tantalum niobium scholars

The behavior of niobium and tantalum is poorly understood in rocks that have undergone significant hydrothermal alteration, and niobium-tantalum minerals of hydrothermal origin are rarely mentioned in the literature. Consequently, the mobility of these critical metals, although widely considered to be negligible, has not been evaluated. In this paper, we …

9. Preparation and characterization of several alkylidene complexes, M (.eta.5-C5H5)2 (alkylidene)X (M = tantalum or niobium), and the x-ray structure of Ta (.eta.5-C5H5)2 (CHC6H5) (CH2C6H5). An investigation of alkylidene ligand rotation. R. Schrock L. Messerle C. D. Wood L. Guggenberger.

Abstract. On-going technological developments, especially in the field of microelectronics and communication have reflected in concomitant increase in the demand for strategic metals such as tantalum (Ta) and niobium (Nb). The extraction of these two metals from ore deposits and secondary resources is based on the generic extractive ...

The refractory metals, so-called because of their elevated melting points, are Ta (m.p. 3000 ts C), Nb (m.p. 2468 ts C), Mo (m.p. 2610 ts C), Re (m.p. 3130 ts C), and W (m.p. 3410 ts C). They are all characterized by great strength and high thermal, chemical, and physical stability. The processing of raw materials to produce the pure metal, chemical and …

19 Citations. Explore all metrics. Abstract. Niobium and tantalum are rare refractory metals of large industrial value.

Section snippets Tantalum-niobium mineral resources. Three main types of Ta and Nb deposits exist (Linnen et al., 2013; Melcher et al., 2017) which could be grouped as: (i) carbonatites and associated rocks (pyrochlore: rich in Nb), (ii) alkaline to peralkaline granites and syenites (rich in Ta, Nb and rare earth elements), and (iii) granites and …

1 Citation. Explore all metrics. Abstract. A stable and continuous leaching process for niobium and tantalum extraction from ferrocolumbium tantalum (FT) was …

During recent years increased interest has been shown in the metal niobium. Because niobium has a high melting point (4376° F) and a low neutron cross-section, the Atomic Energy Commission has encouraged research on new methods of winning the metal from its ores with the ultimate hope of finding a process which would yield niobium metal at a …

DOI: 10.1016/0016-7037(95)00431-9 Corpus ID: 128985488; Distribution of niobium, tantalum, and other highly incompatible trace elements in the lithospheric mantle: The spinel paradox

The mining process of tantalum-niobium in Yichun and the technical reconstruction for the tantalum-niobium tailing mine is investigated. Yichunhas the largest rare-metal reserves in China, the explored reserve of lepidolite accounts for 31% in China and 12% in the world, it reserves of Rb and Cs are also the largest in China.

Summary. Niobium and tantalum do not occur naturally as free metals. The charge to ionic ratio of tantalum and niobium results in strong bonds being formed with …

About the Tantalum-Niobium International Study Center (T.I.C.) An international, non-profit association founded in 1974 under Belgian law. Around 90 members from over 30 countries involved with all aspects of the tantalum and niobium industry supply chain (mining, trading, processing, metal fabrication, capacitor manufacturing, recycling, other ...

: Secondary hard metal contains valuable tantalum and niobium, which could be recovered after chemical recycling of the scrap; however, the environmental impacts of their recycling have not been earlier quantified. This study provides gate-to-gate life cycle inventory data on tantalum and niobium recovery from the Ta − Nb-rich residue after …

Semantic Scholar extracted view of "The science and technology of tungsten, tantalum, molybdenum, niobium and their alloys" by N. Promisel. Skip to search form Skip to main content Skip to account menu. Semantic Scholar's Logo. Search 217,789,938 papers from all fields of science.

Niobium Oxide and Tantalum Oxide Micro- and Nanostructures Grown Using Material Recovered from Mining Tailings †. by. Belén Sotillo. 1, Lorena Alcaraz. 2,*, Félix Antonio López. 2, Francisco José Alguacil. 2, …

Liquid-phase synthesis of highly oxophilic zerovalent niobium and tantalum nanoparticles. Deep black suspensions of very small, highly uniform nanoparticles are obtained with average diameters of 2.1 ± 0.4 nm andWhereas suspensions are chemically and colloidally stable, powder samples are very reactive. Expand.

Niobium and tantalum are transition metals that are almost always found together in nature because they have very similar physical and chemical properties. Their properties of hardness, conductivity, and resistance to corrosion largely determine their primary uses today. The leading use of niobium (about 75 percent) is in the production of high …

ABSTRACT. The norm of elastic constant tensor and the norms of the irreducible parts of the elastic constants of Tantalum, and its alloys at different percentages of Hydrogen, Molybdenum, Niobium, Rhenium and Tungsten are calculated. The relation of the scalar parts norms and the other parts norms and the anisotropy of these alloys are presented.

Abstract The carbothermic reductions of niobium pentoxide and pyrochlore were studied in the temperature ranges 1625–2855 K and 1520–2440 K respectively in an argon transferred-arc plasma using a…. Expand. 4. Semantic Scholar extracted view of "Current Trends in the Production of Tantalum and Niobium" by E. Polyakov et al.

Niobium and tantalum are chemically similar and are associated with each other in nature which makes it very difficult to separate. For many years, the separation of tantalum from niobium involved the fractional crystallization of potassium heptafluorotantalate away from potassium oxypentafluoroniobate monohydrate, this method has been supplanted by …

DOI: 10.1002/cjce.24621 Corpus ID: 251856496; Niobium and tantalum recovery from the primary source and from tin slag, an industrial challenge: a review @article{deOliveira2022NiobiumAT, title={Niobium and tantalum recovery from the primary source and from tin slag, an industrial challenge: a review}, author={Juliana Mendes de …

The processed slag rich in niobium and tantalum is digested with hydrofluric acid, and subjected to solvent extraction for the removal of additional impurities as well as for the separation of niobium and tantalum. This paper reports on the upgradation of tin slag typically containing 3.4% Nb205 and 3.0% Ta205 by a combination of chemical ...

Tantalum concentrations were determined by neutron-activation analysis. The equilibrium distribution coefficient for tantalum dissolved in niobium was found to be 1.4 in the limit of pure niobium. With the addition of approximately 1 1 2% titanium to the solid solution, this distribution coefficient was decreased to slightly less than unity.

Niobium and columbium are synonymous names for the chemical element with atomic number 41; columbium was the name given in 1801, and niobium (Nb) was the name officially designated by the International Union of Pure and Applied Chemistry in 1950. Niobium in the form of ferroniobium is used worldwide, mostly as an alloying element in …

P. Abramov M. Sokolov. Chemistry. Molecules. 2023. The reactions between catechol (H2cat) and niobium (V) or tantalum (V) precursors in basic aqueous solutions lead to the formation of catecholate complexes of different natures. The following complexes…. Expand. [PDF] 1 Excerpt.

Extractive Metallurgy of Tantalum. D. Bose C. Gupta. Materials Science, Engineering. 2001. This paper presents a brief review of extractive metallurgy of tantalum starting from processing of its ore to two pure intermediates K2TaF7 and Ta2O5 and their conversion to pure tantalum metal by….

2022. 4. This paper describes a new technology which is used to recover tantalum and niobium from tungsten residues with the method of acid treatment,which includes diluted acid treatment for desilication,concentrated acid treatment for iron and manganese removal,HF acid leaching of tantalum and niobium and evaporation …

Niobium and tantalum primary minerals are naturally occurring complex oxide ores, majorly of low grade deposits with chemical content of mainly Nb 2 /Ta 2 O 5 …

Publish Date: 25 October 2019. Abstract. Tantalum and niobium identified as the critical materials by the United States, the European Union and Japan, play an important role in …

About the Tantalum-Niobium International Study Center (T.I.C.) An international, non-profit association founded in 1974 under Belgian law. Around 90 members from over 30 countries involved with all aspects of …

In this study, Tantalum-Niobium alloy (TaNb40) implant prepared by 3D —SLS was used as the research subject. ... Some scholars [63-64] prepare d bu lk ultra ne-grained pure Ta by Equal ...

Corpus ID: 225129305. A review on extractive metallurgy of tantalum and niobium. A. Shikika, M. Sethurajan, +2 authors. S. Gaydardzhiev. Published 1 December 2020. …

DOI: 10.1016/j.gca.2020.04.009 Corpus ID: 219098228; Niobium and tantalum in hydrothermal fluids: Thermodynamic description of hydroxide and hydroxofluoride complexes @article{Akinfiev2020NiobiumAT, title={Niobium and tantalum in hydrothermal fluids: Thermodynamic description of hydroxide and hydroxofluoride complexes}, …

Niobium is a lustrous, gray, ductile metal with a high melting point, relatively low density, and superconductor properties. Tantalum is a dark blue-gray, dense, ductile, very hard, and easily fabricated metal. It is highly conductive to heat and electricity and renowned for its resistance to acidic corrosion. These special properties determine ...

Tantalum is an important metal for high-technology applications of the modern world. It is recovered from oxide minerals that are present as minor constituents in rare-metal granites (RMG) and granitic rare-element pegmatites (REP). Significant potential exists as a by-product of spodumene mining from pegmatites, and from Nb-Zr-rare earth …

The global distribution of tantalum deposits and their resources on the geological time scale is analyzed. The analysis is based on the data for 65 deposits of the world with a …

The electrodeposition of carrier-free95Zr for nuclear spectroscopic studies has been successfully achieved using urea-oxalate electrolyte solution. Employing a current density of 40 mA per cm2, over…. Expand. 4. Semantic Scholar extracted view of "Hexavalent Fluorides of Tantalum and Niobium" by G. W. Mellors et al.

Tracing anthropogenic sources of Tantalum and Niobium in Bothnian Bay sediments, Sweden. This study aims to evaluate temporal trends of Tantalum (Ta) and Niobium (Nb) concentrations in northern Baltic Sea sediments with focus on the potential impact from the Rönnskär sulfide ore smelter,….