Research On Key Technology Of Mechanical Centrifugal Granulation Of Blast Furnace Slag

Blast furnace slag is a by-product of ironmaking.It has the characteristics of high output and high grade sensible heat.It is an efficient and recyclable energy resource.At present,water scouring slag is a traditional technology for sensible heat extraction and reuse.This method can obtain high vitreous content of water-quenched slag as a blending material for cement production,and realize resource utilization.However,at the same time,a large amount of sensible heat is taken away by water vapor,which seriously wastes energy and pollutes the environment.Currently,this high-grade sensible heat extraction and reuse method is not perfect,and the technology needs to be improved urgently.Based on this,a centrifugal granulation heat recovery process for blast furnace slag has been proposed.This paper is the research content of the national key R&D project(2017YFB0603602-03).Therefore,aiming at centrifugal granulation heat recovery process for blast furnace slag,on the basis of clarifying the action mechanism and granulation mechanism of dry centrifugal granulation,the realization structure of mechanical centrifugal granulation has been put forward,the centrifugal granulation experiment system with feedback regulation has been developed,and the key structure-granulator has been designed by ourselves.In this system,the key technical issues such as granulated particle quality,crust and slag wool have been studied experimentally.The effects of edge structure,flow rate,rotating speed and melt temperature of granulator on particle size distribution,average particle size and slag wool proportion have been discussed.The scheme of restraining slag wool formation has been put forward.The influence of surface temperature of granulator and coating of special material on the bond has been studied.The results show that the system can successfully realize the centrifugal granulation of blast furnace slag,and feedback the experimental data in real time.The centrifugal granulation process,the splitting mode of the liquid film and the relationship between the size,uniformity of the particles and the structure of the granulator,the experimental conditions have been clarified so that the proportion of slag wool produced is greatly changed.The non-bond and non-crust of granulator surface have been realized.The centrifugal granulation control law has been obtained,which provides theoretical and technical support for the industrial production of blast furnace slag centrif-ugal granulation.