Circular Economy Approaches for Sustainable Recovery of Critical Raw Materials from E-Waste: A Review of Emerging Beneficiation Techniques

The global surge in consumption of electrical and electronic equipment (EEE) has resulted in an unprecedented generation of waste EEE (WEEE), posing significant environmental and health challenges worldwide, especially in developing countries where informal and rudimentary recycling methods prevail. Such unsustainable management approaches exacerbate the loss of critical raw materials (CRMs) embedded in WEEE, which are essential for current EEE technologies, future technological innovation, and sustainable development goals. This study adopts a structured literature approach using Scopus, Web of Science, and Google Scholar, covering studies published between 2015 and 2025. Articles were selected based on relevance to CRM recovery, availability of quantitative performance data, and methodological clarity, resulting in 124 key studies for detailed analysis. The study critically evaluates conventional and emerging beneficiation techniques in terms of recovery efficiency, environmental impact, cost, and scalability. Hydrometallurgical processes achieve recovery efficiencies above 90% for selected metals but generate secondary effluents, while pyrometallurgical routes offer high throughput at the expense of energy demand and emissions. Mechanical processing improves pre-concentration but lacks selectivity for complex fractions. Emerging approaches, including biohydrometallurgy and deep eutectic solvents, show reduced environmental impact with reported recoveries exceeding 95% under controlled conditions, though scale limitations persist. Integration of artificial intelligence and sensor-based sorting improves separation efficiencies to above 95% in pilot systems. Comparative analysis highlights that process integration and feedstock quality strongly influence outcomes. The study identifies key gaps in techno-economic evaluation and life cycle assessment and proposes integrated recovery pathways aligned with circular economy targets.