A Review on the Separation of Niobium and Tantalum by Solvent Extraction

Niobium and tantalum are found together in natural minerals. Leaching with concentrated acid solution or alkaline roasting followed by water/dilute acid leaching results in a solution containing these two metals. In this work, we reviewed the extraction and separation of Nb(V) and Ta(V) from leach liquors in the absence and presence of hydrofluoric acid by acidic, neutral extractants and amines. Several solvent extraction systems were compared in the light of the requirement of hazardous chemicals, extraction/separation efficiency, and stability/solubility of extractants. Since the cationic species of Nb(V) and Ta(V) are unstable in the aqueous solution, the application of acidic extractants for extraction and separation of these metals is limited. Amines can extract Nb(V) as well as Ta(V) irrespective of the presence of fluoride ion but the separation of these metals from the loaded amines should be carried out in stripping process, resulting in process complexity. Another disadvantage encountered for amine is related to high viscosity in extraction process. Neutral extractants are considered as promising extractants which are effective to separate Ta(V) and Nb(V) from either non-fluoride or to moderate fluoride ion concentration in terms of extraction, separation and stripping efficiency. Compared to the traditional methyl iso-butyl ketone (MIBK) based system, methyl isoamyl ketone (MIAK) is found to be a promising extractant to separate Nb(V) and Ta(V).     

白云鄂博矿区富钾板岩中稀土铌矿物特征研究*

采用主要化学成分分析、自动矿物分析系统、偏反光显微镜、场发射扫描电镜、能谱仪等手段对白云鄂博矿区内富钾板岩化学成分、矿物组成以及稀土铌矿物特征等方面进行研究。结果显示，白云鄂博矿区内富钾板岩K2O含量高达13.15%，高SiO2富Al2O3，岩石主要由微斜长石与黑云母组成；富钾板岩中REO与Nb2O5含量分别为0.076%、0.012%，稀土、铌矿物含量低且粒度细小，形态产状多种多样，矿物共生组合与接触关系复杂，指示富钾板岩遭受了后期热液的蚀变改造作用。     

Microstructure and magnetostrictive performance of NbC-doped<100>oriented Fe-Ga alloys

The<100>oriented Fe83Ga17 alloy rods with various NbC contents less than 1at%were prepared by the directional solidification method at a growth rate of 720 mm?h?1. Low NbC-content was found to affect t...     

Influence of Nb5+ ions on phase transitions and polar disorder above TC in PbZrO3 studied by Raman spectroscopy

Micro-Raman light scattering experiments on PbZrO₃ (PZO) single crystal doped with Nb⁵⁺ have been investigated. Special attention was paid to the paraelectric (PE) phase in which nominally forbidden first-order Raman spectra were detected at temperatures far above the phase transition T_C. Complex Raman spectra were observed in the vicinity of three structural phase transitions. These results mainly from the coexistence of phases with different symmetries in a wide temperature range below T_C. The Raman measurements have been compared with dielectric and optical observations and proved that polar nanoregions in a centrosymmetric lattice appear well above T_C. It was shown that doping ABO₃ perovskites with heterovalent ions like Nb⁵⁺ unbalances charge neutrality of the lattice and strongly extends the temperature range of polar regions. The investigations performed point out that in the PE matrix the interaction between electrons and lattice vibrations, as recently suggested for pure PZO, plays an important role.     

Cr13系铸造马氏体不锈钢铌和碳的合理配比关系

 铌作为常用的微合金元素，常被用于细化晶粒、改善钢的强度与韧性，而在不锈钢中关于铌与碳化物质量分数的定量关系以及铌和碳的合理配比的研究工作尚不够深入。通过对不同铌质量分数的1Cr13与3Cr13马氏体不锈钢的组织、碳化物质量分数等进行观察和测量，总结出了比较合理的C-Nb关系式以及这两种元素对碳化物质量分数的影响的定量关系，并结合文献提出了铌元素对Cr13系列马氏体碳化物沉淀的影响原理。结果表明，铌会促进碳化物的沉淀并改变碳化物的成分（碳化物中出现铌元素），并且随着铌质量分数的增加，Cr13系列马氏体不锈钢中的碳化物都出现了指数型增长。得出Cr13系列马氏体不锈钢中碳化物的质量分数与碳和铌的质量分数存在指数型关系，同时合理的C-Nb关系配比呈线性。     

超细Nb_20_5粉末的研制

对采用均匀沉淀法制备陶瓷电容器级(平均粒径为0.1-0.2μm的超细粉末)Nb2O5粉末的最佳工艺条件进行了探讨,研究了均匀沉淀过程中,反应温度、沉淀终点pH值、反应物浓度、脱水剂和添加剂以及焙烧温度对Nb(OH)5粉体粒度分布及粒径的影响。利用TG-DTA、SEM、XRD、比表面积测试仪(BET)和CILAS粒度测试仪进行了测定,结果表明:当H2NbOF5浓度在0.2~0.4M时,以NH3·H2O作沉淀剂,用乙醇、丙酮等作脱水剂,所获沉淀在80~100℃干燥后,制备的Nb(OH)5粉体粒度均匀且分布窄,其平均粒径为0.07 μm,经700℃焙烧后,可制得粒度分布窄、团聚少、比表面积为14.44 m2/g、平均粒径为0.1 μm,且纯度>99.95%的陶瓷电容器级Nb2O5微粉体。该方法具有设备简单、工艺流程短、污染小,产品纯度高等特点。     

白云鄂博中贫氧化矿磁选新工艺综合回收铌的研究

根据铌矿物与其它有用矿物、脉石矿物的磁性差异,采用弱磁—强磁选工艺将包头白云鄂博中贫氧化矿中的铌有效地富集于强磁中矿。本文还介绍了从强磁中矿浮选回收铌的药剂制度及工艺条件,论述了浮选药剂的主要作用。采用强磁中矿直接浮选铌和强磁中矿先浮选稀土后浮选铌均取得较好指标,得到的铌精矿能满足高炉—转炉—电炉—电炉提铌工艺对原料的要求。     

白云鄂博矿床铌资源矿物学基本特征的分析

分析白云鄂博矿床铌资源的矿物学特征以及开发利用途径。白云鄂博矿床主矿、东矿矿体铌资源储量占白云鄂博矿床可利用的铌资源的80%,且铌矿物嵌布粒度细、共生关系复杂。以强磁中矿浮选稀土后的尾矿为原料,采用“反浮选浮铁浮铌强磁选”工艺,可以获得含Nb2O515%以上的铌精矿,从选矿主体流程中回收铌是可行性的。     

Niobium oxide-activated yttrium barium titanate nanorod structured ceramics for energy storage applications

Structure, morphology, and electrical properties of 10 mol% of Nb₂O₅-activated yttrium barium titanate (BT) Ba_(60-z)Ti_(40-x)Nb_zY_xO₃ (BTY₁₀Nb₁₀), barium titanate (BT), and 10 mol% of Y₂O₃-activated BT were explored with calcination and sintering temperatures of 1000°C at 8 h and 1200°C at 6 h, respectively. The thermogravimetric and differential scanning calorimetry (TG–DSC) analysis reported that the total weight loss and residual mass of BT at 1300°C were 16.8 and 83.2%, respectively. The X-ray diffraction (XRD) pattern confirmed that BTY₁₀Nb₁₀ ceramics containing the BaNbO₃ phase were developed. A Raman band of BT at 307 cm^–1 unveiled a blue shift slightly for BTY₁₀ to 298 cm^–1 and for BTY₁₀Nb₁₀ to 306 cm^–1. Average pore area of the ferroelectric BTY₁₀Nb₁₀ was found to be 6.96 nm for the total scanning electron microscopy (SEM) image area of 20.31 nm. Formation of BT nanorods analyzed from transmission electron microscopy (TEM) has been reported in three samples that regulate surface roughness. Moreover, Nyquist diagram of BTY₁₀Nb₁₀ shows two overlapping semicircles as a function of frequency. Nanorod structures led to change the morphology and surface roughness. Recoverable energy storage density and energy storage efficiency were estimated as 2.63 µJ/cm³ and 57%, and BTY₁₀Nb₁₀ ferroelectric showed potential for energy storage applications due to changes in surface morphology and porosity.     

青海交通社铌钽矿床地质特征及控矿规律

交通社铌钽矿床是阿尔金造山带新发现的铌钽矿床。文章以该矿床为研究对象,通过开展矿床地质特征调查,研究总结矿床地质特征及控矿规律。交通社铌钽矿区划分的4条矿化带,其中Ⅰ、Ⅱ、Ⅳ矿带均为金矿;Ⅲ矿带为铌钽矿,圈出铌钽矿体6条,长200~2640m,厚度为4. 87~12. 35 m,品位(Nb2O5) 0. 016%~0. 034%,矿体受碱长花岗岩控制。矿化蚀变主要有:矽卡岩化、硅化、碳酸盐化和云英岩化,铌钽矿与矽卡岩化、云英岩化关系密切,铌钽矿矿石类型主要有铌铁矿石、钽铁矿石。铌钽矿受碱长花岗岩控制,位于碱长花岗岩与矽卡岩化带附近,铌钽矿体明显增高,矿体向深部具有品位变富厚度变大的趋势,铌钽矿中的铌、钽元素来源于碱长花岗岩,碱长花岗岩为成矿提供物质、能量、流体等多种条件,使矽卡岩化带附近大量的Nb、Ta等稀有、稀土元素在二云母片岩中富集,形成了铌钽富矿体。文章针对矿区的实际情况,提出并分析了找矿标志及找矿潜力,以期取得找矿突破。