From which component of e-waste are precious metals recovered?

• A. Battery packs
• B. Plastic housings
• C. Electronic circuit boards
• D. Monitors

Answer: (C)

Precious metals are concentrated in the metal-rich parts of electronics where many components and connections come together—electronic circuit boards. These boards use gold plating on contact fingers and connectors, and they contain solders and various components that include silver and palladium. Because many tiny metallic traces and connectors are packed onto the board, the total amount of valuable metals across a board adds up, making circuit boards the primary source for recovering precious metals from e-waste.

In contrast, battery packs mainly hold lithium, cobalt, nickel, and other energy-storage metals; plastic housings are mostly polymers; and monitors (especially older CRTs) contain significant glass and some copper or aluminum but not large quantities of precious metals. So the best source for precious-metal recovery is the electronic circuit boards.