Describe the extraction of aluminum metal from its named ore, including the description of the extraction process.

Bauxite ore is first purified to obtain pure aluminum oxide ($Al_2O_3$), also known as alumina. This is typically done using the Bayer process, which involves dissolving bauxite in hot concentrated sodium hydroxide solution to form sodium aluminate, filtering out impurities, and then precipitating aluminum hydroxide, which is finally heated to produce pure alumina.

The pure alumina is then dissolved in molten cryolite ($Na_3AlF_6$). Cryolite acts as a solvent, lowering the melting point of alumina from over $2000 \text{ °C}$ to about $950 \text{ °C}$ and increasing its electrical conductivity. The electrolysis takes place in a large steel tank lined with carbon, which acts as the cathode. Large blocks of graphite (carbon) are suspended into the molten mixture to act as anodes.

A high electric current is passed through the molten mixture.
At the cathode (negative electrode): Aluminum ions ($Al^{3+}$) gain electrons and are reduced to molten aluminum metal, which sinks to the bottom of the cell.

At the anode (positive electrode): Oxide ions ($O^{2-}$), from the dissociation of alumina, lose electrons and are oxidized to oxygen gas.

The oxygen gas produced at the anodes reacts with the hot carbon anodes, forming carbon dioxide gas. This causes the anodes to be consumed and they must be replaced periodically.

The molten aluminum is periodically tapped off from the bottom of the cell.