History of aluminium

History of aluminium.
The history of aluminium in human usage goes back at least 2,500 years, when its compound alum was used for dyeing and city defense. During the Middle Ages, alum was traded in international commerce. In the Age of Enlightenment, the earth of alum, alumina, was shown to be an oxide of a new metal which was then discovered in the 1820s. Pure aluminium remained scarce until industrial production began in 1856; since the 1886 discovery of the Hall–Héroult process, production has grown exponentially. Engineering and construction applications began in the first half of the 20th century; aluminium was a vital strategic resource for aviation during both world wars. In 1954, it surpassed copper as the most produced non-ferrous metal. In the following decades, aluminium production spread throughout the world, and the metal became an exchange commodity and gained usage in transportation and packaging. Aluminium production in the 21st century exceeds that of all other non-ferrous metals combined.