Question

Of Al, Cu, and Fe, which metal requires the most energy to extract and purify, and why?

1) Aluminum is the most energy intensive. The oxidation of Al from its ore is achieved by electrolysis.
2) Copper is the most energy intensive. The reduction of Cu from its ore is achieved by electrolysis.
3) Iron is the most energy intensive. The reduction of Fe from its ore is achieved by electrolysis.
4) Aluminum is the most energy intensive. The reduction of Al from its ore is achieved by electrolysis.

Answer 1

Aluminum requires the most energy to extract and purify due to the energy-intensive process of electrolysis, which is necessary because aluminum cannot be extracted using carbon reduction.

Step-by-step explanation:

Among Al (aluminum), Cu (copper), and Fe (iron), aluminum requires the most energy to extract and purify. Aluminum is too high in the electrochemical series to be extracted from its ore using carbon reduction, which would require excessively high temperatures to be economically feasible.

Instead, aluminum extraction relies on electrolysis, a process where electrical energy is used to drive the conversion of aluminum oxide into pure aluminum. This occurs in a molten cryolite solution, bypassing the need for the high melting point of aluminum oxide itself. The Bayer Process first purifies bauxite, the key aluminum ore, into pure aluminum oxide before it undergoes electrolysis.