Abstract

This paper investigates the occurrence of rare earth elements (REEs) in coal fly ash (CFA) as a potential alternative source of critical minerals, which are essential for clean energy applications and advanced chemical technologies. In this study, bulk CFA samples from Lingan and Point Aconi power stations in Nova Scotia were characterized to assess the presence of highly critical rare earth element oxides (HCREEOs) and REE-bearing mineral phases. X‑ray diffraction (XRD) analyses were conducted on both bulk materials and fine fractions (<45μm). Moisture content, particle size distribution, and carbon content were additionally measured to support resource assessment and extend prior research that focused primarily on environmental implications of CFA.

Both CFA samples exhibited low moisture and carbon contents, although the Lingan sample contained comparatively higher carbon content than the Point Aconi sample. Particle-size analysis revealed that the Lingan CFA is dominated by fine and ultrafine particles, whereas the Point Aconi CFA is enriched in intermediate fractions, with both materials largely demonstrating particle sizes within the 75–150μm range.

The identification of REE-bearing phases in these samples indicates the potential for further evaluation of CFA as a viable feedstock for REE recovery. These findings support further investigation into the technical and economic feasibility of commercial extraction of critical REEs from coal fly ash resources from Nova Scotia.

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