Development of an Integrated Model to Recover Precious Metals from Electronic Scrap - A Novel Strategy for E-Waste Management

The authors in this paper makes an attempt to propose a novel integrated model for the recovery of precious metals (gold - Au and silver - Ag) for the management of e-waste using a combination of hydrometallurgical (chemical) and biometallurgical (low cost biomass) processes. Chemical process involves leaching of gold/silver from electronic scrap using cyanide. The leachate containing gold/silver complex thus obtained is then subjected to biosorption process using low-cost biomass. The model proposed by us will help to strengthen the ‘processing’ part of the functional elements employed for proficient e-waste management. Feasibility study was also conducted to explore the possibility of removal/recovery of silver-cyanide using low-cost biosorbents. Results showed that Eicchornia root biomass and Waste tea powder were efficient biosorbents for leached silver-cyanide from electronic scrap. The concentrated silver-cyanide recovered could further be used as an input material for electroplating industry.