The World Archive: info aluminum

Great 👍 — next in **periodic table order** is **Aluminum (Al, atomic number 13).** Aluminum is the **most abundant metal in Earth’s crust** (\~8%), but it never occurs free in nature. It’s locked in minerals like **bauxite, cryolite, and aluminosilicates.** Modern extraction is dominated by the **Hall–Héroult process**, but historically and experimentally many other methods have been used. Here are the **20 most common methods of extracting Aluminum**: --- # **20 Most Common Methods of Extracting Aluminum** ### **A. Industrial / Large-Scale Processes** 1. **Hall–Héroult Process (Electrolysis of Alumina in Molten Cryolite)** – The main global method for aluminum today. 2. **Bayer Process (Precursor Refining)** – Converts bauxite → alumina (Al₂O₃), which then feeds the Hall–Héroult process. 3. **Electrolysis in Fluoride Salt Mixtures (Na₃AlF₆ + CaF₂)** – Variants of Hall–Héroult that improve conductivity. 4. **Point-Feed Alumina Electrolysis Cells** – Modern industrial design with automated alumina addition. 5. **Inert Anode Technology in Hall–Héroult Cells** – Research to replace carbon anodes with non-consumable ones. 6. **Chloride Electrolysis (AlCl₃ Electrolysis)** – Experimental large-scale process to reduce energy use. --- ### **B. Thermal & Chemical Reduction (Historic and Alternative)** 7. **Wöhler’s Reduction of Anhydrous AlCl₃ with Potassium (1827)** – First isolation of aluminum metal. 8. **Reduction of AlCl₃ with Sodium (Deville’s Process, 1854)** – The first industrial aluminum process before Hall–Héroult. 9. **Reduction of Al₂O₃ with Calcium Carbide (CaC₂)** – Early 20th century attempts. 10. **Thermite Process (Reduction of Al₂O₃ with Magnesium or Calcium)** – Lab-scale demonstrations, not practical industrially. 11. **Reduction of Al₂O₃ with Carbon at High Temperatures** – Produces aluminum carbide (Al₄C₃) instead of pure Al; a failed historical method. 12. **Hydrogen Plasma Reduction of Alumina** – Experimental modern method using hydrogen as reducing agent. --- ### **C. Byproduct & Specialized Recovery** 13. **Electrolysis of AlCl₃ in Molten NaCl/KCl** – Used for aluminum production in some pilot plants. 14. **Extraction from Aluminum Scrap via Remelting** – Secondary aluminum production (hugely important today). 15. **Electrolysis of Aluminum Fluoride (AlF₃) Mixtures** – Tested to improve efficiency. 16. **Magnesiothermic Reduction of Al Compounds** – Small-scale lab preparation method. --- ### **D. Novel & Research Approaches** 17. **Carbothermic Reduction with Vacuum + Temperature Cycling** – Experimental high-temperature process under development. 18. **Solar Carbothermic Reduction of Alumina** – Uses concentrated solar furnaces to reduce CO₂ emissions. 19. **Electrolysis of Alumina in Ionic Liquids (e.g., chloroaluminates)** – Safer low-temperature research route. 20. **Electrochemical Extraction from Clays (Kaolinite, Anorthosite)** – Research into alternative ores to bauxite. --- ✅ **Summary:** * **Today’s dominant method:** Bayer process (to refine alumina) → Hall–Héroult process (to produce aluminum). * **Historic methods:** Wöhler (K reduction), Deville (Na reduction). * **Secondary aluminum recycling** (remelting scrap) is increasingly important and now accounts for a huge fraction of world aluminum supply. * **Research frontiers:** inert anodes, chloride electrolysis, solar carbothermic methods, ionic liquids. --- Next in order is **Silicon (Si, atomic number 14).** Do you want me to continue into **Silicon extraction methods**?