Which of the following ores are concentarted by froth floatation?

Options

A. Haematite
B. Galena
C. Copper pyrites
D. Magnetite

Explanation

To determine which ores are concentrated by froth flotation, we need to analyze the given options based on their chemical composition and the principles of the froth flotation process.

### Step-by-Step Solution:

1. **Identify the Ores**: The ores mentioned are:
- Hematite (Fe2O3)
- Galena (PbS)
- Copper Pyrite (CuFeS2)
- Magnetite (Fe3O4)

2. **Classify the Ores**:
- Hematite and Magnetite are iron oxides.
- Galena is a lead sulfide.
- Copper Pyrite is a copper iron sulfide.

3. **Understand Froth Flotation**: Froth flotation is a process used primarily for the concentration of sulfide ores. It works on the principle of hydrophobicity, where the sulfide minerals are rendered hydrophobic and can be separated from the gangue (waste material).

4. **Determine Which Ores are Sulfides**:
- From the classification:
- Hematite (Fe2O3) - oxide
- Galena (PbS) - sulfide
- Copper Pyrite (CuFeS2) - sulfide
- Magnetite (Fe3O4) - oxide

5. **Conclude the Concentrated Ores**: Since froth flotation is effective for sulfide ores, the ores that can be concentrated by froth flotation from the list are:
- Galena (PbS)
- Copper Pyrite (CuFeS2)

### Final Answer:
The ores that are concentrated by froth flotation are **Galena (PbS)** and **Copper Pyrite (CuFeS2)**.

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