Uses of Vanadium

Vanadium is also used in the titanium alloy T16A14V (with 4% V). This alloy accounts for 50% of all titanium-based alloys. 

The major use of vanadium, besides metallurgy, is as a catalyst in the chemical industry. Vanadium pentoxide has replaced platinum as a catalyst for manufacturing sulfuric add. 

In 2001 vanadium products, corresponding to about 58000 tonnes of vanadium were produced. China accounted for half of this quantity. South Africa for 30%. 

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Carbon Reduction. The production of ferrovanadium by reduction of vanadium concentrates with carbon has been supplanted by other methods. An important development has been the use of vanadium carbide as a replacement for ferrovanadium as the vanadium additive in steelmaking. A... 

Vanadium compounds, including those which may be involved in the production, processing, and use of vanadium and vanadium alloys, are irritants chiefly to the conjuctivae and respiratory tract. Prolonged exposure may lead to pulmonary compHcations. However, responses are acute, never chronic. Toxic effects vary with the vanadium compound involved. For example, LD q (oral) of vanadium pentoxide dust in rats is 23 mg/kg of body weight (24). 

Superconductivity. One potential future use of vanadium is in the field of superconductivity. The compound V Ga exhibits a critical current at 20 T (20 X lO" G), which is one of the highest of any known material. Although niobium—zirconium and Nb Sn have received more attention, especiahy in the United States, the vanadium compound is being studied for possible future appHcation in this field since V Ga exhibits a critical temperature of 15.4 K as opposed to 18.3 K for Nb Sn. 

Conversion of fused pentoxide to alloy additives is by far the largest use of vanadium compounds. Air-dried pentoxide, ammonium vanadate, and some fused pentoxide, representing ca 10% of primary vanadium production, are used as such, purified, or converted to other forms for catalytic, chemical, ceramic, or specialty appHcations. The dominant single use of vanadium chemicals is in catalysts (see Catalysis). Much less is consumed in ceramics and electronic gear, which are the other significant uses (see Batteries). Many of the numerous uses reported in the Hterature are speculative, proposed. 

Minor uses of vanadium chemicals are preparation of vanadium metal from refined pentoxide or vanadium tetrachloride Hquid-phase organic oxidation reactions, eg, production of aniline black dyes for textile use and printing inks color modifiers in mercury-vapor lamps vanadyl fatty acids as driers in paints and varnish and ammonium or sodium vanadates as corrosion inhibitors in flue-gas scmbbers. 

An interest has been developed in the use of vanadium naphthenates as accelerators. In 1956 the author found that if MEKP was added to a polyester resin containing vanadium naphthenate the resin set almost immediately, that is, while the peroxide was still being stirred in. Whereas this effect was quite reproducible with the sample of naphthenate used, subsequent workers have not always obtained the same result. It would thus appear that the curing characteristics are very dependent on the particular grade of resin and of vanadium naphthenate used. It was also observed by the author that the gelation rate did not always increase with increased temperature or accelerator concentration and in some instances there was a retardation. Subsequent workers have found that whilst the behaviour of the naphthenate varies according to such factors as the resin and catalyst used, certain vanadium systems are of value where a high productivity in hand lay-up techniques is desired. 

In the beginning of the twentieth century, surgical techniques were developed for the fixation of bone fractures with a plate and screw combination. Sherman-type bone plates were fabricated from the best available alloy at the time, vanadium steel. By the 1920s the use of vanadium steel became questionable because of poor tissue compatibility. At that time however, no other alloy was available with high strength and good corrosion resistant properties. 

Maleic can be made by oxidation of butane or benzene. The process would otherwise be virtually impossible without the use of vanadium pen-toxide as the Catalyst. It enables extensive reconfiguration of either feedstoclcs molecular structure into the anhydride structure. 

The major use of vanadium is as an alloying metal to make a strong and corrosion-resistant form of steel that is well suited for structures such as nuclear reactors. It does not absorb neutrons or become stretched by heat and stress, as does normal stainless steel, thus making vanadium ideal for the construction of nuclear reactors. 

At least a third of the chapters in this book deal with the use of vanadium in one of its several oxidation states. New analytical techniques have become available that make it possible to characterize these materials more precisely and to determine the exact nature of the active centers. We appear to be on the threshold of exciting breakthroughs in fundamental research that should result in signihcant improvements to industrial oxidation processes. Our hope is that this book will provide insights and stimulate additional research that will achieve these goals. 

Research related to the use of vanadium phosphates or V2O5 as oxidants of gases such as CO and SO2 in commercial processes shows that solid vanadyl sulfate can serve as a gas-permeable solid-phase electrolyte [102]. Two reversible redox features are observable at slow scan rates (20-150 mV s ) by CV in a gas-tight two-electrode cell packed with powdered VOSO4 3H2O between a 10-mm carbon disk and a 3-mm glassy carbon electrode. The V(IV/V) couple was observed at 0.55 V versus C, and the V(IV/III) couple was observed at —0.97 V. Unlike in aqueous solution where vanadyl sulfate is reduced to [V(H20)6] ", the V=0 bond in the solid remains intact. The oxidation of CO(g) can be observed when it is introduced into this cell. 

Uses of Vanadium, (a) Vanadium Steels.—By far the largest proportion of the world s production of vanadium is absorbed in the production of ferrovanadium alloy for the manufacture of vanadium steels, which usually contain up to 0-8 per cent, of vanadium. The effect of the addition of vanadium to a steel is to increase its tensile strength enormously, also its hardness, and its resistance to shock and fatigue.6 A good carbon steel containing about 1-10 per cent, of carbon has an elastic limit of about 30 tons per square inch and an ultimate... 

Explores the chemistry, environmental influences, pharmacological applications, and technological uses of vanadium Compiles the results from research on the aqueous coordination reactions characterizing the vanadium(V) oxidation state Details the application of NMR spectroscopy to the speciation of vanadium compounds... 

Artificial dyes in the laboratory of the Lancashire calico-printer John Lightfoot included his own invention of aniline black he also pioneered new methods for mordanting and the use of vanadium in aniline black printing.104A general account has been given of the role of rosaniline in the development of the synthetic dye industry.105 A paper on quinones focuses chiefly on the case of anthraquinone and the synthesis of alizarin from anthracene.106... 

The Ziegler-Natta catalysts have acquired practical importance particularly as heterogeneous systems, mostly owing to the commercial production of linear high- and low-density polyethylenes and isotactic polypropylene. Elastomers based on ethylene-propylene copolymers (with the use of vanadium-based catalysts) as well as 1,4-cz s-and 1,4-tran.y-poly(l, 3-butadiene) and polyisoprene are also produced. These catalysts are extremely versatile and can be used in many other polymerisations of various hydrocarbon monomers, leading very often to polymers of different stereoregularity. In 1963, both Ziegler and Natta were awarded the Nobel Prize in chemistry. 

It can be noted that since the initial use of vanadium(V) in acid medium for the biaryl oxidative coupling by Kende and Schlessinger, improvements have been made using other metal oxides, including manganese(III), cerium(IV), ruthenium(IV) and thallium(III) as illustrated above in the Magnus and Enders syntheses [87,129]. 

Fischer-Tropsch synthesis and BASF s use of vanadium oxide to produce sulfuric acid. 

Although the major use of vanadium, manganese, and cobalt is as alloying metals with iron in making specialty steels, chromium is widely used as a plating metal because it is highly resistant to corrosion. Of even greater importance is its use in stainless steels that will be addressed in the next section. 

Vanadium phosphates have been established as selective hydrocarbon oxidation catalysts for more than 40 years. Their primary use commercially has been in the production of maleic anhydride (MA) from n-butane. During this period, improvements in the yield of MA have been sought. Strategies to achieve these improvements have included the addition of secondary metal ions to the catalyst, optimization of the catalyst precursor formation, and intensification of the selective oxidation process through improved reactor technology. The mechanism of the reaction continues to be an active subject of research, and the role of the bulk catalyst structure and an amorphous surface layer are considered here with respect to the various V-P-O phases present. The active site of the catalyst is considered to consist of V and V couples, and their respective incidence and roles are examined in detail here. The complex and extensive nature of the oxidation, which for butane oxidation to MA is a 14-electron transfer process, is of broad importance, particularly in view of the applications of vanadium phosphate catalysts to other processes. A perspective on the future use of vanadium phosphate catalysts is included in this review. 

The major industrial use of vanadium is in alloy steels and cast iron, to which it lends ductility and shock resistance. Conunercial production is mainly as the iron alloy ferrovanadium, a tough, high-speed steel containing around 4-5% V. In ferrovanadium manufacture, vanadium pentoxide is reduced in an airtight electric furnace by ferrosilicon. ... 

Most heterocyclic nuclei undergo the sulfonation reaction. Sulfonation of pyridine is difficult. The yield of 3"pyridinesulfonic acid by sulfonation at 390° with oleum is only 13%. The yield is greatly improved by the use of vanadium or mercury salts as catalysts. A critical study of the factors influencing the yield has been made, and a maximum yield of 71% is reported. Fuming sulfuric acid converts quinoline to practically pure 8-quinolinesulfonic acid (54%). The action of concentrated sulfuric acid on dibenzofuran gives 2-dibenzofuransulfonic acid (75%). ... 

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