Perfect 👍 — next in **periodic table order** is **Strontium (Sr, atomic number 38).**
Strontium is an **alkaline earth metal** that does **not occur free** in nature. It is primarily obtained from **celestite (SrSO₄) and strontianite (SrCO₃)**. Industrial extraction involves **conversion to soluble salts, precipitation, and reduction to metallic strontium**.
Here are the **20 most common methods of extracting Strontium**:
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# **20 Most Common Methods of Extracting Strontium**
### **A. Extraction from Strontium Minerals**
1. **Acid Leaching of Celestite (SrSO₄ + H₂SO₄ → SrSO₄ sol + H₂O)** – Converts mineral to soluble strontium sulfate solution.
2. **Conversion of SrSO₄ to SrCO₃ using Na₂CO₃** – Produces strontium carbonate.
3. **Acid Dissolution of Strontianite (SrCO₃ + HCl → SrCl₂ + CO₂ + H₂O)** – Produces soluble strontium chloride.
4. **Fractional Crystallization of Sr Salts** – Separates Sr salts from Ca and Ba.
5. **Ion Exchange Purification** – Removes impurities and separates Sr from Ca/Ba.
6. **Solvent Extraction from Sr Solutions** – Uses organic extractants to purify Sr.
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### **B. Reduction to Metallic Strontium**
7. **Aluminothermic Reduction of SrO → Sr + Al₂O₃** – Industrial method.
8. **Calciothermic Reduction of Sr Compounds** – Produces metallic strontium.
9. **Electrolytic Reduction of Molten SrCl₂** – High-purity metallic Sr production.
10. **Magnesiothermic Reduction of Sr Compounds** – Laboratory or experimental method.
11. **Hydrogen Reduction of SrO** – Produces fine strontium powder.
12. **Vacuum Distillation of Strontium Metal** – Purification of metallic Sr.
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### **C. Extraction from Byproducts / Specialized Sources**
13. **Recovery from Byproduct of Calcium or Barium Processing** – Sr often coexists with Ca/Ba.
14. **Recovery from Phosphate Fertilizer Production Residues** – Trace strontium present.
15. **Recovery from Strontium-Containing Industrial Slags** – Leaching and precipitation.
16. **Recovery from Seawater or Brine (Low Concentration)** – Rare, hydrometallurgical extraction.
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### **D. Laboratory / Experimental Methods**
17. **Reduction of SrCl₂ with Sodium** – Laboratory metallothermic reduction.
18. **Aluminothermic Reduction of SrCO₃** – Lab-scale metallic Sr production.
19. **Plasma Reduction of Strontium Compounds** – Experimental high-purity method.
20. **Solar-Thermal Reduction of SrO or SrCl₂** – Experimental renewable energy method.
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✅ **Summary:**
* **Main industrial sources:** Celestite (SrSO₄) and strontianite (SrCO₃).
* **Primary extraction steps:** Mineral → soluble salt → fractional crystallization/ion exchange → precipitation → reduction to metallic strontium.
* **Metallic strontium:** Produced via aluminothermic, calciothermic, electrolytic, or magnesiothermic reduction.
* **Byproduct sources:** Calcium/barium processing residues, phosphate fertilizers.
* **Laboratory/experimental:** Na/Al reductions, hydrogen reduction, plasma, solar-thermal methods.
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Next in periodic order is \*\*Yttrium (Y, atomic number 39).
Do you want me to continue with **20 extraction methods for Yttrium**?
