期刊文献+
共找到496篇文章
< 1 2 25 >
每页显示 20 50 100
Preparation of sodium molybdate from molybdenum concentrate by microwave roasting and alkali leaching
1
作者 Fengjuan Zhang Chenhui Liu +2 位作者 Srinivasakannan Chandrasekar Yingwei Li Fuchang Xu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CSCD 2024年第1期91-105,共15页
The preparation process of sodium molybdate has the disadvantages of high energy consumption,low thermal efficiency,and high raw material requirement of molybdenum trioxide,in order to realize the green and efficient ... The preparation process of sodium molybdate has the disadvantages of high energy consumption,low thermal efficiency,and high raw material requirement of molybdenum trioxide,in order to realize the green and efficient development of molybdenum concentrate resources,this paper proposes a new process for efficient recovery of molybdenum from molybdenum concentrate and preparation of sodium molybdate by microwave-enhanced roasting and alkali leaching.Thermodynamic analysis indicated the feasibility of oxidation roasting of molybdenum concentrate.The effects of roasting temperature,holding time,and power-to-mass ratio on the oxidation product and leaching product sodium molybdate (Na_(2)MoO_(4)·2H_(2)O) were investigated.Under the optimal process conditions:roasting temperature of 700℃,holding time of 110 min,and power-to-mass ratio of 110 W/g,the molybdenum state of existence was converted from MoS_(2) to Mo O3.The process of preparing sodium molybdate by alkali leaching of molybdenum calcine was investigated,the optimal leaching conditions include a solution concentration of 2.5 mol/L,a liquid-to-solid ratio of 2 mL/g,a leaching temperature of 60℃,and leaching solution termination at pH 8.The optimum conditions result in a leaching rate of sodium molybdate of 96.24%.Meanwhile,the content of sodium molybdate reaches 94.08wt%after leaching and removing impurities.Iron and aluminum impurities can be effectively separated by adjusting the pH of the leaching solution with sodium carbonate solution.This research avoids the shortcomings of the traditional process and utilizes the advantages of microwave metallurgy to prepare high-quality sodium molybdate,which provides a new idea for the highvalue utilization of molybdenum concentrate. 展开更多
关键词 molybdenum metallurgy microwave oxidation roasting removing impurities sodium hydroxide leaching
下载PDF
Reclamation of CO_(2) sodium silicate used sands by steam leaching 被引量:1
2
作者 Ji-jun Lu Wei He +1 位作者 Lei Yang Hua-fang Wang 《China Foundry》 SCIE EI CAS CSCD 2023年第6期537-544,共8页
The bond film on the surface of the CO_(2) sodium silicate used sands is not easy to decompose,therefore,it is difficult to reclaim used sands.A new reclamation method of CO_(2) sodium silicate used sands was develope... The bond film on the surface of the CO_(2) sodium silicate used sands is not easy to decompose,therefore,it is difficult to reclaim used sands.A new reclamation method of CO_(2) sodium silicate used sands was developed by steam leaching,which can reduce the water consumption of reclamation and improve the removal effect of sodium silicate bond film.Firstly,the leaching effect of the sodium silicate sands after 20/200/400/600/800/1,000°C heat preservation treatment was simulated.Furthermore,the influence of the leaching time on the removal effect of the sodium silicate bond film was studied.Finally,the casting properties of the reclaimed sands after the leaching reclamation treatment were tested.The results show for simulated used sands after 30 min of steam leaching,the removal ratio of the alkali exceeds 84.1%,the removal ratio of silicate is 86.2%,and the removal ratio of carbonate is 93.6%.The removal rate of alkali,silicate and carbonate is relatively low in the leaching time of 30-50 min.Considering the reclamation effect and cost,the leaching time is controlled in 30 min.Water consumption is only 60%of the mass of used sands for 30 min steam leaching,while it is 200%for wet reclamation.Morphological analysis shows that most of the hazardous substances in the used sands are removed in 30 min steam leaching,and the reclaimed sands surface after steam leaching in 50 min is as smooth as new sands.After 30 min of steam leaching,the alkali removal effect of the factory used sands can reach 81.5%,the water consumption by the steam leaching reclamation is 58%of the mass of the used sand,which is similar to the result of simulated used sands.The performance of reclaimed sands obtained after 30 min steam leaching is better than that of new sands when the amount of sodium silicate added is 6%of the mass of the reclaimed sands and the CO_(2) blowing time is 15 s:the 24 h ultimate compressive strength of reclaimed sands is 5.6 MPa(equated with new sands),and the collapsibility compressive strength is 5.2 MPa,which is lower than the collapsibility compressive strength of new sands(7.7 MPa).This indicates that the reclamation of CO_(2) sodium silicate used sands by steam leaching is a feasible method. 展开更多
关键词 sodium silicate sands steam leaching simulated temperature RECLAMATION
下载PDF
Leaching kinetics of selenium from selenium-tellurium-rich materials in sodium sulfite solutions 被引量:18
3
作者 郑雅杰 陈昆昆 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第2期536-543,共8页
The leaching kinetics of selenium from selenium-tellurium-rich materials in sodium sulfite solutions was studied. The morphologies of selenium-tellurium-rich materials are mainly spheroid and columnar bodies and the r... The leaching kinetics of selenium from selenium-tellurium-rich materials in sodium sulfite solutions was studied. The morphologies of selenium-tellurium-rich materials are mainly spheroid and columnar bodies and the range of particle size of selenium-tellurium-rich materials is between 17.77μm and 56.58μm, which contain 41.73%selenium and 40.96%tellurium. The ranges of experimental elements are 126-315 g/L of sodium sulfite concentration, 100-400 r/min of agitation speed, 23-95 ℃ of reaction temperature, 7:1-14:1 of liquid-solid ratio and 17.77-56.58μm of average particle size. The results show that the leaching rate increases with increasing the sodium sulfite concentration, agitation speed, reaction temperature or liquid-solid ratio and the leaching rate decreases with increasing the particle size. The reaction temperature has the significant effects on the selenium leaching rate which increases from 21%to 67%with increasing temperature from 23 ℃ to 95 ℃. The experimental data agree quite well with the Avrami model for leaching, with model parameter of 0.235 and apparent activation energy of 20.847 kJ/mol. 展开更多
关键词 SELENIUM TELLURIUM sodium sulfite leaching kinetics
下载PDF
Leaching kinetics of scheelite concentrate with sodium hydroxide in the presence of phosphate 被引量:7
4
作者 Ting-ting LI Yan-bai SHEN +5 位作者 Si-kai ZHAO Yao-yu YIN Rui LU Shu-ling GAO Cong HAN De-zhou WEI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第3期634-640,共7页
The reaction kinetics for the leaching of low-grade scheelite concentrate was investigated in an autoclave with sodium hydroxide in the presence of phosphate. The effects of stirring speed (300-600 r/min), reaction te... The reaction kinetics for the leaching of low-grade scheelite concentrate was investigated in an autoclave with sodium hydroxide in the presence of phosphate. The effects of stirring speed (300-600 r/min), reaction temperature (353-383 K), sodium hydroxide concentration (1.69-6.76 mol/L) and phosphate concentration (0.68-1.69 mol/L) on the WO3 dissolution ratio were studied. The results showed that the WO3 dissolution ratio was practically independent of stirring speed, while it increased with increasing the reaction temperature, and the concentrations of sodium hydroxide and phosphate. The experimental data were consistent with the shrinking core model, with a surface chemical reaction as the leaching rate-determining step. The apparent activation energy was calculated as 49.56 kJ/mol, and the reaction orders with respect to the concentrations of sodium hydroxide and phosphate were determined as 0.27 and 0.67, respectively. The kinetics equation of the leaching process was established. 展开更多
关键词 KINETICS leaching sodium hydroxide PHOSPHATE SCHEELITE
下载PDF
Enhancing the leaching effect of an ion-absorbed rare earth ore by ameliorating the seepage effect with sodium dodecyl sulfate surfactant 被引量:13
5
作者 Yongbing Zhang Boyuan Zhang +3 位作者 Siqi Yang Zhigang Zhong Hepeng Zhou Xianping Luo 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2021年第6期995-1002,共8页
Ameliorating the problem of low leaching efficiency,long leaching period,and high agent consumption should be studied to efficiently exploit ion-absorbed rare earth ore resources.In this study,the surfactant sodium do... Ameliorating the problem of low leaching efficiency,long leaching period,and high agent consumption should be studied to efficiently exploit ion-absorbed rare earth ore resources.In this study,the surfactant sodium dodecyl sulfate(SDS) is used to enhance the leaching effect of an ion-absorbed rare earth ore by ameliorating the seepage effect for the first time.The effects of surfactant concentration,leaching agent dosage,solution flow velocity,and solution pH on the leaching rate were explored,and the mechanism of SDS was discussed.Under the optimum conditions,the addition of a small amount of SDS(mass fraction0.04%) can increase the leaching rate by about 5%,shorten the leaching period,and reduce the consumption of the leaching agent.SDS significantly ameliorates the seepage effect of the ore body by reducing the surface tension of the leaching agent and ameliorating the wettability of the mineral surface.This effect is the main factor that improves the leaching efficiency.DFT(density functional theory) calculation results show that SDS can react with rare earth ions,which reduces the adsorption strength on clay mineral surfaces.Hence,rare earth ions are easily exchanged by ammonium ions,and mass transfer is enhanced. 展开更多
关键词 Ion-absorbed rare earth ore SURFACTANT sodium dodecyl sulfate leaching Seepage effect ADSORPTION
下载PDF
Microemulsion leaching of vanadium from sodium-roasted vanadium slag by fusion of leaching and extraction processes 被引量:8
6
作者 Yun Guo Hong-yi Li +4 位作者 Yi-heng Yuan Jie Huang Jiang Diao Gang Li Bing Xie 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2021年第6期974-980,共7页
The fusion of the leaching and purification processes was realized by directly using microemulsion as the leaching agent.The bis-(2-ethyhexyl)phosphoric acid(DEHPA)/n-heptane/NaOH microemulsion system was established ... The fusion of the leaching and purification processes was realized by directly using microemulsion as the leaching agent.The bis-(2-ethyhexyl)phosphoric acid(DEHPA)/n-heptane/NaOH microemulsion system was established to directly leach vanadates from sodium-roasted vanadium slag.The effect of the leaching agent on the leaching efficiency was investigated,in addition to the molar ratio of H_(2)O/NaDEHP(W),DEHPA concentration,solid/liquid ratio,stirring time,and leaching temperature.In optimal situations,the vanadium leaching efficiency reaches 79.57%.The X-ray diffraction characterization of the leaching residue and the Raman spectrum of the microemulsion before and after leaching demonstrate the successful entry of vanadates from the sodium-roasted vanadium slag into the microemulsion.The proposed method successfully realizes the leaching and purification of vanadates in one step,thereby greatly reducing production costs and environmental pollution.It also offers a new way to achieve the green recovery of valuable metals from solid resources. 展开更多
关键词 vanadium slag sodium roasting clinker microemulsion leaching extraction
下载PDF
Kinetics and leaching behaviors of aluminum from pharmaceutical blisters in sodium hydroxide solution 被引量:2
7
作者 王重庆 王晖 +2 位作者 顾帼华 符剑刚 刘又年 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第12期4545-4550,共6页
A hydrometallurgical process was developed for recycling pharmaceutical blisters.Leaching aluminum from pharmaceutical blisters using sodium hydroxide(NaOH) solutions was investigated with respect to leaching behavior... A hydrometallurgical process was developed for recycling pharmaceutical blisters.Leaching aluminum from pharmaceutical blisters using sodium hydroxide(NaOH) solutions was investigated with respect to leaching behaviors and kinetics.AL9(34) orthogonal design of experiments suggests that the most significant factor is NaOH concentration followed by temperature and leaching time.Factorial experiments demonstrate that the leaching rate of aluminum increases with increasing of the factors.The optimum conditions are temperature of 70 °C,leaching time of 20 min,NaOH concentration of 1.25 mol/L,liquid-to-solid mass ratio of 15:1 and agitation speed of 400 r/min.Under optimum conditions,the leaching rate is up to 100%,implying that aluminum and polyvinyl chloride(PVC) plastic in pharmaceutical blisters are separated completely.Kinetics of leaching aluminum is best described by the product layer diffusion control model,and the activation energy is calculated to be 19.26 kJ/mol. 展开更多
关键词 ALUMINUM KINETICS leaching behavior pharmaceutical blisters sodium hydroxide
下载PDF
Sodium sulfide leaching of low-grade jamesonite concentrate in production of sodium pyroantimoniate 被引量:5
8
作者 杨天足 江名喜 +1 位作者 赖琼琳 陈进中 《Journal of Central South University of Technology》 2005年第3期290-294,共5页
Sodium sulfide leaching of a low-grade jamesonite concentrate in the production of sodium pyroantimoniate through the air oxidation process and the influencing factors on the leaching rate of antimony were investigate... Sodium sulfide leaching of a low-grade jamesonite concentrate in the production of sodium pyroantimoniate through the air oxidation process and the influencing factors on the leaching rate of antimony were investigated. In order to decrease the consumption of sodium sulfide and increase the concentration of antimony in the leaching solution, two-stage leaching of jamesonite concentrate and combination leaching of high-grade stibnite concentrate and jamesonite concentrate were used. The experimental results show that the consumptions of sodium sulfide for the two-stage leaching process and the combination leaching process are decreased by 20% and 60% compared to those of one-stage leaching process respectively. The final concentrations of antimony in the leaching solutions of both processes are above 100g/L. 展开更多
关键词 sodium sulfide jamesonite concentrate leaching LOW-GRADE
下载PDF
Gold-leaching performance and mechanism of sodium dicyanamide 被引量:2
9
作者 Gen-zhuang Li Jue Kou +4 位作者 Yi Xing Yang Hu Wei Han Zi-yuan Liu Chun-bao Sun 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2021年第11期1759-1768,共10页
In this work,sodium dicyanamide(SD)was used as a leaching reagent for gold recovery,and the effects of the SD dosage and solution pH on the gold-leaching performance were investigated.A gold recovery of 34.8%was obtai... In this work,sodium dicyanamide(SD)was used as a leaching reagent for gold recovery,and the effects of the SD dosage and solution pH on the gold-leaching performance were investigated.A gold recovery of 34.8%was obtained when SD was used as the sole leaching reagent at a dosage of 15 kg/t.In the presence of a certain amount of potassium ferrocyanide(PF)in the SD solution,the gold recovery was found to increase from 34.8%to 57.08%.Using the quartz crystal microbalance with dissipation(QCM-D)technique,the leaching kinetics of SD with and without PF were studied.The QCM-D results indicate that the gold-leaching rate increased from 4.03 to 39.99 ng·cm^(–2)·min^(–1) when the SD concentration was increased from 0 to 0.17 mol/L,and increased from 39.99 to 272.62 ng·cm^(–2)·min^(–1) when 0.1 mol/L of PF was used in combination with SD.The pregnant solution in the leaching tests was characterized by X-ray photoelectron spectroscopy and electrospray mass spectrometry,which indicated that Au and(N(CN)2)–in the SD solution formed a series of metal complex ions,[AuNax(N(CN)2)x+2]–(x=1,2,3,or 4). 展开更多
关键词 gold leaching sodium dicyanamide QCM-D leaching kinetics potassium ferrocyanide
下载PDF
Study on Mechanism of Gold Leaching by Thiourea in the Presence of Sodium Sulphite 被引量:1
10
作者 HU Yue-hua GUO Guang-fa QIU Guan-zhou 《Journal of Central South University》 SCIE EI CAS 2000年第3期113-116,共4页
The linear potential sweep voltammetry and electrochemical methods were used to study the mechanism and kinetics of gold dissolution in thiourea solution in the absence and presence of sodium sulphite.The results show... The linear potential sweep voltammetry and electrochemical methods were used to study the mechanism and kinetics of gold dissolution in thiourea solution in the absence and presence of sodium sulphite.The results show that in the absence of sodium sulfite the dissolution rate of gold in thiourea solution is relatively slow and it increases with the increase of the concentration of thiourea and decreases with pH. Thiourea is easily oxidized to formamidine disulphide, which reduces the leaching efficiency and increases reagent consumption. In the presence of sodium sulphite, the effective concentration of thiourea is increased and the dissolution rate of gold in thiourea solution is greatly increased. The activation energy required for gold dissolution in thiourea solution with sodium sulphite is 20.9 kJ·mol -1 which is much lower than 55.0 kJ·mol -1 in the absence of sodium sulphite. It is evident that sodium sulphite has a significant effect on the electrochemical reaction kinetics of gold in thiourea solution. 展开更多
关键词 GOLD leaching THIOUREA sodium SULPHITE MECHANISM
下载PDF
Enhanced extraction of scandium and inhibiting of iron from acid leaching solution of red mud by D2EHPA and sodium chloride 被引量:3
11
作者 LIWang LIU Yue ZHU Xiao-bo 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第10期3029-3039,共11页
D2EHPA(P204),tri-butyl-phosphate(TBP)and sodium chloride(NaCl)were attractive for selective extraction of scandium from acid leaching solution of red mud.The extraction parameters of P204 concentration(X_(P204)),NaCl ... D2EHPA(P204),tri-butyl-phosphate(TBP)and sodium chloride(NaCl)were attractive for selective extraction of scandium from acid leaching solution of red mud.The extraction parameters of P204 concentration(X_(P204)),NaCl concentration(C_(NaCl)),pH value,reaction time,stirring speed and O/A were investigated to extract scandium and separate iron from the acid leaching solution.The extraction mechanism was analyzed by Fourier transform infrared spectroscopy(FT-IR)and thermodynamic theory.The single-stage extraction efficiency of scandium,iron andβ(Sc/Fe)were 99.1%,9.4%and 1061.2,respectively,with C_(NaCl) of 75 g/L and XP204 of 0.75 at solution pH value of 1.2 and stirring speed of 200 r/min for 6 min,in which a good separation effect of scandium and iron was obtained.The vibration absorption peak Sc─O was contributed to the extraction of scandium with P204.The complex[FeCln]^(3−n) existed in the solution with adding NaCl into the acid leaching solution.The value of n was higher and the valence state of the complex[FeCln]^(3−n) was lower with an increase of chloride concentration,which restricts the extraction efficiency of iron with P204.The extraction of three stages in the counter-current simulation experiments was carried out according to the McCabe-Thiele diagram.Gibbs free energy change(ΔG)of−5.93 kJ/mol,enthalpy change(ΔH)of 23.45 kJ/mol and entropy change(ΔH)of 98.54 J/(mol·K)were obtained in the solvent extraction proces,which indicate that the extraction reaction is easily spontaneous and endothermic and a proper increase of temperature is conducive to the extraction of scandium. 展开更多
关键词 SCANDIUM selective extraction D2EHPA/sodium chloride leaching solution red mud
下载PDF
Molybdenum removal from copper ore concentrate by sodium hypochlorite leaching 被引量:7
12
作者 Liu Youcai Zhong Hong Cao Zhanfang 《Mining Science and Technology》 EI CAS 2011年第1期61-64,共4页
The removal of molybdenum from a copper ore concentrate by sodium hypochlorite leaching was investigated. The results show that leaching time,liquid to solid ratio,leaching temperature,agitation speed,and sodium hypoc... The removal of molybdenum from a copper ore concentrate by sodium hypochlorite leaching was investigated. The results show that leaching time,liquid to solid ratio,leaching temperature,agitation speed,and sodium hypochlorite and sodium hydroxide concentrations all have a significant effect on the removal of molybdenum.The optimum process operating parameters were found to be:time,4 h;sodium hydroxide concentration,10%;sodium hypochlorite concentration,8%;liquid to solid ratio,10:1;temperature,50℃;and, agitation speed,500 r/min.Under these conditions the extraction of molybdenum is greater than 99,9%and the extraction of copper is less than 0.01%.A shrinking particle model could be used to describe the leaching process.The apparent activation energy of the dissolution reaction was found to be approximately 8.8 kJ/mol. 展开更多
关键词 Wet leaching Copper concentrate MolybdenumKinetic sodium hypochlorite
下载PDF
Leaching kinetics of molybdenum from Ni-Mo ore in sulfuric acid solution with sodium peroxodisulfate as oxidant 被引量:3
13
作者 刘志雄 尹周澜 +1 位作者 陈义光 熊利芝 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第3期874-879,共6页
The leaching kinetics of molybdenum from Ni-Mo ore in sulfuric acid solution with sodium peroxodisulfate was studied.The effects including leaching temperature, reaction time, particle size, stirring speed, and concen... The leaching kinetics of molybdenum from Ni-Mo ore in sulfuric acid solution with sodium peroxodisulfate was studied.The effects including leaching temperature, reaction time, particle size, stirring speed, and concentrations of sulfuric acid and sodium peroxodisulfate were investigated. The leaching process of molybdenum from Ni-Mo ore is controlled by the chemical reaction through the solid layer across the unreacted shrinking core. The apparent activation energy of the leaching of molybdenum is calculated to be 41.0 k J/mol and the leaching kinetics equation of molybdenum from Ni-Mo ore is expressed as1-(1-a)1/3=3405.7exp[-41030.0/(RT)]t. 展开更多
关键词 Ni-Mo ore leaching kinetics molybdenum oxidant sodium peroxodisulfate
下载PDF
Leaching of vanadium,sodium,and silicon from molten V?Ti-bearing slag obtained from low-grade vanadium-bearing titanomagnetite 被引量:1
14
作者 Yuan-yuan Zhu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2016年第8期898-905,共8页
The water leaching process of vanadium, sodium, and silicon from molten vanadium-titanium-bearing(V-Ti-bearing) slag obtained from low-grade vanadium-bearing titanomagnetite was investigated systematically. The resu... The water leaching process of vanadium, sodium, and silicon from molten vanadium-titanium-bearing(V-Ti-bearing) slag obtained from low-grade vanadium-bearing titanomagnetite was investigated systematically. The results show that calcium titanate, sodium aluminosilicate, sodium oxide, silicon dioxide and sodium vanadate are the major components of the molten V-Ti-bearing slag. The experimental results indicate that the liquid-solid(L/S) mass ratio significantly affects the leaching process because of the respective solubilities and diffusion rates of the components. A total of 83.8% of vanadium, 72.8% of sodium, and 16.1% of silicon can be leached out via a triple counter-current leaching process under the optimal conditions of a particle size below 0.074 mm, a temperature of 90°C, a leaching time of 20 min, an L/S mass ratio of 4:1, and a stirring speed of 300 r/min. The kinetics of vanadium leaching is well described by an internal diffusion-controlled model and the apparent activation energy is 11.1 kJ/mol. The leaching mechanism of vanadium was also analyzed. 展开更多
关键词 titanomagnetite vanadium metallurgy leaching kinetics sodium silicon leaching rate
下载PDF
Leaching kinetics of low-grade copper ore containing calcium-magnesium carbonate in ammonia-ammonium sulfate solution with persulfate 被引量:20
15
作者 刘志雄 尹周澜 +1 位作者 胡慧萍 陈启元 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第11期2822-2830,共9页
The leaching kinetics of copper from low-grade copper ore was investigated in ammonia-ammonium sulfate solution with sodium persulfate. The effect parameters of stirring speed, temperature, particle size, concentratio... The leaching kinetics of copper from low-grade copper ore was investigated in ammonia-ammonium sulfate solution with sodium persulfate. The effect parameters of stirring speed, temperature, particle size, concentrations of ammonia, ammonium sulfate and sodium persulfate were determined. The results show that the leaching rate is nearly independent of agitation above 300 r/min and increases with the increase of temperature, concentrations of ammonia, ammonium sulfate and sodium persulfate. The EDS analysis and phase quantitative analysis of the residues indicate that bornite can be dissolved by persulfate oxidization. The leaching kinetics with activation energy of 22.91 kJ/mol was analyzed by using a new shrinking core model (SCM) in which both the interfacial transfer and diffusion across the product layer affect the leaching rate. A semi-empirical rate equation was obtained to describe the leaching process and the empirical reaction orders with respect to the concentrations of ammonia, ammonium sulfate and sodium persulfate are 0.5, 1.2 and 0.5, respectively. 展开更多
关键词 low-grade copper ore calcium-magnesium carbonate leaching kinetics ammoniacal solution sodium persulfate activation energy shrinking cure model
下载PDF
Oxidative leaching behavior of metalliferous black shale in acidic solution using persulfate as oxidant 被引量:5
16
作者 刘志雄 向延鸿 +4 位作者 尹周澜 吴贤文 蒋剑波 陈义光 熊利芝 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第2期565-574,共10页
The oxidative dissolution of metalliferous black shale in sulfuric acid solution using sodium persulfate as an oxidant was investigated. The effects of leaching factors including leaching temperature, leaching time, s... The oxidative dissolution of metalliferous black shale in sulfuric acid solution using sodium persulfate as an oxidant was investigated. The effects of leaching factors including leaching temperature, leaching time, stirring speed, initial concentration of sodium persulfate and sulfuric acid and particle size on the leaching rate were studied as well. The leaching kinetics of molybdenum, nickel and iron from metalliferous black shale shows that the leaching rate is controlled by a chemical reaction through a layer on the unreacted shrinking core. The leaching process follows the kinetics model 1-(1-a)^1/3=kt with apparent activation energies of 34.50, 43.14 and 71.79 kJ/mol for Mo, Ni and Fe, respectively. The reaction orders in sodium persulfate are 0.80, 1.01 and 0.75 for molybdenum, nickel and iron, respectively, while in sulfuric acid, these orders are 0.45, 0.75 and 0.50 for molybdenum, nickel and iron, respectively. In addition, the reaction mechanism for the dissolution of the metalliferous black shale was discussed. 展开更多
关键词 metalliferous black shale oxidative leaching KINETICS sodium persulfate
下载PDF
Molybdenite alkali fusion and leaching:reactions and mechanism 被引量:7
17
作者 Reza Ebrahimi-Kahrizsangi Mohammad Hasan Abbasi Ali Saidi 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2010年第2期127-131,共5页
The production of MoO3 from Sarcheshmeh molybdenite concentrate via a pyro-hydrometallurgical process was studied.The molybdenite concentrate and sodium carbonate were premixed and fused under air atmosphere.Then the ... The production of MoO3 from Sarcheshmeh molybdenite concentrate via a pyro-hydrometallurgical process was studied.The molybdenite concentrate and sodium carbonate were premixed and fused under air atmosphere.Then the fused products were leached in water and the dissolved molybdenum was recovered as ammonium molybdate.The ammonium molybdate was then calcined to produce mo-lybdic oxide.At the fusion stage,the effect of the mass ratio of carbonate to sulfide on the reaction products and the solubility of the products was investigated.The results show that during the fusion,sodium molybdate and sodium sulfate are the final reaction products and sodium sulfide is detected as an intermediate reaction product.By melting at 850℃with 5wt%excess carbonate,the maximum solubility of the products is obtained.The molybdenum is recovered from the solutions as ammonium molybdate. 展开更多
关键词 MOLYBDENITE alkali fusion leaching sodium molybdate molybdic oxide
下载PDF
Process for recycle of spent lithium iron phosphate battery via a selective leaching-precipitation method 被引量:23
18
作者 LI Hao-yu YE Hua +1 位作者 SUN Ming-cang CHEN Wu-jie 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第11期3239-3248,共10页
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
关键词 lithium iron phosphate batteries selective leaching RECOVERY sodium persulfate lithium carbonate
下载PDF
ONE-STEP LEACHING OF SOME REFRACTORY GOLD CONCENTRATECONTAINING ARSENIC AND THEORY ANALYSIS 被引量:2
19
作者 Mao Anzhang Qiu Guanzhou +2 位作者 Deng Zhenling Shi Xichang Xu Jing (Department of Mineral Engineering, Central South University of Technology. Changsha 410083, China)Wang Dianzuo (Beijing General Research Institute for Nonferrous Metals, Beijing 100088) 《Journal of Central South University》 SCIE EI CAS 1997年第2期92-95,共4页
A new technology of one-step leaching of refractory gold concentrate containing arsenic and sulfur was studied and 96. 8% of gold was extracted in an hour by this technology. Themodynamic possibility of reactions of a... A new technology of one-step leaching of refractory gold concentrate containing arsenic and sulfur was studied and 96. 8% of gold was extracted in an hour by this technology. Themodynamic possibility of reactions of arsenopyrite. pyrite and gold with sodium hypochlorite in NaOH medium, and solution chemistry of H3AuO3 at different pH values were analyzed. The reason why the gold wrapped by FeAsS, FeS2 can be leached out rapidly by grnding of porcelain ball mill. is explained. 展开更多
关键词 REFRACTORY GOLD concentate sodium HYPOCHLORITE ONE-STEP leaching of GOLD
下载PDF
Pressure leaching of bismuth sulfide concentrate containing molybdenum and tungsten in alkaline solution 被引量:3
20
作者 张杜超 杨天足 +1 位作者 刘伟锋 吴江华 《Journal of Central South University》 SCIE EI CAS 2012年第12期3390-3395,共6页
The leaching results of bismuth sulfide concentrate containing molybdenum and tungsten in air-H2O2-NaOH system, pressure-O2-Na2CO3 system and pressure-O2-NaOH system were investigated. The results show that the extrac... The leaching results of bismuth sulfide concentrate containing molybdenum and tungsten in air-H2O2-NaOH system, pressure-O2-Na2CO3 system and pressure-O2-NaOH system were investigated. The results show that the extraction of molybdenum, tungsten and sulfur goes up with the increase of NaOH concentration, oxygen partial pressure and reaction time. The extraction of molybdenum and tungsten also rises up with temperature, but the leaching ratio of sulfur increases initially to a peak of 98% at 150℃ and then decreases with the increase of temperature. Under the optimal conditions, the extraction of molybdenum, tungsten and sulfur is more than 95.6%, 93.8% and 96.0%, respectively, and the main phases of residue are Bi2O3 and Fe2O3. Therefore, the method of pressure leaching in alkaline solution is provided as an effective separation of molybdenum, tungsten and sulfur from bismuth and a beneficial pretreatment for consequent process. 展开更多
关键词 bismuth sulfide concentrate MOLYBDENUM TUNGSTEN pressure leaching sodium hydroxide
下载PDF
上一页 1 2 25 下一页 到第
使用帮助 返回顶部