Assessment of Time-Gated Raman Spectroscopy for Online Mineralogy of a Spodumene Ore

Abstract

This paper investigates the applicability of time-gated Raman spectroscopy (TRS) for online mineralogy identification, focusing on a Li-bearing spodumene ore. The study provides an overview of existing online mineralogy tools and points out some limitations of elemental analysis techniques. Dense media separation concentrate and tailing samples used originated from a deposit in Quebec, Canada. Various techniques, including ICP-AES, XRD, laser diffraction, and specific gravity determination, were used for detailed sample characterization. Samples and their mixtures at known ratios were prepared as powder and slurries, before being analyzed using TRS, followed by spectrum quantitative analysis. Results show a linear correlation between spodumene percentage by weight and the main Raman peak height or area, in both dry and slurry form, with a higher determination coefficient in slurry form. TRS also provided indications as to the gangue minerals present in the samples. This study shows the potential for TRS as a tool for online mineralogical assessment of spodumene ores, and further work should target the determination of detection limits and quantification of both valuable and gangue minerals.