Roles of MgO and Al2O3 on the Viscous and Structural Behavior of Blast Furnace Primary Slag, Part 1: C/S = 1.3 Containing TiO2

Abstract

This research provides fundamental insight into the roles of MgO and Al 2 O 3 on the viscous and structural behaviors of CaO−SiO 2 −MgO−Al 2 O 3 −10 mass% TiO 2 −5 mass% FeO (CaO/SiO 2 = 1.3) system primary blast furnace slag. The slag viscosity is measured by the rotating cylinder method, which is essential to the efficient and stable operation of a blast furnace. The network structure characterization of the quenched vitreous samples was conducted using Fourier Transformation Infrared (FTIR) and Raman spectroscopy. Usual viscous behaviors (that the slag viscosity and the activation energy decrease or increase with increasing MgO or Al 2 O 3 content) were observed, corresponding to changes in the network structure certified by FTIR and Raman analyses. It seems that the addition of MgO and Al 2 O 3 prefers to modify the Si−O and Ti−O network in the present slag. When the slag composition reaches 10% MgO and 12% Al 2 O 3 , unexpected viscous behaviors (that MgO increases viscosity and Al 2 O 3 decreases viscosity) are discovered. The roles of MgO and Al 2 O 3 could be interpreted by changes in the arrangement structure of ions in liquid, corresponding to changes in the primary equilibrium phase region determined in phase diagrams and variation in the difference between the experimental and liquidus temperature, respectively.

Effect of Al2O3 and TiO2 on Viscosity, Surface Tension, and Density of Blast Furnace Slag with CaO/SiO2 = 1.13

“…[ 1 ] Recently, low‐cost iron ores with high‐alumina content have been increasingly used in the BF process. [ 2 ] Iron ore with high Al 2 O 3 content is widely available in India and Australia. [ 3 ] BF slags produced using raw materials rich in TiO 2 can have both beneficial and detrimental effects.…”

Fluoride Leaching of Titanium from Ti-Bearing Electric Furnace Slag in [NH4+]-[F−] Solution

“…At present, iron and vanadium in vanadium titanomagnetite concentrate are mainly recovered by the blast furnace process. Titanium in the blast furnace titanium slag cannot be effectively recovered [27,28]. The direct reduction-electric furnace smelting process is an effective method to utilize iron and enrich titanium from vanadium titanomagnetite concentrate, and has been commercialized in South Africa and New Zealand [29].…”

“…The intercept of fitted straight line and vertical axis in Figure 10 was calculated to be 7.41. ln k 0 = 7.41 (28) Thus, the preexponential factor k 0 can be expressed as:…”

Viscosity of BOF Slag

“…Thereby, the viscosity of investigated BF slags decreases with increasing TiO 2 content [23,24]. The viscosity of BF slag was examined as a function of TiO 2 and Al 2 O 3 content in [25] and as a function of MgO and Al 2 O 3 in [26,27].…”

“…The structure of FeO-containing nickel slag was analyzed by Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy in [21,22]. The effect of TiO 2 and FeO [24], TiO 2 and Al 2 O 3 [25], and MgO and Al 2 O 3 [26,27] on the structure of BF slag was investigated using FTIR and Raman analysis. In [29], the effect of Al 2 O 3 and FeO contents on the structure of highly basic CaO-MgO-SiO 2 -Al 2 O 3 -FeO slag was also analyzed using FTIR.…”