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Aluminium (or aluminum) 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 .
Aluminium (or aluminum in North American English) is a chemical element; it has symbol Al and atomic number 13. Aluminium has a density lower than that of other common metals, about one-third that of steel. It has a great affinity towards oxygen, forming a protective layer of oxide on the surface when exposed to air.
Charles Martin Hall (December 6, 1863 – December 27, 1914) 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.
Chapter 1. The History of Aluminium Before the 19th Century. Historical background of aluminium in ancient times; archeological findings containing aluminium; first historic mentions of aluminium articles; information about 'alum' – compound substances with chemical structures containing aluminium; production technologies alum and areas of their application in the Ancient Times and Middle Ages.
Aluminium is the most abundant metallic element in the Earth's crust, but it is rarely found in its elemental state. It occurs in many minerals, but its primary commercial source is bauxite, a mixture of hydrated aluminium oxides and compounds of other elements such as iron.
An alum (/ ˈ æ l ə m /) is a type of chemical compound, usually a hydrated double sulfate salt of aluminium with the general formula X Al(SO 4) 2 ·12 H 2 O, such that X is a monovalent cation such as potassium or ammonium. [1] By itself, "alum" often refers to potassium alum, with the formula KAl(SO 4) 2 ·12 H 2 O.
It was recognised as an element by Guyton de Morveau, Lavoisier, Berthollet, and Fourcroy in 1787. [6] The earliest gold artifacts were discovered at the site of Wadi Qana in the Levant. [13] Silver is estimated to have been discovered in Asia Minor shortly after copper and gold. [14] There is evidence that iron was known from before 5000 BC. [15]
The Bayer process is the principal industrial means of refining bauxite to produce alumina (aluminium oxide) and was developed by Carl Josef Bayer.Bauxite, the most important ore of aluminium, contains only 30–60% aluminium oxide (Al 2 O 3), the rest being a mixture of silica, various iron oxides, and titanium dioxide. [1]