Aluminum production starts with bauxite ore, which contains aluminum oxide (Al₂O₃).
The Bayer Process extracts alumina from bauxite by dissolving it in sodium hydroxide and filtering out impurities.
The resulting alumina (aluminum oxide) is a white powder used in aluminum smelting.
The Hall-Héroult Process is used to extract aluminum metal from alumina.
Alumina is dissolved in molten cryolite (Na₃AlF₆) inside electrolytic cells.
A strong electric current passes through the solution, separating aluminum, which collects at the bottom of the cell.
The liquid aluminum is periodically siphoned off for further processing.
The molten aluminum is cast into large ingots, slabs, or billets for further processing.
These are either direct-chill (DC) cast or continuous cast.
Aluminum slabs are preheated to around 400–600°C (750–1,100°F).
The slabs are passed through a series of rolling mills to reduce thickness.
This process improves mechanical properties and refines the grain structure.
The aluminum is further rolled at room temperature to achieve the desired thickness.
Cold rolling increases strength and improves surface finish.
Heat treatments, such as annealing, relieve stresses and improve workability.
Various tempers (e.g., H14, H32, T6) are applied depending on the end-use application.
Various finishing techniques improve the sheet’s properties:
Cleaning & Degreasing – Removes oils and contaminants.
Anodizing – Forms a protective oxide layer for corrosion resistance.
Coating & Painting – Enhances appearance and adds extra protection.
Embossing & Texturing – Provides decorative or functional surface finishes.
Sheets are cut into desired sizes and shapes using shearing, laser cutting, or water jet cutting.
Rolls of aluminum are slit into narrower widths for specific applications.
