Solidification Theoretical And Experimental Research On Centrifugal Granulation Of Blast Furnace Slag

Blast furnace slag is the main by-product in the process of smelting the pig iron.It contains rich resources. The high temperature of slag easily adheres together. The processing method of blast furnace slag can directly affect the recovery and utilization of the slag particles. The key of slag processing is timely solidification and heat recovery of the particles. It is necessary to solidify the liquid blast furnace slag for uniform and spherical slag particles to obtain a better effect of heat recovery, improve heat transfer and develop high value-added slag byproduct.This paper studies the influential factors on the solidification of blast furnace slag from the theoretical study, numerical simulation and experimental study. The theoretical studies on slag solidification, which includes three aspects. Firstly, it studies liquid slag breakup from the slag crushing mechanism, wave theory. Secondly, high temperature liquid solidified slag contains complex phase process. Building a mathematical model of phase change analyses phase change characteristics. Finally, building a physical model of slag solidification. One of the purposes of molten blast furnace slag solidification timely is the recovery of waste heat. It analyses the solidification and heat transfer of slag. The characteristics of heat transfer during solidification can be concisely summed up as “a heat, two moved, three pass”. Numerical simulation of solidification process of molten slag was carried out by using CFD FLUENT software. Studying on the change of the temperature, solid fraction during solidification. The simulation results show that the temperature distribution and movement of the phase interface during slag cooling process. The effect of slag viscosity on solidification and the main effect of slag composition and temperature on slag viscosity were all analyzed. The effect of slag viscosity on particle diameter was also analyzed. The disk speed and disk diameter impacted on particle solidification time. The effect of factors on solidification was followed: particle diameter, disk speed, disk diameter. By optimizing experimentalsystem, setting up experimental platform in the laboratory to investigate the effect of slag composition on viscosity and viscosity on solidification. When the nitrogen pressure is 0.7KPa,the nitrogen flow rate in the pipe is 30m/s,the inner and outer nozzle cone angle combination is(90°,120°),disk speed is 1800r/min,the slag particle diameter can be obtained for 1~2mm,When the disk speed is 1200~1800r/min,uniform and spherical slag can be obtained.The solidification of molten blast furnace slag is the focus of this paper. Master the rules on slag solidification can provide a theoretical basis to obtain heat recovery and high value-added materials.