Study On The Rheological Properties Of Titanium-Bearing Blast Furnace Slag With Different Content Of TiC

As a strategic metallurgical resource,vanadic titanomagnetite is the raw material of ironmaking,Vanadia extraction and manufacture of metal titanium and titania-dioxide with high utilization value.China is rich in vanadium-titanium magnetite resources,possess more than 180 million tons totally,and most are in the Panxi and Hebei Chengde region.But the typical low-grade and multi-element isomorphous ore restricts its comprehensive utilization.Under conditions of strong reducing and high temperature,some titanium compound is reduced to high melting point materials TiC,TiN and their solid solution Ti(C,N),forming a complex heterogeneous system of gas-solid-liquid phase,which will cause a series of special issues,such as iron-slag,slag foam.In order to solve the above problems,it is necessary to research the rheological properties of titanium-bearing blast furnace slag with different content of TiC.The process of smelting vanadic titanomagnetite by BF was simulated to generate titanium-bearing BF slag,on the base of chemical compositions of Pan-steel titanium-bearing BF slag.Slag samples of CaO-SiO2-Al2O3-MgO-TiO2 are prepared in laboratory and adding different content of TiC,and research the non-Newtonian rheological behavior of titanium-bearing BF slag with rheological principles and methods,study the effect of the fluidity and viscosity of the slag with different content of TiC by a high-temperature rheometer.And then,confirm the relationship between the viscosity and shear rate and shear stress.At last,build the rheological constitutive equation which can determine the type of fluid at different temperatures and reveal a non-Newtonian rheological behavior and the law of heterogeneous titanium-containing.In addition the microstructures of slag under an extremely cold conditions cooling in liquid nitrogen were characterized by XRD,SEM-EDS,and mineralogical microscope.When we are aware of the the non-Newtonian fluid,we try to verify whether it has the priority of thixotropic,electric rheology and phenomenon of Weissenberg.The results showed as follows:(1)When increasing the content of TiC in high titanium slag,its viscosity show a growth either,the increasing changes the structure and distribution of slag.As a solid phase TiC provide a crystal nucleus for the crystallization of the other solid phase,such as perovskite,then all of the crystallization dispersion in the slag system.When temperature came to be lower,perovskite crystal continues to grow up which will increase the viscosity of slag system apparently.(2)TiC≥4wt%,slag system appear a much more apparent yield stress,slag must overcome yield stress within the system firstly when flowing.And similar to the law of the static friction force is greater than the dynamic frictional force in physics,in the slag system,the static yield stress is greater than the dynamic yield stress either.(3)TiC>6wt%,slag system show a obvious phenomenon of shear thinning,and the shear thinning of the molten slag leads to the plastic pseudoplastic fluid slag can be converted into Newtonian fluid in high shear rate.(4)The research of thixotropy of the molten slag shows that,TiC=8wt%,the constant temperature time is profitable for perovskite and the other solid phase crystallization growing up,which will increase the viscosity of the slag system.And at a high temperature the thixotropic hysteresis curve demonstrate a good thixotropic characteristic.TiC<6wt%,the constant temperature time still has a certain influence on slag viscosity,but no obvious hysteresis curve showed.(5)Form the research ER properties:TiC=8wt%,excluding the effect of shear thinning and constant temperature,the rheological properties of the slag has an obvious change when increasing the electric field and decreasing immediately.TiC=0wt%,it can not be sure whether electric field has an influence of the slag internal structure.This shows that TiC as high dielectric constant of solid suspended particles,has an influence of the rheological properties of the slag.(6)The study of phenomenon of Weissenberg show that:TiC=8wt%and TiC=0wt%,no apparent phenomenon of Weissenberg has been observed.