High-Speed PIXE: Automated Mineralogy using a Color X-Ray Camera

Methods of automated mineralogy form the analytical backbone of geometallurgy. Most of them exploit the combined imaging and analytical capabilities of optical and scanning electron microscopes. Typical results are „phase maps“ either derived from the distribution of major elements or determined directly. The effective application of such methods for strategic metals which are won as by-products from other metal ores is handicapped by the restricted possibilities to determine the spatial distribution of such trace elements like In, Ga, Ge or the rare earth elements (REE). The recently comissioned High-Speed PIXE (Particle Induced X-Ray Emission) setup at the Helmholtz-Institute Freiberg for Resource Technologies will overcome these limitations.
We use the SLcam® X-ray Color Camera - a novel pnCCD Pixel detector (264 x 264 = 69696 Pixel) combined with a polycapillary X-ray optic (Scharf et al., 2011) as the detector for the element specific X-ray radiation. This design allows us the simultaneous determination of the trace element distribution on a 12 * 12 mm2 area with a lateral
resolution of about 50 μm. First results of geometallurgical applications of this method are presented.