History of the Metal

In the first century AD, according to Pliny the Elder, a master presented Tiberius, an Emperor, with a very light and beautiful goblet made of a silvery metal. The giver said that he had produced this new metal out of usual clay. He naturally expected some gratitude, but instead he was punished. The short-sighted governor gave orders for the master’s head to be cut off and for his workshop to be destroyed to prevent a drop in gold and silver prices.

This story is just a fable, but what about the facts? The first step in extracting aluminium was made by the famous Paracelsus in the 16th century. From alums he separated an «aluminous soil» which contained the oxide of a then unknown metal. In the middle of the 18th century, the experiment was repeated by Andreas Marggraf, a German chemist. He called the aluminium oxide ‘alumina’ (Latin word ‘alumen’ — astringent). From that moment, the scientific community was made aware the existence of aluminium. However, as it was not found in its pure form, it was not really recognized.

In 1808, Humphry Davy, an Englishman, tried to extract aluminium through electrolysis. Though he did not succeed, the scientist gave the metal its current name. Hans-Christian Oersted’s experiments succeeded in 1825. By passing chlorine through a hot mixture of alumina and coal, he produced aluminium chloride. By heating this with potassium amalgam, Oersted extracted a metal similar to tin in its properties. The scientist published this information in a little-known magazine and terminated his experiments. Friedrich Wohler, a German scientist, picked up where Oersted had left off and spent 18 years working to produce an aluminium ingot.

In 1854, Saint-Claire Deville, a French chemist and industrialist, developed a more efficient method. He applied sodium as a deoxidizing agent instead of expensive potassium. At the World Exhibition in 1855 in Paris, the ‘silver made of clay’ created a furor. Emperor Napoleon III, at whose table the most honorary guests were served food on aluminium tableware, dreamed of supplying his army with cuirasses made of this light metal. He greatly supported Deville and later constructed several aluminium smelters. However, Deville’s metal was still too expensive. Only jewellery and luxury articles were made from aluminium at that time.

A cheaper method to produce aluminium appeared only at the end of the 19th century. Charles Hall, an American student, and Paul Heroult, a French engineer, developed it simultaneously and independently of each other. The electrolysis of aluminium oxide melted in cryolite produced wonderful results, but required a lot of power. When constructing the first smelter, this problem was solved by building the facility near the famous Rhine waterfall in Switzerland.

Karl Josef Bayer, an Austrian engineer working in Russia, developed an alumina production technology which made the new method even cheaper. The Bayer and Hall-Heroult processes are still applied at modern aluminium smelters.

Though this new industrial material was very good in some areas of application, pure aluminium was not solid enough. This problem was solved by Alfred Wilm, a German chemist, who melted aluminium with small quantities of cuprum, magnesium and manganese. He discovered that the alloy became increasingly solid several days after the melting of these metals. Duralumin was first produced in Dueren, Germany, in 1911 and the alloy was named after the city. The first aircraft made from duralumin was built in 1919.

This was the beginning of the aluminium world’s triumph. While only 8,000 tonnes of the metal was produced in 1900, its production volume had reached 24 million tonnes one hundred years later.