A coupled model with computational fluid dynamics and population balance model to investigate the non-metallic inclusions behavior including growth,size distribution and removal in gas-stirred ladles was established.In the present study,the phenomena of inclusions turbulent random motion,bubbles wake and slag eye forming on molten steel surface were considered,and the multiple mechanisms both that promote inclusion growth due to inclusion-inclusion collision caused by turbulent random motion,shear rate in turbulent eddy and difference inclusion Stokes velocities,and that promote inclusion removal due to bubble- inclusion turbulence random collision,bubble-inclusion turbulent shear collision,bubble-inclusion buoyancy collision,inclusion own floatation near slag-metal interface,bubble wake capture and wall adhesion were investigated.The importance of different mechanisms and total inclusion removal ratio under different conditions,and the distribution of inclusion number densities in ladle were discussed and clarified.The results show that at low gas flow rate,the inclusion growth is mainly attributed to both turbulent shear collision and Stokes collision which is notably affected by the Stokes collision efficiency,and the inclusion removal is mainly attributed to the bubble -inclusion buoyancy collision and inclusion own floatation near slag-metal interface.At higher gas flow rate,the inclusions appear turbulence random motion in bubbly plume zone,and both the inclusion-inclusion and inclusion-bubble turbulent random collisions become important for inclusion growth and removal.