Applications of hyperspectral mineralogy for geoenvironmental characterisation

Technological innovations and emerging analytical capabilities are transforming the mineralogical and textural analysis of rock samples and drill core. Accurate mineralogical identification and systematic documentation can enhance deposit knowledge across the mining chain. From the earliest stages of mine-life, accurate mineralogical identification can also enhance environmental characterisation which traditionally utilises a range of wet chemical tests to predict acid generation and acid neutralisation potential. An enhanced understanding of both the ore and gangue mineralogy allows accurate prediction of the geoenvironmental characteristics of future waste materials. This study presents examples using thermal infrared (TIR) hyperspectral data for domaining acid neutralisation capacity in an exploration drill hole in a volcanic hosted massive sulfide (VHMS) district and a porphyry Cu-Au deposit by rapidly identifying the distribution and relative abundance of carbonate-group minerals. The results are validated using mineralogical and chemical analytical techniques (XRD and EMPA) and are compared to industry standard chemical tests (paste pH, NAG pH) used for acid base accounting (ABA) of mine materials. Utilising hyperspectral core scanning platforms for identifying acid neutralising domains can facilitate deposit-scale geoenvironmental modelling from the earliest of mine stages and improve long-term waste management practices.