Simulation And Research On Dry Granulation Process Of Molten Steel Slag By Rotary Disk

The steel output of China has ranked the first in the world since1996.As the steeloutput is increasing, the steel slag as the byproduct of the steel production process isincreasing accordingly. But the large accumulative steel slag not only pollutes theenvironment, but also occupies a mass of land. So exploring some methods to handleand apply the steel slag effectively has become one of the vital tasks in the steelindustry.Based on the research status of molten steel slag dry processing, the theoreticalanalysis on the principle and properties of dry granulation process of molten steel slagby rotary disk has been completed in the paper. Then the Gambit commercial softwareis used to establish the simulation model of dry granulation process of molten steelslag by rotary disk and the ANSYS FLUENT software is used to proceed with thedynamic simulation analysis of the granulation process. In the simulation process, themolten steel slag is injected into the rotary disk and the molten steel slag flies awayfrom the edge of rotary disk with the effect of the centrifugal force. Then the moltensteel slag will be rapidly cooled down to particles in the cool air outside the rotarydisk. By changing the key parameters such as the uplift angle of the rotary disk, therotating speed of the rotary disk, the speed of the cooling air and the flow of themolten steel slag, the study on the important parameters to influence the temperatureand the diameter of steel slag droplets in the granulation process has been done. Basedon the analysis results of simulation model of dry granulation process of molten steelslag by rotary disk, the time and the diameter of cooling down the recycledhigh-temperature steel slag particles have been calculated. The deviation of filmthickness by simulation and by experiment is less than10%, which proves theapplicability of simulation model. The result will be helpful to research the structuraldesign and process parameters of dry granulation machine of molten steel slag byrotary disk. The simulation results are as follows:When the uplift angle of the rotary disk ranges from7°to10°,it will not clearlyinfluence the thickness of the steel slag film on the edge of the rotary disk,temperature，diameter and velocity of the steel slag droplet.When the rotating speed of the rotary disk increases from90rad/s to120rad/s,thetemperature dropping velocity of the steel slag will accelerate accordingly with the increasing of the rotating speed of the rotary disk,while the diameter of the steel slagwill decline with the increasing of the rotating speed of the rotary disk and thedeclining amplitude is0.005m or so.When the speed of the cooling air rises from5m/s to20m/s, the temperaturedropping velocity of the steel slag will accelerate accordingly with the rising of thespeed of the cooling air, while the diameter of the steel slag will decline with therising of the speed of the cooling air and the declining amplitude is between0.004mand0.008m.When the flow of the molten steel slag entering into the rotary disk increases,the diameter of the steel slag droplet will increase，and the time of cooling down thesteel slag droplet will increase.Within the given parameter range designed by the granulation machine theapproximate range of the diameter of the steel slag particles after cooling down themolten steel slag to room temperature is from7.87mm to15.74mm according to thesimulation calculation.