Rheological Transitions of the Solid-Bearing Slag During Cooling Process

• Published in: Metallurgical and materials transactions. B, Process metallurgy and materials processing science Vol. 49; no. 5; pp. 2649 - 2657
• Main Authors: Liu, Zhuangzhuang, Malfliet, Annelies, Blanpain, Bart, Guo, Muxing
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.10.2018; Springer Nature B.V
• Subjects: ALUMINIUM OXIDES; Aluminum oxide; Basic converters; Characterization and Evaluation of Materials; Chemistry and Materials Science; Cooling; Cooling rate; CRYSTALS; FURNACES; LIQUIDS; MATERIALS SCIENCE; Metallic Materials; MICROSTRUCTURE; Nanotechnology; OXYGEN; Rheological properties; Rotation; SHEAR; Shear thinning (liquids); Silicon dioxide; SILICON OXIDES; SLAGS; SODIUM OXIDES; SOLIDS; STRESSES; Structural Materials; Surfaces and Interfaces; Thin Films; THIXOTROPY; TIME DEPENDENCE; VISCOSITY; Yield strength; Yield stress; Apparent Yield Stress; Rheological Transitions; Shear Thinning Regime; Continuous-cooling Conditions; Slag Microstructure
• ISSN: 1073-5615; 1543-1916
• DOI: 10.1007/s11663-018-1324-6

The viscosity of basic oxygen furnace slag modified by the addition of Al 2 O 3 , SiO 2 , and Na 2 O was measured via a rotational-type rheometer. The experiment was performed under both continuous cooling condition (5 °C/min) at a constant rotational speed (30 rpm) and isothermal condition at various rotational speeds (between 2 and 120 rpm). The present work suggests that during cooling from liquid to solid, the slag successively undergoes Newtonian regime, shear thinning (time depedent) and thixotropy with a time-dependent apparent yield stress. The corresponding slag microstructure is (1) a fully liquid or partially liquid slag with negligible crystal–crystal interaction in the Newtonian regime, (2) a liquid slag with crystal aggregates/clusters in the shear thinning regime and (3) a skeletal solid network in the regime of thixotropy with a certain level of apparent yield stress.