NUMERICAL MODELING OF MACRO-SCALE BRITTLE ROCK CRUSHING DURING IMPACTS

Badr, Salah, A.; Abdelhaffez, Gamal, S.

doi:10.21608/jesaun.2012.114619

NUMERICAL MODELING OF MACRO-SCALE BRITTLE ROCK CRUSHING DURING IMPACTS

Document Type : Research Paper

Authors

¹ Mining Eng. Dept., Faculty of Engineering., king Abdulaziz University, Jeddah, Saudi Arabia

² Secondment from Mining Engineering Department, Faculty of Engineering, Assiut University, Egypt.

10.21608/jesaun.2012.114619

Abstract

Several machines, such as percussion drills and crushers use the physical effect of compression to crush hard and brittle rocks. These machines are still sized rather by empirical than by scientific approaches. In order to investigate the principles of comminution by compression of single large rock fragment, a numerical model developed by Particle Flow Code “PFC®” program was developed to simulate the dynamics of this system. The model simulates a single rock fragment crushed by a number of fixed kinetic energy ram blows. The simulated fragment is circler granite disk of unit thickness with grain matrix at the range from 2 to 4 mm. The model results indicates that cracks generated due compression are more popular compared to those due shear and this conduct increases with increase of number of hits. The impact energy is consumed mainly in form of friction energy ≈ 52 to 61% inside the fragmented matrix while strain energy stays at the range of ≈ 5%. The rock matrix tends to consume more of these energies as number of impacts increases due change to crushed matrix milling and cushioning. The energy consumed in crushing the rock fragment represents at the range from 32 to 45% of impact energy and tends to decrease as number of hits increase.

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