Vanadium in Nature

The recovery of vanadium from these slags is of commercial interest because of the depletion of easily accessible ores and the comparatively low concentrations (ranging from less than 100 ppm to 500 ppm) of vanadium in natural deposits (147,148). In the LILCO appHcations the total ash contained up to 36% 20 (147). Vanadium is of value in the manufacture of high strength steels and specialized titanium alloys used in the aerospace industry (148,149). Magnesium vanadates allow the recovery of vanadium as a significant by-product of fuel use by electric utiUties (see Recycling, nonferrous LffiTALS). 

E. Bayer, E. Koch and G. Anderegg, Amavadin, an example for selective binding of vanadium in nature studies of its complexation chemistry and a new structural proposal, Angew.Chem.Int.Ed.Engl. 26 (1987) 545-546. 

The concentration of vanadium in natural waters (sea and river) has been found to be very low and in the range of 0.5-2.5 j,g/liter [14], The principle dissolved species in seawater appears to be V02(0H)3 [15]. Environmental mobilization of vanadium and its compounds occurs by a number of means in the net transport of vanadium into the oceans. Some of these transport processes include terrestrial runoff, industrial emissions, atmospheric washout (vanadium in the air comes only from human activity, as there are no significant natural sources), and river transport and oil spills, resulting in a complex ecological cycle [16]. 

T. Yamane, Y. Osada, and M. Suzuki. Continuous flow system for the determination of trace vanadium in natural waters utilizing in-line preconcentration/separation coupled with catalytic photometric detection. Talanta 45 583-589,1998. 

Physical and Chemical Properties. Titanium dioxide [13463-67-7] occurs in nature in three crystalline forms anatase [1317-70-0] brookite [12188-41 -9] and mtile [1317-80-2]. These crystals are essentially pure titanium dioxide but contain small amounts of impurities, such as iron, chromium, or vanadium, which darken them. Rutile is the thermodynamically stable form at all temperatures and is one of the two most important ores of titanium. 

Because of the strategic nature of many of the uses, vanadium is one of the materials designated in the National Defense Stockpile Inventory. The goals for 1980 for vanadium-containing materials was 907 metric tons of contained vanadium in ferrovanadium, and 6985 t of contained vanadium in vanadium pentoxide. As of March 1981, the inventory consisted of 4911 of contained vanadium in vanadium pentoxide there was no ferrovanadium in the inventory (22). 

The residual portion of feedstocks contains a large concentration of contaminants. The major contaminants, mostly organic in nature, include nickel, vanadium, nitrogen, and sulfur. Nickel, vanadium, and sodium are deposited quantitatively on the catalyst. This deposition poisons the catalyst permanently, accelerating production of coke and light gases. 

Although the neutron activation analysis is inherently more sensitive than the atomic absorption spectrometry, both procedures yield a reliable measurement of vanadium in seawater at the natural levels of concentration. 

The CL signal arises from the reaction of luminol with I2 produced by the latter reaction. Other reactions are also available including KIO3-KI [68], H202-KI [69], and H202-Na2S203 reactions [70] catalyzed by Mo(VI), among others. Similar reactions could also be used for the determination of trace vanadium(V) ions [71, 72], The developed methods were applied to the determination of trace elements in natural waters and other matrices with detection limits below the ng/mL levels for traces of molybdenum and vanadium. 

Ethylene-propylene (30-60 mole per cent) copolymers produce substances which are rubbery in nature. They are prepared by using Ziegler catalysts based on vanadium oxychloride/aluminium trihexyl by solution process at 40°C using chlorobenzene or pentane as a solvent. These can be vulcanised with peroxides. Ethylene-propylene-hexa 1, 4-diene terpolymers are rubbers which can be vulcanised with sulphur. 

The above techniques have a wide array of applications, including those that are both analytical and physicochemical (such as bonding) in nature. Typical examples of research include the surface chemistry of ferrite minerals (38) and the valence states of copper in a wide array of copper (39) minerals. Other areas of bonding that have been studied include the oxidation state of vanadium (40) in vanadium-bearing aegirities (also using x-ray photoelectron spectroscopy) and the. surface features of titanium perovskites (41). ... 

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. 

B. Wet Processes.—These vary considerably in detail according to the nature and amount of constituents other than vanadium in the ore. An outline of the operations involved in the case of patronite is as follows The ore is roasted with common salt or sodium carbonate and then extracted either (a) with water to give an alkaline solution of sodium vanadate and soluble vanadates of other metals, any lead, zinc, copper, etc., being left in the residue or (b) with sulphuric acid to produce a solution of vanadyl sulphate. Acid extraction is usually employed when the vanadium content of the material is low. The alkaline extract from (a) is treated with excess of sodium carbonate in order to precipitate calcium and aluminium, after removal of which,... 

Other metalloporphyrins can also be found in Nature, though they do not seem to perform any vital physiological function. For example, the copper(II) complex of uroporphyrin-III (Table 1) occurs in high concentrations in the wing feathers of Turacus indicus, and is the source of most commercial samples of uroporphyrin-III. Chlorophyll degradation products, as the nickel and vanadium complexes, are found in oil shales and as a troublesome contaminant in crude petroleum oils. 

VANADINITE. The mineral vanadimte corresponds to the formula Pb VO Cl, being composed of lead chloride and lead vanadate in the proportion of 90.2% of the former and 9.8% of the latter. It crystallizes in the hexagonal system, is usually prismatic, but the ciystals are often skeletal or cavernous it may be found in crusts. Its fracture is uneven brittle hardness. 2.75-3 specific gravity. 6.86 fresh fractures show a resinous luster color, yellow, yellowish-brown, reddish-brown, and red streak, white to yellowish translucent to opaque. Vanadinite, not a common mineral, occurs as an alteration product in lead deposits. It is found in the Ural Mountains, Austria, Spain, Scotland, Morocco, the Transvaal, Argentina, and Mexico, In the United States it occurs in Arizona, New Mexico, and South Dakota, It is used as an ore of vanadium and to some extent of lead as well. It is interesting to note that this mineral was first described as a chromate upon its discovery in Mexico in 1801, It was not until the discovery of the element vanadium in 1830 that the true nature of this compound was known. 

Unlike metalloporphyrins, the nonporphyrinic metal compounds are poorly characterized with respect to molecular structure and properties. Examining the nature of the nickel and vanadium in these compounds is important from the standpoint that often most of the Ni and V in a petroleum is nonporphyrinic, as shown in Table II. Sugihara et al. (1970) suggested that the nonporphyrin metal compounds comprise a wide variety of coordinated complexes resulting from the reaction of inorganic forms of the metals with polar organic molecules. Larson and Beuther (1966) speculated that the nonporphyrinic metal complexes are simply... 

Collier, R. (1984) Particulate and dissolved vanadium in the North Pacific Ocean. Nature, 309, 441-444. 

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