Recovery of Rare Earth Elements from Mining Tailings: A Case Study for Generating Wealth from Waste

Abstract

The growing demand for rare earth elements (REE) driven by their applications in modern technologies has caused the need to search for alternative sources of these elements as their extraction from traditional deposits is limited. A potential source of light rare earth elements (LREE) may be the monazite present in the mining waste generated in the Bagre-Nechí mining district in Colombia due to the processing of sands containing alluvial gold. Consequently, in this research, a systematic evaluation has been carried out for the extraction of (Formula presented.), (Formula presented.), and (Formula presented.) from a leach liquor obtained from monazite present in alluvial gold mining tailings. The leaching process carried out with (Formula presented.) indicated the recovery of approximately 90% of (Formula presented.) and (Formula presented.) and (Formula presented.) of (Formula presented.) ; the solvent extraction tests of these elements showed that increasing the contact time and pH of the leaching liquor positively affects the extraction of lanthanum, cerium, and neodymium, achieving extractions close to 100% with (Formula presented.) and to a lesser extent with (Formula presented.). McCabe–Thiele diagrams for extraction with (Formula presented.) indicated the requirement of three stages for the extraction of (Formula presented.), (Formula presented.) and (Formula presented.).