An advanced analytical assessment of rare earth element concentration, distribution, speciation, crystallography and solid-state chemistry in fly ash

Abstract Fly ash represents a promising alternative source of rare earth elements (REE). However, information on REE containing mineral phases and their association with other fly components, vital for recovery from ash, is currently lacking. Herein, the mass fraction, distribution, crystallography solid-state chemistry REE, U Th in Nigerian simulated samples were characterised using range laboratory synchrotron x-ray based analytical techniques to underpin future extraction methodologies. Inductively coupled plasma spectrometry following full-acid digest forty-five revealed recoverable average total content which ranged between 442 mgkg−1and 625 mgkg−1, comprising over 30 wt% critical Nd, Eu, Tb, Dy, Y Er. These within found be most frequently associated discrete monazite, xenotime Y-bearing zircon particles, former detected, could beneficiated through gravity separation. Analysis monazite particles isolated composite complimentary suite radiation core-shell pattern, shell rich colocalised Ce, Nd La, core enrich both Th. Ce was exist mixed trivalent tetravalent oxidation state, structure amorphized due high temperature combustion process. Such results demonstrate strong co-association physical distribution ash; knowledge can subsequently used optimise or develop more selective, cost-effective environmentally friendly solvent methodology, by targeting strongly surface bound particles.