The remaining clear liquid is cooled, causing white crystals to settle out [1, 6].
To start the animation, imagine giant excavators scooping this red earth into a massive grinding mill. The rock is crushed into a fine powder, ready for its first big chemical makeover [6]. Act II: The White Powder (The Bayer Process) How Aluminium is made animation
A fine, snowy white powder called Alumina (aluminum oxide) [1, 6]. Act III: The Lightning Strike (The Hall-HĂ©roult Process) The remaining clear liquid is cooled, causing white
The aluminum in the rock dissolves into the liquid, while the unwanted "red mud" (iron and silica) sinks to the bottom and is filtered out [1, 6]. Act II: The White Powder (The Bayer Process)
This is the most dramatic part of the animation. Alumina is very stable; you can’t just melt it with fire to get the metal out. You have to "shock" it [1, 6].
The crushed bauxite enters a high-pressure "pressure cooker" filled with hot caustic soda [1, 6].