World aluminum

The aluminum industry consumes much more carbon, as baked anode composites, than the total of all other industrial uses for baked and graphitized carbon products. The free world s total annual aluminum production capacity is approximately 16 million short tons, about one-third being produced in the United States. World aluminum production involves the consumption (oxidation) of about eight million tons of anode carbon. Production occurs by electrolytic deposition from cryolite-alumina melts using a process patented simultaneously, but independently, in 1886 by Hall in America and Heroult in France. While minor process modifications have been made in the intervening years, and productivity greatly increased, substantially the same process is still used. The industrial electrolytic cell consists of a shallow carbon vessel about 10 ft. wide by 30 ft. long, and 1-2 ft. deep, which acts as the cathode and contains the fused salt bath and molten aluminum product. The carbon anodes are supported above the cathode and lowered into the cell at the rate of... 

Aluminum. Aluminum is used extensively in modem India particularly in house wiring and the transmission of electrical power, about 50% of the production going for this use. All of the technology has been imported primarily from the United States. Production has increased from about 3000 metric tons in 1951 to 180,000 metric tons in 1977. It is estimated that the demand for aluminum in 1984 will be 400,000 metric tons. The demand is likely to increase dramatically since the per capita use in India is 0.4 vs. 22 kg in the United States and of 2.9 kg in the rest of the world. Aluminum today is produced in five producing plants, four of them in the private sector and one in the pubhc sector. The most serious problem with the aluminum industry is the pricing pohcy. By law, 50% of production goes to the government at a fixed price, so-called levy metal. The current levy price is 903 a metric ton vs. a production cost of 1,084 per metric ton. 

World Aluminum Mining Refinery, and Smelter Capacity Fiandbook 1985—1996, Australian Mineral Economics, T.td., Sydney, 1989. 

International Aluminium Institute (AIA, London 2003), www.world-aluminium.organd www.world-aluminum.org... 

Wohler is generally credited with having isolated the metal in 1827, although an impure form was prepared by Oersted two years earlier. In 1807, Davy proposed the name aluminum for the metal, undiscovered at that time, and later agreed to change it to aluminum. Shortly thereafter, the name aluminum was adopted to conform with the "ium" ending of most elements, and this spelling is now in use elsewhere in the world. 

Cesium, an alkali metal, occurs in lepidolite, pollucte (a hydrated silicate of aluminum and cesium), and in other sources. One of the world s richest sources of cesium is located at Bernic Lake, Manitoba. The deposits are estimated to contain 300,000 tons of pollucite, averaging 20% cesium. 

Corundum. Comndum [1302-75-5] (see Aluminum compounds) is a naturally occurring massive crystalline mineral composed of aluminum oxide. It is an impure form of the gems mby and sapphke. Prior to 1900 comndum was an important abrasive for the production of grinding wheels. Today it is mainly employed as a loose abrasive for grinding and polishing optical lenses. Almost all the world s supply of comndum now comes from Africa, primarily from Zimbabwe. 

The first reported synthesis of acrylonitrile [107-13-1] (qv) and polyacrylonitrile [25014-41-9] (PAN) was in 1894. The polymer received Htde attention for a number of years, until shortly before World War II, because there were no known solvents and the polymer decomposes before reaching its melting point. The first breakthrough in developing solvents for PAN occurred at I. G. Farbenindustrie where fibers made from the polymer were dissolved in aqueous solutions of quaternary ammonium compounds, such as ben2ylpyridinium chloride, or of metal salts, such as lithium bromide, sodium thiocyanate, and aluminum perchlorate. Early interest in acrylonitrile polymers (qv), however, was based primarily on its use in synthetic mbber (see Elastomers, synthetic). 

Although a few simple hydrides were known before the twentieth century, the field of hydride chemistry did not become active until around the time of World War II. Commerce in hydrides began in 1937 when Metal Hydrides Inc. used calcium hydride [7789-78-8J, CaH2, to produce transition-metal powders. After World War II, lithium aluminum hydride [16853-85-3] LiAlH, and sodium borohydride [16940-66-2] NaBH, gained rapid acceptance in organic synthesis. Commercial appHcations of hydrides have continued to grow, such that hydrides have become important industrial chemicals manufactured and used on a large scale. 

Iron [7439-89-6J, Fe, from the Latin ferrum, atomic number 26, is the fourth most abundant element in the earth s cmst, outranked only by aluminum, sihcon, and oxygen. It is the world s least expensive and most useful metal. Although gold, silver, copper, brass, and bron2e were in common use before iron, it was not until humans discovered how to extract iron from its ores that civilization developed rapidly (see Mineral processing and recovery). 

Lead [7439-92-17, Pb, is an essential commodity ia the modem iadusttial world, ranking fifth ia tonnage consumed after iron (qv), copper (qv), aluminum (see Aluminumand aluminum alloys), and 2iac (see Zinc and zinc alloys). In 1993, the United States accounted for 30% of the 4,450,000 metric tons of refined lead consumed by the Western world. Slightly over half of the lead produced ia the world now comes from recycled sources (see Recycling, NONFERROUS LffiTALS). 

A conservative estimate of the total value of the products from the mineral industry is ca 3.9 trillion ia terms of 1992 dollars (4). This estimate does not include the value of products derived from secondary sources such as recycling (qv) or reclamation. Secondary recovery is significant for certain commodities. For example, in 1992 ca 30% of the world steel (qv) production, 46% of the world refined lead output, 15% of the world refined copper (qv) production, and ca 30% of the aluminum (see Aluminumand ALUMINUM alloys) output from the Western world were clearly identified as being derived from scrap. The value of the world mineral commodity export trade in 1992 was ca 616,698 million ia 1992 dollars. This accounted for ca 18% of all commodities exported (4). 

Sodium ethoxide was the first metal alkoxide described in 1837 (1). The alkoxides of many transition metals were developed after World War II (2—5). Today some alkoxides, including those of sodium, potassium, magnesium, aluminum, zirconium, and titanium, are commercially important. The name metal alkoxides is preferred, although metal alcoholates is also used. 

Table 10. Annual World Production of Aluminum, Copper, Magnesium, Lead, and Zinc, 10 t/yr ...

Eigure 1 illustrates the Bayer process as it is practiced in the 1990s. The primary purpose of a Bayer plant is to process bauxite to provide pure alumina for the production of aluminum. World production of Al(OH)2 totaled ca 55 x 10 t in 1988. Practically all of the hydroxide was obtained by Bayer processing and 90% of it was calcined to metallurgical grade alumina (AI2O2). However, about 10% of the bauxite processed serves as feedstock to the growing aluminum chemicals industry. 

Gibbsite is aii important technical product and world production, predominantly by the Bayer process, is more than 50 million metric tons aimuaHy. Alost (90%) is calcined to alumina [1344-28-1 j, Al202, to be used for aluminum production. Tlie remainder is used by the chemical industry as filler for paper, plastics, rubber, and as the starting material for the preparation of various aluminum compounds, alumina ceramics, refractories, polishing products, catalysts, and catalyst supports. 

The demand for sihcon in the 1990s has exceeded the installed Western world capacity. The difference has been supplemented by shipments from China, the Ukraine, and Russia. In 1993, Chinese exports reached 117,000 t, whereas exports from Ukraine and Russia were around 40,000 t (19). In 1995, the exports from China increased to 155,000 t, whereas the exports from the CIS (former USSR) countries declined. The sihcon metal shipped from these countries has been high in iron and calcium and has been used primarily in the secondary aluminum market. 

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. 

Forming-Die Alloys. The tonnage of slab zinc used in this appHcation is small. The use of zinc alloy dies started in the aircraft industry during World War II (119). Zinc-based alloys cast in sand and plaster molds continue to be used for short-mn dies for steel and aluminum stampings in the automotive and aircraft industries (120). Considerable cost savings are realized with these low melting zinc-based alloys which are easy to poHsh, machine, weld, and remelt. 

Oxide films on aluminum are produced by anodi2ing in a chromic acid solution. These films are heavier than those produced by chemical conversion and thinner and more impervious than those produced by the more common sulfuric acid anodi2ing. They impart exceptional corrosion resistance and paint adherence to aluminum and were widely used on military aircraft assembHes during World War II. The films may be dyed. A typical anodi2ing bath contains 50 to 100 g/L CrO and is operated at 35—40°C. The newer processes use about 20 volts dc and adjust the time to obtain the desired film thickness (184). 

Talc. Talc (qv) [14807-96-6] (Cl Pigment White 26, Cl No. 77019), is finely powdered, native, hydrous magnesium sihcate, 3MgO 4Si02 H20 (soapstone) sometimes containing a small amount of aluminum siUcate. It is produced ia many parts of the world, including France, Italy, India, and the United States. 

Chromium Oxide is present in just about every maintenance shop in the world. We call it the GRINDING WHEEL The abrasive material in your electric grinding wheel Is Chromium Oxide. Cheap wheels may tend to use aluminum oxide. 

One of the first applications of the Redux process was in construction of structural aluminum parts for the de Havilland bomber Sea Hornet produced during World War II ([198], pp. 80-81 [202,203]). In the original fonn, it consisted of a two-part adhesive including a low viscosity liquid phenolic known... 

Because gluing of wood members was a very common method of fabricating aircraft during this time, there are innumerable examples. One unusual and interesting example, as mentioned above, is the de Havilland Mo.squito of 1940. In many respects the Mosquito was a bridge between the old world of wood aircraft and the increasingly predominant world of aluminum aircraft (Fig. 2). 

The demand for aviation gasoline during World War II was so great that isobutanc from alkylation feedstock was insufficient. This deficiency was remedied by isomerization of abundant normal butane into isobutane using the isomerization catalyst aluminum chloride on alumina promoted by hydrogen chloride gas. 

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