6 - Hybrid bioleaching—an emerging technique for extraction of critical metals from WEEE

Abstract

Waste electrical and electronic equipment (WEEE) or electronic waste (e-waste) is getting generated at a faster rate owing to persistent user demand and accelerated product obsolescence rate. The demand for critical metals for use in consumer products is growing rapidly considering limited primary reserve. Printed circuit board (PCB), the core component of WEEE, is recognized as an ancillary reserve of critical metals. Biometallurgy or bioleaching technique employing mostly acidophilic microorganisms for metal extraction from WEEE is time-consuming despite higher efficiency. Hybrid bioleaching combining hydrometallurgy using safer ligands and biometallurgy is an emerging technique for efficient and faster metal extraction from WEEE. In this context, an attempt has been made to provide an overview of the process along with current research trends and future research perspectives. Moreover, the strengths, weaknesses, opportunities, and threats analysis has been presented to assess the industrial applicability of the technique for profitable beneficiation from WEEE.