Effect of CaF_(2) and CaO/Al_(2)O_(3) on viscosity and structure of TiO_(2)-bearing slag for electroslag remelting  

作　　者：Jian-tao Ju Kang-shuai Yang Zhi-hong Zhu Yue Gu Li-zhong Chang 

机构地区：[1]School of Metallurgical Engineering,Xi’an University of Architecture and Technology,Xi’an,710055,Shaanxi,China [2]Shaanxi Engineering Research Center of Metallurgical,Xi’an,710055,Shaanxi,China [3]School of Metallurgy Engineering,Anhui University of Technology,Ma’anshan,243002,Anhui,China

出　　处：《Journal of Iron and Steel Research International》2021年第12期1541-1550,共10页

基　　金：This study was funded by the National Natural Science Foundation of China(No.51774225).

摘　　要：The relationship between the viscosity and structure of CaF_(2)-CaO-Al_(2)O_(3)-MgO-TiO_(2)slag with different CaF_(2)contents and CaO/Al_(2)O_(3)ratios was studied using the rotating cylinder method,Fourier transform infrared spectroscopy,and Raman spectrometry.The activity coefficients of CaF_(2)and the CaO/Al_(2)O_(3)ratio were determined to understand the correlation between viscosity and structure of the slag.The results suggest that the slag viscosity reduces gradually with an increase in CaF_(2)content from 14.1 to 28.1 wt.%or CaO/Al_(2)O_(3)ratio from 0.9 to 1.5,and correspondingly apparent activation energy for viscous flow reductions.The addition of CaF_(2)does not change the structure of the molten slag;however,the relaxation effect of the anionic species and the hindrance effect of the cationic species are promoted by substituting part of the non-bridging oxygens(NBO)with F−ions from CaF_(2),which is attributed to the formation of NBO-Ca^(2+)-F−and NBO-Ca^(2+)-NBO,respectively.However,as the CaO/Al_(2)O_(3)ratio increases,some of the Q4 units in the aluminate structure are depolymerized into Q2 units,so that the relative strength of the Al-O-Al linkage decreases,and the relative fraction of Ti2O64−chains increases,whereas that of O-Ti-O chains decreases slightly,resulting in depolymerization on the slag structure.Additionally,the effect of the CaO/Al_(2)O_(3)ratio on the structure was greater than that of CaF_(2)because of the greater depolymerization effect.The variation in the activity can indirectly explain the relationship between the viscosity and structure of the aluminate structural units based on thermodynamic analysis.

关 键 词：VISCOSITY TiO_(2)-bearing slag Fourier transform infrared spectroscopy Raman spectrum Thermodynamic 

分 类 号：TF777[冶金工程—钢铁冶金]