Recovery of ultra fine grained silver and copper from PC board scraps

PC board scraps were leached to recover Cu, Ag, Au and Pd. Due to the high cost of the shredding and to avoid secondary pollution from dusts, board scraps were cut into 5 x 5 cm(2) pieces. Nitric acid was used and effect of leaching parameters; the leachant concentration, temperature, time and L/S were studied and optimized using response surface methodology (RSM). Silver (87 wt.%) and copper (98 wt.%) were leached. Ultra fine grained silver (ca. 400 nm) was obtained by precipitation. Ultrafine grained copper (ca. 100 nm) was obtained by electrowinning. (C) 2012 Elsevier B.V. All rights reserved.