Argentite ore is concentrated by froth flotation process.
Argentite is a sulphide ore.

Options

A. If both (A) and ( R) are correct and ( R) is the correct explanation of (A).
B. If both (A) and ( R) are correct, but ( R) is not the correct explanation of (A).
C. If (A) is correct, but ( R) is incorrect.
D. If (A) is incorrect, but ( R) is correct.

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion and Reason**: The assertion states that "Argentite ore is concentrated by froth flotation process." The reason given is that "Argentite is a sulphide ore."

2. **Identifying the Nature of Argentite**: Argentite is a silver sulfide mineral with the chemical formula Ag₂S. It is indeed classified as a sulfide ore.

3. **Froth Flotation Process**: The froth flotation process is a method used primarily for the concentration of sulfide ores. In this process, the ore is mixed with water and a frothing agent (like pine oil). The ore particles become hydrophobic (repel water) while the gangue (impurities) particles remain hydrophilic (attract water).

4. **Application to Argentite**: Although argentite is a sulfide ore, it is not concentrated using the froth flotation process. Instead, argentite is typically concentrated through a leaching process, where it reacts with sodium cyanide to form a soluble complex.

5. **Conclusion**: Since the assertion that argentite is concentrated by froth flotation is incorrect, while the reason that argentite is a sulfide ore is correct, the final conclusion is that the assertion is incorrect and the reason is correct.

6. **Final Answer**: Therefore, the correct option is D: Assertion is incorrect, Reason is correct.

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