The powdered ore is agitated with water or washed with running stream of water. The heavy ore particles and lighter impurities are separated . This method of concentration is known as

Options

A. metallurgy
B. leaching
C. gravity separation
D. froth floatation process.

Answer

To solve the question regarding the method of concentration where powdered ore is agitated with water or washed with a running stream of water, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Process**: The question describes a method where powdered ore is mixed with water. The aim is to separate heavier ore particles from lighter impurities.

2. **Identifying the Method**: This method involves the use of water to facilitate the separation based on density. The heavier ore particles will settle or remain while the lighter impurities are washed away.

3. **Recognizing the Principle**: The principle behind this method is based on the difference in specific gravity between the ore and the impurities. Heavy ores have a higher specific gravity compared to lighter gangue materials.

4. **Conclusion**: Given the description and the principles involved, this method of concentration is known as **gravity separation**.

### Final Answer:
The method of concentration described is known as **gravity separation**.

---