Transition of Blast Furnace Slag from Silicate Based to Aluminate Based: Density and Surface Tension
- Chongqing University, College of Materials Science and Engineering (China)
The effects of the Al{sub 2}O{sub 3} concentration and Al{sub 2}O{sub 3}/SiO{sub 2} ratio on the density and surface tension of molten aluminosilicate CaO-SiO{sub 2}-Al{sub 2}O{sub 3}-9 mass pct MgO-1 mass pct TiO{sub 2} slag were investigated at temperatures from 1723 K to 1823 K (1450 °C to 1550 °C) using the Archimedean method and the maximum bubble pressure (MBP) technique, respectively. The mechanism of the changes in density and surface tension with composition was analyzed from the viewpoint of the degree of polymerization in the structure and the types of oxygen species in the melts. At a fixed CaO/SiO{sub 2} ratio of 1.20, the density decreased with increasing Al{sub 2}O{sub 3} content up to 25 mass pct, subsequently increasing. Increasing the Al{sub 2}O{sub 3}/SiO{sub 2} ratio from 0.47 to 0.92 caused an increase in the density at a fixed CaO content, and the density decreased slightly when the Al{sub 2}O{sub 3}/SiO{sub 2} ratio was greater than 0.92. Based on the structural information, the density decreased when the Al{sub 2}O{sub 3} content enhanced the network structure and increased when the (Q{sub 2} + Q{sub 3})/(Q{sub 0} + Q{sub 1}) ratio and structural complexity decreased. The surface tension increased with increasing Al{sub 2}O{sub 3} content and Al{sub 2}O{sub 3}/SiO{sub 2} ratio. On the one hand, the surface-active component of SiO{sub 2} decreased; on the other hand, the concentration of [AlO{sub 4}]{sup 5−} tetrahedra and metal cations that act as charge compensators increased at the melt surface. A model based on the anionic and cationic radii and the Butler equation was employed to predict the surface tension, and an iso-surface tension diagram was obtained at 1773 K (1500 °C).
- OSTI ID:
- 22857935
- Journal Information:
- Metallurgical and Materials Transactions B, Process Metallurgy and Materials Processing Science, Vol. 49, Issue 3; Other Information: Copyright (c) 2018 The Minerals, Metals & Materials Society and ASM International; http://www.springer-ny.com; Country of input: International Atomic Energy Agency (IAEA); ISSN 1073-5615
- Country of Publication:
- United States
- Language:
- English
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