Great 👍 — now we move on to **Bismuth (Bi, atomic number 83).**
Bismuth is a **post-transition metal** found mainly in **bismuthinite (Bi₂S₃)** and also as a byproduct of lead, copper, tin, silver, and gold smelting. It is rare but industrially important due to its low toxicity and unique properties.
Here are the **20 most common methods of extracting Bismuth**:
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# **20 Most Common Methods of Extracting Bismuth**
### **A. Extraction from Primary Ores**
1. **Mining of Bismuthinite (Bi₂S₃)** – The main natural source.
2. **Mining of Native Bismuth** – Rare, direct metallic deposits.
3. **Crushing and Grinding of Ore** – Prepares ore for separation.
4. **Gravity Concentration** – Initial enrichment due to high density.
5. **Froth Flotation of Bismuth Sulfides** – Separates Bi₂S₃ from gangue.
6. **Roasting of Bismuth Sulfides** – Converts Bi₂S₃ → Bi₂O₃ + SO₂.
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### **B. Smelting and Refining**
7. **Reduction of Bi₂O₃ with Carbon in Furnaces** – Produces crude metallic Bi.
8. **Blast Furnace Smelting with Fluxes** – Industrial-scale production.
9. **Electrolytic Refining of Bismuth** – Produces ultra-pure Bi.
10. **Liquation Process (Melting and Separation)** – Exploits low melting point of Bi to separate it.
11. **Vacuum Distillation Refining** – Removes volatile impurities.
12. **Zone Refining (Laboratory-Scale Ultra-Purification)** – Produces semiconductor-grade Bi.
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### **C. Recovery as a Byproduct**
13. **Recovery from Lead Smelting** – Bismuth is extracted from lead bullion.
14. **Recovery from Copper Smelting** – Found in copper refinery anode slimes.
15. **Recovery from Tin Ores** – Present in cassiterite smelting residues.
16. **Recovery from Silver and Gold Refining** – Collected from refining byproducts.
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### **D. Secondary Sources & Modern Methods**
17. **Recovery from Industrial Waste and Slags** – Hydrometallurgical leaching methods.
18. **Recovery from E-Waste and Solder Alloys** – Bismuth-tin solders processed chemically.
19. **Chlorination of Bismuth Compounds** – Conversion of Bi₂O₃ → BiCl₃, then reduction.
20. **Laboratory Reduction of Bismuth Salts (BiCl₃, Bi(NO₃)₃)** – Produces pure Bi for experiments.
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✅ **Summary:**
* **Industrial sources:** Mainly bismuthinite, but most bismuth is produced as a **byproduct** of lead, copper, tin, and precious metal refining.
* **Key steps:** Ore concentration → roasting → carbon reduction → refining (electrolytic, vacuum, liquation).
* **Secondary recovery:** From slags, industrial waste, and electronic solders.
* **Purification:** Electrolysis, vacuum distillation, and zone refining.
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Next in periodic table order is **Polonium (Po, atomic number 84).**
⚠️ Polonium is **extremely radioactive and rare**, so its “extraction methods” are very different from typical metals (nuclear synthesis and radiochemical isolation).
Would you like me to still list the **20 methods for Polonium extraction** (including historical/modern nuclear production routes)?
