A semi-scaled experiment for metals separating and recovering from waste printed circuit boards by slurry electrolysis

Waste printed circuit boards (WPCBs) are considered as the most complicated and valuable component among e-waste. Slurry electrolysis can separate and recover metals from the extremely complex WPCBs. To promote its industrial application, a 5000 mL scale experiment was conducted to confirm industrial feasibility. Those results showed that copper and total metal recovery rates were 94.5 % and 75.2 % under the optimized conditions (30 g/L WPCBs, 10 g/L CuSO4 center dot H2O, 30 g/L NaCl, 190 g/L H2SO4, 30 g/L H2O2, 298 K temperature, 250 r/min stirring speed, 300 A/m(2) and 8 h). The copper purity was 92.9 %, and SEM-EDS analyses indicated the main dendritic metals recovered were copper and lead. USEtox toxicity potential evaluation results demonstrated human toxicity and ecotoxicity of WPCBs sharply decreased after treatment. A cost analysis of this process indicated that the $ 1.0 cost was partially offset by the $ 1.9 return from 1 kg WPCBs. Thus, slurry electrolysis has a promising industrial future for e-waste recycling/utilization. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.