Which of the following is/are use(s) of calcination?

Options

A. To convert carbonate into oxide
B. To remove organic matter
C. To remove moisture
D. All of these

Answer

To solve the question regarding the uses of calcination, we will analyze each option provided and determine their validity based on the principles of calcination.

### Step-by-Step Solution:

1. **Understanding Calcination**:
- Calcination is a thermal treatment process in which ores are heated to high temperatures in the absence of air or limited air. This process is primarily used to convert metal carbonates into metal oxides.

2. **Analyzing the Options**:
- **Option 1: Convert carbonate into oxide**:
- This is a primary use of calcination. For example, when calcium carbonate (CaCO₃) is heated, it decomposes to form calcium oxide (CaO) and carbon dioxide (CO₂).
- **Conclusion**: This option is correct.

- **Option 2: To remove organic matter**:
- During calcination, any organic matter present in the ore can be burned off due to the high temperatures. This is an important step to purify the ore before further processing.
- **Conclusion**: This option is also correct.

- **Option 3: To remove moisture**:
- While calcination primarily focuses on the conversion of carbonates to oxides, the heating process can also drive off moisture from the ore. This is particularly relevant for ores that may contain water in their structure.
- **Conclusion**: This option is correct as well.

3. **Final Conclusion**:
- Since all three options are valid uses of calcination, the correct answer to the question is **"all of these."**

### Final Answer:
The uses of calcination include:
- Converting carbonate into oxide
- Removing organic matter
- Removing moisture
Thus, the answer is **"all of these."**