Automated Mineralogy: from drill cores to sub-micron information

The transition towards cleaner energy and the manufacture of associated new technologies will require extraction of mineral resources at volumes much greater than at present. Consequently, identification of new deposits is both economically and strategically important, driving a boom in mineral exploration coupled with a need to lower the environmental impact through more efficient mining capabilities. Crucial is an understanding of mineralogy and texture across scales, and thus improving knowledge at each stage of the mining cycle from exploration through to production and ultimately to waste handling. A key tool in this understanding is Automated Mineralogy. Automated Mineralogy has been integral to process mineralogy for more than two decades, with SEM being the traditional analytical platform. However, the extension of Automated Mineralogy using scanning micro-XRF instruments allows the technique to be implemented across broader spatial scales. In practice, the same logical workflow can be applied from the scale of large cut or split (minimally prepared) drill-core samples,through to polished thin sections or block mounts of various sample types (fragments or crushed plant material). At the most detailed level, the information obtained can be at the sub-micron scale of mineral classification, or even zonation withing single grains. An example of Automated Mineralogy as applied to Au-Co exploration is presented that highlights the benefit of analysis across scales, integrating information collected using the AMICS platform on drill core measured using scanning micro-XRF, and thin sections measured by SEM. The example will also demonstrate the ability to use the same Automated Mineralogy approach to define and quantify sub-micron information within individual mineral grains.