A grinding power model has been developed to predict the power draw of Outotec's vertical fine grinding mill (HIGmill). The model is based on a combination of laboratory, pilot and full-scale measurements taken over a range of process conditions. The power draw of the mill is influenced by a variety of factors, ranging from simple geometric factors like the grinding disc diameter, spacing and speed to various process factors like the viscosity, density, grinding bead size, fill level and fluidisation velocity. The focus of the model is on scale up to full-scale from laboratory and pilot-scale data, and how to configure the mill for different process scenarios. (C) 2016 Elsevier Ltd. All rights reserved.