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Niobium pentoxide is the inorganic compound with the formula Nb 2 O 5. A colorless, insoluble, and fairly unreactive solid, it is the most widespread precursor for other compounds and materials containing niobium. It is predominantly used in alloying, with other specialized applications in capacitors, optical glasses, and the production of ...
Niobium oxide, archaically called columbium oxide, [1] may refer to: Niobium monoxide (niobium(II) oxide), NbO; Niobium dioxide (niobium(IV) oxide), NbO 2; Niobium pentoxide (niobium(V) oxide), Nb 2 O 5; In addition to the above, other distinct oxides exist general formula Nb 3n+1 O 8n−2 where n ranges from 5 - 8 inclusive, e.g. Nb 8 O 19 (Nb ...
The aluminothermic reaction is used for the production of several ferroalloys, for example ferroniobium from niobium pentoxide and ferrovanadium from iron, vanadium(V) oxide, and aluminium. [1] [2] The process begins with the reduction of the oxide by the aluminium: 3 V 2 O 5 + 10 Al → 5 Al 2 O 3 + 6 V
Niobium forms oxides in the oxidation states +5 (Nb 2 O 5), [77] +4 (NbO 2), and the rarer oxidation state, +2 . [78] Most common is the pentoxide, precursor to almost all niobium compounds and alloys. [61] [79] Niobates are generated by dissolving the pentoxide in basic hydroxide solutions or by melting it in alkali metal oxides.
Ferroniobium is an important iron-niobium alloy, with a niobium content of 60-70%. [1] It is the main source for niobium alloying of HSLA steel and covers more than 80% of the worldwide niobium production. The niobium is mined from pyrochlore deposits and is subsequently transformed into the niobium pentoxide Nb 2 O 5.
A prominent early synthetic application of organoniobium chemistry was the use of dimethoxyethane niobium trichloride, NbCl 3 (DME), as a reagent for the reductive coupling of imines with carbonyl compounds to form amino alcohols. [9] This reagent has found further use in other pinacol-type reductive couplings. [10] [8]
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Niobium(V) can form complexes with hydroxy acids, as well as oxalic acid. The salt formed is more complex than tartaric acid for niobium (as opposed to tantalum). [3] NH 4 [NbO(C 2 O 4) 2 (H 2 O) 2]·3H 2 O starts to lose water at 125°C, and at 630°C, it fully decomposes, forming a compound known as niobium pentoxide; [4] Heating this complex and sodium citrate at 650°C can form sodium ...