Enhanced anodic dissolution of cupronickel alloy scraps by electro-generated reactive oxygen species in acid media

Recycling of the cupronickel alloy scraps not only solves environmental related issues but also realizes the extraction of valuable metals and saves consumption of primary ore resources. Oxidative dissolution is a critical step for the recycling of valuable metal from the alloy scraps. In order to improve the dissolution kinetics and efficiency, a novel integrated electrochemical dissolution strategy for the sustainable recycling of the cupronickel alloy scraps was first developed, where the in-situ electro-generated reactive oxygen species (ROS) were employed as the indirect oxidative mediator. Much higher dissolved concentration of Ni, Zn, and Cu was reached by the present integrated strategy than that of the direct anodic dissolution process, which is attributed to the in-situ produced oxidative H2O2 and ·OH via oxygen reduction reaction and electro-Fenton-like reaction, respectively. Moreover, the large quantity of ROS can be electro-generated, thus achieving high dissolved concentration, under the optimum condition with the preset potential of 0.3 V (vs. Ag/AgCl) or current density of 2.54 mA/cm2, respectively. This novel synergistic strategy may serve as a promising and cost-effective technique for the alloy scraps recycle and valuable metal extraction.