A model for the coordination number of multi-sized spheres in a packed bed as a function of size distribution and porosity is evaluated using a CT scanner. The model being investigated was only evaluated using a particle packing algorithm by the authors, and not experimentally. This is done with the aim of using this model to quantify the distribution of grains within pellets used as ore bearing feed to the blast furnace. This allows for the prediction of the distributed phase transformation that occurs in pellets, and results in a better overall understanding of the bed in the blast furnace, which can result in a minimisation of the coke feed to these furnaces. Experiments were done using glass spheres of various diameters to construct packed beds of different size distributions which were then scanned in a CT scanner. The images from the CT scanner were subject to image analysis and the coordination number of the spheres calculated. The results obtained compared favourably with the model predictions. (c) 2005 Elsevier Ltd. All rights reserved.