Beyond Remediation: Evaluating the Economic Potential of Recovering REEs and High-Value Metals from Acidic Mine Drainage

Abstract

The rising demand for critical raw materials (CRMs) and limited European supply drive the search for alternative sources. Acidic mine waters (AMWs) are promising for metal recovery and water reclamation. Although treatment technologies exist, large-scale use is hindered by economic uncertainties. This study evaluates the technoeconomic feasibility of recovering CRMs from AMWs via an integrated process with selective precipitation, ion exchange, nanofiltration, and electrodialysis with bipolar membranes (EDBM). Five scenarios explore different recovery, regeneration, and purification setups. Under these conditions, approximately 1242 t/year of ZnS(s), 5147 t/year of Mg(OH)2(s), 6.65 t/year of heavy rare earth element (HREE) oxides, and 14.23 t/year of light rare earth element (LREE) oxides can be recovered. The results indicate that none of the recovery schemes can be economically viable, with annual net costs ranging from 6.6 million €/year to 12.7 million €/year. Metal precipitation (as hydroxide and sulfide) is the costliest stage, followed by reagent regeneration, where chemical use accounts for 23–90% of costs. Including EDBM increases electricity costs by up to 23%. Although the results highlight that AMW valorization as a circular approach can be useful for obtaining valuable raw materials, reducing supply risks, and reducing EU dependency, the economic results show the need for public subsidies or targeted policy incentives to bridge the viability gap.