Simulation of fines migration using a non-Newtonian lattice Boltzmann-discrete element model Part I: 2D implementation aspects

Purpose - The purpose of this paper is to present a novel computational framework capable of simulating the block cave phenomenon of fines migration in two dimensions. Fines migration is characterised by the faster movement of fine and often low-grade material towards the draw point in comparison to larger, blocky material. A greater understanding of the kinematic behaviour of fines and ore within the cave during draw is integral to the solution of this problem. Design/methodology/approach - The lattice Boltzmann method (LBM) is employed in a nonlinear form to represent the fines as a continuum, and it is coupled to the discrete element method (DEM) which is used to represent large blocks. The issues relevant to this approach, such as fluid-solid interaction, the synchronisation of explicit schemes, and the characterisation of a bulk material as a non-Newtonian fluid are discussed. Findings - Results of the 2D simulations reveal migration trends for the geometries, material properties and operational sequences analysed. By executing an extensive programme of numerical experiments the influence of these and other relevant block cave factors on the migration of fines could be isolated. Originality/value - To the authors' knowledge, this is the first time the LBM has been used to simulate the flow of bulk materials. The non-Newtonian LBM-DEM framework is also a novel approach to the investigation of fines migration, which until now has been limited to scale models, cellular automata or pure DEM simulations. The results of the 2D migration analyses highlight the potential for this novel approach to be applied in an industrial context and also encourage the extension of the framework to 3D.