Perfect 👍 — next in **periodic table order** is **Tungsten (W, atomic number 74).**
Tungsten is a **transition metal** that occurs primarily in **scheelite (CaWO₄)** and **wolframite ((Fe,Mn)WO₄)**. Industrial extraction involves **concentration, chemical conversion to tungstates, and reduction** to produce metallic tungsten.
Here are the **20 most common methods of extracting Tungsten**:
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# **20 Most Common Methods of Extracting Tungsten**
### **A. Extraction from Ores**
1. **Mining of Scheelite or Wolframite Ores** – Primary tungsten sources.
2. **Crushing and Grinding of Ore** – Prepares material for chemical processing.
3. **Gravity and Magnetic Separation** – Concentrates tungsten ores.
4. **Flotation to Separate Tungstate Minerals** – Enriches WO₄²⁻ minerals.
5. **Alkaline Digestion (NaOH Fusion) of Scheelite** – Converts CaWO₄ to soluble sodium tungstate.
6. **Acid Digestion (HCl or H₂SO₄) of Wolframite** – Produces soluble tungstate salts.
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### **B. Conversion to Tungsten Compounds**
7. **Precipitation of Ammonium Paratungstate (APT, (NH₄)₁₀W₁₂O₄₁·xH₂O)** – Key intermediate for tungsten metallurgy.
8. **Conversion of APT to Tungsten Trioxide (WO₃)** – Calcination step.
9. **Purification of WO₃ by Recrystallization** – Removes molybdenum and other impurities.
10. **Preparation of Tungsten Hexafluoride (WF₆)** – Laboratory or specialized applications.
11. **Production of Tungsten Carbide (WC) from WO₃** – For tool and industrial use.
12. **Conversion to Tungsten Chlorides (WCl₆, WCl₄)** – For chemical reduction methods.
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### **C. Reduction to Metallic Tungsten**
13. **Hydrogen Reduction of WO₃ → W** – Main industrial method for producing tungsten metal powder.
14. **Carbon Reduction of WO₃ (Carbothermic)** – Produces tungsten powder or ingots.
15. **Reduction of WCl₆ with Alkali Metals (Na or K)** – Laboratory or specialty metallic tungsten.
16. **Vacuum or Electron Beam Melting of Tungsten Powder** – Produces high-purity tungsten metal.
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### **D. Recovery and Secondary Sources**
17. **Recovery from Tailings of Tungsten Mines** – Leaching + precipitation of residual tungsten.
18. **Recovery from Scrap Tungsten Alloys** – Recycling tool steel or superalloy scrap.
19. **Recovery from Tungsten-Containing Catalysts** – Hydrometallurgical extraction.
20. **Recovery from Industrial Slags Containing Tungsten** – Leaching and chemical separation.
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✅ **Summary:**
* **Main industrial sources:** Scheelite (CaWO₄), Wolframite ((Fe,Mn)WO₄).
* **Primary extraction steps:** Ore concentration → chemical conversion to ammonium paratungstate → WO₃ → reduction to metallic tungsten.
* **Metallic tungsten:** Produced via hydrogen reduction, carbothermic reduction, or alkali-metal reduction.
* **Byproduct/secondary sources:** Mine tailings, scrap alloys, catalysts, industrial slags.
* **Laboratory/experimental:** WF₆ preparation, WCl₆ reduction, vacuum melting.
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Next in periodic order is \*\*Rhenium (Re, atomic number 75). Do you want me to continue with **20 extraction methods for Rhenium**?
