Perfect 👍 — next in **periodic table order** is **Lanthanum (La, atomic number 57).**
Lanthanum is a **lanthanide (rare earth metal)** that occurs primarily in **monazite (Ce,La,Th)PO₄** and **bastnäsite (Ce,La)(CO₃)F**. Industrial extraction involves **acid or alkaline digestion, solvent extraction, and reduction**.
Here are the **20 most common methods of extracting Lanthanum**:
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# **20 Most Common Methods of Extracting Lanthanum**
### **A. Extraction from Rare Earth Ores**
1. **Crushing and Grinding of Monazite or Bastnäsite** – Prepares ore for chemical treatment.
2. **Acid Digestion (H₂SO₄ or HCl) of Monazite** – Dissolves lanthanum and other REEs.
3. **Alkaline Digestion (NaOH) of Monazite** – Converts phosphate to soluble lanthanum salts.
4. **Leaching of Bastnäsite with Acid or Alkali** – Produces soluble lanthanum compounds.
5. **Purification by Precipitation of Thorium and Other Impurities** – Removes radioactive and heavy elements.
6. **Solvent Extraction of Lanthanum Salts** – Organophosphorus extractants separate La³⁺ from other REEs.
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### **B. Separation and Concentration**
7. **Ion Exchange Separation of Lanthanum** – Separates La³⁺ from cerium, neodymium, and other REEs.
8. **Fractional Precipitation of Lanthanum Oxalate** – Concentrates La by selective precipitation.
9. **Conversion to Lanthanum Carbonate (La₂(CO₃)₃)** – Precursor for reduction.
10. **Conversion to Lanthanum Oxide (La₂O₃) by Calcination** – Prepares for metallic reduction.
11. **Selective Precipitation Using Ammonium or Oxalic Salts** – Lab or pilot-scale purification.
12. **Extraction from Mixed REE Solutions via Chelating Agents** – Improves separation efficiency.
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### **C. Reduction to Metallic Lanthanum**
13. **Calciothermic or Metallothermic Reduction of La₂O₃ → La** – Common industrial method.
14. **Electrolytic Reduction of Molten LaCl₃** – Produces high-purity metallic lanthanum.
15. **Vacuum Distillation of Metallic Lanthanum** – Purification for ultra-high purity La.
16. **Hydrogen Reduction of Lanthanum Halides** – Laboratory method.
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### **D. Recovery from Byproducts / Secondary Sources**
17. **Recovery from Monazite Sands during Thorium Extraction** – Lanthanum collected as a byproduct.
18. **Recovery from Bastnäsite Refining** – La separated during cerium or neodymium extraction.
19. **Recovery from Spent Rare Earth Catalysts** – Leaching + precipitation.
20. **Recovery from Recycled Electronics Containing REEs** – Hydrometallurgical extraction.
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✅ **Summary:**
* **Main industrial sources:** Monazite, bastnäsite.
* **Primary extraction steps:** Ore crushing → acid/alkaline digestion → purification → precipitation → reduction/electrolysis → metallic lanthanum.
* **Metallic lanthanum:** Produced via calciothermic/metallothermic reduction or molten salt electrolysis.
* **Byproduct sources:** Thorium extraction residues, bastnäsite processing, spent REE catalysts, recycled electronics.
* **Laboratory/experimental:** Hydrogen reduction, vacuum distillation, selective chelation.
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Next in periodic order is \*\*Cerium (Ce, atomic number 58).
Do you want me to continue with **20 extraction methods for Cerium**?
