Which of the following ores is concentrated by 'magnetic separation' process?

Options

A. ZnS
B. `Al_(2)O_(3).2H_(2)O`
C. `Fe_(3)O_(4)`
D. `Fe_(2)O_(3)`

Explanation

To solve the question "Which of the following ores is concentrated by the 'magnetic separation' process?", we need to follow these steps:

### Step-by-Step Solution:

1. **Understand the Magnetic Separation Process**:
- Magnetic separation is a method used to separate magnetic materials from non-magnetic ones. It is primarily used for ores that contain ferrous (iron) minerals.

2. **Identify the Given Options**:
- We need to analyze the options provided in the question. The common ores that are typically considered in such questions include:
- A) Hematite (Fe2O3)
- B) Magnetite (Fe3O4)
- C) Bauxite (Al2O3·2H2O)
- D) Zinc Blende (ZnS)

3. **Determine the Magnetic Properties of Each Ore**:
- **Hematite (Fe2O3)**: This ore is not magnetic. It is known as alpha hematite and does not respond to magnetic separation.
- **Magnetite (Fe3O4)**: This ore is magnetic and can be concentrated using magnetic separation.
- **Bauxite (Al2O3·2H2O)**: This is not magnetic and is primarily an aluminum ore.
- **Zinc Blende (ZnS)**: This is also not magnetic and is a source of zinc.

4. **Conclusion**:
- Based on the magnetic properties, the only ore that can be concentrated by magnetic separation is **Magnetite (Fe3O4)**.

5. **Final Answer**:
- Therefore, the correct answer is **option B: Fe3O4 (Magnetite)**.