How was silver recovered from lead ores in ancient times?

In ancient times, the recovery of silver from lead ores was a multi-step metallurgical process that relied on the distinct chemical properties of the metals involved.

• Preparation and Smelting: Ores were first hand-sorted, crushed, and washed to isolate the mineral content. Because these minerals were primarily sulfides, they were roasted to form oxides and subsequently smelted to produce an impure lead-silver alloy, often referred to as lead bullion.12
• Cupellation: The primary method for separating silver from this alloy was cupellation. The alloy was melted in a shallow, porous receptacle known as a cupel, made of bone ash or refractory clay.13
• Oxidation: A blast of air was directed over the molten mass, which preferentially oxidized the lead. The resulting lead oxide was either skimmed from the surface or absorbed into the porous cupel, leaving behind the purified silver and any gold present in the original ore.134

This technique was highly effective and remained the standard for fire-refining silver from lead-bearing deposits for centuries, notably at the famous Laurium mines in ancient Greece.12