Tungsten Concentrations in Mittersill Scheelite Ore Quantified with X-Ray Computed Tomography

Abstract

Drill cores from the Mittersill tungsten mine, also called Felbertal, were scanned with a drill core scanner using X-ray computed tomography (XCT) and X-ray fluorescence (XRF). Matrix amphiboles and quartz stand out as peaks in the XCT attenuation histogram, whereas the main ore mineral scheelite has distinctly high attenuation. Volumetric concentrations of the XCT high attenuation phase show an excellent correlation with tungsten lab assay values for 56 samples. One outlier, which can be attributed to a high bismuth concentration, as observed with the drill core scanner, needs a correction term to fall close to the linear relation formed by all other samples. The results suggest the technique could be used for rapid tungsten analysis in this, or similar, geological settings. It is evident that scheelite shows up as high attenuation values in the XCT data, which enables further ore characterization studies in 3D.