Perfect 👍 — next in **periodic table order** is **Rhenium (Re, atomic number 75).**
Rhenium is a **transition metal** that occurs in **molybdenite (MoS₂)** as a minor component and in **copper and lead ores**. Industrial extraction involves **oxidation, leaching, solvent extraction, and reduction** to produce metallic rhenium.
Here are the **20 most common methods of extracting Rhenium**:
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# **20 Most Common Methods of Extracting Rhenium**
### **A. Extraction from Molybdenite and Other Ores**
1. **Mining of Molybdenite (MoS₂) Concentrates** – Primary source of rhenium.
2. **Roasting of MoS₂ Concentrates** – Converts ReS₂ to Re₂O₇.
3. **Oxidation in Air at High Temperature** – Forms volatile Re₂O₇.
4. **Capture of Volatile Re₂O₇ from Roasting Gas** – Condensation into soluble rhenium compounds.
5. **Leaching of Rhenium from Roasted Material with Water or Alkali** – Produces perrhenate solution (ReO₄⁻).
6. **Removal of Molybdenum and Other Impurities** – Precipitation or solvent extraction.
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### **B. Concentration and Purification**
7. **Solvent Extraction of Perrhenate Ions** – Separates ReO₄⁻ from other ions.
8. **Ion Exchange Chromatography** – Laboratory or industrial scale separation of Re.
9. **Fractional Crystallization of Ammonium Perrhenate (NH₄ReO₄)** – Key intermediate for metallic rhenium.
10. **Precipitation with Cations (e.g., Cu²⁺, Pb²⁺)** – Concentrates rhenium.
11. **Purification by Recrystallization of Ammonium Perrhenate** – Removes residual impurities.
12. **Electrolytic Purification of Re Compounds** – Produces ultra-high-purity rhenium intermediates.
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### **C. Reduction to Metallic Rhenium**
13. **Hydrogen Reduction of Ammonium Perrhenate → Re** – Main industrial method.
14. **Reduction of Re₂O₇ with Carbon at High Temperature** – Produces metallic rhenium.
15. **Reduction of ReO₄⁻ Solutions Using Metallic Reductants** – Laboratory method.
16. **Vacuum Melting or Electron Beam Melting of Rhenium** – Produces high-purity rhenium metal.
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### **D. Recovery and Secondary Sources**
17. **Recovery from Roaster Flue Dusts from Mo Refining** – Leaching + precipitation.
18. **Recovery from Superalloy Scrap Containing Rhenium** – Hydrometallurgical or pyrometallurgical extraction.
19. **Recovery from Copper and Lead Smelting Byproducts** – Leaching and solvent extraction.
20. **Recovery from Industrial Slags Containing Rhenium** – Chemical extraction and purification.
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✅ **Summary:**
* **Main industrial sources:** Molybdenite concentrates, copper/lead ores.
* **Primary extraction steps:** Roasting → Re₂O₇ volatilization → leaching → ammonium perrhenate formation → reduction to metallic rhenium.
* **Metallic rhenium:** Produced via hydrogen reduction, carbon reduction, or electron beam melting.
* **Byproduct/secondary sources:** Flue dusts, superalloy scrap, copper/lead smelting residues, industrial slags.
* **Laboratory/experimental:** Ion exchange, solvent extraction, crystallization, reduction methods.
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Next in periodic order is \*\*Osmium (Os, atomic number 76). Do you want me to continue with **20 extraction methods for Osmium**?
