Which of the following statements are correct in connection with the extraction of silver?

Options

A. silver is obatined as a by-product in the extraction of copper, lead and zinc.
B. Silver is obtained from the anode slime formed in the electrolytic refining of copper and zinc
C. Zinc is used to extract silver by solvent extraction from molten lead in Parke's process
D. Pattinsons process is used for desilverization of lead

Answer

To determine which statements are correct regarding the extraction of silver, we can analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement A: Silver is obtained as a by-product in the extraction of copper, lead, and zinc.**
- **Analysis:** This statement is true. During the extraction of copper, lead, and zinc, silver is often found in the ores and can be recovered as a by-product.
- **Conclusion:** Statement A is correct.

2. **Statement B: Silver is obtained from the anode slime formed in the electrolytic refining of copper and zinc.**
- **Analysis:** This statement is also true. In the electrolytic refining process, anode slime, which is the residue left after the electrolysis, contains valuable metals including silver, which can be extracted.
- **Conclusion:** Statement B is correct.

3. **Statement C: Zinc is used to extract silver by solvent extraction from molten lead in the Parkes process.**
- **Analysis:** This statement is true as well. The Parkes process is specifically designed for the desilverization of lead, where zinc is used to extract silver from molten lead.
- **Conclusion:** Statement C is correct.

4. **Statement D: The Pattinson process is used for the desilverization of lead.**
- **Analysis:** This statement is true. The Pattinson process is a method used to remove silver from lead, making it a valid statement.
- **Conclusion:** Statement D is correct.

### Final Conclusion:
All statements (A, B, C, and D) regarding the extraction of silver are correct.