Challenges and avenues for acid mine drainage treatment, beneficiation, and valorisation in circular economy: A review

Mining activities are notorious for their environmental impact, with acid mine drainage (AMD) being among the most significant issues. Specifically, AMD has recently been a topical issue of prime concern, primarily due to magnitude its environmental, ecotoxicological, and socioeconomic impacts. originates from both active abandoned mines (primarily gold coal) is encountered in Canada, China, Russia, South Africa, USA, other countries strong mining industry. Owing acidity, contains elevated levels dissolved (toxic) metals, metalloids, rare-earth elements, radionuclides, sulfates. Practical cost-effective solutions prevent formation still pending, while treatment (driven by frequent input chemicals energy) or passive (based on oxidation/reduction) technologies typically employed first more efficient contaminants removal, however, at expense process complexity, cost, materials energy consumption. More recently, under circular economy concept, hybrid (combination technologies) particularly integrated (sequential stepwise treatment) systems have explored beneficiation valorisation. These costly install operate but cleaner production since they can effectively pollution be used closed-loop sustainable management (e.g., zero liquid discharge (ZLD) systems). Herein, body knowledge treatment, (metals/minerals recovery), valorisation (water reclamation), life cycle assessment (LCA) comprehensively reviewed discussed, focus placed economy. Future research directions introduce reuse, recycle, resource recovery paradigms wastewater inspire innovation valorising this toxic hazardous effluent also provided. Overall, appears promising reclaimed water recovered minerals/metals could offset costs However, main challenges include high-cost, co-contamination minerals, generation higly heterogeneous mineralised sludge. • The beneficiation, was Focus opportunities introducing state-of-the-art relevant LCA studies summarised discussed Challenges related minerals reclamation were highlighted Knowledge gaps identified future proposed