Estimation of Rock Comminution Characteristics by Using Drill Penetration Rates

Abstract

The characterization of rock properties is a vital task in the challenge for hard rock mining operation. A simplified and straightforward characterization of rock properties provides information about the safety of ground structure (e.g. slope, tunnel, etc.), and the strategy to improve productivity in terms of rock breakage process. The penetration-rate of drilling has been proposed to quantify the comminution characteristics of rock by virtue of real-time logging of drilling performance otherwise the data is obtained from a time- and cost-consuming laboratory test; this is called measurement while drilling. In the mining industry, this technique can be a useful tool that has allowed for the meticulous and routine data collection of geological information from blasthole drilling operations. In this study, the mechanical performance of drill and its interaction with the rock properties is investigated in laboratory scale. The rock properties include tensile strength, hardness, and grindability, which is considered as the influential parameters of the required energy consumption for the comminution processes. For sandstone samples, the penetration-rate data shows a good correlation with tensile strength, hardness, and Bond work index; this implies that penetration-rate data can be a good indicator to estimate comminution characteristics. Additionally we carried out the same test with limestone samples. Second, field study is conducted to investigate the interaction between current blast design and rock fragmentation. Fabricating the blast design and fragmentation through the blast operation might enable to construct proper strategy to reduce the energy cost of downstream processes including crushing and grinding by using the rock characteristics measured from the blasthole drilling. The concept of this process is a part of Mine-to-Mill optimization. The thesis proposed the blueprint of Mine-to-Mill optimization, providing a guideline for further in-situ research.