How mant metals are commercially extracted by pyrometallurgy from the given metal ?
`Cu, Fe, Sn, Au, K, Na`.

Explanation

To determine how many metals can be commercially extracted by pyrometallurgy from the given list of metals (Cu, Fe, Sn, Au, K, Na), we will analyze each metal based on the principles of pyrometallurgy.

### Step-by-Step Solution:

1. **Understanding Pyrometallurgy**:
- Pyrometallurgy is a method of extracting metals from their ores through the application of heat. It is primarily used for metals that are less electropositive.

2. **Analyzing Each Metal**:
- **Cu (Copper)**: Copper is extracted via pyrometallurgy. The ore Cu2O is treated with copper sulfide at high temperatures (around 1000°C) to produce copper and sulfur dioxide.
- **Fe (Iron)**: Iron is also extracted through pyrometallurgy. Iron oxide is reduced using carbon at very high temperatures (around 1800°C) to yield iron and carbon monoxide.
- **Sn (Tin)**: Tin can be extracted from tin oxide (SnO) using carbon as a reducing agent at high temperatures, making it suitable for pyrometallurgy.
- **Au (Gold)**: Gold is not extracted via pyrometallurgy. It is typically extracted using cyanide leaching, which occurs at lower temperatures.
- **K (Potassium)**: Potassium cannot be extracted through pyrometallurgy. It is highly reactive and is usually obtained through electrolysis.
- **Na (Sodium)**: Sodium, like potassium, is also not extracted via pyrometallurgy due to its high reactivity and is obtained through electrolysis.

3. **Conclusion**:
- From the analysis, the metals that can be commercially extracted by pyrometallurgy from the given list are Copper (Cu), Iron (Fe), and Tin (Sn). Therefore, the total number of metals that can be extracted by pyrometallurgy is **3**.

### Final Answer:
**3 metals (Cu, Fe, Sn) are commercially extracted by pyrometallurgy from the given metals.**

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