|
Aluminothermic Reaction
Aluminothermic reactions are exothermic chemical reactions using aluminum as the reducing agent at high temperature. The process is industrially useful for production of alloys of iron. The most prominent example is the thermite reaction between iron oxides and aluminum to produce iron itself: : Fe2O3 + 2 Al → 2 Fe + Al2O3 This specific reaction is however not relevant to the most important application of aluminothermic reactions, the production of ferroalloys. For the production of iron, a cheaper reducing agent, coke, is used instead via the carbothermic reaction. History Aluminothermy started from the experiments of Russian scientist Nikolay Beketov at the University of Kharkiv in Ukraine, who proved that aluminum restored metals from their oxides under high temperatures. The reaction was first used for the carbon-free reduction of metal oxides. The reaction is highly exothermic, but it has a high activation energy since strong interatomic bonds in the solids m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Goldschmidt
Johannes Wilhelm "Hans" Goldschmidt (18 January 1861 – 21 May 1923) was a German chemist notable as the discoverer of the Thermite reaction. He was also co-owner of the Chemische Fabrik Th. Goldschmidt, as of 1911 Th. Goldschmidt AG (later to become part of Evonik Industries) and its most important chemis'' The reaction, also called the Goldschmidt process, is used for Exothermic welding, thermite welding, often used to join railway tracks. Thermites have also been used in metal refining, disabling munitions, and in incendiary weapons. Some thermite-like mixtures are used as pyrotechnic initiators in fireworks. His grave is preserved in the Protestant ''Friedhof I der Jerusalems- und Neuen Kirchengemeinde'' (Cemetery No. I of the congregations of Jerusalem's Church and New Church) in Berlin-Kreuzberg, south of Hallesches Tor. Biography He was born in Berlin on 18 January 1861. He was a student of Robert Bunsen. His father, Theodor Goldschmidt, was the founder of the chem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metallurgy
Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys. Metallurgy encompasses both the science and the technology of metals; that is, the way in which science is applied to the production of metals, and the engineering of metal components used in products for both consumers and manufacturers. Metallurgy is distinct from the craft of metalworking. Metalworking relies on metallurgy in a similar manner to how medicine relies on medical science for technical advancement. A specialist practitioner of metallurgy is known as a metallurgist. The science of metallurgy is further subdivided into two broad categories: chemical metallurgy and physical metallurgy. Chemical metallurgy is chiefly concerned with the reduction and oxidation of metals, and the chemical performance of metals. Subjects of study in chemical metallurgy include mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inorganic Reactions
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorganic compounds comprise most of the Earth's crust, although the compositions of the deep mantle remain active areas of investigation. Some simple carbon compounds are often considered inorganic. Examples include the allotropes of carbon (graphite, diamond, buckminsterfullerene, etc.), carbon monoxide, carbon dioxide, carbides, and the following salts of inorganic anions: carbonates, cyanides, cyanates, and thiocyanates. Many of these are normal parts of mostly organic systems, including organisms; describing a chemical as inorganic does not necessarily mean that it does not occur within living things. History Friedrich Wöhler's conversion of ammonium cyanate into urea in 1828 is often cited as the starting point of modern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicothermic Reaction
Silicothermic reactions are thermic chemical reactions using silicon as the reducing agent at high temperature (800-1400°C). The most prominent example is the Pidgeon process for reducing magnesium metal from ores. Other processes include the Bolzano process and the magnetherm process. All three are commercially used for magnesium production. The silicothermic process for magnesium production was developed commercially in Canada during the Second World War''Encyclopedia of materials, parts and finishes'', 2nd edition, Mel M. Schwartz, 2002, p. 371, by Lloyd Montgomery Pidgeon. See also *Aluminothermic reaction *Calciothermic reaction Calciothermic reactions are metallothermic reduction reactions (more generally, thermic chemical reactions) which use calcium metal as the reducing agent at high temperature. Calcium is one of the most potent reducing agents available, usually dra ... References Metallurgy Metallurgical processes Inorganic reactions Silicon {{reactio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calciothermic Reaction
Calciothermic reactions are metallothermic reduction reactions (more generally, thermic chemical reactions) which use calcium metal as the reducing agent at high temperature. Calcium is one of the most potent reducing agents available, usually drawn as the strongest oxidic reductant in Ellingham diagrams, though the lanthanides best it in this respect in oxide processes. On the other hand, this trend does not continue to other compounds that are non-oxides, and for instance lanthanum is produced by the calciothermic reduction of the chloride, calcium being a more potent reducing agent than lanthanum involving chlorides. Calciothermic processes are used in the extraction of metals such as uranium, zirconium, and thorium from oxide ores. An interesting way of performing calciothermic reductions is by in-situ generated metallic calcium, dissolved in molten calcium chloride, as shown in the FFC Cambridge Process. See also * Aluminothermic reaction * Silicothermic reaction Silicother ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermite
Thermite () is a pyrotechnic composition of metal powder and metal oxide. When ignited by heat or chemical reaction, thermite undergoes an exothermic reduction-oxidation (redox) reaction. Most varieties are not explosive, but can create brief bursts of heat and high temperature in a small area. Its form of action is similar to that of other fuel-oxidizer mixtures, such as black powder. Thermites have diverse compositions. Fuels include aluminum, magnesium, titanium, zinc, silicon, and boron. Aluminum is common because of its high boiling point and low cost. Oxidizers include bismuth(III) oxide, boron(III) oxide, silicon(IV) oxide, chromium(III) oxide, manganese(IV) oxide, iron(III) oxide, iron(II,III) oxide, copper(II) oxide, and lead(II,IV) oxide. The reaction, also called the Goldschmidt process, is used for thermite welding, often used to join railway tracks. Thermites have also been used in metal refining, disabling munitions, and in incendiary weapons. Some thermite-like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rail Tracks
A railway track (British English and UIC terminology) or railroad track (American English), also known as permanent way or simply track, is the structure on a railway or railroad consisting of the rails, fasteners, railroad ties (sleepers, British English) and ballast (or slab track), plus the underlying subgrade. It enables trains to move by providing a dependable surface for their wheels to roll upon. Early tracks were constructed with wooden or cast iron rails, and wooden or stone sleepers; since the 1870s, rails have almost universally been made from steel. Historical development The first railway in Britain was the Wollaton Wagonway, built in 1603 between Wollaton and Strelley in Nottinghamshire. It used wooden rails and was the first of around 50 wooden-railed tramways built over the next 164 years. These early wooden tramways typically used rails of oak or beech, attached to wooden sleepers with iron or wooden nails. Gravel or small stones were packed around the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferrovanadium
Ferrovanadium (FeV) is an alloy formed by combining iron and vanadium with a vanadium content range of 35–85%. The production of this alloy results in a grayish silver crystalline solid that can be crushed into a powder called "ferrovanadium dust".Hathaway, G. J.; Proctor, N. H. ''Proctor and Hughes chemical hazards of the workplace''; Wiley-Interscience: Hoboken, 2004. Ferrovanadium is a universal hardener, strengthener and anti-corrosive additive for steels like high-strength low-alloy steel, tool steels, as well as other ferrous-based products. It has significant advantages over both iron and vanadium individually. Ferrovanadium is used as an additive to improve the qualities of ferrous alloys. One such use is to improve corrosion resistance to alkaline reagents as well as sulfuric and hydrochloric acids. It is also used to improve the tensile strength to weight ratio of the material. One application of such steels is in the chemical processing industry for high pressure h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niobium Pentoxide
Niobium pentoxide is the inorganic compound with the formula Nb2 O5. 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 lithium niobate.Francois Cardarelli (2008) ''Materials Handbook'' Springer London Structure It has many polymorphic forms all based largely on octahedrally coordinated niobium atoms.Wells A.F. (1984) ''Structural Inorganic Chemistry'' 5th edition Oxford Science Publications The polymorphs are identified with a variety of prefixes. The form most commonly encountered is monoclinic H- Nb2 O5, which has a complex structure with a unit cell containing 28 niobium atoms and 70 oxygen, where 27 of the niobium atoms are octahedrally coordinated and one tetrahedrally. There is an uncharacterised solid hydrate, , the so-called niobic acid (previously calle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferroniobium
Ferroniobium is an important iron-niobium alloy, with a niobium content of 60-70%. 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 Nb2O5. This oxide is mixed with iron oxide and aluminium and is reduced in an aluminothermic reaction to niobium and iron. The component metals can be purified in an electron beam furnace or the alloy can be used as it is. For alloying with steel the ferroniobium is added to molten steel before casting. The largest producers of ferroniobium are the same as for niobium and are located in Brazil and Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot .... External links * *ISO 545 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
