Hydrometallurgical recovery of metals from e-waste

The recovery of metals from waste electrical and electronic equipment has already been highlighted as important due to the increased consumption worldwide with the advancements in “state of the art” products. Hydrometallurgical techniques used for this waste are a vital process that has resulted in active attempts to recover precious metals that can be further reutilized as a secondary resource. Significant amounts of valuable metals, specifically copper, silver, gold, nickel, and lead are being recovered that are strategically important in other processes. Hydrometallurgical processing mainly involves the use of a series of acids to leach out the metals from E-waste and further separation and purification using extraction, adsorption, and ion exchange to concentrate the precious metal. Printed circuit boards that are made up of large amounts of these precious metals have proven a promising ground for hydrometallurgical recovery. In this chapter, we present the hydrometallurgical steps taken to recover these precious metals from different components of E-waste and the latest trends in acid treatments used in the leaching process.