Numerical and experimental study on ore-collecting characteristics of deep-sea seafloor massive sulfide

The particles of seafloor massive sulfide (SMS) formed by mechanical breaking can be characterised by highdensity and coarse particles, and there is little research on their collection. In this study, the computational fluid dynamics-discrete element method (CFD-DEM) was used to conduct numerical simulations of the deep-sea seafloor massive sulfide ore collection process. First, the characteristics of the ore collecting flow field were studied. The flow field exhibited complex transient characteristics owing to the irregular movement of the particles. The ore collection mechanism was studied, and the dynamic characteristics of the particles were quantitatively analyzed. The particles were driven by the cutting arm, tilted upward, and rolled up. When rolled up to the effective range of negative pressure suction of the collecting hard pipe, the particles were subjected to the coupling effect of swirling flow and negative pressure suction flow and were finally transported to the inside of the collecting hard pipe. Simultaneously, through a comparative analysis, it was found that the dynamic characteristics of the collected particles were very similar, and the velocity, kinetic energy, slip velocity and vorticity of the particles had the characteristics of transient oscillation. The research presented in this paper has reference significance for the efficient collection and optimal control of flow fields.