The surface morphology of compacted and crushed gangue presents self-similarity and other fractal characteristics. This research constructed a fractal model for the particle size of compacted and crushed gangue based on fractal theory and particle size distribution information. To investigate the fractal characteristics of compacted gangue, compaction experiments were carried out under varied stresses and with different particle sizes. Results showed that the particle size distributions of crushed gangue specimens with two distinct lithology exhibited fractal characteristics. Fractal dimension of each crushed specimen ranged from 0.352 to 2.654, with increase of stress, the particle size of each specimen tended to be distributed in a more dispersed fashion. Meanwhile, the fractal dimension increased with increased content of small particles, and tended to be a definite value. While the fractal dimension decreased with increased rock strength for the same initial particle size gradation and stress. (C) 2016 Elsevier B.V. All rights reserved.