Abstract: In order to research three-dimensional （3D） characterization of the pore structure features in the packed ore particle bed are focused. X-ray computed tomography（CT）scanning was applied to deriving the cross-sectional images of specimens with single particle size of 1~3，3~5，5~7，7~9，9~10 mm. Based on the in-house developed 3D image analysis programs using Matlab， the volume porosity， pore size distribution and degree of connectivity were calculated and analyzed in detail. The results show that the porosity， equivalent pore radius and median pore diameter （d50） increase with the increase of grain size. The pore connectivity of samples with different grain size deposits obtained by cluster labeling method exceeds 80%， and the curves keeps a fast growth rate first and then slow growth rate with the increase of particle size. The results provide a reference for further understanding the pore characteristics and permeability of tailings heap formed by heap leaching process.

Key words: Ore particle beds, CT image, Pore structure