Sustainable Metal Recovery From E‐Waste: Exploring Greener Leachates in Hydrometallurgical Processes

ABSTRACT The accumulation of electronic waste (e‐waste) poses environmental hazards and leads to the loss of valuable metals such as gold, silver, copper, and rare earth elements. Conventional hydrometallurgical leachates, including cyanide, thiosulfate, and aqua regia, are effective but highly toxic and generate significant secondary waste. This review examines greener alternatives—ionic liquids (ILs), supercritical fluids (SCFs), and deep eutectic solvents (DESs)—evaluating their leaching efficiency, operational conditions, and environmental performance. Although these methods offer advantages such as tunable properties, biodegradability, and reduced emissions, challenges remain in toxicity control, recovery efficiency, and commercial scalability. The review highlights knowledge gaps, emphasizes the need for process optimization, and discusses regulatory and infrastructural considerations for industrial adoption. Overall, it provides a comparative assessment to support the development of sustainable and economically viable e‐waste recycling technologies.