Why can galena be mined as a source of both lead and silver?

Galena is frequently mined as a source of both lead and silver because it often naturally contains silver within its mineral structure. Because silver is a valuable byproduct, its recovery is an integral part of the economic processing of lead ores.123

During the extraction process, lead concentrates are first smelted to produce a lead bullion that contains impurities, including silver. To recover the silver, metallurgists typically use the Parkes process, which involves adding zinc to the molten bullion. The silver reacts with the zinc to form insoluble compounds that can be skimmed off the surface.4

Following this, the remaining residue undergoes cupellation, a high-temperature process conducted under strongly oxidizing conditions. In this stage, the lead is oxidized and removed, leaving behind the noble silver and gold in their elemental forms. This efficient recovery of precious metals from lead-bearing ores accounts for a significant portion of the world's total silver production.42