Coal mine waste rock dumps generate salt that may leach into pits or other water bodies. The potential leach rates need to be predicted over decadal time scales in order to inform management of pit lakes and waste rock after mining ceases. Due to the difficulty of representative in-situ monitoring of leaching, parameters for models and/or salt decay curves are usually derived from laboratory experiments. The various scaling uncertainties, including particle sizes and hydrological conditions, mean there are questions about the reliability of model predictions. To address this we have set up a meso-scale experimental facility, representing a one cubic meter volume of waste rock, subject so far to 15 months of imposed wetting-drying cycles for two rock types. The water balance and salt load data collected permit simple flow and transport models to be calibrated, and comparisons to be made to upscaled laboratory-derived leaching parameters, both for total salt (by converting electrical conductivity) and individually for six major ions. Results show that the calibrated models represent observed total salt loads well, and permit preliminary derivation of empirical scaling factors. The variance of results between the rock types and between ions calls for further investigation of the scaling processes and optimisation of experiments.