Sodium metavanadate

The principal vanadium-bearing ores are generally cmshed, ground, screened, and mixed with a sodium salt, eg, NaCl or Na2C02- This mixture is roasted at ca 850°C and the oxides are converted to water-soluble sodium metavanadate, NaVO. The vanadium is extracted by leaching with water and precipitates at pH 2—3 as sodium hexavanadate, Na V O, a red cake, by the addition of sulfuric acid. This is then fused at 700°C to yield a dense black product which is sold as technical-grade vanadium pentoxide. This product contains a minimum of 86 wt % V20 and a maximum of 6—10 wt % Na20. 

In gas reforming plants, e.g. the hot potassium carbonate process for CO removal, sodium metavanadate is used to prevent mild-steel corrosion". Banks reports" that this treatment does not reduce the rather high corrosion rate of Cu-30Ni in these plants. 

Sodium metavanadate (Na20 V205), having a MP of approximately 1165 °F (629 °C)... 

The effect of inorganic additives upon ignition delay in anilinium nitrate-red finning nitric acid systems was examined. The insoluble compounds copper(I) chloride, potassium permanganate, sodium pentacyanonitrosylferrate and vanadium(V) oxide were moderately effective promoters, while the soluble ammonium or sodium metavanadates were very effective, producing vigorous ignition. 

The effects of various metal oxides and salts which promote ignition of amine-red fuming nitric acid systems were examined. Among soluble catalysts, copperQ oxide, ammonium metavanadate, sodium metavanadate, iron(III) chloride (and potassium hexacyanoferrate(II) with o-toluidine) are most effective. Of the insoluble materials, copper(II) oxide, iron(III) oxide, vanadium(V) oxide, potassium chromate, potassium dichromate, potassium hexacyanoferrate(III) and sodium pentacyanonitrosylferrate(II) were effective. 

Metavanadate (VOs") can form indefinite chains as well as cyclic structures. Sodium metavanadate is also commercially available. Hence, the investigator should be aware of which vanadate is being utilized in the studies. 

No adverse effects on fertility, reproduction, or parturition were found when male and female rats were treated with sodium metavanadate by gavage and then mated. ... 

Cerous Orthovanadate, CeV04, has been prepared as dark red needles by fusing sodium metavanadate with cerous chloride.5... 

Copper Metavanadate.—Addition of copper sulphate solution to sodium metavanadate throws down a precipitate which consists mainly of copper metavanadate, which is light yellow. The precipitate may, however, be green or blue, because its composition varies considerably. Copper metavanadate can also be produced eleetrolytically. On being fused at a high temperature in a graphite crucible it forms copper and vanadium carbide.10... 

Indium Metavanadate, In(V03)3.2H20, is a yellow substance produced by the action of sodium metavanadate on indium chloride solution.12... 

Uranyl-vanadates.—By adding uranic anhydride to fused potassium or sodium metavanadate, microscopic, rectangular, fluorescent plates of the compositions K(U02)V04 and Na(U02)V04 are obtained. These are probably derivatives of a relatively stable uranyl-... 

In a typical process, the vanadium ore is roasted with sodium chloride in the presence of air to produce sodium metavanadate ... 

Crystals were spread over a strip of Parafilm . Both the photochemical reactor and the strip with crystals were placed in a dry box and purged with nitrogen for 1 h. A 40 mg portion of 4-methyl-6,6-diphenylbicyclo[3.1.0]hex-3-en-2-one 1 was irradiated under conditions described above for 10 min through a 5 mm filter solution of 10 3 M sodium metavanadate in 5% sodium hydroxide. The mixture was chromatographed on preparative TLC plate eluted with 7% ether in hexane. Band 1 (28.0 mg, 70%) contained 3-methyl-4,5-diphenylphenol 2. Crystallization from hexane gave 14.1 mg (35%) of colorless crystals, mp 109-110 °C. 

Mg as magnesium oxide Fe as Ferrous fumarate Zn as zinc oxide Ti as titanium dioxide Cu as cupric oxide Mo as sodium molybdate I as potassium iodide V as sodium metavanadate Sn as tin(II) chloride... 

Two step oxidation of tall oil fatty acid using peroxyformic acid and nitric acid/sodium metavanadate were used to produce azelaic acid. 

Reproducible preparation of H3+JtPMoi2-xVxO40 C 1-3, MO 2 xVx) was established by Tsigdinos and Hallada [55], An aqueous solution of Na2HP04 and sodium metavanadate is acidified with a concentrated sulfuric acid. To this mixture is added an aqueous solution of Na2Mo04 2H20. The detailed procedure is available in the literature. Note that excess sodium metavanadate is used. 

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