Aluminium is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has a great affinity towards oxygen, and forms a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, non-magnetic and ductile. It has one stable isotope, 27Al; this isotope is very common, making aluminium the twelfth most common element in the Universe. The radioactivity of 26Al is used in radiodating.
The Hall–Héroult process is the major industrial process for smelting aluminium. It involves dissolving aluminium oxide (alumina) in molten cryolite, and electrolysing the molten salt bath, typically in a purpose-built cell. The Hall–Héroult process applied at industrial scale happens at 940–980 °C and produces 99.5–99.8% pure aluminium. Recycled aluminum requires no electrolysis, thus it does not end up in this process. This process contributes to climate change through the emission of carbon dioxide in the electrolytic reaction and consumption of large amounts of electrical energy.
Aluminium hydroxide, Al(OH)3, is found in nature as the mineral gibbsite (also known as hydrargillite) and its three much rarer polymorphs: bayerite, doyleite, and nordstrandite. Aluminium hydroxide is amphoteric, i.e., it has both basic and acidic properties. Closely related are aluminium oxide hydroxide, AlO(OH), and aluminium oxide or alumina (Al2O3), the latter of which is also amphoteric. These compounds together are the major components of the aluminium ore bauxite.
Norsk Hydro ASA is a Norwegian aluminium and renewable energy company, headquartered in Oslo. It is one of the largest aluminium companies worldwide. It has operations in some 50 countries around the world and is active on all continents. The Norwegian state owns 34.3% of the company through the Ministry of Trade, Industry and Fisheries. A further 6.5% is owned by Folketrygdfond, which administers the Government Pension Fund of Norway. Norsk Hydro employs approximately 35,000 people. Hilde Merete Aasheim has been the CEO since May, 2019.
Alcoa Corporation is an American industrial corporation. It is the world's eighth largest producer of aluminum, with corporate headquarters in Pittsburgh, Pennsylvania. Alcoa conducts operations in 10 countries. Alcoa is a major producer of primary aluminum, fabricated aluminum, and alumina combined, through its active and growing participation in all major aspects of the industry: technology, mining, refining, smelting, fabricating, and recycling.
Charles Martin Hall was an American inventor, businessman, and chemist. He is best known for his invention in 1886 of an inexpensive method for producing aluminum, which became the first metal to attain widespread use since the prehistoric discovery of iron. He was one of the founders of Alcoa. Alfred E. Hunt, together with Charles Hall and a group of five other individuals – his partner at the Pittsburgh Testing Laboratory, George Hubbard Clapp; his chief chemist, W. S. Sample; Howard Lash, head of the Carbon Steel Company; Millard Hunsiker, sales manager for the Carbon Steel Company; and Robert Scott, a mill superintendent for the Carnegie Steel Company – raised $20,000 to launch the Pittsburgh Reduction Company, which was later renamed Aluminum Company of America and shortened to Alcoa.
AMAG is the biggest company in the Austrian Aluminium industry sector. It is situated in the village of Ranshofen, which is in Braunau am Inn.
Aluminum Corporation of China Limited, is a Chinese company listed in Hong Kong and in New York. A multinational aluminium company, its headquarters are in Beijing, People's Republic of China. It is the world's second-largest alumina producer and third-largest primary aluminium producer.
Aluminium recycling is the process by which scrap aluminium can be reused in products after its initial production. The process involves simply re-melting the metal, which is far less expensive and energy-intensive than creating new aluminium through the electrolysis of aluminium oxide (Al2O3), which must first be mined from bauxite ore and then refined using the Bayer process. Recycling scrap aluminium requires only 5% of the energy used to make new aluminium from the raw ore. For this reason, approximately 36% of all aluminium produced in the United States comes from old recycled scrap. Used beverage containers are the largest component of processed aluminum scrap, and most of it is manufactured back into aluminium cans.
Aluminium alloys are alloys in which aluminium (Al) is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon, tin and zinc. There are two principal classifications, namely casting alloys and wrought alloys, both of which are further subdivided into the categories heat-treatable and non-heat-treatable. About 85% of aluminium is used for wrought products, for example rolled plate, foils and extrusions. Cast aluminium alloys yield cost-effective products due to the low melting point, although they generally have lower tensile strengths than wrought alloys. The most important cast aluminium alloy system is Al–Si, where the high levels of silicon (4.0–13%) contribute to give good casting characteristics. Aluminium alloys are widely used in engineering structures and components where light weight or corrosion resistance is required.
Aluminium–lithium alloys are a set of alloys of aluminium and lithium, often also including copper and zirconium. Since lithium is the least dense elemental metal, these alloys are significantly less dense than aluminium. Commercial Al–Li alloys contain up to 2.45% lithium by mass.
United Company RUSAL, international public joint-stock company is the world's second largest aluminium company by primary production output. It was the largest until overtaken by China Hongqiao Group in 2015. UC RUSAL accounts for almost 9% of the world's primary aluminium output and 9% of the world's alumina production.
The Electric Smelting and Aluminum Company, founded as Cowles Electric Smelting and Aluminum Company, and Cowles Syndicate Company, Limited, formed in the United States and England during the mid-1880s to extract and supply valuable metals. Founded by two brothers from Ohio, the Cowles companies are remembered for producing alloys in quantity sufficient for commerce. Their furnaces were electric arc smelters, one of the first viable methods for extracting metals.
Aleris Corporation was an American aluminum rolled products producer, based in Beachwood, Ohio. The company had approximately 5,000 employees globally as of mid 2015.
China Zhongwang Holdings Limited is the second largest industrial aluminium extrusion product developer and manufacturer in the world and the largest in Asia and China. The company is headquartered in Liaoyang, China.
Alcan was a Canadian mining company and aluminum manufacturer. It was founded in 1902 as the Northern Aluminum Company, renamed Aluminum Company of Canada in 1925, and Alcan Aluminum in 1966. It took the name Alcan Incorporated in 2001. During that time, it grew to become one of the world's largest aluminum manufacturers.
Mitsubishi Materials Corporation, or MMC, is a Japanese company. It is a manufacturer of cement products, copper and aluminum products, cemented carbide tools, and electronic materials. It is one of the core companies of Mitsubishi Group.
The Hoopes process is a metallurgical process, used to obtain the aluminium metal of very high purity. The process was patented by William Hoopes, a chemist of the Aluminum Company of America (ALCOA) in 1925.
Aluminium metal is very rare in native form, and the process to refine it from ores is complex, so for most of human history it was unknown. However, the compound alum has been known since the 5th century BCE and was used extensively by the ancients for dyeing. During the Middle Ages, its use for dyeing made it a commodity of international commerce. Renaissance scientists believed that alum was a salt of a new earth; during the Age of Enlightenment, it was established that this earth, alumina, was an oxide of a new metal. Discovery of this metal was announced in 1825 by Danish physicist Hans Christian Ørsted, whose work was extended by German chemist Friedrich Wöhler.
