Perfect 👍 — next in **periodic table order** is **Osmium (Os, atomic number 76).**
Osmium is a **transition metal** that occurs primarily in **platinum group metal ores** (PGMs) such as **osmiridium**, **platinum nuggets**, and **nickel-copper sulfide ores**. Industrial extraction involves **concentration, chemical separation, and reduction**.
Here are the **20 most common methods of extracting Osmium**:
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# **20 Most Common Methods of Extracting Osmium**
### **A. Extraction from Platinum Group Ores**
1. **Mining of PGM Ores (Nickel-Copper or Platinoid Ores)** – Primary source of osmium.
2. **Crushing and Grinding of Ore** – Prepares material for concentration.
3. **Gravity and Magnetic Separation** – Enriches osmium-containing minerals.
4. **Froth Flotation** – Concentrates PGMs including Os, Ir, Pt, Rh, Ru, Pd.
5. **Smelting to Separate Base Metals** – Osmium remains in the noble metal fraction.
6. **Acid Digestion of PGM Concentrates (Aqua Regia)** – Dissolves noble metals for separation.
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### **B. Chemical Separation of Osmium**
7. **Precipitation as Osmium Tetroxide (OsO₄)** – Selective oxidation of osmium.
8. **Volatilization of OsO₄** – Exploits its high volatility to separate osmium from other PGMs.
9. **Reduction of OsO₄ to Metallic Osmium** – Converts OsO₄ back to elemental osmium.
10. **Solvent Extraction of OsO₄** – Organic solvents selectively extract osmium.
11. **Ion Exchange Separation** – Purifies osmium from platinum, iridium, ruthenium, and palladium.
12. **Selective Precipitation of Osmium Salts** – Produces intermediates like ammonium osmium salts.
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### **C. Conversion to Osmium Compounds**
13. **Conversion to Osmium Chlorides (OsCl₃, OsCl₄)** – For laboratory and industrial use.
14. **Formation of Osmium Oxides (OsO₂, OsO₄)** – Intermediates for purification or catalytic applications.
15. **Calcination of Osmium Compounds** – Removes impurities before final reduction.
16. **Preparation of Osmium Alloys** – Mixed with platinum, iridium, or ruthenium for industrial applications.
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### **D. Recovery and Secondary Sources**
17. **Recovery from Platinum Refinery Residues** – Flue dusts and sludges treated for osmium.
18. **Recovery from Scrap Catalysts Containing PGMs** – Hydrometallurgical or pyrometallurgical extraction.
19. **Recovery from Nickel-Copper Smelting Slags** – Chemical leaching and selective precipitation.
20. **Laboratory-Scale Extraction from Secondary Sources** – Includes analytical isolation and purification of osmium.
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✅ **Summary:**
* **Main industrial sources:** Platinum group ores, nickel-copper sulfide ores.
* **Primary extraction steps:** Ore concentration → smelting → acid digestion → selective oxidation to OsO₄ → reduction to metallic osmium.
* **Metallic osmium:** Produced by reduction of OsO₄ or osmium salts.
* **Byproduct/secondary sources:** Platinum refinery residues, PGM scrap catalysts, smelting slags.
* **Laboratory/experimental:** Ion exchange, solvent extraction, selective precipitation, oxidation/reduction cycles.
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Next in periodic order is \*\*Iridium (Ir, atomic number 77). Do you want me to continue with **20 extraction methods for Iridium**?
