Recycling of Printed Circuit Boards for Cooper Extraction: a Review of the Methods Employed

The accelerated pace of technological innovations, the frequency of replacement of electrical and electronic equipment and the consequent decrease in the useful life of these devices have caused the generation of electronic waste in the world to increase significantly in recent years, with a projection of continuous and accelerated growth until 2030. In addition, statistics show that the formal recycling rate does not keep up with this growing waste stream, and most electronic waste is being disposed of incorrectly or directed to conventional treatment in landfills and incineration, posing a serious danger to the environment. Waste printed circuit boards are an economically attractive urban mining source for recycling due to their high content of common and precious metals (copper being the most abundant metal) often higher than their respective primary resources. Thus, this review article aims to provide a comprehensive analysis of the situation of electronic waste in the world, the main processes used for recycling waste printed circuit boards, including pyrometallurgy, hydrometallurgy, and biohydrometallurgy, their advantages, disadvantages, and the challenges to achieve a cleaner recycling process that promotes a high recovery rate of metals with less environmental impact.