Utilization of Life Cycle Assessment methodology to compare two strategies for recovery of copper from printed circuit board scrap

Abstract

Abstract Waste electrical and electronic equipment (WEE) is a source of valuable materials which poses great risks to environment and human health if improperly managed. To overcome this barrier and close the loop in a production chain, several end-of-life (EoL) strategies based on reuse, recovery and recycling are under development. Material recovery from printed circuit board (PCB) scrap may contribute to reduce the environmental impacts caused by the extraction of high-valued and/or highly toxic materials from nature. However, each recovery process itself requires resource consumption and generates some forms of impact. Given that situation, Life Cycle Assessment (LCA) methodology can aid decision-making processes on which EoL strategy to adopt. The goal of this study consisted of applying LCA methodology to evaluate and compare two processes for recovering copper from PCB scrap. Initially, a review was conducted, focusing on material recovery processes adopted as EoL options for WEEE management; several methods for copper recovery from PCB scrap were found. LCA methodology was then applied in order to evaluate and compare two of these processes. Both combine mechanical and electrochemical processing and have similar efficiency; one of them employs sulfuric acid and the other employs acqua regia (combination of nitric and chloridric acid). Evaluation of the impact categories considered in the study has shown that the process that uses acqua regia has better environmental performance. The work reported here can be seen as a starting point for more in-depth evaluations of these and other material recovery processes, especially in countries such as Brazil, where WEEE management is often neglected – in the absence of a well-structured recycling chain, it is usually disposed of in landfills. In that light, the paper presents some closing remarks and suggestions for future research.