Discovery of Fluorine
In 1530, German mineralogist Georgius Agricola described the use of the mineral fluorspar in metal refining. Fluorspar (which we now know is mainly calcium fluoride) was very useful because it combined with the unwanted parts of metal ores, allowing the pure metal to flow and be collected.
The element fluorine had not yet been discovered and the ‘fluor’ in fluorspar came from the Latin word ‘fluere,’ meaning ‘to flow,’ because this is what it allowed metals to do. The element name fluorine ultimately came from the ‘fluor’ in fluorspar.
Several chemists carried out experiments on fluorspar in the early 1800s including Gay Lussac, Louis Jacques Thenard, Humphry Davy, Carl Wilhelm Scheele and Joseph Priestley.
Often they produced what they called fluoric acid – now named hydrofluoric acid – a highly reactive and potentially deadly acid. Even small splashes of this acid on skin can be fatal.Several early attempts to isolate fluorine led to blindings and fatalities. English chemist Humphrey Davy wrote: “[fluoric acid] is a very active substance, and must be examined with great caution.
In 1809, French scientist Andre-Marie Ampere proposed that fluoric acid was a compound of hydrogen with a new element. He exchanged letters with Humphry Davy, and in 1813 Davy announced the discovery of the new element fluorine, giving it the name suggested to him by Ampere.
Davy wrote: “… it appears reasonable to conclude that there exists in the fluoric compounds a peculiar substance, possessed of strong attractions for metallic bodies and hydrogen… it may be denominated fluorine, a name suggested to me by M. Ampere.”
Fluorine was finally isolated in 1886, by French chemist Henri Moissan – whose own work was interrupted four times by serious poisoning caused by the element he was pursuing.
Moissan isolated fluorine by electrolysis of dry potassium hydrogen fluoride and anhydrous hydrofluoric acid.
To limit corrosion he carried out his work in a platinum container and cooled the electrolytic solution in it to -23oF (-31 oC.) The stoppers were made out of fluorite (a more modern name for our old friend fluorspar, which we began this section with). Fluorine was produced at the positive electrode.
Henri Moissan received the 1906 Nobel Prize in Chemistry for his achievement.
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