RT Journal Article T1 Mine waste from carbonatite deposits as potential rare earth resource: Insight into the Phalaborwa (Palabora) Complex A1 Gómez Arias, Alba A1 Yesares Ortiz, María Dolores A1 Díaz, Joaquín A1 Caraballo, Manuel A. A1 Maleke, Maleke A1 Sáez, Reinaldo A1 Heerden, Esta van A1 Vermeulen, Danie A1 Nieto, José Miguel AB The Phalaborwa (Palabora) Igneous Complex (PIC), South Africa, has been mined for the last six decades for copper and phosphate, among others commodities. As a result, more than 4500 Mt. of mining wastes have been deposited in waste rock dumps (WRDs) and tailing impoundments. This study aims to investigate the potential of the PIC wastes (WRDs and tailings) as a secondary resource of rare earth elements (REE) and its possible processing options, by means of both mineralogical and geochemical determinations, using X-ray diffraction (XRD), petrographic and scanning electron microscope with energy dispersive spectroscopy (SEM–EDS) and electron probe micro-analyzer (EPMA). The samples were also submitted to a REE leachability assay based in a sequential extraction procedure. Phoscorites and carbonatites are major lithologies in the WRDs and contain a notable concentration of REE, of which 0.2 and 0.1 wt%, respectively, would be easily extractable. The mineralogical results show monazite as the main REE-mineral (∑REE 60 wt%), while fluorapatite and calcite are the most important REE-bearing minerals (∑REE 1 and 0.5 wt%, respectively) for their abundance. On the other hand, the tailings are comprised mostly by monomineralic particles of calcite, dolomite, pyroxene, fluorapatite, magnetite and phlogopite. Based on the geochemical results, the extraction of REE from monazite, fluorapatite, calcite and dolomite, from tailings produced by both the Cu and the phosphate mines, might produce up to 5.65 and 1.75 kg of REE per ton, respectively. Therefore, tailings from PIC have the potential to become an asset. An approach to circular economy by re-processing mining wastes would extend the lifetime of the PIC mines and their benefits, while reducing the waste of resources and their environmental impact. PB Elsevier SN 0375-6742 YR 2022 FD 2022-01 LK https://hdl.handle.net/20.500.14352/71319 UL https://hdl.handle.net/20.500.14352/71319 LA eng NO Ministerio de Ciencia e Innovación (MICINN) NO Department of Science and Innovation, South Africa NO UNESCO NO Science Foundation Ireland NO Technology and inovation agency, South Africa NO National Agency for Research and Development DS Docta Complutense RD 16 abr 2025