Enhancement of Rutile Formation by ZrO₂ Addition in Ti-bearing Blast Furnace Slags

Abstract

Enhancement of rutile crystallization in Ti-bearing Blast Furnace (Ti-BF) Slag caused by various ZrO 2 additions was clarified by Single Hot Thermocouple Technique (SHTT). Time-temperature-transformation (TTT) curves were obtained to analyze the variation trend of crystallization behavior. The results showed that the incubation time of primary crystal, i.e., rutile, at high temperature was first prolonged with increasing ZrO 2 addition from 0 to 3 wt.%, and then visibly shortened with further addition of ZrO 2 up to 5 wt.%. However, final amount of crystal precipitated was monotonously enhanced by the increasing ZrO 2 addition. Meanwhile, Fourier Transform Infrared spectroscopy (FTIR) test was applied to investigate structure of the slag and it was found that degree of polymerization (DOP) for the slag was enhanced and the structural group related to Zr-O-Zr group became more pronounced with increasing ZrO 2 concentration, which agreed well with the variation trend of the crystallization behaviors of slags. These results have highlighted that addition of ZrO 2 could enhance rutile crystallization, which is of great importance for potentially extracting Ti element from the slag.

Effect of TiO2 and 11 minor elements on the reactivity of ground‐granulated blast‐furnace slag in blended cements

“…The selection was based on earlier research that showed chemical durability increased in the order Mg>Ca>Sr>Ba for boro‐aluminosilicate glasses, suggesting that increasing cation sizes may destabilize the glass 26‐29 . And third Ce, P, Sn, and Zr were added to the industrial slag as nucleating agent to test if phase separation and possibly perovskite precipitation could be initiated to increase GGBS reactivity 30‐36 …”

“…[26][27][28][29] And third Ce, P, Sn, and Zr were added to the industrial slag as nucleating agent to test if phase separation and possibly perovskite precipitation could be initiated to increase GGBS reactivity. [30][31][32][33][34][35][36] In laboratory scale trials, around 100 g of an industrial GGBS modified by additions of one minor element at a time were produced. Amorphous state of resulting slags was checked by X-ray diffraction (XRD) and scanning electron microscopy (SEM) and composition by X-ray fluorescence (XRF).…”

Recent progress of efficient utilization of titanium-bearing blast furnace slag

“…9(c)). Acidic oxide B 2 O 3 presents the synergetic effect of reduced basicity and viscosity, thereby effectively accelerating the recrystallization of rutile [76]. ZrO 2 serves as a nucleating agent to promote the formation of homogeneous grains and facilitates subsequent beneficiation [77].…”

Phase equilibria of MgO–Al2O3–TiO2 system at 1600°C in air: Emphasis on pseudobrookite and spinel solid solution phases

“…6 Recently, the selective crystallization and phase separation (SCPS) process has been proposed for the comprehensive recovery of titania resource. 21,22 The key of SCPS process is to select a suitable titania enrichment phase, and the titania-containing phases of perovskite (CaO⋅TiO 2 ), [23][24][25][26] rutile (TiO 2 ), 27 pseudobrookite (solid solution formed by end-members of MgO⋅2TiO 2 , Al 2 O 3 ⋅TiO 2 , FeO⋅2TiO 2 , and Ti 2 O 3 ) 28 are therefore received most of the attention as the titania enrichment phase. For perovskite, the similar dendrite structure and density with other mineral lead to the low TiO 2 enrichment rate (≤40 wt.%), 29 and the associate with spinel phase also lead to the poor dissociation.…”