Rock drilling in the mining industry
The process of drilling and blasting is widely used to fragment rock into smaller pieces and is one of the critical elements in the excavation process of mining applications. Accurate drilling of boreholes is essential for good blasting performance and enables the proper degree of fragmentation necessary to achieve the lowest cost of drilling, blasting, loading, hauling and crushing. Drilling is therefore a very important process for the mining industry. The drilling parameters, such as applied pressure and torque, are critical for rate of penetration, but they also affect the subsequent equipment wear. The optimal parameters often rely on the experience of the field operator and is in many ways considered as an empirical black box process. Numerical simulation and modelling have the potential to increase the knowledge and understanding of this important process.
Innovative numerical methods for modelling rock drilling
The rock drilling process includes several physical phenomena, such as contact between drill bit and rock and interactions between drilling fluid, drilling equipment and rock cuttings. Therefore, a digital twin of rock drilling requires the use of multiple numerical approaches in order to capture the complexity of the process. Within the framework of DigiRock, the rock material will be represented by the Bonded Discrete Element Method, the drill bit by the Finite Element Method and the drilling fluid by the Particle Finite Element Method, and novel wear models will be developed. Furthermore, high strain-rate testing of rock materials will be conducted and used to calibrate the models. Finally, a full-scale numerical simulation of rock drilling will be validated towards in-situ drilling at the Boliden Aitik mine.