Study on the Fragmentation Characteristics and Dust Generation Mechanism of Coal Cutting by Pick

ABSTRACT During underground excavation, coal dust generation threatens miners' health and damages ecosystems. Its generation is directly influenced by cutting pick performance and inherent coal properties. This study investigates the effects of coal properties and cutting parameters on coal fragmentation characteristics from a mesoscopic perspective, elucidating the dust generation mechanism during coal cutting. The results demonstrate that after normalizing the elastic modulus, both the damage range and the crack count in coal samples exhibit a decreasing trend with increasing confining pressure and uniaxial compressive strength (UCS), while the proportion of tensile cracks continues to decline. Correspondingly, dust generation follows an identical decreasing trend under these conditions. As the attack angle increases, the internal damage range, the crack count, and dust generation of coal samples first decrease and then increase, whereas the proportion of tensile cracks initially rises before decreasing. With greater cutting depth and larger pick tip angles, the damage range, the crack count, and the dust generation progressively increase, while the proportion of tensile cracks gradually decreases. The variation patterns of cutting force and specific energy (SE) obtained through numerical simulation are largely consistent with laboratory experimental findings. This study thus provides crucial insights for reducing coal dust and enhancing safety through optimized cutting strategies.