Influence of B₂O₃on viscosity and structure of low MgO slag containing titanium

Abstract

The viscous behavior of CaO–SiO2–15.2 wt% Al2O3–4.8 wt% MgO–TiO2–B2O3 slags is studied. The effect of the TiO2 and B2O3 on the viscosity and apparent activation energy, as well as the effect of B2O3 on structure is investigated through Raman spectroscopy. The viscosity and apparent activation energy of CaO–SiO2–15.2 wt% Al2O3–4.8 wt% MgO–TiO2 are decreased with increased TiO2 content, which can be explained by the network modifier role that TiO2 acts in slags. The addition of B2O3 can reduce the viscosity of CaO–SiO2–15.2 wt% Al2O3–4.8 wt% MgO–TiO2–B2O3 slags, and it brings about a turning point on apparent activation energy curves. Raman spectroscopy shows that B2O3 acts as acidic oxide and increases the degree of polymerization of slags. However, with the addition of B2O3, the appearance of two dimensional [BO3] structure units and the low strength energy of B–O bonds can reduce the viscous resistance in molten slags and decrease the viscosity.

Effects of B2O3 on Melting Characteristics and Temperature-Dependent Viscosity of High-Basicity CaO–SiO2–FeOx–MgO Slag

“…It can be found that the viscosity increased with the rise in B 2 O 3 content, in contrast to the experimental results shown in Figure 11. As reported in the literature [10,17], this interesting phenomenon is worthy of investigation to understand the difference between FactSage calculation results and experimental measurement results. trihedral units replace complicated silicate network units, resulting in the viscosity decreasing [11,25,26].…”

“…Most of these phases were identical to the results of Figure 5, implying that the prediction of FactSage was convincing. It was also found that the slag structure initially became complicated and then gradually changed into a simple structure with the phase transformation caused by the addition of B2O3 [17].…”

“…This can be attributed to the change in slag structure. With the B2O3 content increasing, twodimensional (2D) triangular [BO3] units occur in the slag system, gradually becoming the dominant structure associated with B-O arrangements, favoring slag flowability and resulting in an apparent reduction in activation energy [17]. This can be attributed to the change in slag structure.…”

Effect of B2O3/SiO2 molar ratio and B2O3 content on viscosity and structure of B2O3–SiO2–Al2O3–Na2O–TiO2 glass lubricant

“…26,27 The effect of B 2 O 3 con-tent on the viscosity and structure of silicate-based slags was studied in the past. [26][27][28][29][30][31][32] Sadaf et al 26 investigated the viscosity and crystallization behavior of (45 − 0.556x) CaO-(36 − 0.444x) SiO 2 -(4 + x) B 2 O 3 -4 Al 2 O 3 -8 Na 2 O-2 MgO-Li 2 O slag at 1300 • C. No crystallization phenomenon was observed when B 2 O 3 content exceeded 6 wt.%. Although the increase of B 2 O 3 content improved the degree of polymerization (DOP), it reduced the provided percentage of silicate unit in the melt due to the increase of [BO 3 ] unit.…”

“…Similar phenomena were found by some other researchers. 27,29,30,31 [BO 3 ] convert to [BO 4 ] by binding with free oxygen (FO, O 2− ), where [BO 4 ] can randomly attached to [SiO 4 ]. This leads to the depolymerization of the silicate network, which can be reflected by the amount of nonbridging oxygen (NBO, O − ) in the melt.…”