The process of heating the ore strongly in excess of air so that the volatile impurities are removed and the ore is changed to oxide is known as

Options

A. Calcination
B. Roasting
C. Froth floatation
D. Leaching

Answer

To solve the question, we need to identify the correct term for the process of heating an ore in excess air to remove volatile impurities and convert the ore into an oxide.

### Step-by-Step Solution:

1. **Understanding the Processes**:
- **Calcination**: This is the process of heating ores in the absence of air or in a limited supply of air. It is primarily used to drive off volatile substances and convert carbonates to oxides.
- **Roasting**: This process involves heating the ore in excess air. It is typically used for sulfide ores to remove moisture and non-metallic impurities, converting them into oxides.
- **Froth Flotation**: This is a method used for the separation of minerals from ores based on their hydrophobic properties. It does not involve heating.
- **Leaching**: This refers to the process of extracting a substance from a solid by dissolving it in a liquid. It is not related to heating.

2. **Identifying the Correct Process**:
- Since the question specifies that the process involves heating the ore strongly in excess of air, we can eliminate calcination, froth flotation, and leaching.
- The only process that fits the description is roasting, as it specifically involves heating in excess air to remove volatile impurities and convert the ore to oxide.

3. **Conclusion**:
- Therefore, the correct answer to the question is **roasting**.

### Final Answer:
The process of heating the ore strongly in excess of air so that the volatile impurities are removed and the ore is changed to oxide is known as **roasting**.

---