Perfect 👍 — next in **periodic table order** is **Cerium (Ce, atomic number 58).**
Cerium 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 Cerium**:
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# **20 Most Common Methods of Extracting Cerium**
### **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 cerium and other REEs.
3. **Alkaline Digestion (NaOH) of Monazite** – Converts phosphate to soluble cerium salts.
4. **Leaching of Bastnäsite with Acid or Alkali** – Produces soluble cerium compounds.
5. **Purification by Precipitation of Thorium and Other Impurities** – Removes radioactive and heavy elements.
6. **Solvent Extraction of Cerium Salts** – Organophosphorus extractants separate Ce³⁺/Ce⁴⁺ from other REEs.
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### **B. Separation and Concentration**
7. **Oxidation of Cerium(III) to Cerium(IV) (Ce³⁺ → Ce⁴⁺)** – Allows selective precipitation.
8. **Precipitation of Cerium as Ce(OH)₄** – Concentrates cerium from mixed REE solutions.
9. **Conversion to Cerium Carbonate (Ce₂(CO₃)₃)** – Precursor for oxide formation.
10. **Calcination to Cerium Oxide (CeO₂)** – Prepares for reduction or industrial use.
11. **Ion Exchange Separation of Cerium** – Separates cerium from lanthanum, neodymium, and others.
12. **Fractional Precipitation Using Oxalates or Hydroxides** – Lab or pilot-scale separation.
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### **C. Reduction to Metallic Cerium**
13. **Calciothermic or Metallothermic Reduction of CeO₂ → Ce** – Main industrial method.
14. **Electrolytic Reduction of Molten CeCl₃** – Produces high-purity metallic cerium.
15. **Vacuum Distillation of Cerium Metal** – Purification for ultra-high purity Ce.
16. **Hydrogen Reduction of Cerium Halides** – Laboratory-scale method.
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### **D. Recovery from Byproducts / Secondary Sources**
17. **Recovery from Monazite Sands during Thorium Extraction** – Cerium collected as a byproduct.
18. **Recovery from Bastnäsite Refining** – Cerium separated during lanthanum 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 → selective precipitation → reduction/electrolysis → metallic cerium.
* **Metallic cerium:** Produced via calciothermic/metallothermic reduction or molten salt electrolysis.
* **Byproduct sources:** Thorium extraction residues, bastnäsite processing, spent REE catalysts, recycled electronics.
* **Laboratory/experimental:** Oxidation of Ce³⁺ to Ce⁴⁺, vacuum distillation, hydrogen reduction.
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Next in periodic order is \*\*Praseodymium (Pr, atomic number 59).
Do you want me to continue with **20 extraction methods for Praseodymium**?
