Amongest the following , how many ores can be concentrated by froth flotation process :
Galena, sphalerit, cassiterite, calamine, chalcocite, haematite, argentite.

Explanation

To determine how many ores can be concentrated by the froth flotation process from the given list, we will analyze each ore based on its composition and the suitability for the froth flotation method.

### Step-by-Step Solution:

1. **Understanding Froth Flotation Process**:
- The froth flotation process is primarily used for the concentration of ores based on their hydrophobic (water-repelling) properties. It is particularly effective for sulfide ores.

2. **Analyzing Each Ore**:
- **Galena (PbS)**: This is a sulfide ore of lead. It can be concentrated using the froth flotation process.
- **Sphalerite (ZnS)**: This is a sulfide ore of zinc. It can also be concentrated using the froth flotation process.
- **Cassiterite (SnO2)**: This is an oxide ore of tin. It is not concentrated by froth flotation; instead, it is usually concentrated by gravity separation methods.
- **Calamine (ZnCO3)**: This is a carbonate ore of zinc. Like cassiterite, it is not suitable for froth flotation.
- **Chalcocite (Cu2S)**: This is a sulfide ore of copper. It can be concentrated using the froth flotation process.
- **Haematite (Fe2O3)**: This is an oxide ore of iron. It is not concentrated by froth flotation; it is typically concentrated by magnetic separation or gravity separation.
- **Argentite (Ag2S)**: This is a sulfide ore of silver. However, it is not concentrated by froth flotation; instead, it is usually processed by leaching.

3. **Counting the Suitable Ores**:
- From the analysis, the ores that can be concentrated by the froth flotation process are:
- Galena
- Sphalerite
- Chalcocite
- Therefore, there are a total of **3 ores** that can be concentrated by the froth flotation process.

### Final Answer:
The total number of ores that can be concentrated by the froth flotation process is **3**.

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