Determination of Niobium and Tantalum in Minerals, Ores and Concentrates Using Ion Exchange.

Kallmann, Silve; Oberthin, Hans.; Liu, Robert

doi:10.1021/ac60186a007

Cited by 30 publications

(5 citation statements)

References 28 publications

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“…Analysis for tantalum as a major or minor component or trace element in raw materials, ferroniobium -tantalum, scrap materials, and alloys must be distinguished from analysis for impurities in tantalum products. The classical method of analyzing for tantalum is by gravimetry after extraction as the fluoro complex on an ion-exchange resin [132]. Low concentrations, i.e., in the µg/g region, are usually determined photometrically [131].…”

Section: Discussionmentioning

confidence: 99%

Tantalum and Tantalum Compounds

Andersson¹,

Reichert²,

Wolf³

2000

Ullmann's Encyclopedia of Industrial Chemistry

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Section: Discussionmentioning

confidence: 99%

Tantalum and Tantalum Compounds

Andersson¹,

Reichert²,

Wolf³

2000

Ullmann's Encyclopedia of Industrial Chemistry

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“…Unlike Ti, Ta is highly conductive of heat and electricity, and is relatively rare, found primarily in tantalite, and columbite (66), and to a lesser extent coltan. Although Ta has been shown to have high biocompatibility in animals (3,4,10) and humans (2), it is costly to mine and manufacture, making it one of the most expensive of the commonly used orthopedic materials (67).…”

Section: Tantalummentioning

confidence: 99%

Biological Strategies for Improved Osseointegration and Osteoinduction of Porous Metal Orthopedic Implants

Lewallen

Riester

Bonin

et al. 2015

Tissue Engineering Part B: Reviews

149

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The biological interface between an orthopedic implant and the surrounding host tissue may have a dramatic effect upon clinical outcome. Desired effects include bony ingrowth (osseointegration), stimulation of osteogenesis (osteoinduction), increased vascularization, and improved mechanical stability. Implant loosening, fibrous encapsulation, corrosion, infection, and inflammation, as well as physical mismatch may have deleterious clinical effects. This is particularly true of implants used in the reconstruction of load-bearing synovial joints such as the knee, hip, and the shoulder. The surfaces of orthopedic implants have evolved from solid-smooth to roughened-coarse and most recently, to porous in an effort to create a three-dimensional architecture for bone apposition and osseointegration. Total joint surgeries are increasingly performed in younger individuals with a longer life expectancy, and therefore, the postimplantation lifespan of devices must increase commensurately. This review discusses advancements in biomaterials science and cell-based therapies that may further improve orthopedic success rates. We focus on material and biological properties of orthopedic implants fabricated from porous metal and highlight some relevant developments in stem-cell research. We posit that the ideal primary and revision orthopedic load-bearing metal implants are highly porous and may be chemically modified to induce stem cell growth and osteogenic differentiation, while minimizing inflammation and infection. We conclude that integration of new biological, chemical, and mechanical methods is likely to yield more effective strategies to control and modify the implant-bone interface and thereby improve long-term clinical outcomes.

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“…The use of methyl ethyl ketone as the eluent for the cellulose column separation of niobium and tantalum in dilute hydrofluoric acid-ammonium fluoride solutions represented a significant advance over the tannin precipitations. The anionicexchange separation of niobium from tantalum and other metals from a hydrochloric-hydrofluoric acid medium is accomplished by elution with ammonium chloride-hydrofluoric acid (46). This same type of ion-exchange separation is used to determine Nb along with Ta in various matrices, such as Inconel (47), FeNb alloys (48), and titanium (49).…”

Section: Vol 16 Niobium and Niobium Compoundsmentioning

confidence: 99%

Niobium and Niobium Compounds

Schlewitz¹

2000

Kirk-Othmer Encyclopedia of Chemical Technology

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Niobium, discovered by Hatchett in 1801, was first named columbium. In 1844, Rosed thought he had found a new element associated with tantalum (see TANTALUM AND TANTALUM COMPOUNDS). He called the new element niobium, for Niobe, daughter of Tantalus of Greek mythology. In 1949, the Union of Pure and Applied Chemistry settled on the name niobium, but in the United States this metal is still known also as columbium. Sometimes called a rare metal, niobium is actually more abundant in the earth's crust than lead.Niobium is important as an alloy addition in steels (see STEEL). This use consumes over 90% of the niobium produced. Niobium is also vital as an alloying element in superalloys for aircraft turbine engines. Other uses, mainly in aerospace applications, take advantage of its heat resistance when alloyed singly or with groups of elements such as titanium, zirconium, hafnium, or tungsten. Niobium alloyed with titanium or with tin is also important in the superconductor industry (see HIGH TEMPERATURE ALLOYS; REFRACTORIES).1.1. Properties. Elemental niobium [7440-03-1], Nb, has a cosmic abundance of 0.9 relative to silicon 106 (1), an average value of 24 ppm in the earth's crust (2), and a comparable value on the lunar surface (3). Niobium is a monoisotopic element, although a search for residual radionuclides from the formation of the solar system has established the natural abundance of 92 Nb [13982-37-1], having a half-life, t 1/2 , of 1:7 Â 10 8 yr, to be 1:2 Â 10 À10 % (4). In addition, minute amounts of 94 Nb [14681-63-1], t 1=2 ¼ 2:03 Â 10 4 yr, and 95 Nb [13967-76-5], t 1=2 ¼ 35 d, occur in nature; the former from neutron capture by the stable isotope, and the latter as the daughter of 95 Zr in the fission products of 235 U. Niobium-93 has a nuclear spin of 9/2 and a thermal neutron-capture cross section of 1:1 AE 0:1 Â 10 À28 m 2 (1.1 barns) which makes it of much interest to the nuclear industry (see NUCLEAR REACTORS).Niobium, like vanadium, undergoes no phase transitions from room temperature to the melting point. It is a steel-gray, ductile, refractory metal having a higher melting point than molybdenum and a lower electron work function than tantalum, tungsten, or molybdenum. Niobium closely resembles tantalum in its properties; the former is only slightly more chemically reactive. The metal is resistant to most gases below 2008C, but is air oxidized at 3508C, developing an oxide film of increasing thickness which changes from pale yellow to blue to black at 4008C. Absorption of hydrogen at 2508C and nitrogen at 3008C occurs to form interstitial solid solutions which greatly affect the mechanical properties. Niobium is attacked by fluorine and gaseous hydrogen fluoride and is embrittled by nascent hydrogen at room temperature. It is unaffected by aqua regia and mineral acids at ordinary temperatures, except hydrofluoric acid in which it dissolves. Niobium is attacked by hot concentrated hydrochloric and sulfuric acids, dissolving at 1708C in concentrated sulfuric acid, and by hot alkali carbonates and ...

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Determination of Niobium and Tantalum in Minerals, Ores and Concentrates Using Ion Exchange.

Cited by 30 publications

References 28 publications

Tantalum and Tantalum Compounds

Tantalum and Tantalum Compounds

Biological Strategies for Improved Osseointegration and Osteoinduction of Porous Metal Orthopedic Implants

Niobium and Niobium Compounds

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