Sustainable Metal Recovery from Electroplating Sludge: Bridging Technology and Environmental Regulation

Abstract

Electroplating sludge, a hazardous waste generated from the electroplating industry, contains significant quantities of heavy metals such as Cu, Cr, and Ni. Improper disposal of these metals poses severe environmental and health risks. This study proposes a comprehensive resource recovery process for Cu, Ni, and Cr from electroplating sludge, involving leaching, solvent extraction, stripping, and precipitation. The extraction efficiency of three extractants (P507, LIX984, and M5640) was evaluated, with M5640 demonstrating superior performance in Cu recovery (near 100%) at pH 3.0–4.0. Multi-stage extraction and stripping experiments further optimized metal recovery, achieving high efficiencies for Cu, Cr, and Ni. The recovered metals were precipitated as CuCO3, CrPO4, and Ni(OH)2, with wastewater discharge meeting environmental discharge standards. This study not only enriches the technical approaches for the selective recovery of high-value metals from electroplating sludge with complex components, but also closely aligns with the laws, regulations, and policies of the Chinese government regarding environmental governance. It serves as a driving force for promoting the construction of “waste-free cities” and the establishment of a closed-loop circular economy industrial chain.