Perfect 👍 — next in **periodic table order** is **Arsenic (As, atomic number 33).**
Arsenic is a **metalloid** that rarely occurs free in nature. It is primarily found in **arsenopyrite (FeAsS)**, **realgar (As₄S₄)**, and **orpiment (As₂S₃)**. Industrial extraction usually involves **roasting or sublimation** to obtain elemental arsenic or arsenic trioxide.
Here are the **20 most common methods of extracting Arsenic**:
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# **20 Most Common Methods of Extracting Arsenic**
### **A. Industrial / Large-Scale Methods**
1. **Roasting of Arsenopyrite (FeAsS + O₂ → FeO + As₂O₃ + SO₂)** – Produces arsenic trioxide (As₂O₃).
2. **Sublimation of Arsenic Trioxide (As₂O₃ → As vapour → As solid)** – Produces metallic arsenic.
3. **Direct Sublimation of Native Arsenic** – Rare natural source, lab or specialty method.
4. **Oxidative Roasting of Realgar (As₄S₄ + O₂ → As₂O₃ + SO₂)** – Converts sulfide to oxide.
5. **Oxidative Roasting of Orpiment (As₂S₃ + O₂ → As₂O₃ + SO₂)** – Industrial arsenic oxide production.
6. **Reduction of As₂O₃ with Carbon (Carbothermic)** – Produces elemental arsenic.
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### **B. Hydrometallurgical Methods**
7. **Leaching Arsenic Oxide with NaOH or KOH** – Produces soluble arsenate (Na₃AsO₃ / Na₃AsO₄).
8. **Precipitation of Arsenic Compounds from Leach Solution** – Intermediate for metallic arsenic.
9. **Electrolytic Reduction of Arsenic Salts** – Lab-scale method.
10. **Reduction of Arsenic Chloride (AsCl₃) with Metals (Zn/Al)** – Laboratory preparation of elemental As.
11. **Reduction of Arsenic Oxides with Hydrogen Gas** – Laboratory or small-scale production.
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### **C. Extraction from Byproducts / Residues**
12. **Recovery from Copper Smelting Slags** – Hydrometallurgical leaching and precipitation.
13. **Recovery from Lead and Gold Refining Residues** – Arsenic present as minor byproduct.
14. **Recovery from Roaster Dust in Sulfide Ore Processing** – Collect As₂O₃ from flue gases.
15. **Extraction from Contaminated Soil or Mining Tailings** – Acid leaching → precipitation.
16. **Recovery from Electronic Waste** – Hydrometallurgical methods, rare but possible.
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### **D. Laboratory / Experimental Methods**
17. **Aluminothermic Reduction of As₂O₃** – Produces metallic arsenic.
18. **Magnesiothermic Reduction of Arsenic Oxides** – Lab or research method.
19. **Plasma Reduction of Arsenic Compounds** – Experimental method for high-purity As.
20. **Solar-Thermal Reduction of As₂O₃** – Experimental renewable energy method.
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✅ **Summary:**
* **Main industrial method:** Roasting arsenic-containing sulfides → sublimation to produce As₂O₃ → reduction to metallic arsenic.
* **Metallic arsenic:** Produced via sublimation, carbothermic, hydrogen, or aluminothermic reduction.
* **Byproduct sources:** Copper, lead, gold smelting residues, roaster dust.
* **Laboratory/experimental:** Mg/Al reduction, plasma, solar-thermal.
* **Hydrometallurgical methods:** Leaching with alkali, precipitation, electrolytic reduction.
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Next in periodic order is **Selenium (Se, atomic number 34).**
Do you want me to continue with **20 extraction methods for Selenium**?
