Towards sustainable recycling of critical metals from e-waste: Bioleaching and phytomining

Critical metals are indispensable components of our daily lives, becoming increasingly scarce due to their irreplaceable functions in electronics. As technological progress fuels demand, the reevaluation of end-of-life devices and electronic waste presents a sustainable approach to ensuring metal supplies. However, the extraction of critical metals from electronic waste necessitates careful management to mitigate material loss and address environmental concerns. Conventional large-scale hydrometallurgical and pyrometallurgical methods lack targeted selectivity for critical metals like Ga, In, and REEs . These metals are often lost in pyrometallurgical processes or require extensive purification following chemical leaching. Consequently, attention has shifted to emerging bioleaching and phytomining technologies as alternative selective recovery methods that adhere to sustainability criteria without excessive capital investment. Nevertheless, knowledge of these recovery mechanisms remains limited, and their application faces challenges such as longer processing times and slower yields. This review article seeks to provide insights into these novel technologies for recycling critical metals from end-of-life materials by examining their mechanisms and key parameters, exploring potential optimization strategies, and assessing trade-offs to evaluate their feasibility and sustainability in large-scale operations.