A study on fracture mechanism of quartz crystal under impact crushing

Abstract

The majority of naturally occurring ores consist of crystalline structures. Understanding the fracture behavior of crystals during ore crushing is critical for comprehending the mechanical properties of ores. This study investigates the fracture behavior of quartz crystals under impact crushing conditions. The findings reveal a strong correlation between the mechanical properties of quartz particles and their fracture behavior. At low specific energy of impact crushing (E_cs), the fracture mode of quartz grains is predominantly intergranular. With increasing E_cs, the fracture mode transitions from intergranular to transgranular. During fracture, deformation initiates preferentially in coarse grains, while the proportion of fine grains undergoing deformation increases with E_cs. The results suggest that grain boundary strength and the proportion of fine grains are critical factors influencing the mechanical properties of ores. The study also finds that when subjected to external forces, variations in deformation capacity among grains result in uneven deformation during fracture. The activation of the {0001} < 11–20 > and {10–10} < 11–20 > slip systems promotes plastic deformation in quartz crystals, whereas activation of the {10–11} < 11–20 > slip system hinders plastic deformation in fine grains. Differences in grain deformation capacity during fracture introduce uncertainty in the fracture behavior and crack propagation of quartz grains, elucidating the mechanisms behind the specific particle size distribution observed post-fracture.