479 Vol. 49, No. 4 2012 pp. 479-486 A Comparative Study of Acid Leaching Behavior of Copper from Waste Printed Circuit Boards (PCBs) Min-seuk Kim, Jinki Jeong, Jae-chun Lee , Byung-su Kim and Soo-kyoung Kim Abstract : Leaching of copper from the shredded waste printed circuit boards has been studied in nitric and sulfuric acid solutions. Hydrogen peroxide was added as oxidant in the case of sulfuric acid leaching. Effects of parameters such as acid and hydrogen peroxide concentrations, solution temperature, pulp density, and leaching time were investigated. In the nitric acid solution, an optimum copper dissolution of 96% was obtained in 120 min at 90 temperature, 100 g/L pulp density and 4.0 M HNO3 concentration. In the 2.0 M sulfuric acid solution with 10 vol.% hydrogen peroxide, 87% of copper was leached out in 120 min at 50 temperature and 50 g/L pulp density; the leaching of copper decreased remarkably by increasing the pulp density beyond 50 g/L. Tin and lead, the alloy components of solder, were leached into solution to less than 5% because of precipitation of tin as stannic acid in nitric acid and lead as sulfate in sulfuric acid solutions, respectively. Key words : Waste printed circuit boards, Leaching, copper, Nitric acid, Sulfuric acid . . , , , . 4.0 M, 100 g/L, 90 , 120 , 96% . 2.0 M, 10 vol.%, 50 g/L, 50 , 120 87% , 50 g/L . , . , , , , 2012 4 24 , 2012 8 10 2012 8 23 1) *Corresponding Author( ) E-mail; jclee@kigam.re.kr Address; Mineral Resources Research Division, Korea Institute of Geoscience & Mineral Resources, Daejeon 305-350, Korea (Printed Circuit Boards) . , edge connectors, intergrated circuits, transistors, capacitors, resistors . , 30%, 30%, 40% . (Au), (Ag), (Pd), (Pt) (Cu), (Al), (Zn), (Fe), (Ni), (Pb), (Sn), (Bi), (Sb), (Cr), (Be) . , , (Sun, 1991; Brodersen et al., 1992; Hoffmann, 1992; Cui and Zhang, 2008; Kumar et al., 2010).