Final answer:
The extraction of aluminum is more expensive than iron due to the energy-intensive electrolysis process required after purifying bauxite to aluminum oxide.
Step-by-step explanation:
The extraction of aluminum is more expensive than iron due to the different processes used to obtain each metal from its ore. For aluminum, the Bayer Process is first used to purify bauxite into aluminum oxide. Then, electrolysis is required to separate the aluminum from oxygen, requiring significant amounts of electricity, which is costly.
Since aluminum oxide has a very high melting point, it cannot be reduced by carbon like iron can, necessitating this more energy-intensive procedure. Furthermore, maintaining the molten state of cryolite, an aluminum compound used to dissolve the aluminum oxide during electrolysis, also adds to the overall costs of production.
On the other hand, the recycling of aluminum can substantially reduce costs and is both cost-effective and ecologically sound because it requires much less energy compared to extracting new aluminum.
Hence, the energy requirements and the complexities associated with the extraction methods contribute to the higher cost of aluminum as compared to iron.This process requires significant electricity, further increased by the need to keep cryolite molten, as opposed to the less costly carbon reduction method used for iron.