3/18AM (General session) Rock Engineering / Mining techn

[2K0101-08-02] Edge chipping test with rock using a single button bit

○Jiacheng Song^{1 [Doctoral course]}, Kimihiro Hashiba¹, Katsunori Fukui¹ (1. The University of Tokyo)

Chairperson: Akihiro Hamanaka (Kyushu University)

Keywords:Edge chipping, Button bit, Rock cutting

In mining and tunneling engineering, the efficiency and cost-effectiveness of rock breakage heavily depend on the excavation tools, such as cutting picks, disc cutters, and drilling bits. Hence, it is indispensable to evaluate and estimate the performance and durability of the tools. However, cutting tests and drilling tests using actual excavation tools require a large testing machine and take much time and effort. In this study, edge chipping tests, which have been used for assessing edge toughness of brittle materials, were conducted for appropriately and efficiently estimating the force and energy during rock cutting. In the test, a single button bit was penetrated into a rock block in a close position to a side surface, and a rock broken piece was chipped. This study investigated the effects of rock type, Sanjome andesite and Tage tuff, bit size, 6 and 8 mm in diameter, and seven cutting distances from a side surface on the edge chipping test results. Key measurements included the size, side area, and volume of rock chips, peak loading force, bit penetration depth, and force-penetration curves. These data were analyzed to understand the interplay between rock properties, tool dimensions, and test conditions. They provide essential insights into the forces involved in rock cutting and energy consumption. The findings of this study will be integral to the design and optimization of rock cutting machines.