A review on complex utilization of mine tailings: Recovery of rare earth elements and residue valorization

The mining sector generates massive quantities of mine tailings in response to the ever-growing demand for mineral products. Mine tailings (MTs) pose a major environmental problem because of the challenges associated with their management and storage. Depending on the type of ore extracted and the processing techniques employed, there is a possibility of extracting valuable components from these tailings, such as rare earth elements (REEs). However, optimal utilization of MTs should focus on repurposing all components of the waste, not just the economically valuable ones. This review offers insights into MT types, characterization, and environmental impacts. It evaluates hydrometallurgical and bio-hydrometallurgical routes as promising technologies for the recovery of REEs from tailings and highlights mechanical activation's potential as a pretreatment for enhanced REE extraction. This study explores reuse options for post-extraction MT residues, including construction materials via geopolymerization. The goal of this review is to present current best practices that enable the mining industry to fully recycle both valuable and residual components of MTs. An integrated approach combining reprocessing technologies with reuse applications can transform MTs into circular economy resources.