Validation and performance assessment of a WD-XRF fused bead method for accurate quantification of scandium in nickel laterite deposits

This study focuses on the validation and performance assessment of the Wavelength Dispersive X-ray Fluorescence (WD-XRF) fused bead method for scandium quantification in nickel laterite ores. The calibration of the instrument showed a high correlation (R2 = 0.9962), with a Limit of Detection (LoD) of 20 ppm and a precision of 1.28% RSD. Accuracy was confirmed with good recoveries ranging from 98.05% to 101.46%. The relative expanded uncertainty was calculated at 5.89%. Method and instrumental reproducibility were confirmed by quality control (QC) Chart monitoring using certified reference materials (CRMs) and by relative error (RE) values below 10% for duplicate pulverized samples. The mode of scandium concentration in the samples was found to be 140 ppm. Overall, these results demonstrate that the WD-XRF fused bead method shows good validation performance, with excellent linearity, precision, accuracy, reproducibility, low expanded uncertainty and a low LoD for scandium quantification in complex matrices such as nickel laterite ores.