why can't you use Carbon to extract Aluminium?

and
How do you extract Aluminium using elecrolysis?

http://www.chemguide.co.uk/inorganic/extraction/aluminium.html

Aluminium is too reactive and might form stable compunds.

Aluminium is first extracted from its ore(bauxite) after being purified by NaOH. This is then mixed with cryolite(Na3AlF5) wich lowers its melting point to about 900 degrees Celcius. This molten mixture is then electrolysed. Molten Al will collect at the cathode and O2 gas is given off at the anode.

You cannot use carbon to extract aluminum because of the difference in their chemical reactivity and thermodynamic stability. Carbon is less reactive and stable compared to aluminum, so it cannot displace aluminum from its compounds through a carbon reduction reaction.

To extract aluminum, a process known as electrolysis is commonly used. Here's a step-by-step explanation of how this process works:

1. First, bauxite ore (which contains aluminum oxide, Al2O3) is mined from the ground and refined into alumina (Al2O3) through the Bayer process.

2. The alumina is dissolved in a molten cryolite (Na3AlF6) bath, which lowers the melting point of the mixture. Cryolite is used to make the process more energy-efficient.

3. The bath is then placed in an electrolytic cell, which consists of a steel container lined with carbon (graphite) electrodes.

4. The cathode (negative electrode) is made of carbon, and the anode (positive electrode) is also made of carbon but serves as the source of oxygen (O2) during the process.

5. When an electric current is passed through the cell, it causes the positively charged aluminum ions (Al3+) to move towards the cathode.

6. At the cathode, the Al3+ ions gain three electrons and are reduced to form aluminum metal (Al).

7. Simultaneously, at the anode, oxygen gas (O2) is formed by the oxidation of oxide ions (O2-) obtained from the dissociation of alumina.

8. The molten aluminum metal collects at the bottom of the cell, where it can be periodically tapped off. It is then further processed and purified for various applications.

In summary, electrolysis is used to extract aluminum by passing an electric current through a molten mixture of alumina dissolved in cryolite. The current causes aluminum ions to be reduced at the cathode, forming aluminum metal, while oxygen gas is produced at the anode.