https://www.youtube.com/watch?v=t4HAzfhWtqE Okay but old
Alum (aluminum oxide) was used extensively for dyeing from the 5th century BCE and, in 1595, German chemist Andreas Libavius proposed the name "alumina" for alum.
In 1760, the French chemist Théodore Baron d'Hénouville predicted that the base of alum was a metal but it was 1825 before the Danish physicist Hans Christian Ørsted isolated aluminum describing it as, '. . . a lump of metal which in colour and luster somewhat resembles tin.'
Metals like copper and iron had long been extracted from oxides using high temperatures and carbon to remove the oxygen from the metal but this did not work for aluminum. (Alumina (aluminum oxide) is a refractory material that melts at a temperature of 2,072 °C compared to copper oxide 1,326 °C and iron oxide 1,565 °C).
In 1782, French chemist Antoine Lavoisier considered alumina an oxide of a metal with an affinity for oxygen so strong that no known reducing agents could break the bond. In 1794, he and Louis-Bernard Guyton de Morveau melted alumina to a white enamel in a charcoal fire fed by pure oxygen but found no metal. The American chemist Robert Hare repeated the experiment using an oxyhydrogen blowpipe but also produced a white enamel.
In 1807, British chemist Humphry Davy use electrolysis and alkaline batteries to separate an aluminum alloy from the oxygen, but he had no way of separating the potassium and sodium from the aluminum. He tried several ways to isolate pure aluminum without success but did coin the name aluminum. The American chemist Benjamin Silliman repeated Robert Hare's experiment in 1813 and obtained small granules of aluminum, which almost immediately burned as soon as they were exposed to oxygen.
Swedish chemist Jöns Jacob Berzelius suggested the formula AlO3 for alumina (that is each molecule of alumina consisted of one atom of aluminum and 3 atoms of oxygen) in 1815. The correct formula, Al2O3 (a molecule with two atoms of aluminum and three atoms of oxygen) was established by German chemist Eilhard Mitscherlich in 1821 which allowed Berzelius to determine the correct atomic weight of the metal.
Finally, in 1824, Danish physicist Hans Christian Ørsted reacted anhydrous aluminum chloride with a potassium amalgam, yielding a lump of metal that looked similar to tin. This was probably an aluminum–potassium alloy, rather than pure aluminum. German chemist Friedrich Wöhler failed to duplicated Ørsted's success because of an excessive amount of potassium in the mixture. Berzelius also failed to isolate the metal from molten cryolite (sodium hexafluoroaluminate, Na3AlF6) in 1825 because the solution was too alkaline and dissolved all the newly formed aluminum. In 1852 aluminum was sold at US$34 per ounce ($544 per pound) whereas the price of gold at the time was $19 per ounce.
Electrolysis was first used to produce Aluminum in 1854 by the German chemist Robert Wilhelm Bunsen and French chemist Henri Étienne Sainte-Claire Deville but their technique was not suitable for large scale production because of inadequate electrical supplies. So, production remained exclusively by chemical processing. Napoleon III of France, interested in potential military use of the lightweight metal, promised Deville a subsidy for research.
Deville devised a commercial method for aluminum production in 1854 using sodium to reduce aluminum chloride. This produced 12 small ingots of aluminum which attracted the attention of writers Jules Verne, Charles Dickens and Nikolay Chernyshevsky when they were exhibited at the Exposition Universelle of 1855.
Deville built a smelter in 1856 capable of producing up to 2 kilograms of aluminum per day with a purity of 98%. At first, the process extracted pure alumina by calcination (heating) of ammonium alumina but Deville decided to use bauxite ore in 1859. Bauxite contained up to 30% alumina but the impurities had to be removed by calcining (heating slowly) the bauxite with sodium carbonate and coke. When the alumina was converted to sodium aluminate he added the strongly alkaline, sodium hydroxide (caustic soda) to dissolve the sodium aluminate, filtered the liquid and bubbled carbon dioxide through the solution, causing aluminum hydroxide to precipitate. Finally, the aluminum hydroxide was calcined to produce alumina. In the year 1872, Deville produced 1.8 metric tons of aluminum.
In 1856, William Gerhard set up a plant, in London, separating aluminum from cryolite (sodium hexafluoroaluminate, Na3AlF6) and from 1860 to 1874 British ironmaster Isaac Lowthian Bell produced aluminum using the Deville sodium process. (The metal has been known as aluminium in Britain ever since).
In the 1880s, British engineer James Fern Webster produced aluminum with only 0.8% impurities compared to Deville's at 2% and by 1882 world production of aluminum was 3.6 metric tons. In 1884, American architect William Frishmuth, devised a single process to produce sodium, alumina, and aluminum thereby reducing cost to about $16 per pound (at the time the price of silver was $19 per pound).
In 1885, Aluminium und Magnesiumfabrik started production in Germany. In 1886, American engineer Hamilton Castner found a way to extract sodium, which decreased the cost of aluminum to $8 per pound.
In 1870, the Belgian engineer Zénobe-Théophile Gramme invented the dynamo and, in 1889, the Russian engineer Mikhail Dolivo-Dobrovolsky invented three-phase alternating current permitting large scale electrolytic means of production.
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Engineering
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