Sodium niobium fluoride

Analogous sodium niobium fluorides have not been isolated. 

Modem refining technology uses tantalum and niobium fluoride compounds, and includes fluorination of raw material, separation and purification of tantalum and niobium by liquid-liquid extraction from such fluoride solutions. Preparation of additional products and by-products is also related to the treatment of fluoride solutions oxide production is based on the hydrolysis of tantalum and niobium fluorides into hydroxides production of potassium fluorotantalate (K - salt) requires the precipitation of fine crystals and finishing avoiding hydrolysis. Tantalum metal production is related to the chemistry of fluoride melts and is performed by sodium reduction of fluoride melts. Thus, the refining technology of tantalum and niobium involves work with tantalum and niobium fluoride compounds in solid, dissolved and molten states. 

Once purification of the niobium has been effected, the niobium can be reduced to the metallic form. The double fluoride salt with potassium, K2NbFy, can be reduced using sodium metal. The reaction is carried out in a cylindrical iron vessel filled with alternating layers of K NbF and oxygen-free sodium ... 

Compounds of the same stoichiometry type usually have the same type crystal structure within the row of alkali metals K - Rb - Cs rarely the same type structure with sodium-containing analogues and never ciystallize similarly with lithium-containing compounds. The crystal structure analysis of different fluoride and oxyfluoride compounds clearly indicates that the steric similarity between all cations and tantalum or niobium must be taken into account when calculating the X Me ratio. 

For a long period of time, molten salts containing niobium and tantalum were widely used for the production by electrolysis of metals and alloys. This situation initiated intensive investigations into the electrochemical processes that take place in molten fluorides containing dissolved tantalum and niobium in the form of complex fluoride compounds. Well-developed sodium reduction processes currently used are also based on molten salt media. In addition, molten salts are a suitable reagent media for the synthesis of various compounds, in the form of both single crystals and powdered material. The mechanisms of the chemical interactions and the compositions of the compounds depend on the structure of the melt. 

L.A. Kamenskaya Phys.-Chem. investigations of interactions between niobium and tantalum complex fluorides and oxyfluorides and potassium and sodium fluorides and chlorides in molten conditions. - Abstracts of Dissertation, Kiev, 1976 (in Russian). 

Tantalum can be separated from niobium by recrystallization of the double potassium fluorides. In the commercial process the ore is fused with caustic soda. The insoluble sodium niobate, sodium tantalate, and... 

A method of separation which avoids the preparation of the double fluorides consists in fusing the mixed niobic and t an tali c acids with sodium carbonate and nitrate, the product is digested with warm water and a current of carbon dioxide is passed through the solution. It is claimed that only tantalic acid is precipitated.5 This process has, however, been the subject of adverse criticism.6 Partial separation of niobium from tantalum can be effected by warming the mixed, freshly precipitated, hydrated oxides with a mixture of hydrogen peroxide and hydrochloric acid the niobium dissolves readily, while the tantalum dissolves only sparingly.7... 

Nickel(IV) sodium paraperiodate 1-hydrate (amt.) analysis of, 6 203 Nickel tetracarbonyl, 2 234 Niobium(V) fluoride, 3 179 Nitramide, 1 68, 72 Nitrates, preparation of anhydrous, 5 38... 

NaNj Sodium azide, 1 79 2 139 NaOCSodium butoxide, 1 88 NaOj Sodium superoxide 4 82 Na202-8H20 Sodium peroxide, 3 1 NbFt Niobium (V) fluoride, 3 179 NdClj Neodymium chloride, 1 32 Nd2(C2O4)2 10H2O Neodymiumox-alate, 2 60... 

Na202-8H20 Sodium peroxide, 3 1 NbF5 Niobium(V) fluoride, 3 179 NdCl3 Neodymium chloride, 1 32 5 154n. 

A technique for the separation of pertcchnetalc from mixed fission products by solvent extraction with TBP was described. The extraction was almost quantitative from a sulphuric acid solution. Sodium fluoride was used to provide the zirconium-niobium decontamination and a cation exchange column ensured the decontamination from metallic ions. Tc yields of 92 % were obtained [123. ... 

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