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 × 5 cm2 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.

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► Nitric acid was used as leachant for the PC board scraps.
► Optimization of leaching parameters was carried out using a response surface methodology.
► 82.65% recovery of Ag and 94.08% recovery of Cu were obtained.
► The size of recovered silver particles from the solution was estimated to be less than 400 nm.
► Copper with particle size estimated to be less than 100 nm was recovered from the solution.