Pattinson's Process: Desilverization of Argentiferous Lead

The process which is used for the recovery of the silver from argentiferous lead is called Pattinson's Process, and it involves the desilverization of lead in accordance with the phase diagram of the lead-silver system.

The argentiferous lead is a mixture of molten lead and molten silver containing less than 0.1% of silver. Thus, this is a liquid-liquid mixture with different solubilities. For its recovery, the argentiferous lead is heated above its melting point when a liquid melt consisting of a silver-lead solution is obtained. Now, if the silver-lead solution is cooled, lead continues to separate out and is regularly removed. In the end, a eutectic solution containing 2.6% silver is obtained. Thus, the process increases the percentage of silver in the argentiferous lead. Therefore, the eutectic mixture containing 2.6% silver can be treated for the recovery of silver profitably.

Multiple Choice Question:

Extraction of silver from argentiferous lead (Pb + Ag) involves:

A. Distillation method
B. Cupellation
C. Pattinson’s process
D. Parke’s process ✔