Fracture behavior and energy efficiency of silica under a tensile load using molecular dynamics

Existing theories on the energy consumption of comminution are mainly applicable at the macroscopic and mesoscopic scales, and there is a lack of studies on the fracture behavior and energy efficiency at the microscopic scale. To reveal the energy evolution of the comminution process at the atomic scale, silica was subjected to a tensile load test using a molecular dynamics simulation. The crack propagation behavior, mechanical properties, major energy changes, and energy efficiency were analyzed for the comminution process of silica. The results showed that the mineral morphology and load direction affected the number and propagation path of cracks and that the crack propagation direction was generally perpendicular to the load direction. With an increase in the pre-crack length, the breaking strength, Young's modulus, elastic energy, input energy, and new surface energy of the specimens decreased to varying degrees. The energy efficiency can be significantly improved by creating pre-cracks, changing the morphology of silica to an amorphous state, and applying a load perpendicular to the crack direction. The maximum energy efficiency was 6.69 times the minimum value. This study explains the influence of precracking, mineral morphology, and load direction on energy efficiency at the atomic scale and reveals the fracture mechanism and energy evolution of silica during comminution. This is of positive significance for reducing energy consumption by improving the energy efficiency of comminution processes.

Automated summary

Existing theories on the energy consumption of comminution mainly focus on the macroscopic and mesoscopic scales, neglecting the microscopic scale. In this study, a molecular dynamics simulation was conducted to investigate the energy evolution of the comminution process at the atomic scale. Results showed that mineral morphology and load direction have a significant impact on crack propagation behavior and energy efficiency.