How Aluminium is made animation | Karthi Explains

Summary

The manufacturing of aluminum involves mining bauxite, the primary raw material. After crushing, bauxite is mixed with caustic soda and processed to extract alumina. This is then smelted in a reduction pot using electricity, where alumina reacts to form molten aluminum. The metal is finally cast into various shapes like ingots, demonstrating a complex but fascinating process.

Takeaways

• 🌏 **Aluminum Rarity**: Pure aluminum does not occur naturally; it must be extracted from minerals like bauxite.
• ⛏️ **Raw Material Mining**: Bauxite is the primary source of raw material for aluminum production.
• 🔨 **Ore Processing**: The process begins with crushing bauxite ore and mixing it with caustic soda.
• 🔥 **Heat and Digestion**: The slurry is heated to 270°C in a digester to produce a sodium aluminate solution.
• 🚰 **Impurity Removal**: Impurities settle and are filtered out, leaving a purified sodium aluminate solution.
• 🌡️ **Precipitation**: Aluminum hydroxide seed crystals are added to precipitate large aluminum crystals.
• 🔥 **Calcination**: Crystals are heated to over 960°C to remove water molecules, resulting in alumina powder.
• ⚡ **Smelting**: Smelting requires large amounts of electricity and takes place in a reduction pot lined with carbon.
• 🔌 **Electrolysis**: Alumina is dissolved in molten cryolite to form an electrolyte solution for the electrolytic process.
• 🔄 **Oxygen and Carbon Reaction**: Oxygen released during electrolysis reacts with carbon to form carbon dioxide.
• 💧 **Aluminum Collection**: Molten aluminum is collected and transferred for casting into various forms.

Q & A

What is the most common metal on Earth?

Aluminum is the most common metal on Earth.

Does pure aluminum occur naturally?

No, pure aluminum does not occur naturally.

What are some minerals from which aluminum can be obtained?

Aluminum can be obtained from minerals like cryolite, feldspar, corundum, etc.

What is the primary source of raw material for making aluminum?

The primary source of raw material for making aluminum is bauxite.

How is bauxite ore processed to extract alumina?

Bauxite ore is crushed, mixed with caustic soda, processed in a grinding mill to produce a slurry, heated in a digester, and then filtered to remove impurities.

What is the temperature at which the slurry is heated in the digester?

The slurry is heated to 270 degrees Celsius in the digester.

What is the purpose of adding aluminum hydroxide seed crystals to the sodium aluminate solution?

Adding aluminum hydroxide seed crystals starts the precipitation process, leading to the formation of large aluminum crystals.

What is the temperature range for heating the aluminum crystals in rotary kilns?

The aluminum crystals are heated in rotary kilns to temperatures over 960 to 1100 degrees Celsius.

What is the white powder formed after heating the aluminum crystals?

The white powder formed is known as alumina or aluminum oxide.

How much electricity is required for aluminum smelting?

Aluminum smelting requires a large amount of electricity.

What is the role of cryolite in the smelting process?

Cryolite is used to dissolve alumina crystals to form an electrolyte solution that conducts electricity during the smelting process.

What happens to the freed aluminum atoms during the smelting process?

The freed aluminum atoms settle to the bottom of the pot as molten metal.

How is the molten aluminum collected and further processed?

The molten aluminum is collected in a crucible, transferred to a holding furnace, and then cast as ingots using various casting methods.