Chapter 03 of 5
The Hall-Héroult Revolution
How 'frozen electricity' finally liberated the metal from its ore.
- The Impasse
A Chemical Fortress
By the 1880s, aluminium was still locked in bauxite. No amount of heat or standard chemistry could cheaply break its bond with oxygen.
- Parallel Minds
The 1886 Miracle
Two young men, Charles Hall in America and Paul Héroult in France, independently discovered the solution in the same year. They were both just 22 years old.
- Mechanism
Dissolving the Stone
The breakthrough relied on cryolite, a rare mineral that could dissolve alumina (aluminium oxide) at a lower temperature than its melting point.
17 more cards in this chapter
Could you answer this?
Why did the Hall-Héroult process use the mineral cryolite?
🥈 Aluminium: The Clay That Became Silver
- 01The Elusive Earth of AlumUnderstanding the stubborn chemical bond of 'the silver from clay.'
- 02More Precious Than GoldWhen aluminium was the world's most expensive luxury material.
- 03The Hall-Héroult RevolutionHow 'frozen electricity' finally liberated the metal from its ore.
- 04Duralumin and the Age of FlightThe accidental discovery of age-hardening and high-strength alloys.
- 05The Infinite LoopThe physics of recycling and the metal's modern ubiquitous life.