Question

In the process of calcination, the ore is heated in the___

• A. Presence of O₂
• B. Presence of reducing agent
• C. Absence of O₂
• D. All the above

Answer 1

The Correct Option is C

To solve the problem, we need to understand the process of calcination and its conditions.

1. Understanding Calcination:
Calcination is a thermal treatment process where an ore or mineral is heated to a high temperature, but below its melting point. The primary purpose of calcination is to drive off volatile components (such as water, carbon dioxide, or other gases) from the ore. This process is typically carried out in the absence of air or oxygen to prevent oxidation of the material.

2. Conditions During Calcination:
- Calcination is performed in an inert atmosphere or in the absence of oxygen ($\text{O}_2$). This ensures that the material does not undergo oxidation, which could alter its chemical composition or properties.
- The presence of oxygen would lead to unwanted reactions, such as the formation of oxides, which is not the objective of calcination.

3. Analyzing the Options:
- (1) Presence of $\text{O}_2$: Incorrect. Calcination is performed in the absence of oxygen to avoid oxidation.
- (2) Presence of reducing agent: Incorrect. Reducing agents are not typically used in calcination; the process focuses on removing volatile components without altering the ore's oxidation state.
- (3) Absence of $\text{O}_2$: Correct. Calcination is carried out in the absence of oxygen to prevent unwanted oxidation reactions.
- (4) All the above: Incorrect. Only option (3) is correct.

4. Conclusion:
The correct answer is that the ore is heated in the absence of $\text{O}_2$.

Final Answer: $ {C} $