The process which involves the treatment of the ore with a suitable reagent as to make it soluble while impurities remain insoluble is called :-

Options

A. froth floatation process
B. leaching
C. self reduction
D. hydrometallurgy

Answer

To solve the question regarding the process that involves treating an ore with a suitable reagent to make it soluble while leaving impurities insoluble, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for a specific process in metallurgy where an ore is treated with a reagent to dissolve it, while the impurities do not dissolve.

2. **Identifying Key Terms**: The key terms in the question are "treatment of ore," "suitable reagent," "soluble," and "impurities remain insoluble." These terms suggest a separation process.

3. **Reviewing Options**: The options given are:
- Froth flotation process
- Leaching
- Self-reduction
- Hydrometallurgy

4. **Analyzing Each Option**:
- **Froth Flotation Process**: This is a method used to separate hydrophobic materials from hydrophilic ones, primarily used for sulfide ores.
- **Leaching**: This process involves treating the ore with a solvent (reagent) that dissolves the desired metal while leaving the impurities behind. This matches the description in the question.
- **Self-reduction**: This is a process where an ore is reduced without the addition of an external reducing agent, not relevant to the question.
- **Hydrometallurgy**: This is a broader term that encompasses various processes involving aqueous solutions for metal extraction, but it does not specifically refer to the process described.

5. **Conclusion**: Based on the analysis, the process that involves the treatment of the ore with a suitable reagent to make it soluble while impurities remain insoluble is known as **Leaching**.

### Final Answer:
The correct answer is **Leaching**.

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