Extraction of Gold and Valuable Metals from Electronic Waste — 4p — Bayler Larson

Tremendous amounts of electronic waste (e-waste) is landfilled every year, despite containing valuable metals such as gold, silver, copper, platinum, and palladium. This research is focused on e-waste recycling and recovery of the metal values.  In particular, the research involves the recycling printed circuit boards (PCBs), a specific type of e-waste. Comminution of PCBs generates printed circuit board dust (PCBD), and PCBD served as the feed material for this research. Metals (focus was copper and gold) from PCBDs were physically separated using density, hydrophobicity, and particle size. This research also uses chemical leaching processes containing sulfuric acid/hydrogen peroxide and cyanide solutions to dissolve the metals into solution. Results show recovery rates upwards of 85% recovery of copper is possible by using physical separation methods (wave table), and recovery rate of 95% copper and 35% gold is obtainable by using a combination of leaching and cementation processes.

South Dakota School of Mines & Technology
Jon Kellar