Research On The Slag Evolution Of Ti-bearing Sinter During Softening-melting Process And The Fluidity Of The Blast Furnace Slag

Vanadium-titanium magnetite ore is greatly plenty in China and it is mainly distributed in in Panzhihua of Sichuan,Chengde of Hebei and Ma'anshan of Anhui.Some steel enterprises usually have made it into Ti-bearing sinter for blast furnace production taking its geographical advantage.There is a great difference among the compositions,minerals and microstructure of Ti-bearing sinter and common sinter.And the Ti-bearing sinter has low TFe% compared with common sinter.Traditional viewpoint holds that the blast furnace is weak in permeability and increases the fuel ratio,which results from the poor softening-melting property of Ti-bearing sinter.However,the blast furnace coefficient in melting Ti-bearing sinter is higher than that of some common sinter,not as we think.The reason for this is worth exploring.So this paper has research on the slag evolution of Ti-bearing sinter during softening-melting process and the fluidity of the blast furnace slag.This paper firstly investigated the slag evolution of Ti-bearing sinter during softening-melting process.Temperature,pressure and shrinkage rate curve were obtained during softening-melting process.The process of slag evolution of sinter containing titanium was understood by analyzing interrupted samples at characteristic temperatures using scanning electron microscopy and X-ray diffraction.Based on in-situ composition of final slag in blast furnace,it was simulated by chemical pure reagents.Aiming at supplementing basic theoretical data for titanium during the blast furnace smelting,the influence of basicity,Ti O2,Mg O and Al2O3 content on the viscosity and melting temperature of final slag was studied by testing slag viscosity with different component and analyzing their properties.The influencing regulation of final slag fluidity and stability with different component was also studied.The results show that softening and melting temperature of Ti-bearing sinter are low,the max pressure drop is 547 KPa which is lower than common sinter.In softening and melting process,the mineral phase contains Fe O,melitite and proviskite.The main reason for low softening and melting temperature is low eutectic temperature.The pressure drop curve rises twice which may results from the large difference of melting temperature between slag and metal.The viscosity of titanium slag is very low,which is about 0.2Pa·s at high temperature.With the increase of Ti O2 content,the viscosity of the slag decreases gradually.The melting temperature of titanium slag is between 1340-1390°C,which is higher than that of normal slag for about 100°C.The melting temperature and flow activation energy of titanium slag first increase and then decrease with the increase of Ti O2 content.With the increase of Mg O content in the slag,the viscosity of the titanium slag decreases at high temperature.The content of Mg O has a significant influence on the viscosity at low temperature,at which the viscosity is higher with higher content of Mg O.The basicity has little influence on slag viscosity at high temperature,and the viscosity of the slag decreases with the increase of basicity.At low temperature,the slag basicity has an obvious influence on the viscosity of the slag,the viscosity is higher with higher basicity.The melting temperature of the slag obviously increases with the increase of basicity and it is approximately linear,which indicates that the basicity has a significant influence on the melting temperature of the slag.