Study on Control of Fines Generation in Aggregate Quarry Blasting based on Small-diameter Charge Technology

In a limestone aggregate quarry, excessive fines generation following blasting was primarily caused by extensively developed joint fractures and prolonged implementation of continuous coupled charging configurations. To minimize the generation of blasting fines and improve rock fragmentation, a small-diameter charge technology was developed based on the principles of decoupled charge blasting. Firstly, a fragmentation-damage correlation model for blast-induced fractured rock mass was developed in ANSYS/LS-DYNA based on field-collected measurement data. Secondly, numerical simulations were conducted to evaluate the blasting performance of the small-diameter charge structure relative to traditional decoupled charge methods, thereby confirming the technical viability of the proposed small-diameter charging approach. Thirdly, numerical simulations were conducted to determine the correlation between segmented small-diameter charge lengths and fines generation rates, thereby enabling technical optimization. Finally, field verification tests were conducted in accordance with simulation findings to assess the performance of the refined small-diameter charging method. Numerical simulations demonstrate that the small-diameter charging technique provides superior control over rock fragmentation, with the optimal dust reduction achieved using a dual-segment 2.0 m small-diameter charge configuration. Field tests demonstrate that employing a dual-segment 2.0 m small-diameter charge configuration reduces blasting fines generation by 6.53 percentage points compared to conventional continuous coupled charging, while maintaining comparable boulder yield, offering practical guidance for similar aggregate quarry operations.