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Removal of impurities from scandium chloride solution using 732-type resin

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Journal of rare Earths 2018年第3期36卷 311-316页

作者： Guotao Zhou Qinggang Li Pan Sun Wenjuan Guan Guiqing Zhang Zuoying Cao Li Zeng School of metallurgy and Environment Central South UniversityChangsha 410083China key laboratory of hunan province for metallurgy and material processing of rare metals Changsha 410083China

The deep removal of Al, Fe（Ⅱ/Ⅲ）, Ca, Zr, Ti and Si from scandium chloride solution was carried out by using 732-type strong acid cation exchange resin. The effects of pH value, contact time and complexing agents（EDTA） on the purification process are investigated. The results indicate that the 732-type resin have a good scandium selectivity and the adsorption order is Sc 〉 Fe（Ⅲ）〉Al 〉 Ca 〉 Zr 〉 Ti 〉 Si in the pH range of 1-3. The separation of Sc and Zr, Si, Ti can be directly carried out because the resin have a good adsorption effect on Sc, AI and Fe（Ⅲ） but poor adsorption effect on Zr, Si and Ti under the condition of pH = 2.5 and contact time 180 min. The Fe（Ⅱ）, Ca and Al are selectively adsorbed on the resin by adding reducing agent ascorbic acid and EDTA into the solution for reducing Fe（Ⅲ） to Fe（Ⅱ） and complexing *** using two-step ion exchange adsorption separation method, the removal rates of Fe（Ⅲ）, Ti, Al, Ca, Zr and Si are 95.5%,99.8%,100%,98.2%,98.6% and 100%,respectively.

关键词： Scandium Ion exchange Removal Impurity Reduction rare earths

Coordination leaching of tungsten from scheelite concentrate with phosphorus in nitric acid

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Journal of Central South University 2016年第6期23卷 1312-1317页

作者：张文娟杨金洪赵中伟王文强李江涛 School of metallurgy and Environment Central South University Changsha 410083 China key laboratory of hunan province for metallurgy and material processing of rare metals Changsha 410083 China

A hydrometallurgical process for tungsten extraction and recovery from scheelite is *** technology includes leaching scheelite using phosphoric acid as chelating agent in nitric acid solutions,extracting tungsten by solvent extraction and reusing leaching *** the leaching process,affecting factors,such as temperature,leaching time,nitric acid and dosage of phosphoric acid,were examined on recovery of *** show that more than 97%of tungsten could be extracted under conditions of leaching temperature of 80-90°C,HNO3 concentration of 3.0-4.0 mol/L,liquild-to-soild ratio of 10:1,H3PO4 dosage of 3 stoichiometric ratio and leaching time of 3 *** extraction was then employed for the W recovery from the leachate with a organic system of 40%(v/v)N235,30%(v/v)TBP,and 30%sulfonated *** 99.93%of W was extracted and ammonium tungstate solution containing 193 g/L W was obtained with a stripping rate of 98.10%under the optimized conditions.

关键词： scheelite nitric acid phosphoric acid coordination leaching

Efficient recovery of tungsten from scheelite concentrates using a sulfur-phosphorus mixed acid leaching system

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Tungsten 2024年第4期6卷 821-832页

作者： Jiang-Tao Li Li-Li Gao Zhong-Wei Zhao Xu-Heng Liu Xing-Yu Chen School of metallurgy and Environment Central South UniversityChangsha410083China key laboratory of hunan province for metallurgy and material processing of rare metals Changsha410083China

In recent years,a new process for leaching scheelite concentrates with sulfur-phosphorus mixed acid has been successfully *** process suffers from the elimination of the retarding effect of calcium sulfate,the selective extraction of tungsten from the H_(3)PW_(12)O_(40)-H_(2)SO_(4)-H_(3)PO_(4)mixture solution,and the removal of introduced ***,in this paper,we investigated the inhibition measures of a calcium sulfate-blocking membrane,the selective extraction of tungsten by ion exchange,and the removal of phosphorus by the magnesium ammonium salt *** results showed that the addition of calcium sulfate whisker seeds and a higher H_(3)PO_(4)concentration inhibited spontaneous diffuse nucleation,promoted crystal growth,and avoided the formation of a dense blocking *** 98 wt.%of the scheelite concentrate was digested by H_(2)SO_(4)-H_(3)PO_(4).The selective adsorption of PW_(12)O_(40)^(3-)was realized using D301 resin,and the extraction efficiency of tungsten exceeded 99.9%.After desorption with ammonia water,PW_(12)O_(40)^(3-)was depolymerized into WO_(4)^(2-)and PO_(4)^(3-).99.9 wt.%of phosphorus was removed in the form of MgNH_(4)PO_(4)by the magnesium ammonium salt method,and the residual phosphorus concentration in the solution was lower than 10 mg·L^(-1).After purification,the highest-grade ammonium paratungstate product was prepared by evaporative crystallization.

关键词： Scheelite concentrates Sulfur-phosphorus mixed acid Calcium sulfate Ion exchange Tungsten

(Ca(OH)_(2)-)NaOH-Na_(2)WO_(4)-H2O和(Ca(OH)_(2)-)NaOH-Na_(3)PO_(4)-H_(2)O体系的热力学与应用

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Journal of Central South University 2023年第4期30卷 1132-1144页

作者：吕世杰李江涛刘旭恒陈星宇何利华孙丰龙赵中伟 School of metallurgy and Environment Central South UniversityChangsha 410083China key laboratory of hunan province for metallurgy and material processing of rare metals Changsha 410083China

白钨矿(CaWO_(4))碱压煮工艺是我国主流的钨冶炼工艺。但是,该工艺的机理仍不是很明确。本文利用相平衡原理,开展了白钨矿浸出过程、浸出渣洗涤过程、浸出液蒸发结晶过程中的热力学研究。根据浸出热力学平衡相图的分析,发现白钨矿中的... 详细信息

白钨矿(CaWO_(4))碱压煮工艺是我国主流的钨冶炼工艺。但是,该工艺的机理仍不是很明确。本文利用相平衡原理,开展了白钨矿浸出过程、浸出渣洗涤过程、浸出液蒸发结晶过程中的热力学研究。根据浸出热力学平衡相图的分析,发现白钨矿中的钙对杂质的浸出有抑制作用(以磷为例),合理地解释了浸出液中磷等杂质始终维持在较低水平的主要原因。在浸出渣稀释-溶解钨酸钠晶体的过程中,利用热力学平衡相图解释了添加磷酸钠作为抑制剂,抑制二次白钨生成的作用机理,并优化了磷酸钠用量、反应时间、反应温度等对逆反应有抑制效果的工艺参数。在钨酸钠浸出液蒸发结晶钨碱分离过程中添加Ca(OH)_(2),在回收利用余碱的同时,还可实现溶液中杂质磷的脱除。该过程的热力学平衡相图表明,蒸发结晶结束区域是Ca_(5)(PO_(4))_(3)OH的稳定区,而CaWO_(4)不稳定,说明了Ca(OH)_(2)的加入不会影响钨的损失。实验结果表明,在蒸发结晶开始时加入理论量的Ca(OH)_(2),可以去除90%的磷,钨的损失率控制在0.2%以下。

关键词： NaOH分解白钨矿赝三元相图蒸发结晶除磷

Research and development trends of hydrometallurgy:An overview based on Hydrometallurgy literature from 1975 to 2019

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Transactions of Nonferrous metals Society of China 2020年第11期30卷 3147-3160页

作者： Li-pan JIA Jiang-jiang HUANG Ze-long MA Xu-heng LIU Xing-yu CHEN Jiang-tao LI Li-hua HE Zhong-wei ZHAO School of metallurgy and Environment Central South UniversityChangsha 410083China hunan key laboratory for metallurgy and material processing of rare metals Changsha 410083China

Modern hydrometallurgy has been developing for more than 100 years and the related articles keep piling *** on a bibliometric analysis of the articles in Hydrometallurgy,the most authoritative journal in the field of hydrometallurgy,we try to catch the research and development trends from a global ***,keywords burstness shows that rare earth,recycling,lithium,ionic liquid,and thorium are the hotspots in recent years,and the economic and technological reasons behind them were discussed in ***,the proportion of biohydrometallurgy grows fast from 5%to 13%and the related articles are almost all about *** are some new directions such as direct preparation of materials in hydrometallurgical processes and ion-imprinted ***,the advanced instrument analysis methods such as XAFS(X-ray absorption fine structure),gene sequencing,and micro-CT promote the deep understanding of hydrometallurgy ***,the cooperation network and contribution of the main institutes were mapped.

关键词： development trends leaching solvent extraction biohydrometallurgy electro-hydrometallurgy CiteSpace

Mathematical model and reaction mechanism of molybdenum and tungsten extraction with TRPO from peroxide solution

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Transactions of Nonferrous metals Society of China 2022年第9期32卷 3123-3135页

作者： Xin-bing XIA Gui-qing ZHANG Wen-juan GUAN Li ZENG Sheng-xi WU Qing-gang LI Zuo-ying CAO School of metallurgy and Environment Central South UniversityChangsha 410083China key laboratory of Metallurgical Separation Science and Engineering in Nonferrous Industry Central South UniversityChangsha 410083China key laboratory of hunan province for metallurgy and material processing of rare metals Changsha 410083China

To understand the behavior of molybdenum and tungsten extracted by tri-alkyl phosphine oxide(TRPO)from peroxide solution,the extraction mechanism was studied by slope method and Raman and FTIR *** empirical formulas of molybdenum and tungsten extraction distribution ratio(D_(Mo)and D_(W))as functions of equilibrium pH,TRPO concentration and temperature were obtained by establishing mathematical ***,the reliability of the empirical formula was verified in the H^(+)-W-Mo-H_(2)O_(2) *** results indicate that the calculated values of D_(Mo)or D_(W)were consistent with the experimental *** apparent extraction equilibrium constants of molybdenum and tungsten wereK_(Mo)^(app)=8.51×10^(3)(0.74≤pH_(e)≤1.7),K_(Mo)^(app)=99.89×10^(3)(1.7

关键词： tungsten molybdenum solvent extraction tri-alkyl phosphine oxide(TRPO) hydrogen peroxide(H_(2)O_(2))

Synthesis and electrochemical properties of Li[Ni_xCo_yMn_(1-x-y)]O_2 (x, y = 2/8, 3/8) cathode materials for lithium ion batteries

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rare metals 2009年第1期28卷 43-48页

作者： HU Chuanyue LI Zheng GUO Jun DU Yong WANG Xingyan LIU Xin YI Tao State key laboratory of Powder metallurgy Central South University Changsha 410083 China Department of Chemistry and material Science Hunan Institute of Humanities Science and Technology Loudi 410007 China

The tmiform layered Li（Ni2/8Co3/8Mn3/8）O2, Li（Ni3/8Co2/8Mn3/8）O2, and Li（Ni3/8Co3/8Mn2/8）O2 cathode materials for lithium ion batteries were prepared using the hydroxide co-precipitation method. The effects of calcination temperature and transition metal contents on the structure and electrochemical properties of the Li-Ni-Co-Mn-O were systemically studied. The results of XRD and electrochemical performance measurement show that the ideal preparation conditions were to prepare the Li（Ni3/8Co3/8Mn2/8）O2 cathode material calcined at 900℃ for 10 h. The well-ordered Li（Ni3/8Co3/8Mn2/8）O2 synthesized under the optimal conditions has the I003/I104 ratio of 1.25 and the R value of 0.48 and delivers the initial discharge capacity of 172.9 mA·h·g^-1, the discharge capacity of 166.2 mA·h·g^-1 after 20 cycles at 0.2C rate, and the impedance of 558 Ω after the first cycle. The decrease of Ni content results in the decrease of discharge capacity and the bad cycling performance of the Li-Ni-Co-Mn-O cathode materials, but the decreases of Mn content and Co content to a certain extent can improve the electrochemical properties of the Li-Ni-Co-Mn-O cathode materials.

关键词： lithium ion batteries cathode material electrochemical properties hydroxide co-precipitation method

3D nitrogen and boron dual-doped carbon quantum dots/reduced graphene oxide aerogel for advanced aqueous and flexible quasi-solid-state zinc-ion hybrid capacitors

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rare metals 2023年第7期42卷 2307-2323页

作者： Jun-Jun Yao Chang Liu Jing-Ying Li Zhong-Liang Hu Ru-Yi Zhou Chen-Chen Guo Xin-Ru Liu Fei-Fan Yang Yi-Rong Zhu hunan key laboratory of Green metallurgy and New Energy materials College of Materials and Advanced ManufacturingHunan University of TechnologyZhuzhou412007China School of Chemistry and Chemical Engineering Hunan Institute of EngineeringXiangtan411104China National&Local Joint Engineering Research Center for Advanced Packaging material and Technology Hunan University of TechnologyZhuzhou412007China

As prospective energy storage devices,zinc-ion hybrid capacitors(ZHCs)still suffer from unsatisfactory cathode ***,the three dimensional(3D)N,B dual-doped carbon quantum dots/reduced graphene oxide(N,B-CQDs/rGO)composite aerogel is prepared via a onepot hydrothermal *** to the synergism of CQDs modification and N,B dual-doping,the resultant N,B-CQDs/rGO composite aerogel delivers superior electrochemical ***,the as-obtained N,B-CQDs/rGO composite aerogel is served as a cathode for aqueous and flexible quasi-solid-state ZHCs for the first ***,the aqueous N,B-CQDs/rGO//Zn ZHC manifests a large energy density of 96.2 Wh·kg^(-1)at80 W·kg^(-1)and still remains a high energy density of 54.7Wh·kg^(-1)at a superb power density of 80 kW·kg^(-1).Meanwhile,kinetic analyses are employed to elucidate the prominent power performance,and various ex situ tests are undertaken to explore the energy storage mechanism of aqueous *** notably,the flexible quasi-solid-state N,B-CQDs/rGO//Zn ZHC displays a desirable energy density(89.1μWh·cm^(-2)),a superior power density(96,000μW·cm^(-2))and exceptional flexible *** present study offers a valuable reference for designing and developing advanced cathode materials for aqueous and flexible quasi-solid-state ZHCs.

关键词： Carbon quantum dots(CQDs) Graphene aerogel Heteroatom dual-doping Energy storage mechanism Zinc-ion hybrid capacitors(ZHCs)

A nanostructured Ni/T-Nb_(2)O_(5)@carbon nanofibers as a long-life anode material for lithium-ion batteries

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rare metals 2021年第2期40卷 374-382页

作者： Si-Ru He Jian-Peng Zou Li-Bao Chen Yue-Jiao Chen State key laboratory of Powder metallurgy Central South UniversityChangsha410083China

In this work,nickel/T-Nb_(2)O_(5)nanoparticles encapsulated in mesoporous carbon nanofibers(denoted as Ni/T-Nb_(2)O_(5)@CNFs)are successfully prepared through a simple electrospinning route and succedent heating *** presence of Ni in carbon nanofibers is beneficial for enhancing the electronic conductivity and the initial Coulombic ***/T-Nb_(2)O_(5)nanoparticles are homogeneously incorporated in carbon nanofibers to form a nanocomposite system,which provides effective buffering during the lithiation/delithiation process for cycling *** Ni/TNb_(2)O_(5)@CNFs show high surface area(26.321 m^(2)·g^(-1))and mesoporous microstructure,resulting in higher capacity and excellent rate *** Ni/T-Nb_(2)O_(5)@CNFs exhibit a remarkable capacity of 437 mAh·g^(-1)at a current density of0.5 A·g^(-1)after 230 cycles and a capacity of 173 mAh·g^(-1)at a current density up to 10.0 A·g^(-1)after 1400 *** work indicates that nickel/T-Nb_(2)O_(5)nanoparticles encapsulated in carbon nanofibers can be a promising candidate for anode material in high-power LIBs.

关键词： Electrospinning Nickel T-Nb_(2)O_(5) Nanofiber anode Lithium-ion batteries