How is Aluminum Made?
Aluminum makes up 8% of the earth's soil and rocks making it the third most abundant element in the earth's crust after oxygen and silicon, respectively.
The compound does not occur in pure form. Instead, the aluminum atoms bind with other metals forming compounds. Unlike other minerals like iron that only require melting to separate the compound, making aluminum is slightly different. With aluminum, the process is complicated and requires significant amounts of energy.
That is why most aluminum smelters are always built within the vicinity of power energy sources.
Step 1- Bauxite Mining
The first step in the production of aluminum is the extraction of bauxites from the ground. Bauxites are the most common raw material in aluminum production. They are mainly made up of aluminum oxide mixed with some other minerals.
If the bauxite contains more than 50% aluminum oxide, it's considered as high quality. However, there is a lot of variation in bauxites. They can be solid, dense, or crumbly. They also vary in color, with the most common one being brick red, brown, or flaming red because of iron oxide.
If the concentration of iron oxide is low, the bauxite can be white or grey. It's also possible to find bauxite in yellow, dark-green, or multi-colour with shades of red, blue, purple, or black depending on the composition.
Step 2 - Alumina Production
After mining the bauxite, the next step in making aluminum is processing the raw material into alumina, a white powder, also known as aluminum oxide.
Depending on the quality of the bauxite, about 4-5 tons of it can yield about 2 tons of alumina, which will produce one ton of aluminum.