Alright — moving on to **Polonium (Po, atomic number 84).**
⚠️ Polonium is **extremely rare, highly radioactive, and toxic**. It does **not occur in mineable quantities** in nature (only trace amounts in uranium ores). Nearly all usable polonium has historically been produced **artificially in nuclear reactors**.
Here are the **20 most common methods of extracting Polonium** (grouped into categories):
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# **20 Most Common Methods of Extracting Polonium**
### **A. Historical Natural Sources**
1. **Trace Extraction from Uraninite (Pitchblende)** – Very tiny natural amounts (\~100 µg per ton of uranium ore).
2. **Chemical Separation from Uranium Ores** – Early Marie Curie method (exceedingly inefficient).
3. **Co-precipitation with Bismuth Compounds** – Used to isolate traces from ores.
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### **B. Reactor-Based Production (Main Modern Source)**
4. **Neutron Irradiation of Bismuth-209** – ^209Bi(n,γ)^210Bi → β-decay → ^210Po.
5. **Irradiation of Lead Targets (Less Common)** – Produces trace polonium isotopes.
6. **High-Flux Nuclear Reactor Bombardment** – Maximizes polonium yield.
7. **Breeder Reactor Production** – Used historically for military polonium.
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### **C. Radiochemical Separation Techniques**
8. **Dissolution of Irradiated Bismuth in Acids (HNO₃, HCl, H₂SO₄)**.
9. **Solvent Extraction of Polonium Compounds** – Separates Po from Bi and Pb.
10. **Ion Exchange Chromatography** – Isolates Po isotopes from other fission products.
11. **Electrolytic Deposition onto Metal Foils** – Collects Po onto platinum, silver, or gold.
12. **Co-precipitation with Tellurium or Selenium Compounds** – Selective separation.
13. **Vacuum Distillation of Polonium** – Exploits its volatility to separate it.
14. **Sublimation under Controlled Atmosphere** – Transfers Po away from impurities.
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### **D. Purification & Isotope Handling**
15. **Electroplating onto Gold Foils** – Produces Po sources for scientific/military use.
16. **Reductive Precipitation from Solutions** – Controlled chemical recovery.
17. **Extraction via Bismuth Oxide Dissolution** – Common lab-scale separation.
18. **Sealed Capsule Purification** – Handling method to contain α-radiation.
19. **Continuous Extraction Loops in Reactors** – Used for steady Po supply in some Cold War facilities.
20. **Isotopic Purification by Half-Life Selection** – Separating ^210Po from short-lived isotopes (e.g., ^208Po, ^209Po).
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✅ **Summary:**
* **Natural extraction** is historically important (Curie era) but impractical.
* **Nuclear irradiation of Bi-209** in reactors is the **only viable large-scale method**.
* **Separation** uses radiochemistry: dissolution, solvent extraction, ion exchange, sublimation, electroplating.
* **Applications**: nuclear batteries, neutron initiators (weapons), static eliminators (obsolete), research isotopes.
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Next in order is **Astatine (At, atomic number 85).**
Since it’s even rarer than polonium (only synthesized artificially in particle accelerators), would you like me to also list the **20 most common methods of extracting Astatine**?
