Vanadium steel production

In practice, the production of vanadium by aluminothermic reduction is also governed by some other considerations. The reduction has to be carried out under an inert atmosphere (helium or argon) to avoid nitrogen pick-up from the air by vanadium metal. The composition of the oxide-aluminum charge has to be so chosen that the thermit (metal obtained by aluminothermic reduction) contains between 11 and 19% aluminum. This is necessary for the subsequent refining step in the vanadium metal production flowsheet. Pure vanadium pentoxide and pure aluminum are used as the starting materials, and the reduction is conducted in a closed steel bomb as shown in Figure 4.17 (C). 

The industrial application of vanadium received its main impetus, however, when the metal entered the domain of metallurgy. In 1893 Moissan applied his electric furnace to the making of alloys of vanadium, and produced ferrovanadium in large quantity. The mechanical properties of vanadium steels were noted by Helouis in 1896,2 but were first thoroughly investigated at Sheffield, England, by Professor Arnold in 1900 (see p. 26), whose work was followed by that of Sankey and Smith in 1904. The discovery of the vast Peruvian deposits in 1905 was followed by the successful preparation from them of a ferrovanadium alloy which could readily be employed in the manufacture of vanadium steels. This process now absorbs nearly all the world s production of vanadium. 

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... 

The element was named by Nils Gabriel Sefstrom (1787-1845) after the Scandinavian goddess of beauty Vanadis. In 1801, Andres Manuel del Rio (1764-1849) identified a new metal he called erythronium (from the Greek for red) that seemed related to uranium and chromium, but he was advised that it was actually lead chromate. In 1830, Sefstrom rediscovered the element and named it, finding out a year later that it was the same material as described by del Rio. Vanadium compounds are found in trace amounts in nature. The majority of vanadium is used as an alloy in steel production. 

Vanadium was discovered in 1802/1803. The current annual world production of V2O5 is 35 000 tons, the majority of which is used in steel production. Small amounts of the element also occur in fossil fuels (Bauer et al. 2002, Tissot and Welte 1984). 

A major commercial use of vanadium has been in steel production (ca. 85% of vanadium production). Vanadium steel, vhich contains 0.1-3% vanadium is tough, strong and heat-resistant, and vithstands strain, vibration and shock. The second largest use area is in nonferrous alloys and nickel-based superalloys for the aerospace industry. Other applications are vanadium containing alloys for batteries and grain refining of aluminum alloys ( 9% of the vanadium production). 

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). 

Ferrophosphoms is produced as a by-product in the electrothermal manufacture of elemental phosphoms, in which iron is present as an impurity in the phosphate rock raw material. The commercial product contains ca 23—29% P and is composed primarily of Fe2P [1310-43-6] and Fe P [12023-53-9] along with impurities such as Cr and V. Ferrophosphoms is used in metallurgical processes for the addition of phosphoms content. Low concentrations (up to - 0.1%) of phosphoms in wrought and cast iron and steel not only increases the strength, hardness, and wear resistance but also improves the flow properties. In large stmctural members and plates, it is desirable to use a type of steel that does not need to be quenched or tempered, and thus does not exhibit weld-hardening. This property is afforded by the incorporation of a small quantity of phosphoms in steel. Ferrophosphoms from western U.S. phosphoms production is used as a raw material for the recovery of vanadium (see Vanadiumand vanadiumalloys). 

Ferrovanadium. The steel industry accounts for the majority of the world s consumption of vanadium as an additive to steel. It is added in the steelmaking process as a ferrovanadium alloy [12604-58-9] which is produced commercially by the reduction of vanadium ore, slag, or technical-grade oxide with carbon, ferrosiHcon, or aluminum. The product grades, which may contain 35—80 wt % vanadium, are classified according to their vanadium content. The consumer use and grade desired dictate the choice of reductant. 

Nuclear and magneto-hydrodynamic electric power generation systems have been produced on a scale which could lead to industrial production, but to-date technical problems, mainly connected with corrosion of the containing materials, has hampered full-scale development. In the case of nuclear power, the proposed fast reactor, which uses fast neutron fission in a small nuclear fuel element, by comparison with fuel rods in thermal neutron reactors, requires a more rapid heat removal than is possible by water cooling, and a liquid sodium-potassium alloy has been used in the development of a near-industrial generator. The fuel container is a vanadium sheath with a niobium outer cladding, since this has a low fast neutron capture cross-section and a low rate of corrosion by the liquid metal coolant. The liquid metal coolant is transported from the fuel to the turbine generating the electric power in stainless steel... 

Ferro-alloys Master alloys containing a significant amount of bon and a few elements more or less soluble in molten bon which improve properties of bon and steels. As additives they give bon and steel better characteristics (increased tensile sbength, wear resistance, corrosion resistance, etc.). For master alloy production carbothermic processes are used for large-scale ferro-sihcon, ferro-chromium, ferro-tungsten, ferro-manganese, ferro-nickel and metallothermic processes (mainly alumino and sihco-thermic) for ferro-titanium, ferro-vanadium, ferro-molybdenum, ferro-boron. 

For industrial purposes vanadium is not required in the elemental state. More than 90 per cent, of the world s production of vanadium is used in the manufacture of special steels, for which purpose an iron-vanadium alloy, known as ferrovanadium, containing from 80 to 40 per cent, of vanadium, is marketed. The method of manufacture of this alloy from vanadium-bearing ores varies considerably with the composition of the ore and the value of the by-products. The process is conveniently divided into two stages ... 

Carbon has a great tendency to combine with vanadium to form carbides, the presence of which in the alloy renders it unsuitable for use in steel manufacture. The successful employment of carbon as the reducing agent is in fact quite recent. Formerly silicon, an iron-silicon alloy, or aluminium was used in place of carbon, but it was difficult to obtain a product which was free from silicon or aluminium, and considerable loss of vanadium took place in the slags.2... 

The production of vanadium metal essentially is the calcium reduction ot vanadium pcntcixide in Ihc presence of iodine and is known its the McKechiiie-Seyboll process. The reaction is earned out in a steel bomb at about 7(K) C. The end products are vanadium metal, lime, and calcium iodide. A similar iodide process also is used in the production of high-purily zirconium. 

There are transition metals in many of the products that people use in daily life. Some of these metals have obvious roles, such as the coin metals of gold, silver, and copper. Iron, which makes up 90% of all metal that is refined, or purified for use, is found in everything from tools to paper staples to washing machines. The most important iron product is steel, an iron-based metal alloy. Most steel made for manufacturing purposes is iron alloyed with the element carbon, which makes the steel much harder than iron alone. Several other transition metals are alloyed with iron to make different kinds of steel for different uses. Vanadium, niobium, molybdenum, manganese, chromium, and nickel are all used in steel alloys. For instance, chromium and nickel are alloyed with iron to create stainless steel, a type of steel that does not rust and is used in surgical instruments, cookware, and tools. Some famous landmarks such as the top of the Chrysler skyscraper in New York City and the St. Louis Gateway Arch are covered in stainless steel. 

Metal powder-coated, through-hardened materials - these materials have been found useful when an alloy does not provide adequate forged quality and for cast materials with specific casting problems. Very fine and very even carbide distribution throughout the entire component offers economically viable (in production terms) and effective wear resistance (temperable matrix with high carbide content). Preferred materials include vanadium-alloyed tool steels. 

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 steel making. A... 

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