The History of Aluminum and Charles Martin Hall

Aluminum is the most abundant metal element in the earth's crust, but it is always found in a compound rather than an easily-refined ore. Alum is one such compound. Scientists tried to tease the metal out of alum, but the process was costly until Charles Martin Hall patented an inexpensive method to produce aluminum in 1889.

History of Aluminum Production

Hans Christian Oersted, a Danish chemist, was the first to produce tiny amounts of aluminum in 1825, German chemist Friedrich Wöhler developed a method that produced enough to study the metal's basic properties in 1845. French chemist Henri Étienne Sainte-Claire Deville finally developed a process that allowed commercial production of aluminum. However, the resulting metal still sold for $40 per kilogram in 1859. Pure aluminum was so rare at that time it was considered a precious metal. 

Charles Martin Hall Discovers the Secret of Cheap Aluminum Production

On April 2, 1889, Charles Martin Hall patented an inexpensive method for the production of aluminum, which brought the metal into wide commercial use.

Read More

Aluminum Properties, Characteristics, and Applications

By Terence Bell

Charles Martin Hall had just graduated from Oberlin College (located in Oberlin, Ohio) in 1885 with a bachelor's degree in chemistry when he invented his method of manufacturing pure aluminum.

Charles Martin Hall's method of processing the metal ore was to pass an electric current through a non-metallic conductor (molten sodium fluoride compound was used) to separate the very conductive aluminum. In 1889, Charles Martin Hull was awarded U.S. patent number 400,666 for his process.

His patent conflicted with that of Paul L.T. Heroult who arrived at the same process independently at practically the same time. Hall had enough evidence of the date of his discovery that the United States patent was award to him rather than Heroult.

In 1888, together with financier Alfred E. Hunt, Charles Martin Hall founded the Pittsburgh Reduction Company now known as the Aluminum Company of America (ALCOA). By 1914, Charles Martin Hall had brought the cost of aluminum down to 18 cents a pound, and it was no longer considered a precious metal. His discovery made him a wealthy man.

Hall obtained several more patents to improve the production of aluminum. He received the Perkin Medal in 1911 for outstanding achievement in applied chemistry. He was on the Board of Trustees for Oberlin College and left them $10 million for their endowment when he died in 1914.

Aluminum from Bauxite Ore

One other inventor needs to be noted, Karl Joseph Bayer, an Austrian chemist, developed a new process in 1888 that could cheaply obtain aluminum oxide from bauxite. Bauxite is an ore that contains a large amount of aluminum hydroxide (Al2O3·3H2O), along with other compounds. The Hall-Héroult and Bayer methods are still used today to produce nearly all of the world's aluminum.

Aluminum Foil

Metal foil has been around for centuries. Foil is solid metal that has been reduced to leaf-like thinness by beating or rolling. The first mass-produced and widely used foil was made from tin. Tin was later replaced by aluminum in 1910, when the first aluminum foil rolling plant “Dr. Lauber, Neher & Cie., Emmishofen.” was opened in Kreuzlingen, Switzerland.

The plant, owned by J.G. Neher & Sons (aluminum manufacturers) started in 1886 in Schaffhausen, Switzerland, at the foot of the Rhine Falls - capturing the falls’ energy to produce aluminum. Neher's sons together with Dr. Lauber discovered the endless rolling process and the use of aluminum foil as a protective barrier. From there began the wide use of aluminum foil in the packaging of chocolate bars and tobacco products. Processes evolved to include the use of print, color, lacquer, laminate and the embossing of the aluminum.