Extraction of Silver from Gold and Silver Ores
The extraction of gold and silver from ores typically involves a process called leaching, where cyanide ions (CN-) are used to dissolve these precious metals. After this initial extraction, silver can be recovered using various methods, with displacement using zinc being a common approach.
Methods of Silver Recovery
- A. Distillation
This method is primarily used for the separation of metals with different boiling points. However, it is not suitable for recovering silver from cyanide solutions.
- B. Zone Refining
Zone refining is a purification technique mainly used for semiconductors and is not commonly applied in the recovery of silver from cyanide leach solutions.
- C. Displacement with Zn
This is the most effective method for recovering silver after leaching. In this process, zinc is added to the cyanide solution containing silver ions. The reaction occurs as follows:
- Zinc displaces silver from the solution, forming solid silver and zinc cyanide.
- This method is highly efficient and economically viable, making it the preferred choice for silver recovery.
- D. Liqution
Liqution is not a recognized method in the context of silver recovery from cyanide solutions.
Conclusion
In summary, the displacement method using zinc (option C) is the most suitable and widely used technique for recovering silver after cyanide leaching. This process effectively extracts silver while ensuring minimal losses and optimal recovery rates.