Which of the following process is related with the removal of sulphur by heating in the air ?

Options

A. Smelting
B. Calcination
C. Annealing
D. Roasting

Explanation

To solve the question regarding the process related to the removal of sulfur by heating in the air, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for a specific process that involves the removal of sulfur by heating in the presence of air.

2. **Identify the Options**: The options provided are:
- A) Smelting
- B) Calcination
- C) Annealing
- D) Roasting

3. **Analyze Each Option**:
- **Smelting**: This process involves applying heat to the ore to extract the base metal, but it does not specifically focus on the removal of sulfur. Therefore, it is not the correct answer.

- **Calcination**: This process involves heating the ore in the absence of air, typically for carbonate ores. Since the question specifies heating in the presence of air, this option is also incorrect.

- **Annealing**: This is a heat treatment process that alters the microstructure of materials to change their mechanical or electrical properties. It does not relate to the removal of sulfur, making it an incorrect choice.

- **Roasting**: This process involves heating the concentrated ore in the presence of excess air. During roasting, sulfur is oxidized to sulfur dioxide, and sulfide ores are converted to their respective oxides. This matches the requirement of the question.

4. **Conclusion**: Based on the analysis, the correct process related to the removal of sulfur by heating in the air is **Roasting**.

### Final Answer:
The correct answer is **D) Roasting**.

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