Simultaneous cathodic and anodic electrodeposition of metal ions from e-waste

The e-waste generation is growing faster than the possibilities of its appropriate recycling or disposal. Improving the efficiency of the metal recovery process electrochemical stage could drive more proper recycling of this waste. This work presents a novel proposal to simultaneously recover metal ions in both electrodes using electrochemical methods to take advantage of electrical charges at the cathode and anode. The simultaneous recovery process here implemented makes use of a leached solution from electronic waste (e-waste) with a high copper concentration and low nickel, iron, silver, and lead content. It was envisaged from the thermodynamic analysis of the leached solution through speciation diagrams. This analysis allows for predicting the potentials at which selective cathodic deposits or codeposits can be obtained with the simultaneous formation of metal oxides at the anode. The information from the thermodynamic study was experimentally corroborated by cyclic voltammetry, and the simultaneous electrochemical process of metal ions was subsequently addressed. At a potential corresponding to 0.195 V vs. NHE, it was possible to obtain a codeposit of copper-silver with simultaneous recovery of lead oxide on the anode.

Automated summary

The growing e-waste generation exceeds the capacity for proper recycling or disposal. This study proposes a novel approach to recover metal ions in both electrodes simultaneously using electrochemical methods. The process utilizes a leached solution from e-waste with high copper concentration and low content of nickel, iron, silver, and lead. Thermodynamic analysis and experimental validation were conducted to predict and confirm the simultaneous electrochemical process of metal ions. A codeposit of copper-silver with concurrent recovery of lead oxide on the anode was achieved.