Research on the Viscosity of CaF2-SiO2-Al2O3-CaO-MgO Slag System by the Thermodynamic Software

2013 ◽  
Vol 634-638 ◽  
pp. 42-46
Author(s):  
Yuan She ◽  
Jian Tao Ju ◽  
Zhi Yuan Jiao ◽  
Zhao Hui Zhang

In order to find out a method of computation on the viscosity of CaF2-SiO2-Al2O3-CaO-MgO slag system, which is accurate, rapid and convenient, a systematic study has been carried out. The refining slag samples have been made by the method of rotation-regression-orthogonal combination design during the test. When the temperature of the flux of the samples were 1600°C~1400°C, the experiment was performed by internal rotating cylinder method involving a spindle with the RTW-10 flux physical properties measuring apparatus in graphite crucible per 50°C, meanwhile, the viscosity of slag system were estimated by thermodynamic software FactSage per 50°C. Then, according to the viscosity results of calculation at 1600°C, the viscosity calculation equation was established, which was the relation of the mass fraction of every components and the value of the slag viscosity. Furthermore, the interaction of two components on the influence of the viscosity of slag was discussed.

2011 ◽  
Vol 295-297 ◽  
pp. 2647-2650 ◽  
Author(s):  
Hong Ming Wang ◽  
Ting Wang Zhang ◽  
Hua Zhu ◽  
Yong Qi Yan ◽  
Yi Nan Zhao

To avoid slag sticking onto the snorkel during CAS-OB ladle refining process, B2O3-CaO(mass ratio equals 1:1) and CaF2-CaO(mass ratio equals 1:1) were respectively employed as modifiers added to decrease the viscosity of ladle slag. The rotary cylinder method was adopted in the viscosity measurements. The results showed that the modifiers could decrease the viscosity of ladle refining slag remarkably. At 1500°C, the viscosity of ladle slag without any modifiers is about 6.0 Pa·s. But by adding more than 10mass% CaO-B2O3 or CaO-CaF2, the slag viscosity at 1500°C could be decreased lower than 1.0 Pa·s. The mechanism of modifiers decreasing the slag viscosity was analyzed.


2020 ◽  
Vol 117 (3) ◽  
pp. 307
Author(s):  
Zhuang Ma ◽  
Zengwu Zhao ◽  
Wentao Guo ◽  
Zhi Wang

In order to utilize niobium concentrate of Bayan Obo effectively, the effect of Nb2O5 and basicity on the viscosity of CaO-SiO2-Nb2O5-5.0 wt.% CeO2-5.0 wt.% CaF2 slag system was studied from 1653 to 1813 K in reducing atmosphere by rotating cylinder method. For the same condition, the as-quenched samples were investigated through X-ray diffraction and Raman spectroscopy. The results show that the viscosity, break temperature and activation energy of viscous flow decrease with the increase of Nb2O5 and basicity. Raman spectra show that the Nb4+ ions exist in the form of [NbO6] octahedron with different distortion and little [NbO4] tetrahedron in the slags. The Nb2O5 addition and basicity lower the degree of polymerization, where the complex Si-O network is depolymerized into simple structural units.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247828
Author(s):  
Zhongyu Zhao ◽  
Junxue Zhao ◽  
Boqiao Qu ◽  
Yaru Cui

A viscosity estimation model for fluorine-containing mold flux for continuous casting was investigated based on the Arrhenius formula and the rotating cylinder method combined with nonlinear regression analysis. This model is highly applicable and not limited by the slag of a certain composition. For most slag compositions, the viscosities estimated with this model deviated from the measured values by no more than 10%, which was in better agreement with the measured values than the viscosities estimated by the Riboud, Iida and Mills models. According to the model calculation and experimental detection, a viscosity isogram of CaF2-Na2O-Al2O3-CaO-SiO2-MgO slag was produced, and the mass fraction of CaF2 in the low-viscosity zone was nearly 14%. An X-ray fluorescence spectrometric analysis of slag after the viscosity test showed that CaF2 and Na2O were significantly reduced, and the measured viscosity was greater than the theoretical viscosity due to the volatilization.


Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 743 ◽  
Author(s):  
Tingle Li ◽  
Changyu Sun ◽  
Sunny Song ◽  
Qi Wang

In view of the fact that Ti–bearing blast furnace primary slag has been explored limitedly and its viscosity–structural property is not fully understood, the phase compositions, viscosity and structure of CaO–8%MgO–Al2O3–SiO2–TiO2–5%FeO slag are investigated by X-ray diffractometer, rotating cylinder method, Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy respectively, considering the effect of Al2O3 and TiO2. The critical temperature that is defined as the temperature below which the viscosity of slag increases quickly, could be explained by the relative amount of perovskite to melilite from phase compositions analysis. The slag viscosity first increases with increasing Al2O3 content from 10 to 15 mass%, and then decreases with the further increase of Al2O3 to 18 mass%. Increasing TiO2 content continuously lowers the viscosity. FTIR and Raman spectra results show that increasing Al2O3 or decreasing TiO2 content leads to complex Si–O and Ti–O networks structure, corresponding to the slag viscosity variation. The effect of weak linkages of Si–O–Al is more dominant when Al2O3exceeds 15 mass%, which results in the decrease of viscosity.


2012 ◽  
Vol 724 ◽  
pp. 460-463 ◽  
Author(s):  
Jian Tao Ju ◽  
Zhen Lin Lu ◽  
Zhi Yuan Jiao ◽  
Jun Yang ◽  
Zhao Hui Zhang

The relationship between the viscosity and the electrical conductivity of CaF2-SiO2- Al2O3-CaO-MgO slag system was deduced through theoretical calculation and experiment. The experiment was designed by quadratic orthogonal rotary regression method. The slag viscosity and conductivity were measured at 1600, and the constant (C) was calculated. The calculating model between each component mass fraction and constant C was performed, and the stability of calculating model was also verified by representative slag. The results showed that the calculating constant (C) of regression model is in good agreement with experimental values. Thus, the relationship between refining slag viscosity and conductivity using the formula at certain temperature is feasible.


2009 ◽  
Vol 95 (12) ◽  
pp. 807-812 ◽  
Author(s):  
Sohei Sukenaga ◽  
Shinichiro Haruki ◽  
Yoshinori Yamaoka ◽  
Noritaka Saito ◽  
Kunihiko Nakashima

2019 ◽  
Vol 38 (2019) ◽  
pp. 897-904
Author(s):  
Wenbin Xin ◽  
Yongchun Deng ◽  
Yinju Jiang ◽  
Yongqiang Wang

AbstractThe viscosity and break temperature of La2O3–SiO2-FeO slag was investigated to develop low-Al2O3 or Al2O3-free slag for the effective recovery of rare-earth metals. When La2O3 content is fixed (45, 50 and 55 mass%), the viscosity and break temperature of La2O3–SiO2-FeO slag decrease with an increase in FeO content and a decrease in SiO2 content. A higher La2O3 content in the La2O3-SiO2-FeO ternary slag yields a lower slag viscosity but a higher break temperature. Individual minor components of Al2O3, MnO and B2O3 does not affect, or decreases slightly the viscosity of La2O3–SiO2-FeO slag, whereas the slag break temperature is reduced so that the reduction ability order is ranked as B2O3 > Al2O3 > MnO. A small amount of two components Al2O3 + MnO and Al2O3 + B2O3 has little effect on the viscosity of the slag but it has an additive effect on the slag break-temperature reduction.


2019 ◽  
Vol 285 ◽  
pp. 391-397
Author(s):  
Kang Lu ◽  
Shu Sen Wu ◽  
Shu Lin Lü ◽  
Chong Lin

The apparent viscosity and rheological behavior of nanoSiCP/Al-5Cu composites were studied by using a high temperature coaxial rotating cylinder viscometer. The results show that mass fraction of nanoSiCP is an important factor for apparent viscosity of the nanoSiCP/Al-5Cu composites, and there is a great enhancement of apparent viscosity of the slurry with the increase of nanoSiCp content. It can attribute to the viscous force between nanoSiCp and matrix alloy melt above the liquidus. The increased amplitude of apparent viscosity in semi-solid state is far less than those in liquid state with the increase of mass fraction of nanoSiCp. The apparent viscosities of the composites reinforced with 0.5%, 1%, 1.5% and 2% nanoSiCp at 700°C were 24.78%, 95.25%, 160.29% and 228.62% higher than that of Al-5Cu alloy, respectively. Besides, the rheological model of nanoSiCP/Al-5Cu composites was established based on the fitting curve, which can precisely describe the relationship between the apparent viscosity of nanocomposites slurry and nanoSiCp mass fraction.


2020 ◽  
Vol 7 (8) ◽  
pp. 200704
Author(s):  
Zhongyu Zhao ◽  
Junxue Zhao ◽  
Zexin Tan ◽  
Boqiao Qu ◽  
Yaru Cui

It was taken as typical steelmaking fluorine-containing slag systems with the remelting electroslag, continuous casting mould flux and refining slag. The volatilization behaviour of each slag system was analysed by thermogravimetric (TG) and mass spectrometry (MS) detection. The results showed that the remelting electroslag volatilized significantly above 1300°C and the volatiles were mainly CaF 2 , MgF 2 with a small amount of SiF 4 and AlF 3 ; the continuous casting mould flux volatilization was divided into two stages, in the first stage (500°C∼800°C), CaF 2 and Na 2 O reacted to form NaF, and in the second stage (greater than 1200°C), the CaF 2 evaporation was highlighted; for CaF 2 -CaO-based refining slag, the volatilization was the most significant at the eutectic point 84% CaF 2 –16% CaO, and the volatility can be reduced by adding 5% SiO 2 . This research will be guiding significance for the composition and performance control of fluorine-containing slag and metallurgical environmental protection in the steelmaking process.


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