This study was conducted in two sections.Initially,the effects of NaCl,MgCl_(2),and urea were investigated on extracting copper and iron from chalcopyrite.Subsequently,CuFe_(2)O_(4)-based electrodes for supercapacitor...This study was conducted in two sections.Initially,the effects of NaCl,MgCl_(2),and urea were investigated on extracting copper and iron from chalcopyrite.Subsequently,CuFe_(2)O_(4)-based electrodes for supercapacitors were synthesized using the extracted solution.The first phase revealed that 3 mol/L NaCl achieved the highest extraction performance,yielding 60%Cu and 23%Fe.MgCl_(2)at 1.5 mol/L extracted 52%Cu and 27%Fe,while a combination of 0.5 mol/L MgCl_(2)and 1.6 mol/L urea yielded 57%Cu and 20%Fe.Urea effectively reduced iron levels.CuFe_(2)O_(4)-based electrodes were then successfully synthesized via a hydrothermal method using a MgCl_(2)-urea solution.Characterization studies confirmed CuFe_(2)O_(4)formation with a 2D structure and 45−50 nm wall thickness on nickel foam.Electrochemical analysis showed a specific capacitance of 725 mF/cm^(2)at 2 mA/cm^(2)current density,with energy and power densities of 12.3 mW·h/cm^(2)and 175 mW/cm^(2),respectively.These findings suggest that chalcopyrite has the potential for direct use in energy storage.展开更多
The goethite residue generated from zinc hydrometallurgy is classified as hazardous solid waste,produced in large quantities,and results in significant zinc loss.The study was conducted on removing iron from FeSO_(4)-...The goethite residue generated from zinc hydrometallurgy is classified as hazardous solid waste,produced in large quantities,and results in significant zinc loss.The study was conducted on removing iron from FeSO_(4)-ZnSO_(4) solution,employing seed-induced nucleation methods.Analysis of the iron removal rate,residue structure,morphology,and elemental composition involved ICP,XRD,FT-IR,and SEM.The existing state of zinc was investigated by combining step-by-step dissolution using hydrochloric acid.Concurrently,iron removal tests were extended to industrial solutions to assess the influence of seeds and solution pH on zinc loss and residue yield.The results revealed that seed addition increased the iron removal rate by 3%,elevated the residual iron content by 6.39%,and mitigated zinc loss by 29.55%in the simulated solution.Seed-induced nucleation prevented excessive nuclei formation,fostering crystal stable growth and high crystallinity.In addition,the zinc content of surface adsorption and crystal internal embedding in the residue was determined,and the zinc distribution on the surface was dense.In contrast,the total amount of zinc within the crystal was higher.The test results in the industrial solution demonstrated that the introduction of seeds expanded the pH range for goethite formation and growth,and the zinc loss per ton of iron removed was reduced by 50.91 kg(34.12%)and the iron residue reduced by 0.17 t(8.72%).展开更多
Objective To explore the correlations of transcranial sonography of substantia nigra(SN-TCS)characteristics with MRI iron deposition on substantia nigra in patients with Parkinson disease(PD).Methods Data of SN-TCS an...Objective To explore the correlations of transcranial sonography of substantia nigra(SN-TCS)characteristics with MRI iron deposition on substantia nigra in patients with Parkinson disease(PD).Methods Data of SN-TCS and craniocerebral MRI in 120 PD patients were retrospectively analyzed.The patients were divided into iron deposition positive group(positive group,n=46)and iron deposition negative group(negative group,n=74)according to quantitative susceptibility mapping(QSM)value.Then parameters of SN-TCS and MRI were compared between groups(both P<0.05),and correlation analysis were also performed.Results The proportion of high echo positive,strong echo area and QSM value of substantia nigra,as well as of hyper-substantia nigra area/midbrain area(S/M)in positive group were all higher than those in negative group(all P<0.001).No significant difference of midbrain area was found between groups(P>0.05).Strong echo area of substantia nigra and S/M based on SN-TCS were both low-medium positively correlated with substantia nigra QSM value showed on MRI(r=0.497,0.529,both P<0.001).Conclusion SN-TCS characteristics of PD patients were correlated with MRI iron deposition on substantia nigra,among which strong echo area and S/M were valuable for evaluating iron deposition on substantia nigra.展开更多
Intermetallic aluminide compounds possess several potential advantages compared to alloyed steels,like enhanced oxidation resistance,lower density and the omittance of critical raw materials.Iron aluminides,compared t...Intermetallic aluminide compounds possess several potential advantages compared to alloyed steels,like enhanced oxidation resistance,lower density and the omittance of critical raw materials.Iron aluminides,compared to other transition metal-aluminides of TM_(3)-Al type,although having a higher density compared to titan-aluminides,have a lower density compared to nickel-aluminides,but also a higher ductility than both alternatives,making this material potentially effective in ballistic protection application.Density-wise,this material may be a worthy alternative to armour steels,which was the aim of this study.Two materials,Fe_(3)Al intermetallic compound(F3A-C)and Armox 500 armour steel were ballistically tested against tungsten-carbide(WC)armour-piercing ammunition,in accordance with STANAG 4569.After ballistic testing,microhardness and metallographic testing were performed,revealing differences in strain hardening,crack propagation mode and exit hole morphology.F3A-C ballistic resistance is similar to that of armour steel,in spite of the lower tensile and impact mechanical properties,relying on a considerably higher strain hardening rate,thermal properties and a lower density.展开更多
This study developed a direct reduction route to smelt refractory high-phosphorus iron ores by using hydrogen rich gas.The effects of temperature,gas composition,and gangue on the reduction behavior of iron ore pellet...This study developed a direct reduction route to smelt refractory high-phosphorus iron ores by using hydrogen rich gas.The effects of temperature,gas composition,and gangue on the reduction behavior of iron ore pellets were investigated.Additionally,the migration behavior of phosphorus throughout the reduction-smelting process was examined.The apparent activation energy of the reduction process increased from 64.2 to 194.2 kJ/mol.Increasing the basicity from 0.5 to 0.9 increased the metallization rate from 85.9%to 89.2%.During the reduction process,phosphorus remained in the gangue phase.Carbon deposition and phosphorus removal behaviors of the pellets were investigated and correlated with the gas composition,temperature,pressure,metallization rate,and basicity.Increasing the FeO and CaO contents led to an increase in the liquidus temperature.A high metallization rate of the pellets reduced the phosphorus removal rate but increased the carbon content of the final iron product.Increasing basicity restricted the migration of phosphorus and improved the rate of phosphorus removal.The optimum dephosphorization parameters were separation temperature of 1823 K,basicity of 2.0,and metallization rate of 82.3%.This study presents a high-efficiency and low carbon method for smelting high-phosphorus iron ores.展开更多
Magnetic separation of iron in rare-earth tailings was achieved by magnetizing roast process with coal as reductant. Effects of the temperature, carbon to oxygen ratio, and cooling type on magnetic susceptibility and ...Magnetic separation of iron in rare-earth tailings was achieved by magnetizing roast process with coal as reductant. Effects of the temperature, carbon to oxygen ratio, and cooling type on magnetic susceptibility and composition of rare-earth tailings were investigated. The results show that roast conditions with the temperature of 650℃, carbon to oxygen ratio of 3.85, and holding time of 2.5 h are in favor of reduction of Fe_2O_3 to Fe_3O_4 when the roasted rare-earth tailings is cooled along with furnace. Under these roast conditions, magnetic susceptibility of rare-earth tailings is 2.36 that is very close to theoretical value（2.33）. However, magnetic separation results of iron in rare-earth tailings cooled along with furnace are not satisfactory. Through comparing magnetic separation results of iron in rare-earth tailings cooled by different ways, it is found that water cooling is more favored of magnetic separation of iron in the roasted rare-earth tailings than furnace cooling and air cooling. Grade and recovery of iron in concentrate from rare-earth tailings cooled by water are 45.00%-49.00% and 65.00%-77.50%, respectively.展开更多
Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice sy...Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice system at different growth stages of rice with different pollution levels.The results showed that Fe concentration decreased and As concentration increased in paddy soils with the FeOS addition,especially in 120 mg/kg As treatment,the As concentration decreased by 16.46%and 30.56%at the maturity stage with 0.5%and 1%FeOS additions,respectively.Compared with the control,the application of FeOS reduced the arsenic content in rice tissues and increased the biomass,with the root biomass increased by 12.68%and the shoot biomass was increased by 8.94%with the addition of 1%FeOS.This may be related to the promotion of iron plaque formation and the transformation of microbial community structure in FeOS treatments,in accordance with the result of gene abundance and Fe/As contents of iron plaque in the study.This study is expected to provide further support and theoretical basis for the application of FeOS in the remediation of As contaminated paddy soil.展开更多
In order to reasonably utilize the abundant resources of high-phosphorus iron ore and ilmenite in China, the technology of top-blown smelting reduction with oxygen enrichment was used to smelt the mixed ore of high-ph...In order to reasonably utilize the abundant resources of high-phosphorus iron ore and ilmenite in China, the technology of top-blown smelting reduction with oxygen enrichment was used to smelt the mixed ore of high-phosphorus iron and ilmenite. The effect, which is related to basicity, reduction temperature, carbon-oxygen ratio and time of ventilated oxygen to iron recovery, dephosphorization rate, content of iron, phosphorus, sulfur and titanium in pig iron, was investigated in the experiment. The results show that an ideal outcome can be gained in condition of 6：4 ration on Mengqiao concentrate and Huimin iron ore, temperature of 1 500℃, basicity of 1.3, 1.0 on molar ration of carbon to oxygen, time of 10 min on blowing-oxygen. The outcome is that there is no foamy slag in generation, a good separation of slag and iron, iron recovery with 91.41%, content of phosphorus with 0.27% and tilanium content less than 0.001%, The atmosphere of strong oxidizing in the upper of reduction container and high potential of oxygen in the composition of slag in this technique bring phosphorus, titanium and silicon into slag, which ensures less content of impurity in pig iron.展开更多
Iron oxides and lead-zinc deposits in host rocks located in ten drainage basins in the coastal plain of the Red Sea,Egypt,have been subjected to important mining activities.The drainage basins were analyzed to estimat...Iron oxides and lead-zinc deposits in host rocks located in ten drainage basins in the coastal plain of the Red Sea,Egypt,have been subjected to important mining activities.The drainage basins were analyzed to estimate the transportations of these minerals. Fourteen soil samples and fifteen plant samples were collected from sites located in the basin and also in neighboring area and chemically analyzed.In展开更多
In recent years,composite pellet production with added reductant has been developed instead of traditional iron production.Composite pellets produced by the addition of appropriate proportions of reductant produce spo...In recent years,composite pellet production with added reductant has been developed instead of traditional iron production.Composite pellets produced by the addition of appropriate proportions of reductant produce sponge iron in the reductant melting process at high temperatures.The elements created in the structure by pellet production directly affect the quality of the product obtained by determining the chemical composition and the appropriate reaction temperature.In this study,sponge iron ore concentrate(scale)and reductant(coke coal dust and sodium bentonite)were mixed at certain proportions to produce composite pellet samples;the effects of addition rate of the reductant material of sodium bentonite(1 wt%−4 wt%)and variation in reaction temperature(900−1200℃)on the metallization and compressive strength properties of the produced composite pellet samples were investigated.The analysis results show that the highest compressive strength is obtained from pellet samples produced with 3%sodium bentonite at 1100℃.Additionally,SEM-EDS analysis results of the samples show that the morphologic structure has much lower porosity rates compared to samples produced under the other conditions which makes the samples denser and increases the metallization properties.展开更多
Flow based Erosion e corrosion problems are very common in fluid handling equipments such as propellers, impellers, pumps in warships, submarine. Though there are many coating materials available to combat erosionecor...Flow based Erosion e corrosion problems are very common in fluid handling equipments such as propellers, impellers, pumps in warships, submarine. Though there are many coating materials available to combat erosionecorrosion damage in the above components, iron based amorphous coatings are considered to be more effective to combat erosionecorrosion problems. High velocity oxy-fuel(HVOF)spray process is considered to be a better process to coat the iron based amorphous powders. In this investigation, iron based amorphous metallic coating was developed on 316 stainless steel substrate using HVOF spray technique. Empirical relationships were developed to predict the porosity and micro hardness of iron based amorphous coating incorporating HVOF spray parameters such as oxygen flow rate, fuel flow rate, powder feed rate, carrier gas flow rate, and spray distance. Response surface methodology(RSM) was used to identify the optimal HVOF spray parameters to attain coating with minimum porosity and maximum hardness.展开更多
Successfully developed an innovative process of direct reduction of cold bound pellets from iron ore concentrate with a coal based rotary kiln, in comparison with the traditional direct reduction of fired oxide pellet...Successfully developed an innovative process of direct reduction of cold bound pellets from iron ore concentrate with a coal based rotary kiln, in comparison with the traditional direct reduction of fired oxide pellets in coal based rotary kilns , possesses such advantages as: shorter flowsheet, lower capital investment, greater economic profit, good quality of direct reduced iron. The key technologies , such as the composite binder and corresponding feasible techniques were employed in practice. A mill utilizing this process and with an annual capacity of 50 thousand ton DRI has been put into operation.展开更多
A feasible approach to selectively recover iron and rare earth elements(REEs)from red mud through acid leaching-coordination-solvent extraction was proposed.The leaching efficiencies of Fe,Al,Ti,Sc,La,Ce,Nd and Y can ...A feasible approach to selectively recover iron and rare earth elements(REEs)from red mud through acid leaching-coordination-solvent extraction was proposed.The leaching efficiencies of Fe,Al,Ti,Sc,La,Ce,Nd and Y can reach up to 95.9%,82.1%,68.3%,93.3%,82.3%,96.9%,98.3%and 95.6%,respectively,under the optimal condition in the leaching process.Aliquat 336 showed excellent extraction performance of iron in chloride-rich solution,and the maximum extraction efficiency can reach over 96%in one time extraction while the loss of other metals was less than 10%,under the condition of Aliquat 336 concentration(v/v)of 30%,aqueous-organic ratio of 1.0 and extraction time of 20 min.Furthermore,P204 can effectively extract the scandium while Al and most other REEs remain in the aqueous phase.This approach may provide a new insight for the recovery of valuable resources from red mud.展开更多
Six additives,i.e.,limestone,lime,magnesite,magnesia,dolomite and light-burned-dolomite,were added for investigating their influences on the pellet quality.For green balls,adding lime and light-burned-dolomite makes t...Six additives,i.e.,limestone,lime,magnesite,magnesia,dolomite and light-burned-dolomite,were added for investigating their influences on the pellet quality.For green balls,adding lime and light-burned-dolomite makes the wet drop strength decrease firstly,and then increase with further increase of additive dosage.Ca(OH)2 affects the bentonite properties at the beginning,but the binding property of Ca(OH)2 will be main when the dosage is higher.The other four additives decrease the drop strength for their disadvantageous physical properties.For preheated pellets,no mater what kind of additive is added,the compressive strength will be decreased because of unmineralized additives.For roasted pellets,calcium additives can form binding phase of calcium-ferrite,and suitable liquid phase will improve recrystallization of hematite,but excessive liquid will destroy the structure of pellets,so the compressive strength of pellet increases firstly and then drops.When adding magnesium additives,the strength will be decreased because of the oxidation of magnetite retarded by MgO.展开更多
Applying spent lithium iron phosphate battery as raw material,valuable metals in spent lithium ion battery were effectively recovered through separation of active material,selective leaching,and stepwise chemical prec...Applying spent lithium iron phosphate battery as raw material,valuable metals in spent lithium ion battery were effectively recovered through separation of active material,selective leaching,and stepwise chemical precipitation.Using stoichiometric Na2S2O8 as an oxidant and adding low-concentration H2SO4 as a leaching agent was proposed.This route was totally different from the conventional methods of dissolving all of the elements into solution by using excess mineral acid.When experiments were done under optimal conditions(Na2S2O8-to-Li molar ratio 0.45,0.30 mol/L H2SO4,60℃,1.5 h),leaching efficiencies of 97.53% for Li^+,1.39%for Fe^3+,and 2.58% for PO4^3−were recorded.FePO4 was then recovered by a precipitation method from the leachate while maintaining the pH at 2.0.The mother liquor was concentrated and maintained at a temperature of approximately 100℃,and then a saturated sodium carbonate solution was added to precipitate Li2CO3.The lithium recovery yield was close to 80%.展开更多
Zinc leaching residue(ZLR) contains high content of valuable metals such as zinc and iron. However, zinc and iron mainly exist in the form of zinc ferrite, which are difficult to separate and recover. This study propo...Zinc leaching residue(ZLR) contains high content of valuable metals such as zinc and iron. However, zinc and iron mainly exist in the form of zinc ferrite, which are difficult to separate and recover. This study proposed a new process involving sulfidation roasting, magnetic separation and flotation to recover zinc and iron in ZLR. Through sulfidation roasting of ZLR with pyrite, zinc and iron were converted into ZnS and Fe3 O4. The effects of pyrite dosage, roasting temperature and roasting time on the sulfidation of zinc in ZLR were investigated. The results showed that the sulfidation percentage of zinc reached 91.8% under the optimum condition. Besides, it was found that ball-milling was favorable for the separation and recovery of zinc and iron in sulfidation products. After ball-milling pretreatment, iron and zinc were enriched from sulfidation products by magnetic separation and flotation. The grade of iron in magnetic concentrates was 52.3% and the grade of zinc in flotation concentrates was 31.7%, which realized the recovery of resources.展开更多
Alkali-leaching and acid-leaching were proposed for the dephosphorization of Changde iron ore, which contains an average of 1.12% for phosphorus content. Sodium hydroxide, sulfuriced, hydrochloric and nitric acids wer...Alkali-leaching and acid-leaching were proposed for the dephosphorization of Changde iron ore, which contains an average of 1.12% for phosphorus content. Sodium hydroxide, sulfuriced, hydrochloric and nitric acids were used for the preparation of leach solutions. The results show that phosphorus occurring as apatite phase could be removed by alkali-leaching, but those occurring in the iron phase could not. Sulfuric acid is the most effective among the three kinds of acid. 91.61% phosphorus removal was attained with 1% sulfuric acid after leaching for 20 rain at room temperature. Iron loss during acid-leaching can be negligible, which was less than 0.25%.The pH value of solution after leaching with1% sulfuric acid was about 0.86, which means acid would not be exhausted during the process and it could be recycled, and the recycle of sulfuric acid solution would make the dephosphorization process more economical.展开更多
The features of the techniques of fast reducing roasting （FRR） and conventional magnetic roasting, as well as tremendous demands of iron ores in iron and steel industry of China, were briefly described. The test equ...The features of the techniques of fast reducing roasting （FRR） and conventional magnetic roasting, as well as tremendous demands of iron ores in iron and steel industry of China, were briefly described. The test equipment suitable for FRR of fine-grained materials was introduced. Weakly magnetic materials with grain size of 〈0.30 mm were converted into strongly magnetic materials by FRR for several to dozens of seconds. In a weakly reducing atmosphere and at 740-800 ~C, refractory powder iron material （〈0.30 mm） which is rich in specularite, limonite and Mg-Mn siderite was subjected to FRR for a few seconds to 60 s. Concentrate with iron grade of 55.67%-55.21%, high contents of Mg and Mn in the ore is obtained and the yield of magnetic separation reaches 81.66%-86.57%. The results of X-ray diffraction （XRD） analysis and magnetism detection of the material before and after FRR indicate that weakly magnetic material is mainly converted into strongly magnetic material Fe304 with specific saturation magnetic moment. The efficiency of FRR is consistent with TFe recovery of magnetic separation; meantime, the specific sa^u＇ation magnetic moment increases from 33 to 42 times after FRR. Calculations show that speeds of flash magnetic roasting are obtained from several dozen to two or three hundred times, compared with rotary kiln or shaft furnace. This indicates that it is practicable to use the fast reducing roasting technique to improve the comprehensive utilization of iron ore resources.展开更多
In order to obtain the distribution rules of in situ stress and mining-induced stress of Beiminghe Iron Mine, the stress relief method by overcoring was used to measure the in situ stress, and the MC type bore-hole st...In order to obtain the distribution rules of in situ stress and mining-induced stress of Beiminghe Iron Mine, the stress relief method by overcoring was used to measure the in situ stress, and the MC type bore-hole stress gauge was adopted to measure the mining-induced stress. In the in situ stress measuring, the technique of improved hollow inclusion cells was adopted, which can realize complete temperature compensation. Based on the measuring results, the distribution model of in situ stress was established and analyzed. The in situ stress measuring result shows that the maximum horizontal stress is 1.75-2.45 times of vertical stress and almost 1.83 times of the minimum horizontal stress in this mineral field. And the mining-induced stress measuring result shows that, according to the magnitude of front abutment pressure the stress region can be separated into stress-relaxed area, stress- concentrated area and initial stress area. At the -50 m mining level of this mine, the range of stress-relaxed area is 0-3 m before mining face; the range of stress-concentrated area is 3-55 m before mining face, and the maximum mining-induced stress is 16.5-17.5 MPa, which is 15-20 m from the mining face. The coefficient of stress concentration is 1.85.展开更多
In this paper,the combined addition of copper or iron and sulphate ions onto TiO_(2) prepared by a simple sol-gel method is studied for formic acid photocatalytic conversion.A wide structural and morphological charact...In this paper,the combined addition of copper or iron and sulphate ions onto TiO_(2) prepared by a simple sol-gel method is studied for formic acid photocatalytic conversion.A wide structural and morphological characterization of the different photocatalysts was performed by X-ray diffraction(XRD),N_(2)-physisorption for BET surface area measurements,scanning and transmission electronic microscopies(SEM and TEM),UV-Vis diffuse spectroscopy(DRS)and X-ray photoelectron spectroscopy(XPS),in order to correlate the physico-chemical properties of the materials to their photocatalytic efficiencies for formic acid oxidation.Results have shown important differences among the catalysts depending on the metal added.Sulphated TiO_(2)/Cu(1%Cu)was the best photocatalyst obtaining about 100% formic acid conversion in only 5 min.The appropriate physico-chemical features of this photocatalyst,given by the addition of combined copper and sulphate ions,explain its excellence in photocatalytic reaction.展开更多
文摘This study was conducted in two sections.Initially,the effects of NaCl,MgCl_(2),and urea were investigated on extracting copper and iron from chalcopyrite.Subsequently,CuFe_(2)O_(4)-based electrodes for supercapacitors were synthesized using the extracted solution.The first phase revealed that 3 mol/L NaCl achieved the highest extraction performance,yielding 60%Cu and 23%Fe.MgCl_(2)at 1.5 mol/L extracted 52%Cu and 27%Fe,while a combination of 0.5 mol/L MgCl_(2)and 1.6 mol/L urea yielded 57%Cu and 20%Fe.Urea effectively reduced iron levels.CuFe_(2)O_(4)-based electrodes were then successfully synthesized via a hydrothermal method using a MgCl_(2)-urea solution.Characterization studies confirmed CuFe_(2)O_(4)formation with a 2D structure and 45−50 nm wall thickness on nickel foam.Electrochemical analysis showed a specific capacitance of 725 mF/cm^(2)at 2 mA/cm^(2)current density,with energy and power densities of 12.3 mW·h/cm^(2)and 175 mW/cm^(2),respectively.These findings suggest that chalcopyrite has the potential for direct use in energy storage.
基金Project(2018YFC1900403) supported by the National Key Research and Development Program of ChinaProject(CX20210197) supported by the Postgraduate Scientific Research Innovation Project of Hunan Province,China+1 种基金Project(202206370103) supported by the China Scholarship CouncilProject(2021zzts0115) supported by the Fundamental Research Funds for the Central Universities,China。
文摘The goethite residue generated from zinc hydrometallurgy is classified as hazardous solid waste,produced in large quantities,and results in significant zinc loss.The study was conducted on removing iron from FeSO_(4)-ZnSO_(4) solution,employing seed-induced nucleation methods.Analysis of the iron removal rate,residue structure,morphology,and elemental composition involved ICP,XRD,FT-IR,and SEM.The existing state of zinc was investigated by combining step-by-step dissolution using hydrochloric acid.Concurrently,iron removal tests were extended to industrial solutions to assess the influence of seeds and solution pH on zinc loss and residue yield.The results revealed that seed addition increased the iron removal rate by 3%,elevated the residual iron content by 6.39%,and mitigated zinc loss by 29.55%in the simulated solution.Seed-induced nucleation prevented excessive nuclei formation,fostering crystal stable growth and high crystallinity.In addition,the zinc content of surface adsorption and crystal internal embedding in the residue was determined,and the zinc distribution on the surface was dense.In contrast,the total amount of zinc within the crystal was higher.The test results in the industrial solution demonstrated that the introduction of seeds expanded the pH range for goethite formation and growth,and the zinc loss per ton of iron removed was reduced by 50.91 kg(34.12%)and the iron residue reduced by 0.17 t(8.72%).
文摘Objective To explore the correlations of transcranial sonography of substantia nigra(SN-TCS)characteristics with MRI iron deposition on substantia nigra in patients with Parkinson disease(PD).Methods Data of SN-TCS and craniocerebral MRI in 120 PD patients were retrospectively analyzed.The patients were divided into iron deposition positive group(positive group,n=46)and iron deposition negative group(negative group,n=74)according to quantitative susceptibility mapping(QSM)value.Then parameters of SN-TCS and MRI were compared between groups(both P<0.05),and correlation analysis were also performed.Results The proportion of high echo positive,strong echo area and QSM value of substantia nigra,as well as of hyper-substantia nigra area/midbrain area(S/M)in positive group were all higher than those in negative group(all P<0.001).No significant difference of midbrain area was found between groups(P>0.05).Strong echo area of substantia nigra and S/M based on SN-TCS were both low-medium positively correlated with substantia nigra QSM value showed on MRI(r=0.497,0.529,both P<0.001).Conclusion SN-TCS characteristics of PD patients were correlated with MRI iron deposition on substantia nigra,among which strong echo area and S/M were valuable for evaluating iron deposition on substantia nigra.
基金support by the project entitled"Interdisciplinarity in Materials Science and Joining Technologies"from the Department of Production Engineering,Faculty of Technical Sciences Novi Sad,Serbia。
文摘Intermetallic aluminide compounds possess several potential advantages compared to alloyed steels,like enhanced oxidation resistance,lower density and the omittance of critical raw materials.Iron aluminides,compared to other transition metal-aluminides of TM_(3)-Al type,although having a higher density compared to titan-aluminides,have a lower density compared to nickel-aluminides,but also a higher ductility than both alternatives,making this material potentially effective in ballistic protection application.Density-wise,this material may be a worthy alternative to armour steels,which was the aim of this study.Two materials,Fe_(3)Al intermetallic compound(F3A-C)and Armox 500 armour steel were ballistically tested against tungsten-carbide(WC)armour-piercing ammunition,in accordance with STANAG 4569.After ballistic testing,microhardness and metallographic testing were performed,revealing differences in strain hardening,crack propagation mode and exit hole morphology.F3A-C ballistic resistance is similar to that of armour steel,in spite of the lower tensile and impact mechanical properties,relying on a considerably higher strain hardening rate,thermal properties and a lower density.
基金Project(U1960205)supported by the National Natural Science Foundation of ChinaProject(2020ZXA01)supported by China Minmetals Science and Technology Special Plan Foundation。
文摘This study developed a direct reduction route to smelt refractory high-phosphorus iron ores by using hydrogen rich gas.The effects of temperature,gas composition,and gangue on the reduction behavior of iron ore pellets were investigated.Additionally,the migration behavior of phosphorus throughout the reduction-smelting process was examined.The apparent activation energy of the reduction process increased from 64.2 to 194.2 kJ/mol.Increasing the basicity from 0.5 to 0.9 increased the metallization rate from 85.9%to 89.2%.During the reduction process,phosphorus remained in the gangue phase.Carbon deposition and phosphorus removal behaviors of the pellets were investigated and correlated with the gas composition,temperature,pressure,metallization rate,and basicity.Increasing the FeO and CaO contents led to an increase in the liquidus temperature.A high metallization rate of the pellets reduced the phosphorus removal rate but increased the carbon content of the final iron product.Increasing basicity restricted the migration of phosphorus and improved the rate of phosphorus removal.The optimum dephosphorization parameters were separation temperature of 1823 K,basicity of 2.0,and metallization rate of 82.3%.This study presents a high-efficiency and low carbon method for smelting high-phosphorus iron ores.
基金Project(2012CBA01205)supported by National Basic Research Program of ChinaProjects(50934004,51274061)supported by the National Natural Science Foundation of ChinaProject(N110502002)supported by the Fundamental Research Funds for the Central Universities,China
文摘Magnetic separation of iron in rare-earth tailings was achieved by magnetizing roast process with coal as reductant. Effects of the temperature, carbon to oxygen ratio, and cooling type on magnetic susceptibility and composition of rare-earth tailings were investigated. The results show that roast conditions with the temperature of 650℃, carbon to oxygen ratio of 3.85, and holding time of 2.5 h are in favor of reduction of Fe_2O_3 to Fe_3O_4 when the roasted rare-earth tailings is cooled along with furnace. Under these roast conditions, magnetic susceptibility of rare-earth tailings is 2.36 that is very close to theoretical value（2.33）. However, magnetic separation results of iron in rare-earth tailings cooled along with furnace are not satisfactory. Through comparing magnetic separation results of iron in rare-earth tailings cooled by different ways, it is found that water cooling is more favored of magnetic separation of iron in the roasted rare-earth tailings than furnace cooling and air cooling. Grade and recovery of iron in concentrate from rare-earth tailings cooled by water are 45.00%-49.00% and 65.00%-77.50%, respectively.
基金Project(2019YFC1803601)supported by the National Key Research and Development Program of ChinaProject(41771512)supported by the National Natural Science Foundation of ChinaProject(2018RS3004)supported by Hunan Science&Technology Innovation Program,China。
文摘Iron-modified biochar(FeOS)is known to be effective at immobilization of arsenic(As)in soils.A pot experiment was conducted to investigate the effects of FeOS on As availability and ttransportation in the soil-rice system at different growth stages of rice with different pollution levels.The results showed that Fe concentration decreased and As concentration increased in paddy soils with the FeOS addition,especially in 120 mg/kg As treatment,the As concentration decreased by 16.46%and 30.56%at the maturity stage with 0.5%and 1%FeOS additions,respectively.Compared with the control,the application of FeOS reduced the arsenic content in rice tissues and increased the biomass,with the root biomass increased by 12.68%and the shoot biomass was increased by 8.94%with the addition of 1%FeOS.This may be related to the promotion of iron plaque formation and the transformation of microbial community structure in FeOS treatments,in accordance with the result of gene abundance and Fe/As contents of iron plaque in the study.This study is expected to provide further support and theoretical basis for the application of FeOS in the remediation of As contaminated paddy soil.
基金Project(51064015) supported by the National Natural Science Foundation of ChinaProject(ZD2010001) supported by the Key Project of Yunnan Province Education of China
文摘In order to reasonably utilize the abundant resources of high-phosphorus iron ore and ilmenite in China, the technology of top-blown smelting reduction with oxygen enrichment was used to smelt the mixed ore of high-phosphorus iron and ilmenite. The effect, which is related to basicity, reduction temperature, carbon-oxygen ratio and time of ventilated oxygen to iron recovery, dephosphorization rate, content of iron, phosphorus, sulfur and titanium in pig iron, was investigated in the experiment. The results show that an ideal outcome can be gained in condition of 6：4 ration on Mengqiao concentrate and Huimin iron ore, temperature of 1 500℃, basicity of 1.3, 1.0 on molar ration of carbon to oxygen, time of 10 min on blowing-oxygen. The outcome is that there is no foamy slag in generation, a good separation of slag and iron, iron recovery with 91.41%, content of phosphorus with 0.27% and tilanium content less than 0.001%, The atmosphere of strong oxidizing in the upper of reduction container and high potential of oxygen in the composition of slag in this technique bring phosphorus, titanium and silicon into slag, which ensures less content of impurity in pig iron.
文摘Iron oxides and lead-zinc deposits in host rocks located in ten drainage basins in the coastal plain of the Red Sea,Egypt,have been subjected to important mining activities.The drainage basins were analyzed to estimate the transportations of these minerals. Fourteen soil samples and fifteen plant samples were collected from sites located in the basin and also in neighboring area and chemically analyzed.In
文摘In recent years,composite pellet production with added reductant has been developed instead of traditional iron production.Composite pellets produced by the addition of appropriate proportions of reductant produce sponge iron in the reductant melting process at high temperatures.The elements created in the structure by pellet production directly affect the quality of the product obtained by determining the chemical composition and the appropriate reaction temperature.In this study,sponge iron ore concentrate(scale)and reductant(coke coal dust and sodium bentonite)were mixed at certain proportions to produce composite pellet samples;the effects of addition rate of the reductant material of sodium bentonite(1 wt%−4 wt%)and variation in reaction temperature(900−1200℃)on the metallization and compressive strength properties of the produced composite pellet samples were investigated.The analysis results show that the highest compressive strength is obtained from pellet samples produced with 3%sodium bentonite at 1100℃.Additionally,SEM-EDS analysis results of the samples show that the morphologic structure has much lower porosity rates compared to samples produced under the other conditions which makes the samples denser and increases the metallization properties.
文摘Flow based Erosion e corrosion problems are very common in fluid handling equipments such as propellers, impellers, pumps in warships, submarine. Though there are many coating materials available to combat erosionecorrosion damage in the above components, iron based amorphous coatings are considered to be more effective to combat erosionecorrosion problems. High velocity oxy-fuel(HVOF)spray process is considered to be a better process to coat the iron based amorphous powders. In this investigation, iron based amorphous metallic coating was developed on 316 stainless steel substrate using HVOF spray technique. Empirical relationships were developed to predict the porosity and micro hardness of iron based amorphous coating incorporating HVOF spray parameters such as oxygen flow rate, fuel flow rate, powder feed rate, carrier gas flow rate, and spray distance. Response surface methodology(RSM) was used to identify the optimal HVOF spray parameters to attain coating with minimum porosity and maximum hardness.
基金The Key Project of the 9th Five year Plan of Ministry of Science andTechnology!(No .960 40 2 0 2A)the Foundation for Unive
文摘Successfully developed an innovative process of direct reduction of cold bound pellets from iron ore concentrate with a coal based rotary kiln, in comparison with the traditional direct reduction of fired oxide pellets in coal based rotary kilns , possesses such advantages as: shorter flowsheet, lower capital investment, greater economic profit, good quality of direct reduced iron. The key technologies , such as the composite binder and corresponding feasible techniques were employed in practice. A mill utilizing this process and with an annual capacity of 50 thousand ton DRI has been put into operation.
基金Project(21707167)supported by the Natural Science Foundation of China
文摘A feasible approach to selectively recover iron and rare earth elements(REEs)from red mud through acid leaching-coordination-solvent extraction was proposed.The leaching efficiencies of Fe,Al,Ti,Sc,La,Ce,Nd and Y can reach up to 95.9%,82.1%,68.3%,93.3%,82.3%,96.9%,98.3%and 95.6%,respectively,under the optimal condition in the leaching process.Aliquat 336 showed excellent extraction performance of iron in chloride-rich solution,and the maximum extraction efficiency can reach over 96%in one time extraction while the loss of other metals was less than 10%,under the condition of Aliquat 336 concentration(v/v)of 30%,aqueous-organic ratio of 1.0 and extraction time of 20 min.Furthermore,P204 can effectively extract the scandium while Al and most other REEs remain in the aqueous phase.This approach may provide a new insight for the recovery of valuable resources from red mud.
基金Project(2008BAB32B06) supported by the Key Projects in the National Science and Technology Pillar Program during the 11th Five-year Plan PeriodProject(2009ybfz20) supported by the Program for Excellent Doctor’s Degree Paper in Central South University,ChinaProject(1343/74333001114) supported by the Postgraduate’s Paper Innovation Fund of Hunan Province,China
文摘Six additives,i.e.,limestone,lime,magnesite,magnesia,dolomite and light-burned-dolomite,were added for investigating their influences on the pellet quality.For green balls,adding lime and light-burned-dolomite makes the wet drop strength decrease firstly,and then increase with further increase of additive dosage.Ca(OH)2 affects the bentonite properties at the beginning,but the binding property of Ca(OH)2 will be main when the dosage is higher.The other four additives decrease the drop strength for their disadvantageous physical properties.For preheated pellets,no mater what kind of additive is added,the compressive strength will be decreased because of unmineralized additives.For roasted pellets,calcium additives can form binding phase of calcium-ferrite,and suitable liquid phase will improve recrystallization of hematite,but excessive liquid will destroy the structure of pellets,so the compressive strength of pellet increases firstly and then drops.When adding magnesium additives,the strength will be decreased because of the oxidation of magnetite retarded by MgO.
基金Project(Z20160605230001)supported by Hunan Province Non-ferrous Fund Project,China。
文摘Applying spent lithium iron phosphate battery as raw material,valuable metals in spent lithium ion battery were effectively recovered through separation of active material,selective leaching,and stepwise chemical precipitation.Using stoichiometric Na2S2O8 as an oxidant and adding low-concentration H2SO4 as a leaching agent was proposed.This route was totally different from the conventional methods of dissolving all of the elements into solution by using excess mineral acid.When experiments were done under optimal conditions(Na2S2O8-to-Li molar ratio 0.45,0.30 mol/L H2SO4,60℃,1.5 h),leaching efficiencies of 97.53% for Li^+,1.39%for Fe^3+,and 2.58% for PO4^3−were recorded.FePO4 was then recovered by a precipitation method from the leachate while maintaining the pH at 2.0.The mother liquor was concentrated and maintained at a temperature of approximately 100℃,and then a saturated sodium carbonate solution was added to precipitate Li2CO3.The lithium recovery yield was close to 80%.
基金Project(2018YFC1900305)supported by the National Key R&D Program of ChinaProject(51825403)supported by the National Science Foundation for Distinguished Young Scholars,China+1 种基金Projects(51634010,51474247,51904354)supported by the National Natural Science Foundation of ChinaProject(2019SK2291)supported by the Key Research and Development Program of Hunan Province,China。
文摘Zinc leaching residue(ZLR) contains high content of valuable metals such as zinc and iron. However, zinc and iron mainly exist in the form of zinc ferrite, which are difficult to separate and recover. This study proposed a new process involving sulfidation roasting, magnetic separation and flotation to recover zinc and iron in ZLR. Through sulfidation roasting of ZLR with pyrite, zinc and iron were converted into ZnS and Fe3 O4. The effects of pyrite dosage, roasting temperature and roasting time on the sulfidation of zinc in ZLR were investigated. The results showed that the sulfidation percentage of zinc reached 91.8% under the optimum condition. Besides, it was found that ball-milling was favorable for the separation and recovery of zinc and iron in sulfidation products. After ball-milling pretreatment, iron and zinc were enriched from sulfidation products by magnetic separation and flotation. The grade of iron in magnetic concentrates was 52.3% and the grade of zinc in flotation concentrates was 31.7%, which realized the recovery of resources.
基金Project (50321402) supported by the National Natural Science Foundation of China project(2004CB619204) supported by Major State Basic Research Development Program of China
文摘Alkali-leaching and acid-leaching were proposed for the dephosphorization of Changde iron ore, which contains an average of 1.12% for phosphorus content. Sodium hydroxide, sulfuriced, hydrochloric and nitric acids were used for the preparation of leach solutions. The results show that phosphorus occurring as apatite phase could be removed by alkali-leaching, but those occurring in the iron phase could not. Sulfuric acid is the most effective among the three kinds of acid. 91.61% phosphorus removal was attained with 1% sulfuric acid after leaching for 20 rain at room temperature. Iron loss during acid-leaching can be negligible, which was less than 0.25%.The pH value of solution after leaching with1% sulfuric acid was about 0.86, which means acid would not be exhausted during the process and it could be recycled, and the recycle of sulfuric acid solution would make the dephosphorization process more economical.
基金Project(20070497048) supported by China Scholarship Council,Ministry of Education of China
文摘The features of the techniques of fast reducing roasting （FRR） and conventional magnetic roasting, as well as tremendous demands of iron ores in iron and steel industry of China, were briefly described. The test equipment suitable for FRR of fine-grained materials was introduced. Weakly magnetic materials with grain size of 〈0.30 mm were converted into strongly magnetic materials by FRR for several to dozens of seconds. In a weakly reducing atmosphere and at 740-800 ~C, refractory powder iron material （〈0.30 mm） which is rich in specularite, limonite and Mg-Mn siderite was subjected to FRR for a few seconds to 60 s. Concentrate with iron grade of 55.67%-55.21%, high contents of Mg and Mn in the ore is obtained and the yield of magnetic separation reaches 81.66%-86.57%. The results of X-ray diffraction （XRD） analysis and magnetism detection of the material before and after FRR indicate that weakly magnetic material is mainly converted into strongly magnetic material Fe304 with specific saturation magnetic moment. The efficiency of FRR is consistent with TFe recovery of magnetic separation; meantime, the specific sa^u＇ation magnetic moment increases from 33 to 42 times after FRR. Calculations show that speeds of flash magnetic roasting are obtained from several dozen to two or three hundred times, compared with rotary kiln or shaft furnace. This indicates that it is practicable to use the fast reducing roasting technique to improve the comprehensive utilization of iron ore resources.
基金Projects(10702072, 10632100) supported by the National Nature Science Foundation of China
文摘In order to obtain the distribution rules of in situ stress and mining-induced stress of Beiminghe Iron Mine, the stress relief method by overcoring was used to measure the in situ stress, and the MC type bore-hole stress gauge was adopted to measure the mining-induced stress. In the in situ stress measuring, the technique of improved hollow inclusion cells was adopted, which can realize complete temperature compensation. Based on the measuring results, the distribution model of in situ stress was established and analyzed. The in situ stress measuring result shows that the maximum horizontal stress is 1.75-2.45 times of vertical stress and almost 1.83 times of the minimum horizontal stress in this mineral field. And the mining-induced stress measuring result shows that, according to the magnitude of front abutment pressure the stress region can be separated into stress-relaxed area, stress- concentrated area and initial stress area. At the -50 m mining level of this mine, the range of stress-relaxed area is 0-3 m before mining face; the range of stress-concentrated area is 3-55 m before mining face, and the maximum mining-induced stress is 16.5-17.5 MPa, which is 15-20 m from the mining face. The coefficient of stress concentration is 1.85.
文摘In this paper,the combined addition of copper or iron and sulphate ions onto TiO_(2) prepared by a simple sol-gel method is studied for formic acid photocatalytic conversion.A wide structural and morphological characterization of the different photocatalysts was performed by X-ray diffraction(XRD),N_(2)-physisorption for BET surface area measurements,scanning and transmission electronic microscopies(SEM and TEM),UV-Vis diffuse spectroscopy(DRS)and X-ray photoelectron spectroscopy(XPS),in order to correlate the physico-chemical properties of the materials to their photocatalytic efficiencies for formic acid oxidation.Results have shown important differences among the catalysts depending on the metal added.Sulphated TiO_(2)/Cu(1%Cu)was the best photocatalyst obtaining about 100% formic acid conversion in only 5 min.The appropriate physico-chemical features of this photocatalyst,given by the addition of combined copper and sulphate ions,explain its excellence in photocatalytic reaction.
