The crushed bauxite enters a high-pressure "pressure cooker" filled with hot caustic soda [1, 6].
The electricity rips the oxygen away from the aluminum. The oxygen bonds with the carbon rods and floats away as CO2, while the pure, heavy molten aluminum sinks to the bottom of the vat [1, 6]. Act IV: The Final Form
Massive carbon rods (anodes) are lowered into the vat, and a colossal electric current—hundreds of thousands of amperes—is surged through the liquid [1, 6].