Which of the following methods is used for obtaining aluminum metal ?

Options

A. Electrolysing fused `Al_2O_3` and cryolite
B. By heating `Al_2O_3` with carbon
C. By heating `Al_2O_3` in muffle furnace
D. By a process called pyrometallurgy

Answer

To determine the method used for obtaining aluminum metal, we can analyze the provided options step by step.

### Step-by-Step Solution:

1. **Understanding Aluminum Extraction**:
Aluminum is primarily extracted from its ore, bauxite, which contains aluminum oxide (Al2O3). The extraction process involves reducing aluminum oxide to aluminum metal.

2. **Electrolysis Method**:
The most common method for extracting aluminum is through electrolysis. This involves the electrolysis of molten aluminum oxide (Al2O3).

3. **Role of Cryolite**:
In the electrolysis process, aluminum oxide is mixed with cryolite (Na3AlF6). Cryolite serves two main purposes:
- It lowers the melting point of aluminum oxide, making the process more energy-efficient.
- It increases the electrical conductivity of the molten mixture, allowing for a more efficient electrolysis process.

4. **Other Methods**:
The other methods mentioned in the options, such as heating Al2O3 with carbon or using a muffle furnace, are not standard methods for aluminum extraction. These methods are generally used for other metals or are less efficient for aluminum.

5. **Conclusion**:
Based on the analysis, the correct method for obtaining aluminum metal is through the electrolysis of fused Al2O3 mixed with cryolite.

### Final Answer:
The method used for obtaining aluminum metal is **electrolyzing fused Al2O3 with cryolite** (Option A).

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