Precipitation behavior of perovskite and anosovite crystals from high Ti-bearing blast furnace slag with small amount of B₂O₃

Abstract

In the present study, the influence of small additions of B 2 O 3 on the precipitation behavior of perovskite and anosovite from high Ti-bearing blast furnace (Ti-BF) slag was studied at temperature range of 1430-1150 °C, and B 2 O 3 concentration range from 0 to 1.5%. Electron probe X-ray microanalysis (EPMA) was used to determine crystal assemblages of the slags quenched from high temperatures and the compositions of the crystals. X-Ray Diffraction (XRD) was applied to verify mineralogical species of each solid crystal. The results show that the primary crystals of the melt slags transformed from perovskite to anosovite when the content of B 2 O 3 was 1.5% at 1300 °C. Anosovite and CaTiO 3 coexisted from 1300 °C to 1200 °C while a new solid phase (Ca, Mg)O•mAl 2 O 3 •nIJSi, Ti)O 2 (CMAST) appeared at 1150 °C. The increasing of B 2 O 3 content in the present slags was favorable to form [TiO 6 ] 8− octahedral units and finally precipitate anosovite crystal. The decreasing reaction temperature would result in the precipitation of CaTiO 3 , even CMAST phase. The study implies a new direction for extracting Ti in anosovite crystal from Ti-BF slag in pan steel.

Evidence of anatase intergrowths formed during slow cooling of reduced ilmenite

“…In their work, Å sbrink and Magné li found that high-temperature Ti 3 O 5 was unstable at room temperature; however, it could be stabilized at room temperature through the addition of Fe. Studies concerning anosovite are limited, with the majority of the published literature focusing on separation of anosovite from Ti-bearing slag (Ren et al, 2016;. The carbothermal reduction of TiO 2 to Ti 3 O 5 has also been well documented (Maitre & Lefort, 1999;Shi et al, 2016).…”

Effect of B₂O₃ on Structure of CaO–Al₂O₃–SiO₂–TiO₂–B₂O₃ Glassy Systems

“…It can The structural information of slags could be used to explain the change of properties. Ren et al, 8) investigated the effect of B 2 O 3 on precipitation behavior of perovskite and anosovite crystals, showed that the increasing B 2 O 3 content in the present slags suppress the precipitation of perovskite and promote the formation of anosovite crystal. Zhang et al, 40) also found that the perovskite was suppressed by B 2 O 3 addition in Ti-bearing blast furnace slag.…”

“…[3][4][5] The accumulation of titanium slag not only wastes valuable titanium resources but also occupies a large amount of land and seriously pollutes the environment. Since the titanium components in blast furnace slag are mainly dispersed in the mineral phase, such as perovskite, carbon (nitrogen) titanium, and a small amount of spinel and diopside, [6][7][8] this makes it considerably difficult to extract Ti from blast furnace slag. Presently, the utilization rate of titanium in Ti-bearing blast furnace slag is low.…”

Upgrading V2O5-WO3/TiO2 deNOx Catalyst with TiO2-SiO2 Support Prepared from Ti-Bearing Blast Furnace Slag

“…Figure 9 shows the XRD pattern of the slag. A broad diffraction peak around 30˝was identified to be CaO-SiO 2 -Al 2 O 3 -TiO 2 glass structure [47], and there was no anatase TiO 2 diffraction peak. Thus, the BFS needs to be treated for getting anatase TiO 2 used as the support of SCR catalyst [17,19].…”

“…Thus, the BFS needs to be treated for getting anatase TiO 2 used as the support of SCR catalyst [17,19]. CaO-SiO2-Al2O3-TiO2 glass structure [47], and there was no anatase TiO2 diffraction peak. Thus, the BFS needs to be treated for getting anatase TiO2 used as the support of SCR catalyst [17,19].…”