Examining Ni-laterite leach mineralogy & chemistry – a holistic multi-scale approach

•We discuss the mineralogy and chemistry of leached Turkish Çaldağ Ni-laterite ore.•Comprehensive characterisation at the mineral grain scale is necessary.•Acid leach extraction inter-relationships are assessed at different experimental scales.•All experimental scales are valuable for determining the actual leaching processes.

Ambient acid leach extraction of Ni-laterites is being heralded as a breakthrough in environmentally conscious mining, however to be successfully exploited they require comprehensive characterisation of their mineralogy and chemistry. This industry-academia collaborative research uses XRD, EPMA and ICPAES techniques to examine the acid leaching characteristics of Turkish Çaldağ ore. Mineral scale and small column scale leach experiments were carried out with material examined over various lengths of time at ambient conditions. The characterised residues and solution leach inter-relationships and selectivities are compared to bottle roll and heap leach results, demonstrating where true correlations exist and where differences exist as a result of the experimental scale limitations.