Numerical investigation of basic oxygen furnace slag modification with gas bottom-blowing and SiO2 modifier

• Published in: Journal of iron and steel research, international Vol. 30; no. 7; pp. 1451 - 1460
• Main Authors: Liu, Chang, Tian, Yu-feng, Xiao, Yong-li, Li, Yong-qian, Li, Yang, Li, Guang-qiang, Wang, Qiang
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.07.2023
• Subjects: Applied and Technical Physics; Engineering; Machines; Manufacturing; Materials Engineering; Materials Science; Metallic Materials; Original Paper; Physical Chemistry; Processes; Basic oxygen furnace slag modification; SiO; Computational fluid dynamics; Discrete phase model; Free CaO; modifier
• ISSN: 1006-706X; 2210-3988
• DOI: 10.1007/s42243-023-01009-0

To avoid the volume expansion of basic oxygen furnace (BOF) slag for use in building materials, a hot slag modification process was proposed to reduce free CaO (f-CaO) in the molten slag. A transient 3D numerical model of BOF molten slag modification by SiO 2 particles was established. The flow and heat transfer of molten slag, movement and dissolution of the modifier, and concentration distribution of f-CaO in slag during the modification of BOF were studied. The distribution of f-CaO concentration is inhomogeneous all over the molten slag. The mixing effect at the slag surface is weaker than that at the half-height plane of the slag. To consume the f-CaO below 2.0 wt.% in the slag, the optimum quantity of the SiO 2 modifier is 10.0% of the mass of the slag. The fine SiO 2 particles help attain a lower final mass fraction of f-CaO and a higher SiO 2 utilization ratio.