Experimental Study on the Viscosity of Stainless Steelmaking Slags

Abstract

The influence of temperature, slag basicity and Cr₂O₃ content on the viscosity of stainless steelmaking slags has been experimentally determined. The viscosity is mostly affected by the combination of basicity and Cr₂O₃ content. The results are discussed by considering the Iida model for the fully liquid slag and the Herschel-Bulkley equation for the solid-bearing slag. For the liquid slag, the predicted viscosity values by the original Iida model do not agree very well with the measured ones, because the model does not include the amphoteric behavior of Cr₂O₃ and underestimates the basic character of Al₂O₃. With the presently optimized parameters in the Iida model, the calculation is consistent with the measured viscosity values of the fully liquid slag with an error of 30%, which is fairly acceptable. At high basicity and high Cr₂O₃ contents, the presence of solid particles in slag has a paramount influence on the viscosity. It was also found that the solid-bearing slags exhibit evident Bingham pseudoplastic behavior with a residual torque of 0.12 mNm and 0.99 mNm in the investigated samples.