What is a depressant ? Give one example.

Explanation

### Step-by-Step Solution:

1. **Definition of a Depressant**:
A depressant is a substance that reduces or depresses the flotation properties of certain materials in a mixture. In the context of mineral processing, it is used to selectively inhibit the flotation of specific minerals while allowing others to float.

2. **Function of a Depressant**:
The primary role of a depressant is to prevent certain minerals from floating during the froth flotation process. This allows for the separation of different minerals based on their flotation characteristics.

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