Recovery of Precious Metal Silver from Scrap Computer Keyboards

Abstract

Silver (Ag) is extensively used in manufacturing of electronic goods due to its low cost and conductivity. In view of the escalating demand, stringent, environment rules, and limited sources of Ag, the present paper is focused on the development of hydrometallurgical process flow-sheet to extract Ag from scrap computer keyboards. These keyboards contain ~0.4% of Ag. Initially, keyboards were dismantled to separate the Mylar sheets scontaining Ag. The same were pyrolyzed at 300 °C for 2 h to get enriched metallic part. About 99.99% Ag was leached using 2 M HNO3 at 60 °C within 30 min in close and proper condensed system. Separation techniques (precipitation/cementation) could be used to obtain pure Ag salt/metal. Based on the laboratory-scale experiments, the process flow-sheet developed is economical, ecofriendly, and has potential to be translated to industry for commercial exploitation after scale up/pilot trial.