Abstract: The internal flow field characteristics of KYF flotation machine of 20 L for liquid-solid two phases were numerically simulated using standard k-ε turbulence model and particle model. The study results show that the flow field in the flotation machine distributes into two cycles up and down， the flow velocity of the mixing and rising zones is higher than that of separating zone. The velocity of mineral particles in mixing and rising zones is inversely proportional to particle size， while the velocity in the separating zone is proportional to particle size. The higher pressure distribution zone is located at the windward of the stator or impeller respectively. Besides， the absolute pressure is proportional to the stirring intensity. The volume fraction of particles is proportional to the particles size in mixing and rising zones and it decreases with the increasing of stirring intensity， which is contrary to the separating zone. Therefore， the rotational impeller speed of 600r/min is more advantageous to improve the working performance of the flotation machine.

Key words: KYF flotation machine, stirring intensity, liquid-solid two phases flow, flow field characteristics, numerical simulation