Which of the following process is not involved in the extraction of `Fe` ?

Options

A. Gravity separation
B. Leaching
C. Roasting
D. Carbon reduction

Answer

To determine which process is not involved in the extraction of iron (Fe), we will evaluate each of the given options based on the common methods used in iron extraction.

### Step-by-Step Solution:

1. **Understanding the Extraction of Iron**:
The extraction of iron typically involves several processes including separation of impurities, conversion of ores, and reduction of oxides to metal.

2. **Evaluating Each Option**:
- **Option A: Gravity Separation**:
This process is used to separate impurities (gangue) from the ore based on density differences. It is commonly employed in the extraction of iron, so this option is involved in the extraction process.

- **Option B: Leaching**:
Leaching is a process where ore is treated with a solvent to dissolve the desired metal while leaving impurities behind. This method is primarily used for metals like gold and copper, but it is not typically used for iron extraction. Therefore, this option is likely the correct answer.

- **Option C: Roasting**:
Roasting involves heating the ore in the presence of excess air to convert sulfide ores into oxides. This process is indeed used in the extraction of iron, particularly for iron sulfide ores. Hence, this option is involved in the extraction process.

- **Option D: Carbon Reduction**:
This process involves reducing iron oxides (like hematite or magnetite) to iron metal using carbon (usually in the form of coke) in a blast furnace. This is a fundamental step in the extraction of iron, so this option is also involved in the extraction process.

3. **Conclusion**:
After evaluating all the options, it is clear that the only process not involved in the extraction of iron is **Leaching**.

### Final Answer:
**Leaching (Option B)** is not involved in the extraction of iron.