Metal extraction from the discarded printed circuit board by leaching

Abstract

In the last years, there is an increasing acknowledgment of our impact on the environment due to our lifestyle, while the need to adopt a more sustainable approach as to our consumption habits emerges as of particular significance. This trend regards industrial sectors affecting the consumption habits and, especially, electronic industry where the short life cycles and the rapidly developing technology have led to increased e-waste volumes, such as discarded electronic equipment. The majority of such elements result in landfills. However, their partial recyclability, due to their material composition (combination of different metals, such as copper, aluminium and steel, attached to, covered with or mixed with several types of plastics and ceramics) along with the unavoidable restrictions in landfills, has led to the development of retrieval techniques for their recycling and re-use, highlighting the significance of e-waste recycling, not only from a waste management aspect but also from a valuable materials' retrieval aspect. In this paper the method of hydrometallurgy is adopted to recycle metals from waste printed circuit board (PCB). An experimental leaching test was built up to recover precious and hazardous metals from the PCB. Experimental results showed that it can be used as metals-formation material to separate metal from PCB during the leaching process. Those results helped to find a way to recover metals and precious metals from PCB. It was revealed that the metal elements in e-waste can be dissolved using this method and further investigation to increase the dissolution rate is required to ensure that the method proposed is applicable in industry. However, dissolved concentration of PCB must be controlled to ensure that it follows the permissible amount set under environmental standard.