26th Australian Institute of Physics Congress and the Australian and New Zealand Conference on Optics and Photonics

Characterising the spectral profile of vanadium: Satellite contributions and implications for rare earth element analysis

Not scheduled

20m

Belinda Hutchinson Building (The University of Sydney )

Poster ANZOS | Photonics and Optics (ANZCOP)

Speaker

Fenglin Zhuo (CSIRO, UNSW Sydney)

Description

The growth of clean technologies has resulted in an increased demand for critical minerals including rare earth elements (REEs). To address this demand, there has been growing need for the development of new techniques to accelerate the discovery, extraction, and processing of REEs from more easily extracted lower-grade ore deposits. A well-established technique used for element identification during mining operations is energy-dispersive X-ray fluorescence (XRF) spectroscopy, which can be easily adapted into portable in-situ analysers to provide rapid results with minimal sample preparation. However, the accurate detection of REEs using these portable XRF analysers is hindered by spectral overlaps between the L-shell emission lines of REEs and the satellite peaks of first-row transition metal-containing species. Satellite peaks arise from a variety of electronic transitions, most notably shake-off (multiple ionisation) and radiative Auger processes which are poorly understood for open shell atoms. Thus, in REE-containing deposits where first-row transition metals such as V are more abundant than REEs such as Pr and Nd, accurate XRF analysis of REE concentration is particularly challenging as spectral counts may be attributed to the wrong element. Therefore, an investigation into the shake-off and radiative Auger satellite contribution in transition metal spectra is critical to informing accurate analysis of energy-dispersive XRF spectra and improving the limit of detection (LOD) of REEs. This can be achieved through careful characterisation of the line shape, energy position, and intensity of the first-row transition metal satellite profiles using high-resolution X-ray emission spectroscopy (XES). This work reports on the characterisation of the V spectral profile using a laboratory X-ray emission spectrometer, including progress towards extracting the shake-off and radiative Auger satellite structures, and potential implications for spectral deconvolution with REEs.