Abstract: In order to ascertain the flow characteristics of spiral and separation behaviors of different mineral particles,numerical simulation of flow field of and particles motion behavior in spirals with diameter of 300 mm,was carried out by utilizing k-ε model for turbulence calculation and VOF model for capturing the air-liquid interface and discrete phase model for the liquid-solid coupling based on the principle of CFD.The influence of spiral interval and feed mass flow on them was discussed as well.The results showed the water velocity isolines exist like obvious bands,its velocity magnitude increases gradually along the direction of spiral depth,and increases gradually from inner to outer along the radial direction.The turbulence kinetic energy appears like ellipse rings in the radial direction,and increases from top to bottom at the outer edge.In the same flow field,the maximum of particle motion speed has negative correlation to its density.When the spiral internal was enlarged,the water depth keeps invariant,however the water velocity and turbulence kinetic energy increased accordingly,and the particle motion speed increased as well,which could accelerate particles banding and separation.The feed mass flow has significant effect on the water depth,flow velocity and turbulence kinetic energy,however it has little influence on the flow distribution characteristics.The particle motion randomness is positively correlated to the factor,resulting in the delay of particles banding with the increasing of feed mass flow,which is disadvantage to the separation process.

Key words: Flow field of spiral, Particle motion, CFD, Numerical simulation, Spiral interval, Feed mass flow