Today in History - 1886

Charles M. Hall produced the first samples of aluminum after several years of intensive work. He had to fabricate most of his apparatus and prepare his chemicals, and was assisted by his older sister Julia Hall (see Craig 1986, CIM Bulletin). The basic invention involves passing an electric current through a bath of alumina dissolved in cryolite, which results in a puddle of aluminum forming in the bottom of the retort. On July 9, 1886, Hall filed for his first patent. This process was also discovered at nearly the same time by the Frenchman Paul Héroult, and it has come to be known as the Hall-Héroult process.