Most ancient emperors favored crowns made of gold and jewels, but French Emperor Napoleon III created an aluminum crown for himself to demonstrate his supreme status. Moreover, at banquets, Napoleon used aluminum cutlery, while other guests used silver cutlery. The golden crown shone brilliantly, and the silver cutlery gleamed brightly, far more valuable and luxurious than the aluminum crown and cutlery. But why did Napoleon III particularly favor aluminum crowns and cutlery?
It turns out that this is because "rarity breeds value". Aluminum is actually not rare on Earth. It is a highly abundant element in the crust, second only to oxygen and silicon and ranking first among metals, with nearly twice as much as iron and nearly a thousand times more than copper. However, aluminum has very active chemical properties, and it is very difficult to obtain metallic aluminum from minerals. Initially, people used metallic potassium to displace metallic aluminum from anhydrous aluminum chloride, a process that was quite complicated. Therefore, aluminum was a very rare metal material in the 19th century. Moreover, to collect enough aluminum powder for recasting into ingots, aluminum was naturally a "sky-high" commodity, far more rare than gold and silver. This is why Napoleon III favored aluminum crowns and cutlery as a symbol of prestige.
The greatest breakthrough in aluminum production was achieved by two young people. In the late 19th century, American youth Hall and French youth Herou independently obtained metallic aluminum by electrolysis. At that time, the famous British chemist Davy had already obtained extremely active metals such as potassium and sodium by electrolysis of molten potassium hydroxide and sodium hydroxide. Aluminum is also very active, so Hall and Herou considered whether electrolysis could be used to obtain metallic aluminum. Alumina (bauxite) is the most common aluminum ore in nature, but due to its extremely high melting point (over 2000°C), it is difficult to become molten and therefore difficult to undergo electrolysis. Through relentless research, Hall and Herou finally discovered that adding another aluminum-containing mineral, cryolite (sodium hexafluoroaluminate, chemical formula Na 3 AlF 6), to alumina could reduce the melting point of the mixture to below 1000°C. Thus, the electrolysis process could be carried out at lower temperatures, greatly reducing energy consumption and simplifying process requirements. Metallic aluminum thus shed its "expensive cloak" and became a cheap commodity, entering thousands of households and no longer being the exclusive "favorite" of the nobility.
It's worth mentioning that Hall and Herou independently invented the process of producing aluminum by electrolysis. Although the processes were slightly different, they ultimately achieved the same goal. The two men did not compete for the "invention rights" of aluminum production by electrolysis, but instead appreciated and exchanged with each other, becoming close friends.