The process takes advantage of two liquid-state properties of zinc.
Because the zinc is immiscible in the lead it remains in a separate layer and is easily removed.
The zinc-silver solution is then heated until the zinc vaporizes, leaving nearly pure silver.
If gold is present in the liquid lead, it can also be removed and isolated by the same process.
[7] The Parkes process was not adopted in the United States, due to the low native production of lead.