Explain about Parke Process?

Parke method for refining lead, which is also a concentration process for silver, relies upon the selective dissolution of silver in molten zinc.  Small amount of zinc, 1-2%. is included to molten lead which contains silver as an impurity. Silver is much more soluble in zinc than in lead; zinc adn lead are insoluble in each other. Therefore, most of the silver concentrates in zinc, which comes to the top of molten lead. The zinc layer solidifies first upon cooling: it is replaced and silver is obained by distilling off zinc, which is collected and used over and over again.