Challenges and opportunities in the recovery of gold from electronic waste

Rapid global technological development has resulted in increased production of electronic waste, which presents both challenges and opportunities in recycling efforts. This review aims to highlight the metal resources in printed circuit boards (PCBs) found in end-of-life electronics and compare primary mining with secondary urban mining. Methodologically, it discusses various metallurgical separation techniques that can selectively and sustainably recover gold from waste PCBs. The research indicates a significant escalation in electronic waste generation, which reached 50 million tonnes in 2018 and is expected to grow at 3–5% annually. Recycling rates remain low, estimated between 20-30%, while a substantial portion of waste electronics is improperly processed, leading to severe environmental consequences due to toxic byproducts. PCBs, containing up to 60 chemical elements and a metal content high as 40%, represent a valuable secondary source for precious metals. The review also discusses potential revenues from e-waste recycling, projected as USD 62.5 billion by 2020, demonstrating both environmental benefits and economic opportunities for a circular economy. Overall, the findings suggest innovative chemical approaches for gold recovery from discarded electronics as a crucial avenue for sustainable practices in e-waste management.