Synthesis of Tantalum and Niobium Fluoride Compounds

Agulyansky, Anatoly

doi:10.1016/b978-044451604-6/50002-1

Cited by 19 publications

(39 citation statements)

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“…Tantalum and niobium oxides are produced by treating acids with ammonia. A by-product of the process is ammonium bifluoride NH 4 F•HF or aqueous solution of ammonium fluoride [8].…”

Section: Ammonium Bifluoridementioning

confidence: 99%

Production of Hydrogen Fluoride by Processing Fluorine-Containing Wastes and by-Products of Modern Industries

Pashkevich

Мамаев

2018

WIT Transactions on Ecology and the Environment

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This article shows the feasibility and possibility of developing a universal industrial method for producing hydrogen fluoride from fluorine-containing wastes and by-products of modern industries (depleted uranium hexafluoride, hydrofluorosilicic acid, ammonium bifluoride, carbon tetrafluoride, and other perfluorocarbons and hydrofluorocarbons, sulfur hexafluoride, nitrogen trifluoride, mixtures containing sodium hexafluoroaluminate, etc.) as alternatives to the conventional industrial method of natural calcium difluoride decomposition with sulfuric acid. As the main process method, we suggest fluoride reduction in a flame of hydrogen-containing fuel and oxygen-containing oxidant, due to the unique thermodynamic stability of hydrogen fluoride. The paper presents the results of thermodynamic calculation and experiments on the proposed method for various fluorides -uranium hexafluoride, carbon tetrafluoride, silicon tetrafluoride, ammonium bifluoride, etc. As a fuel, we consider methane, hydrogen and ammonia as an oxidizing agent, oxygen and air. For the case where water is present in the combustion products, we discuss various dehydrogenation options of hydrofluoric acid. We have demonstrated that the industrial cost hydrogen fluoride produced from the above-listed fluorides is approximately twofold lower than the same parameters for the conventional method of fluorite decomposition using sulfuric acid.

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“…Tantalum and niobium oxides are produced by treating acids with ammonia. A by-product of the process is ammonium bifluoride NH 4 F•HF or aqueous solution of ammonium fluoride [8].…”

Section: Ammonium Bifluoridementioning

confidence: 99%

Production of Hydrogen Fluoride by Processing Fluorine-Containing Wastes and by-Products of Modern Industries

Pashkevich

Мамаев

2018

WIT Transactions on Ecology and the Environment

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“…After the breakdown treatment, the mixed oxides of tantalum Ta 2 O 5 and niobium Nb 2 O 5 are obtained. The first step in the processing is the reaction of the oxides with hydrofluoric acid [10]: Newer processes use the liquid extraction of the fluorides from aqueous solution by organic solvents like Octanol [11], bis(2-ethylhexyl)phosphoric acid (DEHPA) [12], Alamine 336 [13], methyl isobutyl ketone (MIBK) [14,15,16], tri-n-butyl phosphate (TBP) [17,18] or cyclohexanone [19]. The complex niobium and tantalum fluorides are extracted separately from the organic solvent with water and either precipitated by the addition of potassium fluoride to produce a potassium fluoride complex, or precipitated with ammonia as the pentoxide [20]:…”

Section: Extraction and Separation Of Niobium And Tantalum 31 Procesmentioning

confidence: 99%

“…Further purification is necessary to reach the grade for superconductive alloys. Electron beam melting under vacuum is the method used by the two major distributors of niobium [11,24].…”

Section: Extraction and Separation Of Niobium And Tantalum 31 Procesmentioning

confidence: 99%

“…Fig. 1 Proposed Multi-Ore Constituent Concentration Model [25] Agulyanski [11] reported the use of 2-octanol for the separation of niobium and tantalum. The process consists of the collective extraction of tantalum and niobium (5-7 extraction stages), scrubbing (6-9 stages), niobium stripping (5-7 stages) and Tantalum stripping (4-6 stages).…”

Section: Newer Processes Of Extraction and Separation Of Niobium And mentioning

confidence: 99%

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A Review of Niobium-Tantalum Separation in Hydrometallurgy

Ayanda¹,

Adekola²

2011

JMMCE

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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 solvent extraction from fluoride-containing solutions by the use of solvent extractants such as Octanol, bis(2-ethylhexyl)phosphoric acid (DEHPA), Alamine 336, methyl isobutyl ketone (MIBK), tri-nbutyl phosphate (TBP) or cyclohexanone. A detailed review of the various processes involved in the breakdown treatment of niobium and tantalum primary sources, extraction and separation and newer processes of extraction as well as the various technique involved were discussed.

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“…In the extraction process, the lone pair of electrons on the oxygen atom of MIBK attracts hydrogen ions, which generates a cation. This cation combines with the tantalum complex anion electrostatically, which creates the complex 27 H TaF nMIBK  which is hydrophobic and dissolves in methyl isobutyl ketone [14]. The separation factor is equal to the ratio of the distribution ratio of the two metals, which expresses the degree of separation of the two metals.…”

Section: Effect Of Hydrofluoric Acid Concentration On Tantalum and Nimentioning

confidence: 99%

Low-Acid Extraction of Tantalum from a Tantalum-Niobium Pulp by MIBK

Yang

Wang

Wei

et al. 2013

SERDJ

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The technological parameters and the mechanism of low-acid pulp extraction of tantalum were investigated. The results show that hydrofluoric acid concentration, sulfuric acid concentration, organic to pulp phase ratio, the concentration of tantalum and niobium, contact time and temperature have a significant effect; optimum process operating parameters were established as follows: hydrofluoric acid concentration 1.6 mol/L, sulfuric acid concentration 0.6 mol/L, organic to pulp phase ratio 3:1, tantalum concentration 26.61 g/L, niobium concentration 11.64 g/L, contact time 5min and room temperature. Under these experimental conditions, tantalum extraction can reach more than 98% and the separation factors of Ta/Nb, Ta/Fe and Ta/Sn were maximal.According to slope analysis, the equimolar series method and the saturation capacity method, the extraction product was identified as 3MIBK•H 2 TaF 7 .

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Synthesis of Tantalum and Niobium Fluoride Compounds

Cited by 19 publications

References 0 publications

Production of Hydrogen Fluoride by Processing Fluorine-Containing Wastes and by-Products of Modern Industries

Production of Hydrogen Fluoride by Processing Fluorine-Containing Wastes and by-Products of Modern Industries

A Review of Niobium-Tantalum Separation in Hydrometallurgy

Low-Acid Extraction of Tantalum from a Tantalum-Niobium Pulp by MIBK

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