Paul Héroult

Paul Louis T. Héroult

Paul Louis Toussaint Héroult (born April 10, 1863 in Thury-Harcourt , † May 9, 1914 near Antibes) was a French chemist.

Paul Héroult, the son of a tanner, read at the age of 16 while he was still attending school in Caen. Henri Etienne Sainte-Claire Deville's book De l'aluminium, ses propriétés .. , published in Paris in 1859. Deville first made aluminum in 1854 . Since it was expensive to make aluminum using the Deville method, Héroult decided to find a way to make aluminum in an inexpensive way.

Héroult studied at the Collège Sainte-Barbe in Paris and then returned to Caen to work in his father's tannery. In addition, he worked on a process for the production of aluminum. He filed his first patent in February 1886 and was confirmed on April 23, 1886. It described the fused- salt electrolysis of aluminum, which was discovered at almost the same time by the American chemist Charles Martin Hall and which is known as the Hall-Héroult process . However, Héroult rejected the cryolite process and then patented a process for the production of aluminum bronze .

In early 1887, Héroult tried to win the support of Alfred Rangod Pechiney (1833–1916), in whose factory aluminum was produced using the Deville method. Pechiney urged Héroult to modify his electrolytic process, which, however, could not produce pure aluminum.

Héroult therefore sought contact with entrepreneurs in Switzerland, where he ordered a small dynamo machine from Maschinenfabrik Oerlikon that was supposed to supply electricity for the electric furnace he had invented. In the spring of 1887 he came to Zurich for the acceptance of the machine and carried out investigations in Oerlikon that caught the attention of the director of this company, Peter Emil Huber-Werdmüller . Huber immediately recognized the ingenuity and scope of Héroult's invention and tried to secure its industrial exploitation for Switzerland. Here he got in touch with Gustave Naville from Escher Wyss & Cie. as well as Georg Robert Neher , who runs JG Neher Sons & Cie. in Neuhausen and whose company had the rights to use water at the Rhine Falls.

The "Swiss Metallurgical Society" was founded as early as 1887 to test the Héroult process. Héroult became Technical Director and went to the United States in 1888 to defend his patents against Hall's claims. During his absence, the trial runs for his process were successfully completed and on November 18, 1888, the "Aluminum Industrie Aktiengesellschaft" (AIAG) Neuhausen was founded for the purpose of large-scale production of aluminum using the Héroult-Hall process. AIAG was the forerunner of Alusuisse .

Soon electrical arcs were occasionally observed between the surface of the electrolyte and the electrodes, from which Héroult and Martin Kiliani developed the electric arc furnace . This electric arc furnace, the prototype of the modern electric steel furnace , was first used for the direct reduction of iron ore in La Praz in 1903.

swell

• Leo Weisz : Studies on the commercial and industrial history of Switzerland. Second volume. 258 p. Verlag Neue Zürcher Zeitung. Zurich. 1940.
• Lance Day (Ed.): Biographical dictionary of the history of technology. 844 S. Routledge London. 1998. ISBN 0-415-19399-0

Individual evidence

1. ↑ Patent US387876 : Process of preparing aluminum bronze and other alloys. Registered on December 27, 1887 , published on August 14, 1888 , inventor: Paul Héroult (quote: "Again, the flux may evolve gases, which will settle on the carbon anode and tend to polarize it and by preventing free access of the oxygen to the carbon increase the resistance and the cost of production. For instance, I have used cryolite (which can be fused by external heat without a flux) as an electrolyte, and also as a flux in connection with alumina, but have found it objectionable , because it evolves fluorine, which does not, like the oxygen evolved from alumina, combine with the carbon anode and pass off, but settles upon it with the effect above mentioned. "). ‌