3D analysis of equally X-ray attenuating mineralogical phases utilizing a correlative tomographic workflow across multiple length scales

A correlative 3D characterization workflow by micro and nano X-ray computed tomography (Micro-CT, Nano -CT) and analytical scanning electron microscopy (SEM) is presented over different length scales for particle composite materials that apply to any powder at the size scale between 0.3 mu m to 15 mu m. In this case study, an artificial compound of calcite, talcum, dolomite, and magnesite providing constituent particles with similar morphology, size distribution, and chemical composition for multidimensional separation processes is analyzed. First, Micro-CT characterizes the particle morphology and distribution of a larger amalgamated volume. Then, a smaller, site-specifically prepared pillar is imaged by Nano-CT allowing for correlative investigations at higher -resolution. Afterwards, the Nano-CT reconstruction is informed slice-wise by analytical SEM distinguishing particles with different chemical composition. The statistical interpretation of our results is improved by advanced post-processing and multidimensional analysis, allowing for quantitative characterization of the particles' size, phase distribution, and mineral degree of liberation.

Automated summary

A 3D characterization workflow combining micro and nano X-ray computed tomography (Micro-CT, Nano-CT) and analytical scanning electron microscopy (SEM) is introduced for particle composite materials. It can be applied to analyze powders ranging from 0.3 μm to 15 μm. This workflow allows for quantitative characterization of particle size, phase distribution, and mineral degree of liberation.