Which of the following is/are correct for cyanide process of extraction of gold?

Options

A. Sodium cynaide is sweet in taste and is also used in making chocolates
B. Sodium cyanide if escapes into ground water then it produces hydrogen cyanide which is toxic to many animals.
C. It is an example of pyrometallurgy.
D. It is an example of leaching process

Explanation

To solve the question regarding the cyanide process of extraction of gold, we will analyze each statement provided and determine its correctness based on our understanding of the cyanide process.

### Step-by-step Solution:

1. **Understanding the Cyanide Process**:
- The cyanide process, also known as the cyanidation process, is used for extracting gold from its ore. In this process, gold is treated with sodium cyanide, which forms a soluble complex with the gold ions.

2. **Evaluating Statement A**:
- **Statement**: "Sodium cyanide is sweet in taste and is also used in making chocolates."
- **Analysis**: While sodium cyanide may have a sweet taste, it is highly toxic and not safe for consumption. Therefore, this statement is **false**.

3. **Evaluating Statement B**:
- **Statement**: "Sodium cyanide if escapes into the groundwater then it produces hydrogen cyanide which is toxic to many animals."
- **Analysis**: This statement is **true**. If sodium cyanide contaminates groundwater, it can hydrolyze to form hydrogen cyanide, which is indeed toxic to many forms of life.

4. **Evaluating Statement C**:
- **Statement**: "It is an example of pyrometallurgy."
- **Analysis**: Pyrometallurgy involves the use of high temperatures to extract metals, which is not applicable in the cyanide process. Therefore, this statement is **false**.

5. **Evaluating Statement D**:
- **Statement**: "It's an example of leaching process."
- **Analysis**: The cyanide process is indeed a leaching process, where the soluble gold cyanide complex is formed, and impurities are separated out. Thus, this statement is **true**.

### Conclusion:
Based on the analysis:
- Statement A: False
- Statement B: True
- Statement C: False
- Statement D: True

Therefore, the correct options for the cyanide process of extraction of gold are **B and D**.