Froth flotation of copper sulfide is similar to the process for extracting zinc sulfide. Source: Geomartin, CC BY-SA 4.0 Silver Valley galena typically assays at about 10% lead, making it a fairly ...

Ancient Greeks made their coins by extracting silver from lead-rich ore. Greece’s mining and smelting operations ended up seriously polluting Earth’s atmosphere, as modern scientists have ...

Silver fueled the rise of the Roman Empire as its coin-based currency accelerated trade, filled tax coffers and funded military conquests. But the empire’s mining and extracting of silver was ...