Numerical Simulation for Optimisation of Rock Drilling and Loading for Mining

Purpose and goal:

The objective of the pre-study was to develop and evaluate physically realistic numerical models for rock drilling and loading of rock material. The models developed within the project has shown good potential for simulation of drilling and loading where rate of penetration and wear has been predicted. Field measurements of wear and bucket filling has been used for preliminary validation of the model for loading, with adequate agreement.

Due to difficulties to perform on site field measurements of drilling no validation of the drilling model has been conducted within the project. Expected results and effects:

Within the pre-study, rock material has been characterized experimentally at lab-scale at LTU. The characterization has been conducted at high strain-rates and attempts has been made to characterize at high confining pressures. A numerical model of rock has been further developed and evaluated.

The model has been calibrated against experiments and has been used for drilling simulations where transport of rock cuttings has been included. A model for loading and wear has been further developed and evaluated. The model has been used for loading of rock for different bucket geometries. Approach and implementation:

The project was conducted as a collaboration between div. for Solid Mechanics at LTU and Boliden Minerals AB. LTU has been responsible for experimental characterization and model development and Boliden for model development and data gathering in Aitik. In the project proposal field measurements of drilling parameters were planned.

These could not be conducted within the project, partly due to difficulties in visiting Aitik during the Covid-19 pandemic. These field measurements will be performed in a planned full-scale innovation project where Boliden is a project partner.