high-grade mineral resources. In this work, a new process, i.e., a high-temperature chlorination–magnetizing roasting–magnetic separation process, was proposed for recovering Fe and removing Zn, Pb from a low-grade pyrite cinder containing 49.90 wt% Fe, 1.23 wt% Zn, and 0.29 wt% Pb. Various parameters, including the chlorinating conditions(dosage of Ca Cl2, temperature, and time) and the magnetization roasting conditions(amount of coal, temperature, and time) were investigated. The results indicate that the proposed process is effective for Fe recovery and Zn, Pb removal from the pyrite cinder. Through this process, 97.06% Zn, 96.82% Pb, and approximately 90% S can be removed, and 89.74% Fe is recovered as magnetite into the final product under optimal conditions. A purified magnetite concentrate containing 63.07 wt% Fe, 0.16 wt% P, 0.26 wt% S, and trace amounts of nonferrous metals(0.005 wt% Cu, 0.013 wt% Pb, and 0.051 wt% Zn) was obtained. The concentrate can be potentially used as a high-quality feed material for producing oxidized pellets by blending with other high-grade iron ore concentrates.
基金Project supported by the Harvest Plus-China Program (No. HPC-8234)the Key International Cooperative Project (No. 2006DFA31030)the Department of Education of Zhejiang Province (No. N20100339)
文摘Zinc(Zn) is an essential micronutrient for humans,but Zn deficiency has become serious as equally as iron(Fe) and vitamin A deficiencies nowadays.Selection and breeding of high Zn-density crops is a suitable,cost-effective,and sustainable way to improve human health.However,the mechanism of high Zn density in rice grain is not fully understood,especially how Zn transports from soil to grains.Hydroponics experiments were carried out to compare Zn uptake and distribution in two different Zn-density rice genotypes using stable isotope technique.At seedling stage,IR68144 showed higher 68Zn uptake and transport rate to the shoot for the short-term,but no signifi-cant difference was observed in both genotypes for the long-term.Zn in xylem sap of IR68144 was consistently higher,and IR68144 exhibited higher Zn absorption ratio than IR64 at sufficient(2.0 μmol/L) or surplus(8.0 μmol/L) Zn supply level.IR64 and IR68144 showed similar patterns of 68Zn accumulation in new leaves at seedling stage and in de-veloping grains at ripening stage,whereas 68Zn in new leaves and grains of IR68144 was consistently higher.These results suggested that a rapid root-to-shoot translocation and enhanced xylem loading capacity may be the crucial processes for high Zn density in rice grains.
文摘ZA27 alloy has the best performance and the widest applications in high aluminum zinc based die casting alloy series. One of its main applica-tions is used as abrasion resistant alloy,instead of nonferrous alloys such as copper alloy.The frictional wear p
