An ore gives `CO_2` on being treated with dilute hydrochloric acid. Which process should be used to convert this ore into oxide?

Options

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

Explanation

To solve the question regarding the conversion of an ore that produces CO₂ when treated with dilute hydrochloric acid into its oxide, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Nature of the Ore**:
- The ore produces CO₂ when treated with dilute hydrochloric acid. This indicates that the ore is likely a carbonate, as metal carbonates react with acids to release carbon dioxide gas.

2. **Determine the Process for Conversion**:
- To convert a carbonate ore into its corresponding metal oxide, we need to identify the appropriate metallurgical process. The main processes used in metallurgy include calcination, roasting, flotation, and sedimentation.

3. **Understanding Calcination**:
- Calcination is the process of heating a substance in the absence of air (or in a limited supply of air) to bring about thermal decomposition. In the case of carbonates, calcination involves heating the carbonate ore to convert it into its oxide and release CO₂ gas.
- For example, when calcium carbonate (CaCO₃) is heated, it decomposes to form calcium oxide (CaO) and carbon dioxide (CO₂):
\[ \text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2 \uparrow \]

4. **Conclusion**:
- Since the ore in question is a carbonate and we need to convert it into an oxide, the appropriate process to use is **calcination**.

### Final Answer:
The process that should be used to convert the ore into its oxide is **calcination**.

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